Description
The CXA1597M/P is a bipolar IC developed for
recording equalizer amplifier in analog cassette
decks. It is suited specifically for double cassette
decks. Incorporating the filter circuit greatly reduces
the external parts.
Features
Built-in filter required for recording equalizer
amplifiers
Inductor (coil) is unnecessary
Low frequency boost is possible with an external
capacitor
Built-in recording mute function
(requiring only an external time constant circuit to
implement soft mute)
Fade in/out DC controllable
NORM/CrO
2
/METAL tape mode switching function
NORM/HIGH tape speed recording switching
function
DC controllable for recording level calibration
(approximately 6dB variable)
DC controllable for high frequency equalizer
amplifier gain (approximately 4dB variable)
Built-in 2 channels
Small package
Applications
Recording equalizer amplifier for stereo analog
cassette decks (Supports ALPS ELECTRIC CO.,
LTD. HADKH55-series heads)
Block Diagram and Pin Configuration
Structure
Bipolar silicon monolithic IC
Absolute Maximum Ratings
Supply voltage
V
CC
17
V
Operating temperature Topr
20 to +75 C
Storage temperature
Tstg
65 to +150 C
Allowable power dissipation
P
D
(CXA1597M) 500
mW
(CXA1597P) 900
mW
Operating Conditions
Supply voltage Dual power supplies (V
CC
V
EE
)
5.0 to 8.0 V
Single power supply (V
CC
)
10.0 to 16.0 V
1
CXA1597M/P
E95127-ST
Recording Equalizer Amplifier for Stereo Cassette Decks
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
CXA1597M
16 pin SOP (Plastic)
CXA1597P
16 pin DIP (Plastic)
9
10
11
12
13
14
15
16
IREF
REC OUT2
BOOST2
V
CC
REC IN2
REC MUTE
REC CAL
Gp CAL
GND
2
3
4
5
6
7
8
1
REC OUT1
BOOST1
V
EE
REC IN1
TAPE EQ
DGND
SPEED
BIAS
VG
CONTROL
REC EQ 2
REC EQ 1
CXA1597M/P
2
CXA1597M/P
Pin Description
(Ta = 25C, V
CC
= 7.0V, V
EE
= 7.0V, DV
CC
= 5.0V)
Pin
No.
Symbol
I/O
Z (in)
Equivalent circuit
Description
Typical pin voltage
DC
AC
1
SPEED
I
--
Tape speed
switching pin.
Normal/Double
speed
switching.
High = Double
speed
Low = Normal
speed
--
--
10k
1
DGND
2
TAPE EQ
I
--
Tape equalizer
amplifier switching
(NORM/CrO
2
/
METAL
switching) pin.
High = REC EQ
METAL
Medium = REC
EQ CrO
2
Low = REC EQ
NORM
2.5V
--
3
DGND
I
--
Connect to GND.
0.0V
--
50k
5k
5k
DGND
2
4
13
REC IN1
REC IN2
I
50k
Recording
equalizer amplifier
input pin.
0.0V
18dBv
13
GND
50k
4
5
GND (VG)
I
15k
Connect to GND
for positive/
negative dual
power supplies.
Vcc/2 (center
potential) for a
single power
supply. (Connect
a capacitor of
10F or more)
0.0V
--
30k
30k
GND
5
3
CXA1597M/P
6
11
BOOST1
BOOST2
I
9.5k
Connection pin of
an external
capacitor for low
frequency boost.
When low
frequency boost
is unnecessary,
connect to GND
for positive/
negative dual
power supplies;
connect a
capacitor (3.3F
or more) for a
single power
supply.
0.0V
--
7
V
EE
I
--
Connect to the
negative power
supply for
positive/negative
dual power
supplies.
Connect to GND
for a single power
supply.
7.0V
--
11
4.8k 5.5k
35.5k
280
280
34k
GND
6
8
9
REC OUT1
REC OUT2
O
50k
Recording
equalizer amplifier
output pin.
0.0V
3dBv
9
50k
200
200
8
12
IREF
O
--
Reference current
setting pin for
monolithic filter.
The reference
current can be
set by attaching
a resistor
between this pin
and the V
EE
pin.
V
EE
+ 1.2V
--
200
6k
12
10
V
CC
I
--
Positive power
supply connection
pin.
7.0V
--
Pin
No.
Symbol
I/O
Z (in)
Equivalent circuit
Description
Typical pin voltage
DC
AC
4
CXA1597M/P
15
REC MUTE
I
--
Recording mute
ON/OFF selection
pin.
Recording mute
is controlled
with DC
voltages of 0 to
5V.
High =
Recording mute
OFF
Low =
Recording mute
ON
Soft mute and
fader can be
switched over
by changing the
time constant of
the external
time constant
circuit.
--
--
30k
54k
DGND
2.5V
15
16
Gp CAL
I
54k
High frequency
calibration pin.
Controlled with
DC voltages of
0 to 5V
High = High
frequency level
gain increased
Low = High
frequency level
gain reduced
Leave this pin
open when not
using the high
frequency
calibration
function.
2.5V
--
54k
DGND
2.5V
54k
16
Pin
No.
Symbol
I/O
Z (in)
Equivalent circuit
Description
Typical pin voltage
DC
AC
14
REC CAL
I
54k
Recording level
calibration pin.
High =
Recording level
gain increased
Low =
Recording level
gain reduced
Leave this pin
open when not
using the
recording level
calibration
function.
2.5V
--
54k
DGND
54k
14
2.5V
5
CXA1597M/P
Electrical Characteristics
(Ta = 25C, V
CC
= 7.0V, V
EE
= 7.0V)
Recording equalizer amplifier reference output
level (315Hz) (This output level is the tape
reference 0dB which generates magnetic flux of
250nWb/m)
All of the recording equalizer amplifier blocks use
this level as their reference level.
Input level when the reference output level is
315Hz, 3.0dBv
(For measurement, input a 315Hz, 18.5dBv
signal to the REC IN pins (Pins 4 and 13) and
then measure the output level.)
NORM-tape, NORM-speed mode
Input a 3kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
NORM-tape, NORM-speed mode
Input a 8kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
NORM-tape, NORM-speed mode
Input a 12kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
CrO
2
-tape, NORM-speed mode
Input a 3kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
CrO
2
-tape, NORM-speed mode
Input a 8kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
CrO
2
-tape, NORM-speed mode
Input a 12kHz signal (20dB level down) from the
reference to the REC IN pins and then measure the
relative deviation from NORM-NS, 315Hz mode.
METAL-tape, NORM-speed mode
Input a 3kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
METAL-tape, NORM-speed mode
Input a 8kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
8.0
5.0
10.0
20.0
1.9
2.5
7.3
2.9
7.1
11.3
3.9
7.1
12.0
7.0
14.0
3.0
18.5
0.4
4.5
10.3
4.4
9.1
14.3
5.4
9.1
16.0
8.0
16.0
17.0
1.1
6.5
13.3
5.9
11.1
17.3
6.9
11.1
mA
V
V
dBv
dBv
dB
dB
dB
dB
dB
dB
dB
dB
Current consumption (I
CC
)
Operating voltage range 1 (positive/
negative dual power supplies)
Operating voltage range 2
(single power supply)
Recording equalizer amplifier
Recording reference output level
NORM-NORM mode
Recording equalizer amplifier
Recording reference input level
NORM-NORM mode
NORM-NORM mode
REC-EQ frequency response 1
(3kHz, 20dB)
NORM-NORM mode
REC-EQ frequency response 2
(8kHz, 20dB)
NORM-NORM mode
REC-EQ frequency response 3
(12kHz, 20dB)
CrO
2
-NORM mode
REC-EQ frequency response 1
(3kHz, 20dB)
CrO
2
-NORM mode
REC-EQ frequency response 2
(8kHz, 20dB)
CrO
2
-NORM mode
REC-EQ frequency response 3
(12kHz, 20dB)
METAL-NORM mode
REC-EQ frequency response 1
(3kHz, 20dB)
METAL-NORM mode
REC-EQ frequency response 2
(8kHz, 20dB)
Item
Conditions
Min.
Typ.
Max. Unit
Entire LSI
Recording equalizer amplifier
6
CXA1597M/P
METAL-tape, NORM-speed mode
Input a 12kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
NORM-tape, HIGH-speed mode
Input a 5kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
NORM-tape, HIGH-speed mode
Input a 15kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
NORM-tape, HIGH-speed mode
Input a 20kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
CrO
2
-tape, HIGH-speed mode
Input a 5kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
CrO
2
-tape, HIGH-speed mode
Input a 15kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
CrO
2
-tape, HIGH-speed mode
Input a 20kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
METAL-tape, HIGH-speed mode
Input a 5kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
METAL-tape, HIGH-speed mode
Input a 15kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
METAL-tape, HIGH-speed mode
Input a 20kHz signal (20dB level down) to the
REC IN pins and then measure the relative
deviation from NORM-NS, 315Hz mode.
NORM-tape, NORM-speed mode, RL = 2.7k
Input a 1kHz signal and set the output so that
THD (total harmonic distortion) is 1%. (Measure
the distortion of a +11dB level-up signal.)
NORM-tape, NORM-speed mode, RL = 2.7k
Input a 1kHz, 0.0dB (reference input level)
signal and measure the distortion. (Measure the
distortion as THD + N.)
10.4
1.3
4.0
7.4
3.9
8.6
11.4
5.9
9.5
11.8
11.0
--
13.4
0.2
6.5
10.9
5.4
11.1
14.9
7.4
12.0
15.3
12.0
0.14
16.4
1.7
9.0
14.4
6.9
13.6
18.4
8.9
14.5
18.8
--
0.6
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
%
METAL-NORM mode
REC-EQ frequency response 3
(12kHz, 20dB)
NORM-HIGH mode
REC-EQ frequency response 1
(5kHz, 20dB)
NORM-HIGH mode
REC-EQ frequency response 2
(15kHz, 20dB)
NORM-HIGH mode
REC-EQ frequency response 3
(20kHz, 20dB)
CrO
2
-HIGH mode
REC-EQ frequency response 1
(5kHz, 20dB)
CrO
2
-HIGH mode
REC-EQ frequency response 2
(15kHz, 20dB)
CrO
2
-HIGH mode
REC-EQ frequency response 3
(20kHz, 20dB)
METAL-HIGH mode
REC-EQ frequency response 1
(5kHz, 20dB)
METAL-HIGH mode
REC-EQ frequency response 2
(15kHz, 20dB)
METAL-HIGH mode
REC-EQ frequency response 3
(20kHz, 20dB)
NORM-NORM mode
REC-EQ signal handling
NORM-NORM mode
REC-EQ total harmonic distortion
(1kHz, 0.0dB, RL = 2.7k
)
Recording equalizer amplifier
Item
Conditions
Min.
Typ.
Max. Unit
7
CXA1597M/P
NORM-tape, NORM-speed mode, Rg = 5.1k
With no signal, measure the noise using the "A"-
WGT filter. (The measured value is indicated as
the relative value compared to the reference
level.)
NORM-tape, NORM-speed mode
With no signal, measure the DC offset voltage of
the REC OUT pin.
NORM-tape, NORM-speed mode, REC-MUTE = 0.5V
Input a 1kHz signal (+12dB level up) and
measure the attenuation when REC MUTE is on.
(Use a 1kHz BPF.)
NORM-tape, NORM-speed mode, REC-MUTE = 2.5V
Input a 1kHz, 0.0dB (reference level) signal and
measure the attenuation characteristics curve of
the soft mute function. (when REC-MUTE = 2.5V)
NORM-tape, NORM-speed mode, REC-CAL = 5.0V
Input a 315Hz signal (20dB level down) and
measure the amount of change compared to
when the REC-CAL function is at the standard
setting.
NORM-tape, NORM-speed mode, REC-CAL = 0.0V
Input a 315Hz signal (20dB level down) and
measure the amount of change compared to
when the REC-CAL function is at the standard
setting.
NORM-tape, NORM-speed mode, Gp-CAL = 5.0V
Input a 8kHz signal (20dB level down) and
measure the amount of change compared to
when the Gp-CAL function is at the standard
setting.
NORM-tape, NORM-speed mode, Gp-CAL = 0.0V
Input a 8kHz signal (20dB level down) and
measure the amount of change compared to
when the Gp-CAL function is at the standard
setting.
TAPE EQ control pin voltage
TAPE EQ control pin voltage
TAPE EQ control pin voltage
SPEED control pin voltage
SPEED control pin voltage
57
500
--
7.0
4.1
8.9
3.9
5.9
4.2
2.2
0.0
3.5
0.0
65
0.0
91
5.5
6.1
6.9
5.9
3.9
--
--
--
--
--
--
500
80
4.0
8.1
4.9
7.9
1.9
V
CC
2.8
0.5
V
CC
0.5
dB
mV
dB
dB
dB
dB
dB
dB
V
V
V
V
V
NORM-NORM mode
REC-EQ S/N ratio 1
("A"-WGT filter)
NORM-NORM mode
Output DC offset voltage
(REC OUT pin)
NORM-NORM mode
REC-EQ mute characteristics 1
(REC-MUTE = 0.5V)
NORM-NORM mode
REC-EQ mute characteristics 2
(REC-MUTE = 2.5V)
NORM-NORM mode
REC-EQ REC-CAL characteristics 1
(REC-CAL = 5.0V)
NORM-NORM mode
REC-EQ REC-CAL characteristics 2
(REC-CAL = 0.0V)
NORM-NORM mode
REC-EQ Gp-CAL characteristics 1
(GP-CAL = 5.0V)
NORM-NORM mode
REC-EQ Gp-CAL characteristics 2
(GP-CAL = 0.0V)
Recording equalizer amplifier
Mode control
Control circuit high level
Mode control
Control circuit medium level
Mode control
Control circuit low level
Mode control
Control circuit high level
Mode control
Control circuit low level
Control circuit
Ternary
switching
Binary
switching
Item
Conditions
Min.
Typ.
Max. Unit
8
CXA1597M/P
Electrical Characteristics Measurement Circuit
REC OUT2
V
CC
BOOST2
IREF
REC IN2
REC CAL
REC MUTE
Gp CAL
REC OUT1
V
EE
BOOST1
GND (VG)
REC IN1
DGND
TAPE EQ
SPEED
CXA1597M/P
A
9
10
11
12
13
14
15
16
2
3
4
5
6
7
8
1
R12
5.1k
R13
27k
SW8
C8
2.2
SW6
AC Voltmeter
Distortion
Analyzer
Oscilloscope
DC Voltmeter
R17
2.7k
SW10
"A" WTG
DIN Audio
1kHz BPF
Noise Filter
DC 5V
Supply
Power
Supply
Power
Supply
Audio SG
DC
Ammeter
DC
Ammeter
GND
0.5V
2.5V
4.0V
5.0V
R7
620
C6
10
R10
10k
SW1
REC MUTE
OFF
ON
C2
1
25V
C3
1
25V
ON
OFF
SW5
CAL ON/OFF
C1
100
25V
REC CAL
50k
GP CAL
R6
2k
R4
27k
R2
18k
R1 2k
R3 27k
R5 18k
Note
1. Resistor tolerance
2. Capacitor tolerance
Coupling Capacitor
5
%
1
%
5
%
2
%
10%
:
:
50k
C11 0.47
C13 100
C15
4.7
50V
R19 100
R15 10k
SW12
2ch
1ch
SW14
Filter
OUT
IN
SW2
SPEED
HIGH
SW3
METAL
SW4
METAL
METAL
120
s
70
s
NORM
R9
10k
R8
10k
C4
10
C5
10
SW7
C7
2.2
R11
5.1k
SW9
C9
10
C10 0.47
C12
100
25V
C14
4.7
50V
R14 10k
R18
100
R16
2.7k
SW11
2ch
1ch
SW13
SW15
SW16
SW17
A
9
CXA1597M/P
Application Circuit (Positive/Negative Dual Power Supplies)
REC OUT2
V
CC
BOOST2
IREF
REC IN2
REC CAL
REC MUTE
Gp CAL
REC OUT1
V
EE
BOOST1
GND (VG)
REC IN1
DGND
TAPE EQ
SPEED
CXA1597M/P
C8
3.3
50V
R7
12k
C12
75p
L2
27mH
REC OUT2
(to HEAD)
C10
150p
C7
3.3
50V
R6
12k
C9
150p
L1
27mH
C11
75p
GND
GND
GND
GND
GND
GND
REC CAL
(DC control)
REC Mute
(Soft Mute/Fader)
Gp CAL
(DC control)
Tape Speed
(NORM/HIGH)
TAPE EQ
(METAL/CrO2/NORMAL)
LINE IN1
V
EE
C4
0.47
35V
R3
27k
C2
3.3
50V
RV2
10k
R2
10k
R5
5.6k
GND
GND
LINE IN2
V
CC
V
EE
C6
100
25V
C3
0.47
35V
C1
3.3
50V
RV1
10k
R1
10k
R4
5.6k
C5
100
25V
V
EE
9
10
11
12
13
14
15
16
2
3
4
5
6
7
8
1
REC OUT1
(to HEAD)
Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for
any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same.
10
CXA1597M/P
Description of Operation
1. Recording equalizer amplifier
The primary features of the CXA1597 recording equalizer amplifier are that by taking full advantage of
monolithic filter technology, an LC resonance circuit consisting of a coil and capacitor normally required for
high frequency compensation is dispensed with and medium and low-frequency sensitivity compensation is
performed with its internal filter alone.
This IC has the circuit configuration shown in Fig. 1 to provide the optimum frequency response required for
recording equalizer amplifiers.
L1
27mH
GND
GND
GND
R1
50k
V
CC
Gm3
1
1
Gm2
Gm5
OP4
1
OP3
OP2
VGS
R7
34k
VGS
R3
35k
R8
4.8k
C1
0.47
GND
C2
200p
R4
5.5k
R11
40k
GND
R13
50k
R9
24k
R10
8k
C4
100p
GND
C3
100p
GND
R5
20k
R6
20k
R2
5k
VGS
VGS
GND
GND
Gm4
VGS
BIAS
CONTROL
6dBv
6dBv
+6dBv
REC OUT
3dBv
7dBv
7dBv
0dBv
REC IN
18.5dBv
V
CC
V
EE
GND (VG)
IREF
DGND
TAPE EQ
REC MUTE
SPEED
to Control IC
V
EE
GND
V
EE
R1 27k
GND
GND
REC HEAD
Bias
OSC
C7
75p
R14
12k
C5
3.3
C6
150p
GND
REC CAL
CALIBRATION
Gp CAL
DV
CC
R15
50k
R16
50k
BOOST
IfM
IGL
IGH
If/Q
IfQ
IGP
Fig. 1. CXA1597 functional circuit block diagram
The symbols (Gm2, Gm3, Gm4, Gm5) shown in Fig. 1 denote "voltage
current converter circuits" and
"multiplier circuits."
The "voltage
current converter circuits" convert the voltage between the positive and negative input pins into
current by using the IC's internal resistance. The "multiplier circuits" multiply the current generated by the
"voltage
current converter circuits" with a coefficient.
The recording equalizer amplifier requires the six parameters shown in Fig. 2 (G
L
, G
H
, G
P
, f
M
, f
P
, and Q) to
implement its frequency response. These parameters are controlled by each control current shown in Fig. 1
(IGL, IGH, IGP, IfM, If/Q, and IfQ).
Therefore, the CXA1597 reduces fluctuations caused by the temperature characteristics and unevenness of its
internal resistance by using currents which are independent of the internal resistance (currents which depend
on external resistance) and those which are dependent on the internal resistance.
This IC uses currents dependent on the internal resistance where equalizer amplifier gain is determined and
currents dependent on external resistance where the filter time constant is determined. This is because the
generatrix of the coefficient for the "multiplier circuits" is generated in the IC so that it depends on the internal
resistance. Consequently, the gain relationship of G
L
, G
H
and G
P
is such that because the current obtained by
the "voltage
current converter circuits" is converted into voltage by the I-V amplifier in the final stage of Fig.
1, the control currents are controlled by currents dependent on the internal resistance. In this way, the
coefficients for conversion [voltage
current
voltage] all become ratios to the internal resistance, so that
the fluctuations of temperature characteristics and unevenness are reduced.
11
CXA1597M/P
Also, the relationship of time constants f
M
, f
P
and Q is configured by the product of the current obtained with
the "voltage
current converter circuits" and the IC's internal capacitance connected to the output of each
"multiplier circuit". By using the currents determined by the CXA1597 external resistance which are not
dependent on the internal resistance for control, the coefficients for voltage
current conversion become
certain ratios to the internal resistance; therefore, the frequency response does not depend on the internal
resistance.
G
P
Q
G
H
f
P
f
M
G
L
Low frequency boost
Gain [dB]
Frequency [Hz]
Fig. 2. Conceptual diagram of CXA1597 frequency response
2. Low frequency boost
The CXA1597 implements low frequency boost simply by attaching an external capacitor. As shown in Fig. 1,
this IC contains a resistance-based attenuation circuit after the input amplifier, with one of the resistors
connected to the BOOST pins (Pins 6 and 11). When a capacitor is connected to these BOOST pins (Pins 6
and 11), the following transfer function is obtained.
G
BOOST
(s) = (s = j
)
From the above, items f
1
, f
2
, A
1
, and A
2
in Fig. 3 are transformed into the following:
f
1
= =
f
2
=
A
1
=
A
2
= =
s C
1
R
7
R
8
+ R
7
s C
1
(R
4
R
7
+ R
7
R
8
+ R
8
R
4
) + (R
4
+ R
7
)
R
4
+ R
7
2
C
1
(R
4
R
7
+ R
7
R
8
+ R
8
R
4
)
R
7
R
8
R
4
R
7
+ R
7
R
8
+ R
8
R
4
R
4
R
7
R
4
+ R
7
1
(
)
2
C
1
+ R
8
R
7
R
8
R
7
+ R
8
R
7
R
8
R
7
+ R
8
R
4
+
1
2
C
1
R
8
R
7
R
4
+ R
7
12
CXA1597M/P
Here, R
4
= 5.5k
, R
7
= 34k
, and R
8
= 4.8k
. Therefore, A
1
and A
2
take on the following values.
A
1
= 0.861 (times) = 1.30 (dB); A
2
= 0.433 (times) = 7.26 (dB)
The difference between A
1
and A
2
is approximately 6 dB, so that 6 dB boost can be applied for low frequency
boost. The boost frequency response can be freely set with the value of the external C
1
capacitor.
f
2
f
1
Gain [dB]
Frequency [Hz]
6dB
oct
A
1
A
2
Fig. 3. CXA1597 low frequency boost frequency response
3. Recording mute function
The CXA1597 recording mute function is implemented by using a built-in recording mute circuit which varies
the recording equalizer amplifier gain according to the magnitude of the DC voltage applied to the REC
MUTE pin (Pin 15) just like an electronic volume control. For this reason, any desired soft mute (gradual
signal attenuation without distortion) or fader (fade in/out) can be freely set depending on momentary
changes in the DC voltage applied to the REC MUTE pin (Pin 15).
The CXA1597 recording mute circuit operation is such that the reference voltage source used to generate the
control currents (IGL, IGH, and IGP) to control each gain (G
L
, G
H
, and G
P
) shown in Fig. 1 is varied by the
voltage input to the REC MUTE pin (Pin 15), so that the recording signal is attenuated while maintaining the
respective gain ratios. Eventually, when the recording signal is completely muted, only the I-V amplifier in the
final stage is connected to the output pin (REC OUT). Therefore, the noise of the monolithic filter consisting of
each "voltage
current converter circuit" and "multiplier circuit" is attenuated simultaneously with the
recording signal. At this point in time, the I-V amplifier in the final stage is functioning almost as a buffer,
providing a significant amount of mute. Fig. 4 illustrates the recording mute waveforms.
Fig. 4. Recording mute waveform
13
CXA1597M/P
4. Recording level calibration function
The CXA1597 allows the recording level to be finely adjusted with a DC voltage. The recording equalizer
amplifier gain can be varied by approximately 6dB simply by applying DC voltage to the REC CAL pin (Pin
14). Circuit operation for this function is such that each gain (G
L
, G
H
, and G
P
) is varied relative to the
reference voltage source which controls currents (IGL, IGH, and IGP) by varying its voltage as in the case of
the recording mute circuit.
The input resistance of the REC CAL pin (Pin 14) is 54k
as described in the Pin Description, which is
equivalent to the internal resistance. This means the voltage converted into current by the internal resistance
is the difference between the DC voltage applied to the REC CAL pin (Pin 14) and the internal reference
voltage (2.5V), so that all coefficients become ratios to the internal resistance. Recording level can be finely
adjusted independent of the temperature characteristics and unevenness inherent in the IC.
This recording calibration function performs in all modes (NORM/CrO
2
/Metal tape, NORM/HIGH speeds, as
well as the recording mute mode).
When not using the recording level calibration function, simply leave the REC CAL pin (Pin 14) open, and the
voltage on the REC CAL pin (Pin 14) is matched to the internal reference voltage (2.5V), with the recording
level set for the standard output gain.
5. High frequency equalizer amplifier calibration function
In addition to the recording level calibration function, the CXA1597 allows high frequency equalizer amplifier
characteristics to be controlled with DC voltage. By simply applying DC voltage to the G
P
CAL pin (Pin 16) as
in the case of the recording level calibration function, the recording equalizer amplifier gain (only the G
P
gain)
can be varied by approximately 4dB. This function also relatively varies the G
P
gain when the recording
level calibration function is activated. Circuit operation for this function is such that the voltage applied to the
pin is converted into current by the internal resistance as in the case of recording level calibration, and that
the "multiplier circuits" provide a coefficient to the control current according to the value of the G
P
gain
control current (IGP) for the mode currently set.
Therefore, the calibration of high frequency equalizer amplifier characteristics is independent of the
temperature characteristics and unevenness inherent in the IC, as in the case of recording level calibration.
This function, too, operates in all modes.
When not using the high frequency equalizer amplifier calibration function, simply leave the G
P
CAL pin (Pin
16) open, and the high frequency equalizer amplifier characteristics are set for standard output gain.
Fig. 5 schematically shows the recording level/high frequency equalizer amplifier calibration functions.
Fig. 5. Conceptual diagram of recording level/high frequency equalizer amplifier calibration functions
The noise level of the recording equalizer amplifier is relatively changed by varying its frequency characteristics.
GP CAL
f
P
f
M
REC CAL
Gain [dB]
Frequency [Hz]
REC CAL
REC CAL
14
CXA1597M/P
6. Temperature characteristics and accuracy of the recording equalizer amplifier
The temperature characteristics of the built-in monolithic filter and the filter cut-off frequency depend on the
27k
external resistance connected to the IREF pin (Pin 12). For low frequency boost, however, the cut-off
frequency becomes uneven depending on the temperature characteristics or unevenness of the internal
resistance since its time constant is configured by the product of an external capacitor and the internal
resistance.
Also, the recording equalizer frequency response depends on unevenness in the absolute, as well as relative
values of the internal capacitance. Furthermore, the high frequency response indicates a high element
sensitivity at the filter because the band-pass filter Q is high. Compared to low frequency, although the
unevenness inherent in the IC is more likely to occur, this occurs relatively, and not individually for channels 1
and 2.
15
CXA1597M/P
Notes on Operation
1. Power supply
The CXA1597 is designed basically for positive/negative dual power supplies, and can also operate with a
single power supply. Connect the power supplies for each case as shown below:
V
CC
(Pin 10)
V
EE
(Pin 7)
GND (Pin 5) DGND (Pin 3)
Positive/negative dual
power supplies
Single power supply
Positive power supply
Power supply
Negative power supply
GND
GND
GND
GND
Control voltage
Min.
Max.
3-state
2-state
High level
Medium level
Low level
High level
Low level
H
HIGH SPEED
METAL TAPE
4.2
2.2
0.0
3.5
0.0
V
CC
2.8
0.5
V
CC
0.5
For a single power supply, connect a decoupling capacitor (10F or more) to the GND (VG) pin (Pin 5).
The ripple rejection ratio depends on the capacitance of this capacitor.
2. Operation mode control (NORM/CrO
2
/METAL tape, NORM/HIGH speed)
The CXA1597 incorporates an electronic switch and its operation is controlled by the DC voltage applied to
the two mode control pins - TAPE EQ pin (Pin 3) and SPEED pin (Pin 1).
The mode control voltages are as follows
The voltages in the table to the left are the
values relative to DGND.
Operation mode control table
Pin No.
Pin name
Pin voltage
Remarks
M
CrO
2
TAPE
L
NORMAL SPEED
NORMAL TAPE
2-state
3-state
1
2
Note: Pin voltage = Medium when the 3-state input pin is open.
SPEED
TAPE EQ
If the switching click noise presents a problem, add time constant circuits of 0.1 to 1s to the mode control
pins. Since the mode control circuit has a linear region of approximately 300mV, this time constant circuit
may effectively reduce the switching click noise.
16
CXA1597M/P
3. Recording mute function (soft mute, fade in/out)
As described in Description of Operation, the CXA1597 recording mute function is implemented by using a
built-in recording mute circuit which varies the recording equalizer amplifier gain according to the magnitude
of the DC voltage applied to the REC MUTE pin (Pin 15) just like an electronic volume control. Consequently,
the muting time can be varied according to momentary changes of the DC voltage applied to the REC MUTE
pin (Pin 15) and, furthermore, the recording signal can be gradually attenuated without causing distortion.
The table below shows the relationship between the DC voltage applied to the REC MUTE pin (Pin 15) and
the attenuation.
Control voltage
Recording mute ON
Attenuation 6.6dB
Recording mute OFF
Positive/negative dual power supplies
Single power supply
DGND to 0.5V
DGND to 0.5V
2.5V
2.5V
4.0V to V
CC
4.0V to V
CC
Referenced to the DGND pin (Pin 3).
4. Low frequency boost (low frequency compensation)
The CXA1597 low frequency boost function can be implemented simply by connecting a capacitor to the
BOOST pins (Pins 6 and 11) as described in Description of Operation. Although the boost is fixed to 6dB, the
time constant which determines the cut-off frequency can be set to any desired value depending on the
capacitance of the external capacitor. The pole (f1) and zero (f2) shown in Fig. 3. Low frequency boost
frequency response can be expressed, with the external capacitor assumed to be CB, as follows:
f
1
= (Hz), f
2
= (Hz)
Based on the above equation, determine the best low frequency response.
However, the resistance which determines the time constant along with the external capacitor is the internal
resistance, so that the cut-off frequency tends to fluctuate depending on the unevenness and temperature
characteristics inherent in the IC. Note that the unevenness and the temperature characteristics of the
internal resistance that determines the low frequency boost frequency response are approximately 20% and
+2500 ppm/C, respectively.
When not using low frequency boost, follow the procedure described below.
a) For positive/negative dual power supplies
Connect the BOOST pins (Pins 6 and 11) to GND.
b) For single power supply
Connect a fairly large capacitor (3.3F or more) to the BOOST pins (Pins 6 and 11) or simply leave the
BOOST pins open. If the BOOST pins are left open, note that the output level increases by 6dB, so the
input reference should be set 6dB down. The CXA1597 is basically designed for positive/negative dual
power supplies and the BOOST pins cannot be easily connected to GND as in the case of
positive/negative dual power supplies.
1
2
C
B
(9.53k
)
1
2
C
B
(4.8k
)
17
CXA1597M/P
5. Recording level calibration
The CXA1597 allows the recording level to be finely adjusted with a DC voltage as described in Description
of Operation. Therefore, the recording level can be varied by approximately 6dB simply by applying DC
voltages of 0 to 5V (for positive/negative dual power supplies) to the REC CAL pin (Pin 14).
The table below shows the input range regulation of control voltages with the power supplies used.
1
,
2
Up
Typ.
Down
Positive/negative dual power supplies
Single power supply
2.5V to V
CC
2.5V to V
CC
2.5V
2.5V
DGND to 2.5V
DGND to 2.5V
1
Although the above range of voltages can be input to the control pin, the controllable input voltage range
is as follows:
2.5V < Vup
5.0V
DGND
Vdown < 2.5V
2
Control voltages for this IC are referenced to the DGND pin (Pin 3).
Also note that when not using this recording calibration function, simply leave the REC CAL pin (Pin 14)
open, so that the voltage on the REC CAL pin is matched to the internal reference voltage (2.5V), with
the recording level set for the standard gain.
6. High frequency calibration
The CXA1597 allows the high frequency equalizer amplifier characteristics to be finely adjusted with a DC
voltage as described in Description of Operation. Therefore, the recording level in high frequencies (peak)
can be varied by approximately 4dB simply by applying DC voltages of 0 to 5V (for positive/negative dual
power supplies) to the G
P
CAL pin (Pin 16).
The table below shows the input range regulation of control voltages with the power supplies used.
3
,
4
3
Although the above range of voltages can be input to the control pin, the controllable input voltage range
is as follows:
2.5V < Vup
5.0V
DGND
Vdown < 2.5V
4
Control voltages for this IC are referenced to the DGND pin (Pin 3).
Also note that when not using this high frequency calibration function, simply leave the G
P
CAL pin (Pin
16) open, so that the voltage on the G
P
CAL pin is matched to the internal reference voltage (2.5V), with
the high frequency equalizer amplifier characteristics set for the standard gain.
7. Monolithic filter (the resistance connected to the IREF pin)
To increase the accuracy of the frequency response of its internal monolithic filter, the CXA1597 entrusts the
control current that determines the filter time constant to an external resistance. Specifically, this resistance
is the 27k
external resistor connected to the IREF pin (Pin 12). This means that the accuracy of the
recording equalizer amplifier frequency response is determined by the resistance connected to the IREF pin.
Therefore, the resistor used for this purpose must be free of unevenness and have excellent temperature
characteristics (e.g., a metallic film resistor).
Also note that the recording equalizer amplifier frequency response can be shifted as desired by altering the
value of the resistance connected to the IREF pin. For example, when the resistance value is reduced, the
frequency response is shifted to the high-frequency side, and when the resistance value is increased, the
frequency response is shifted to the low-frequency side.
Up
Typ.
Down
Positive/negative dual power supplies
Single power supply
2.5V to V
CC
2.5V to V
CC
2.5V
2.5V
DGND to 2.5V
DGND to 2.5V
18
CXA1597M/P
Frequency response (NORMAL speed)
Frequency [Hz]
Output response [dB]
10
100k
10k
1k
100
10.0
0.0
10.0
20.0
30.0
Frequency response (HIGH speed)
Frequency [Hz]
Output response [dB]
10
100k
10k
1k
100
10.0
0.0
10.0
20.0
30.0
V
CC
, V
EE
= 7.0V
0dB = NORM-NORM, 315H, 23dBv (20dB)
(Tape) (Speed)
NORM -HIGH
CrO
2
-HIGH
METAL-HIGH
Load characteristics
R
L
Load resistance [
]
Maximum output level [dB]
100
0
10
14
1k
10k
V
CC
, V
EE
= 7.0V
MODE: NORM-NORM
(Tape) (Speed)
0dB = 3dBv (REC OUT pin)
THD + N = 1%
315Hz
1kHz
V
CC
, V
EE
= 7.0V
0dB = NORM-NORM, 315H, 23dBv (20dB)
(Tape) (Speed)
NORM -NORM
CrO
2
-NORM
METAL-NORM
2
4
6
8
12
Example of Representative Characteristics
19
CXA1597M/P
Output level vs. Mute voltage
REC MUTE pin voltage [V]
1.0
1.0
3.0
5.0
0.0
2.0
4.0
6.0
0
100
80
60
40
20
Output level [%]
V
CC
, V
EE
= 7.0V
MODE: NORM-NORM
(Tape) (Speed)
100% = 1kHz, + 12dB
(at 315Hz, 3dBv)
f = 1kHz
Output level vs. Mute voltage
REC MUTE pin voltage [V]
1.0
3.0
5.0
0.0
2.0
4.0
6.0
100
0
20
40
60
80
Output level [dB]
V
CC
, V
EE
= 7.0V
MODE: NORM-NORM
(Tape) (Speed)
0dB = 1kHz, + 12dB
(at 315Hz, 3dBv)
f = 1kHz
Output level vs. Mute voltage
80
Output level [dB]
REC MUTE pin voltage [V]
0.5
1.0
5.0
0
20
40
60
V
CC
, V
EE
= 7.0V
MODE: NORM-NORM
(Tape) (Speed)
0dB = 1kHz, + 12dB
(at 315Hz, 3dBv)
f = 1kHz
Total harmonic distortion
Output level [dB]
T. H. D + N [%]
10
0.1
1.0
10
0
10
20
V
CC
, V
EE
= 7.0V
0dB = 3dBv, R
L
= 2.7k
MODE: NORM-NORM
(Tape) (Speed)
315Hz
1kHz
3kHz
6.3kHz
10kHz
15kHz
20
CXA1597M/P
REC CAL and Gp CAL frequency response
Frequency [Hz]
Output response [dB]
10
100k
10k
1k
100
10.0
0.0
10.0
20.0
40.0
V
CC
, V
EE
= 7.0V
0dB = NORM-NORM, 315Hz, 23dBv (20dB)
REC CAL & Gp CAL Open
(Tape) (Speed)
Gp CAL = 5.0V
Gp CAL = 2.5V
Gp CAL = 0.0V
30.0
REC CAL = 5.0V
REC CAL = 2.5V
REC CAL = 0.0V
Output level vs. REC CAL voltage
REC CAL pin voltage [V]
Output level [dB]
10
0
10
2.0
1.0
5.0
1.0
0.0
4.0
2.0
3.0
8.0
7.0
6.0
V
CC
, V
EE
= 7.0V
MODE: NORM-NORM Gp CAL = Open
(Tape) (Speed)
0dB = REC CAL pin and Gp CAL pin Open
20dB (at 315Hz, 3dBv)
315Hz
3kHz
8kHz
12kHz
Output level vs. Gp CAL voltage
Gp CAL pin voltage [V]
Output level [dB]
5
0
5
2.0
1.0
5.0
1.0
0.0
4.0
2.0
3.0
7.0
6.0
V
CC
, V
EE
= +7.0V
MODE: NORM-NORM REC CAL = Open
(Tape) (Speed)
0dB = Gp CAL pin and REC CAL pin Open
20dB (at 315Hz, 3dBv)
315Hz
3kHz
8kHz
12kHz
21
CXA1597M/P
Supply voltage vs. Current consumption
V
CC
Supply voltage [V]
5
6
7
8
I
CC
Current consumption [mA]
10
11
12
13
22
CXA1597M/P
Package Outline
Unit: mm
CXA1597M
CXA1597P
PACKAGE STRUCTURE
PACKAGE MATERIAL
LEAD TREATMENT
LEAD MATERIAL
PACKAGE WEIGHT
SONY CODE
EIAJ CODE
JEDEC CODE
SOP-16P-L01
SOP016-P-0300-A
COPPER ALLOY
SOLDER PLATING
EPOXY RESIN
16PIN SOP (PLASTIC) 300mil
9.9 0.1
+ 0.4
16
9
1
8
1.27
0.45 0.1
5.3 0.1
+ 0.3
7.9
0.4
6.9
1.85 0.15
+ 0.4
0.5
0.2
0.2 0.05
+ 0.1
0.1 0.05
+ 0.2
0.2g
0.15
M
0.12
PACKAGE STRUCTURE
PACKAGE MATERIAL
LEAD TREATMENT
LEAD MATERIAL
PACKAGE WEIGHT
EPOXY RESIN
SOLDER PLATING
COPPER
19.2 0.1
+ 0.4
9
1
8
2.54
0.5 0.1
1.2 0.15
3.0 MIN
0.5 MIN
3.7 0.1
+ 0.4
6.4 0.1
+ 0.3
7.62
0.25 0.05
+ 0.1
0 to 15
16
16PIN DIP (PLASTIC) 300mil
1.0 g
SONY CODE
EIAJ CODE
JEDEC CODE
DIP-16P-01
DIP016-P-0300-A
Similar to MO-001-AE
PDF 
ZIP