1
SY88813V
Micrel, Inc.
M9999-072505
hbwhelp@micrel.com or (408) 955-1690
3.3V/5V 155Mbps PECL LOW POWER
LIMITING POST AMPLIFIER WITH PECL
SIGNAL DETECT
SY88813V
Rev.: B
Amendment: /0
Issue Date:
July 2005
TYPICAL APPLICATIONS CIRCUIT
APPLICATIONS
s
155Mbps SONET/SDH
s
Small form factor transceivers
s
High-gain line driver and line receiver
s
Single 3.3V or 5V power supply
s
Up to 155Mbps operation
s
Low noise PECL data outputs
s
Chatter-free PECL Signal Detect (SD) output
s
TTL /EN input
s
Programmable SD level set (SD
LVL
)
s
Available in a tiny 10-pin MSOP (3mm) package
FEATURES
DESCRIPTION
The SY88813V low power limiting post amplifier is
designed for use in fiber-optic receivers. The device connects
to typical transimpedance amplifiers (TIAs). The linear signal
output from TIAs can contain significant amounts of noise
and may vary in amplitude over time. The SY88813V
quantizes these signals and outputs PECL level waveforms.
The SY88813V operates from a single +3.3V or +5V
power supply, over temperatures ranging from 40
C to
+85
C. With its wide bandwidth and high gain, signals with
data rates up to 155Mbps and as small as 5mV
PP
can be
amplified to drive devices with PECL inputs.
The SY88813V generates a PECL signal-detect output.
A programmable signal-detect level set pin (SD
LVL
) sets
the sensitivity of the input amplitude detection. SD asserts
high if the input amplitude rises above the threshold set by
SD
LVL
and deasserts low otherwise. /EN deasserts the true
output signal without removing the input signal. Typically
4.6dB SD hysteresis is provided to prevent chattering.
V
CC
/EN
GND
GND
To
CDR
SY88813V
3k
From
Transimpedance
Amp.
D
OUT
/D
OUT
V
REF
V
CC
SD
LVL
D
IN
/D
IN
0.1
F
0.1
F
0.1
F
0.1
F
SD
50
R
pd
50
100
R
pd
R
pd
For 3.3V, R
pd
= 120
For 5V, R
pd
= 220
2
SY88813V
Micrel, Inc.
M9999-072505
hbwhelp@micrel.com or (408) 955-1690
PIN DESCRIPTION
Pin Number
Pin Name
Type
Pin Function
1
/EN
TTL Input:
Enable: Deasserts true data output when high.
Default is high.
2
DIN
Data Input
True data input.
3
/DIN
Data Input
Complementary data input.
4
VREF
Reference voltage.
5
SDLVL
Input
Signal-Detect Level Set: A voltage between V
CC
and V
REF
on this pin
sets the threshold for the data input amplitude at which SD will be
asserted.
6
GND
Ground
Device ground.
7
SD
PECL Output
Signal-Detect: Asserts high when the data input amplitude rises above
the threshold set by SD
LVL
.
8
/DOUT
PECL Output
Complementary data output.
9
DOUT
PECL Output
True data output.
10
VCC
Power Supply
Positive power supply.
LOSLVL
GND
6
5
1
/EN
DIN
/DIN
VREF
10 VCC
DOUT
/DOUT
/LOS
9
8
7
2
3
4
10-Pin MSOP (K10-1)
PACKAGE/ORDERING INFORMATION
Ordering Information
Package
Operating
Package
Lead
Part Number
Type
Range
Marking
Finish
SY88813VKC
K10-1
Commercial
813V
Sn-Pb
SY88813VKCTR
(1)
K10-1
Commercial
813V
Sn-Pb
SY88813VKG
K10-1
Industrial
813V with
Pb-Free
Pb-Free bar-line indicator
NiPdAu
SY88813VKGTR
(1)
K10-1
Industrial
813V with
Pb-Free
Pb-Free bar-line indicator
NiPdAu
Note:
1. Tape and Reel.
3
SY88813V
Micrel, Inc.
M9999-072505
hbwhelp@micrel.com or (408) 955-1690
Absolute Maximum Ratings
(1)
Supply Voltage (V
CC
) ....................................... 0V to +7.0V
Input Voltage (D
IN
,
/D
IN
) ......................................... 0 to V
CC
Output Current (I
OUT
)
Continuous ............................................................. 50mA
Surge .................................................................... 100mA
/EN Voltage ............................................................ 0 to V
CC
V
REF
Current ......................................... 800
A to +500
A
SD
LVL
Voltage ........................................................ 0 to V
CC
Lead Temperature (soldering, 20 sec.) ................... +260
C
Storage Temperature (T
S
) ....................... 55
C to +125
C
Operating Ratings
(2)
Supply Voltage (V
CC
) .............................. +3.0V to +3.6V or
............................................................ +4.5V to +5.5V
Ambient Temperature (T
A
), Note 3 ............ 40
C to +85
C
Junction Temperature (T
J
), Note 3 .......... 40
C to +120
C
Package Thermal Resistance
MSOP
(
JA
) Still-Air .................................................. 113
C/W
(
JB
) Still-Air .................................................... 74
C/W
V
CC
= 3.0V to 3.6V or 4.5V to 5.5V; R
LOAD
= 50
to V
CC
2V; T
A
= 40
C to +85
C; typical values at V
CC
= 3.3V, T
A
= 25
C
Symbol
Parameter
Condition
Min
Typ
Max
Units
I
CC
Power Supply Current
no output load
21
40
mA
SD
LVL
SD
LVL
Voltage
V
REF
V
CC
V
V
IH
/EN Input HIGH Voltage
2.0
V
V
IL
/EN Input LOW Voltage
0.8
V
I
IH
/EN Input HIGH Current
V
IN
= 2.7V
20
A
V
IN
= V
CC
100
A
I
IL
/EN Input LOW Current
V
IN
= 0.5V
0.3
mA
V
OH
PECL Output HIGH Voltage
50
to V
CC
2V output load
V
CC
1.085 V
CC
0.955 V
CC
0.880
V
V
OL
PECL Output LOW Voltage
50
to V
CC
2V output load
V
CC
1.830 V
CC
1.705 V
CC
1.555
V
V
OFFSET
Differential Output Offset
100
mV
V
IHCMR
Common Mode Range
Note 5
GND +1.7
V
CC
V
V
REF
Reference Voltage
Note 6
V
CC
1.38
V
CC
1.32
V
CC
1.26
V
Notes:
1. Permanent device damage may occur if absolute maximum ratings are exceeded. This is a stress rating only and functional operation is
not implied at conditions other than those detailed in the operational sections of this data sheet. Exposure to absolute maximum ratlng
conditions for extended periods may affect device reliability.
2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
3. Commercial devices are guaranteed from 0
C to +85
C ambient temperature.
4. Specification for packaged product only.
5. The V
IHCMR
range is referenced to the most positive side of the differential input signal.
6. The current provided into or from V
REF
must be limited to 800
A source and 500
A sink.
DC ELECTRICAL CHARACTERISTICS
4)
4
SY88813V
Micrel, Inc.
M9999-072505
hbwhelp@micrel.com or (408) 955-1690
V
CC
= 3.0V to 3.6V or 4.5V to 5.5V; R
LOAD
= 50
to V
CC
2V; T
A
= 40
C to +85
C; typical values at V
CC
= 3.3V, T
A
= 25
C
Symbol
Parameter
Condition
Min
Typ
Max
Units
HYS
SD Hysteresis
electrical signal
2
4.6
8
dB
t
OFF
SD Release Time
0.1
0.5
s
t
ON
SD Assert Time
0.2
0.5
s
t
r
,t
f
Differential Output Rise/Fall Time
1000
ps
(20% to 80%)
V
ID
Differential Input Voltage Swing
5
1800
mV
PP
V
OD
Differential Output Voltage Swing
V
ID
18mV
PP
1500
mV
PP
V
ID
=
5mV
PP
400
mV
PP
V
SR
SD Sensitivity Range
5
50
mV
PP
A
V(Diff)
Differential Voltage Gain
38
dB
B
3dB
3dB Bandwidth
200
MHz
S
21
Single-Ended Small-Signal Gain
26
32
dB
Note :
7. Specification for packaged product only.
AC ELECTRICAL CHARACTERISTICS
(7)
TYPICAL OPERATING CHARACTERISTICS
0
10
20
30
40
50
60
70
80
90
100
0
-0.2 -0.4 -0.6 -0.8 -1.0 -1.2
V
ID
(mVp-p)
SD
LVL
(referenced to V
CC
) (V)
3.3V SD Assert and Deassert
Levels vs. SD
LVL
3.3V
T
A
= 25
C
155Mbps
Pattern 2
23
-1
0
10
20
30
40
50
60
70
80
90
100
0
-0.2 -0.4 -0.6 -0.8 -1.0 -1.2
V
ID
(mVp-p)
SD
LVL
(referenced to V
CC
) (V)
5V SD Assert and Deassert
Levels vs. SD
LVL
5.0V
T
A
= 25
C
155Mbps
Pattern 2
23
-1
5
SY88813V
Micrel, Inc.
M9999-072505
hbwhelp@micrel.com or (408) 955-1690
DETAILED DESCRIPTION
The SY88813V low power limiting post amplifier operates
from a single +3.3V or +5V power supply, over temperatures
from 40
C to +85
C. Signals with data rates up to 155Mbps
and as small as 5mV
PP
can be amplified. Figure 1 shows
the allowed input voltage swing. The SY88813V generates
a SD output. SD
LVL
sets the sensitivity of the input amplitude
detection.
Input Amplifier/Buffer
Figure 2 shows a simplified schematic of the SY88813V's
input stage. The high-sensitivity of the input amplifier allows
signals as small as 5mV
PP
to be detected and amplified.
The input amplifier allows input signals as large as
1800mV
PP
. Input signals are linearly amplified with a typically
38dB differential voltage gain. Since it is a limiting amplifier,
the SY88813V outputs typically 1500mV
PP
voltage-limited
waveforms for input signals that are greater than 18mV
PP
.
Applications requiring the SY88813V to operate with high-
gain should have the upstream TIA placed as close as
possible to the SY88813V's input pins to ensure the best
performance of the device.
Output Buffer
The SY88813V's PECL output buffer is designed to drive
50
lines. The output buffer requires appropriate termination
for proper operation. An external 50
resistor to V
CC
2V
for each output pin provides this. Figure 3 shows a simplified
schematic of the output stage and includes an appropriate
termination method.
Signal-Detect
The SY88813V generates a chatter-free PECL SD similar
to the SY88813V's output buffer. SD is used to determine
that the input amplitude is large enough to be considered a
valid input. SD asserts high if the input amplitude rises
above the threshold set by SD
LVL
and deasserts low
otherwise. /EN deasserts the true output signal without
removing the input signals. Typically 4.6dB SD hysteresis is
provided to prevent chattering.
Signal-Detect Level Set
A programmable signal-detect level set pin (SD
LVL
) sets
the threshold of the input amplitude detection. Setting a
voltage on SD
LVL
between V
CC
and V
REF
sets this threshold.
If desired, a resistor divider between V
CC
and V
REF
, as
shown in Figure 4, also creates this threshold. The smaller
the voltage difference from SD
LVL
to V
CC
, the smaller the
SD sensitivity. Hence, larger input amplitude is required to
assert SD. "Typical Operating Characteristics" shows the
relationship between the input amplitude detection sensitivity
and the SD
LVL
voltage.
Hysteresis
The SY88813V provides typically 4.6dB SD electrical
hysteresis. By definition, a power ratio measured in dB is
10log(power ratio). Power is calculated as V
2
IN
/R for an
electrical signal. Hence the same ratio can be stated as
20log(voltage ratio). While in linear mode, the electrical
voltage input changes linearly with the optical power and
hence the ratios change linearly. Therefore, the optical
hysteresis in dB is half the electrical hysteresis in dB given
in the datasheet. The SY88813V provides typically 2.3dB
SD optical hysteresis. As the SY88813V is an electrical
device, this datasheet refers to hysteresis in electrical terms.
With 6dB SD hysteresis, a voltage factor of two is required
to assert or deassert SD.
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