1
System Logic
Semiconductor
SLS
DC-TO-DC CONVERTER CONTROL CIRCUITS
The SL34063A is a monolithic control circuit containing the primary functions required for DC-to-DC converters. These
devices consist of an internal temperature compensated reference, comparator, controlled duty cycle oscillator with
an active current limit circuit, driver and high current output switch. This series was specifically designed to be
incorporated in Step-Down and Step-Up and Voltage-Inverting applications with a minimum number of external
components.
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Operation from 3.0 V to 40 V Input
Low Standby Current
Current Limiting
Output Switch Current to 1.5 A
Output Voltage Adjustable
Frequency Operation to 100 kHz
Precision 2% Reference
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Power Supply Voltage
V
CC
40
Vdc
Comparator Input Voltage Range
V
IR
-0.3 to +40 Vdc
Switch Collector Voltage
V
C(switch)
40
Vdc
Switch Emitter Voltage (Vpin 1 = 40 V)
V
E(switch)
40
Vdc
Switch Collector to Emitter Voltage
V
CE(switch)
40
Vdc
Driver Collector Voltage
I
C(driver)
40
Vdc
Driver Collector Current (Note 1)
I
C(driver)
100
mA
Switch Current
I
SW
1.5
A
Power Dissipation and Thermal Characteristics
Ceramic Package, U Suffix T
A
= +25C
Thermal Resistance
Plastic Package, P Suffix T
A
= +25C
Thermal Resistance
SOIC Package, D Suffix
TA
= +25C
Thermal Resistance
P
D
R
JA
P
D
R
JA
P
D
R
JA
1.25
100
1.25
100
625
160
W
C/W
W
C/W
mW C/
W
Operating Junction Temperature
TJ
+150
C
Operating Ambient Temperature Range
T
A
0 to +70
C
Storage Temperature Range
Tstg
-65to+150 C
SL34063A
2
System Logic
Semiconductor
SLS
SL34063A
ORDERING INFORMATION
Device
Temperature Range Package
34063AD 0 to +70C
SO-8
34063AP1
Plastic DIP
ELECTRICAL CHARACTERICISTICS
(V
CC
= 5.0 V, T
A
= 0 to +70
o
C unless otherwise specified.)
Characteristics
Symbol
Min
Typ
Max
Unit
OSCILLATOR
Frequency (V
Pin 5
= 0 V, C
T
= 1.0 nF, T
A
= 25C)
fosc
24
33
42
kHz
Charge Current (V
CC
= 5.0 V to 40 V, T
A
= 25C)
Ichg
24
33
42
A
Discharge Current (
V
CC
= 5.0 V to 40 V, T
A
= 25C)
Idischg
140
200
260
A
Discharge to Charge Current Ratio (Pin7 to Vcc, T
A
=25C)
Idischg/Ichg 5.2
6.2
7.5
--
Current Limit Sense Voltage (Ichg = Idischg, T
A
= 25C)
Vlpk(sense) 250
300
350
mV
OUTPUT SWITCH (Note 3)
Saturation Voltage, Darlington Connection (I
SW
= 1.0 A,
Pins 1, 8 connected)
V
CE
(sat)
--
1.0
1.3
V
Saturation Voltage (I
SW
= 1.0 A, R
Pin 8
= 82
to V
CC
.
Forced
= 20)
V
CE
(sat)
--
0.45
0.7
V
DC Current Gain (I
SW
= 1.0 A, V
CE
=
5.0 V, T
A
= 25C) h
FE
50
120
--
--
Collector Off-State Current (V
CE
= 40V)
I
C
(off)
--
0.01
100
A
COMPARATOR
Threshold Voltage (T
A
= 25C)
(T
A
= T
LOW
to T
HIGH
)
Vth
1.225
1.21
1.25
--
1.275
1.29
V
Threshold Voltage (T
A
= 25C) **
Vth
1.2375
1.25
1.2625 V
Threshold Voltage Line Regulation (V
CC
= 3 0 V to 40 V)
Regime
1.4
5.0
mV
Input Bias Current (Vin=0V)
I
IB
--
-40
-400
nA
TOTAL DEVICE
Supply Current (V
CC
= 5 0 V to 40 V, C
T
= 1 0 nF, V
pin7
= V
CC
.
V
Pin5
> Vth, Pin 2 = Gnd, Remaining pins open)
I
CC
2.5
4.0
mA
NOTES:
1. Maximum package power dissipation limits must be observed.
2.Low duty cycle pulse techniques are used during test to maintain Junction temperature as close to ambient temperature as
possible
3.If the output switch is driven into hard saturation (non Darlington configuration) at low switch currents (< 300 mA) and high
driver currents (>30 mA), it may take up to 2.0
s to come out of saturation This condition will shorten the off' time at
frequencies > 30 kHz, and is magnified at high temperatures This condition does not occur with a Darlington configuration,
since the output switch cannot saturate If a non Darlington configuration is used, the following output drive condition is
recommended
Forced
of output switch = I
C
, output/(Ic, driver -7.0 mA*) > 10
*The 100
. resistor in the emitter of the driver device requires about 7.0 mA before the output switch conducts
**Possible version for shipment
Pin connection
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