SG2524
REGULATING PULSE WIDTH MODULATORS
COMPLETE PWM POWER CONTROL CIRCUITRY
UNCOMMITTED OUTPUTS FOR SINGLEENDED OR PUSH PULLAPPLICATIONS
LOW STANDBY CURRENT8mA TYPICAL
OPERATIONUP TO 300KHz
1% MAXIMUM TEMPERATURE VARIATION
OF REFERENCEVOLTAGE
DESCRIPTION
The SG2524, and SG3524 incorporate on a single monolithic chip all thefunction required for the
construction of regulating power suppies inverters
or switching regulators.They can also be usedas
the control element for high power-outputapplications. The SG3524 family was designed for
switching regulators of either polarity, transformer-coupled dc-to-dc converters, transformerless voltage doublers and polarityconverter applications employing fixed-frequency, pulse-width
modulation techniques. The dual alternating outputs allows either single-ended or push-pull appli-
SG3524
DIP16 SO16
ORDERING NUMBERS: SG2524N (DIP16)
SG3524N (DIP16)
SG2524P (SO16)
SG3524P (SO16)
cations. Each device includes an on-ship reference, error amplifier, programmable oscillator,
pulse-steering flip flop, two uncommitted output
transistors, a high-gain comparator, and currentlimiting andshut-down circuitry.
BLOCK DIAGRAM
June 2000
This is advanced information on a new product now in development or undergoingevaluation. Details are subject to change without notice.
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SG2524 - SG3524
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
IN
I
C
I
R
I
T
P
tot
T
stg
T
op
PIN CONNECTION(Top view)
Supply Voltage 40 V
Collector Output Current 100 mA
Reference Output Current 50 mA
Current Through CTTerminal – 5 mA
Total Power Dissipation at T
=70°C 1000 mW
amb
Storage Temperature Range – 65 to 150 °C
Operating Ambient Temperature Range:
SG2524
SG3524
–25to85
0to70
°C
C
°
THERMAL DATA
Symbol Parameter DIP16 SO16 Unit
R
th j-amb
R
th j-alumina
(*) Thermal resistance junction-alumina with the device soldered onthe middle of an alumina supporting substrate measuring 15 x 20mm;
0.65mm thickness with infiniteheatsink.
Thermal Resistance Junction-ambient Max.
Thermal Resistance Junction-alumina (*) Max.
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80
–
50
–
°C/W
C/W
°
SG2524- SG3524
ELECTRICAL CHARACTERISTICS (unless otherwise stated, these specifications apply for Tj = -25 to
+85°C for the SG2524, and0 to70°C for the SG3524,V
= 20V, and f = 20KHz).
IN
Symbol Parameter Test Condition
SG2524 SG3524
Min. Typ. Max. Min. Typ. Max.
REFERENCE SECTION
V
∆V
∆V
Output Voltage 4.8 5 5.2 4.6 5 5.4 V
REF
Line Regulation VIN= 8 to 40V 10 20 10 30 mV
REF
Load Regulation IL= 0 to 20mA 20 50 20 50 mV
REF
Ripple Rejection f = 120Hz, T
Short Circuit Current
=0,Tj=25°C 100 100 mA
V
REF
=25°C66 66dB
j
Limit
∆V
/∆T Temperature Stability Over Operating
REF
0.3 1 0.3 1 %
Temperature range
V
∆
Long Term Stability Tj = 125°C, t = 1000Hrs 20 20 mV
REF
OSCILLATOR SECTION
f
MAX
f/∆T Temperature Stability Over Operating
∆
Maximum Frequency CT= 0.001µF, RT=2KΩ 300 300 KHz
Initial Accuracy R
Voltage Stability V
and CTConstant 5 5 %
T
= 8 to 40V, Tj=25°C1 1%
IN
22%
Temperature Range
Output Amplitude Pin 3, T
Output Pulse Width C
=25°C 3.5 3.5 V
j
= 0.01µF, Tj=25°C 0.5 0.5 µs
T
ERROR AMPLIFIER SECTION
V
G
CMV Common Mode Voltage T
CMR Common Mode Rejection T
V
Input Offset Voltage VCM= 2.5V 0.5 5 2 10 mV
OS
Input Bias Current 2 10 2 10 µA
I
b
Open Loop Voltage Gain 72 80 60 80 dB
V
=25°C 1.8 3.4 1.8 3.4 V
j
=25°C7070dB
j
B Small Signal Bandwidth A
Output Voltage Tj=25°C 0.5 3.8 0.5 3.8 V
O
= 0dB, Tj=25°C 3 3 MHz
V
COMPARATOR SECTION
Duty-cycle % Each Output On 0 45 0 45 %
V
Input Threshold Zero Duty-cycle 1 1 V
IT
Maximum Duty-cycle 3.5 3.5 V
Input Bias Current 1 1 µA
I
b
CURRENT LIMITING SECTION
Sense Voltage Pin 9 = 2V with Error
190 200 210 180 200 220 mV
Amp. Set for Max. Out.
T
=25°C
j
Sense Voltage T.C. 0.2 0.2 mV/°C
CMV Common Mode Voltage –1 1 –1 1
OUTPUT SECTION(each output)
Collector-emitter Voltage 40 40 V
Collector Leackage Curr. V
Saturation Voltage I
Emitter Output Voltage V
Rise Time RC=2KΩ,Tj=25°C 0.2 0.2
t
r
Fall Time RC=2KΩ,Tj=25°C 0.1 0.1 µs
t
f
(*) Total Standby Current VIN= 40V 8 10 8 10 mA
I
q
(*) Excluding oscillator charging current,error and current limit dividers, and with outputs open.
= 40V 0.1 50 0.1 50 µA
CE
= 50mA 1 2 1 2 V
C
= 20V 17 18 17 18 V
IN
Unit
µ
s
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