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SG3525 Series Datasheet

SG3525

DC-DC Converters

The SG3525 series of pulse width modulator inte-grated circuits are designed to offer improved per-formance and lowered external parts count whenused in designing all types of switching power sup-plies. The on-chip + 5.1 V reference is trimmed to ±1 % and the input common-mode range of the erroramplifier includes the reference voltage eliminatingexternal resistors. A sync input to the oscillator al-lows multiple units to be slaved or a single unit to besynchronized to an external system clock.

SG3525 Data sheet.pdf

SG3525 Pin Configuration and Function

Pin No	Function	Description
1	INV.INPUT	inverting input
2	N.I+INPUT	complementary non-inverting input
3	SYNC	This pinout can be used for synchronizing the IC with an external oscillator frequency.
4	OSC.OUTPUT	It's the oscillator output of the IC, the frequency of the IC may be confirmed at this pin out.
5, 6	CT, RT	These are termed CT, RT respectively. Basically these pinouts are connected with an external resistor and a capacitor for setting up the frequency of the inbuilt oscillator stage or circuit. Ct must be attached with a calculated capacitor while the Rt pin with a resistor for optimizing the frequency of the IC.
7	discharge	A resistor connected across this pin#7 and pin#5 fixes the dead time of the IC.
8	Soft-Start	used for soft starting for enabling output after some time
9	Compensation	compensation pin used with feedback to avoid rapid fluctuations in output voltage with the change in load or input voltage.
10	Shutdown	shut down pin. IF shut down pin = 0 it will work and if shut down pin = 1 means connected with 5 volts it will remain in shut down mode.
11, 14	output A, output B	output pins. These pins provide input to MOSFETs and as I have already mentioned, there is no need to connect any Mosfet driver because sg3525 has a built-in MOSFET driver circuit.
12	ground	ground
13, 15	Vcc, Vi	power pins. Vc should be between 5-35 volt and Vin should be between 8-35 volt.
16	Vref	reference pin and it is used to set reference voltage through pin 1 or 2. It can also be used to give 5 volts to shut down the pin in case you want to shut down sg3525 through a push-button.