TDA 4862

Semiconductor Group

3

1998-02-16

Pin Definitions and Functions

Pin Symbol Function

1

V

SENSE

Voltage Amplifier Inverting Input;

V

With a capacitor connected to

V

2

V

AOUT

Voltage Amplifier Output;

V

overshoot the input voltage will be clamped at 5 V. Input voltage less

than 2.2 V is inhibiting the gate driver. If the current flowing into this pin

is exceeding an internal defined margin the multiplier output voltage is

reduced to prevent the MOSFET from overvoltage damage.

3

MULTIN Multiplier Input;

MULTIN is the second multiplier input and connected via a resistive

divider to the rectifier output voltage.

4

I

SENSE

Current Sense Minus;

I

current. The input is internally clamped at – 0.3 V to prevent negative

input voltage interaction. An internal low pass filter suppresses voltage

spikes when turning the MOSFET on.

5

DETIN

Zero Current Detector Input;

DETIN is connected to an auxiliary winding monitoring the zero crossing

of the inductor current.

6

GND

Ground;

All voltages are measured with respect to GND.

V

bypassed directly to GND with a 0.1

µF or larger ceramic capacitor.

7

GTDRV

Gate Drive Output;

GTDRV is the output of a totem-pole circuitry for direct driving a

MOSFET. A clamping network bypasses low state source current and

high state sink current.

8

V

CC

Positive Supply Voltage;

V

turn-ON threshold for normal operation. A 100 nF or lager ceramic

capacitor connected to

V

charge external MOSFET gate capacitances.