TS19706CS datasheet(6/9 Pages) TSC

6 / 9 page

TS19706CS

Taiwan Semiconductor

Version: A1605

APPLICATION INFORMATION

Function Description

The TS19706CS is configurable for either isolated primary side Flyback regulation or non-isolated buck-boost

current regulation topologies. The IC active power factor correction in Flyback mode and achieves constant current

accuracy and low total harmonic distortion (THD) using Boundary Conduction Mode (BCM) operation. An

integrated 630V switching MOSFET reduces the external components required for application implementation. The

TS19706CS has built-in VCC over voltage protection, open LED protection, short LED protection, over temperature

protection, and primary-side current limit.

The average output current can be expressed as below.

Where:

• IOUT_avg is the average output current

• NP is the primary-side turn ratio

• NS is the secondary-side turn ratio

• ƞ is the efficiency

• RS is the sensing resistor connected between the MOSFET source and the GND

Pin Definitions

COM (Compensation)

This is the output of the gm amplifier. Connect with a suitable RC network to ground.

GND (Ground)

GND is the reference node of internal circuit.

CS (Current Sense)

MOSFET current signal sensing for multiplication and current limit setting function.

Where:

• ICS(LIMIT) is the input current sence

• RS is the sensing resistor connected between the MOSFET source and GND

DRN (Drain)

Internal Power MOSFET Drain.

VCC

Power supply for the controller during normal operation. The controller will start up when VCC reaches 15.3V (typical)

and will shut-down when VCC voltage is below 7.8V (typical). A decoupling capacitor should be connected between

the VCC and GND pin as close as possible.

The TS19706CS performs VCC over voltage protection though VCC pin. Once VCC pin exceeds in 34V, TS19706CS

turns off and latchs out the MOSFET switcher until VCC goes below VCC_OFF.

OUT_avg

0.370

CS(LIMIT)

1.35

TS19706CS Datasheet(PDF) 6 Page - Taiwan Semiconductor Company, Ltd