WS3110S8P データシートの表示（PDF） - Shenzhen Winsemi Microelectronics Co., Ltd

部品番号

コンポーネント説明

メーカー

WS3110S8P

High Performance LED Driver

Shenzhen Winsemi Microelectronics Co., Ltd 

WS3110

The switch current is detected by a sense resistor into

the SENSE pin. The internal Leading-edge blanking

chops off the sense voltage spike at initial MOSFET on

state due to snubber diode circuit reverse recovery and

thus reduce the external RC filter circuit. The current limit

comparator is disabled and cannot turn off the external

MOSFET during the blanking period. PWM duty cycle is

determined by voltage level at comp pin and mult pin.

Error Amplifier and soft-start

The comp pin is the error amplifier output of WS3110,

and a 1 uF capacitor is connect from comp to GND to

make the CC loop stable.

During the startup period, an internal 300uA current will

quickly charge up comp to 1.5V, then the CC loop will

adjust the comp voltage according to the load condition.

Since the sink/source current of the error amplifier is

very small, the voltage of comp will rise slowly after

startup, and the PWM duty also increase slowly, so that

the soft-start is realized. The soft-start time depends on

the value of the compensation capacitor.

Saturation protection of transformer

The Source pin of WS3110 is used to detect the

operating state of the transformer and the internal power

MOS. When the Vds of the internal power mos (voltage

between Source pin and CS pin) is over 2.1V, the

internal power MOS saturation protection is triggered;

and when the voltage of pin Source is over 3.3V, the

transformer saturation protection will be triggered

Protection Controls

Good power supply system reliability is achieved with

auto-recovery protection features including cycle by

cycle over current protection (OCP), VCC over-voltage

protection (VCC-OVP) and under voltage lockout

(UVLO), output LED short/open protection, CS pin

short/open protection, and over-temperature protection

(OTP).

7/8

Steady, keep you advance

Share Link: