WS21351 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

WS21351

Half-bridge power IC for CFL lamps

Shenzhen Winsemi Microelectronics Co., Ltd 

Lamp ignites successfully, the voltage on pin CPH

continues to increase until it internally limits at 6V

(VCPH_MAX). The frequency stops decreasing when

VCPH reach 5V and stays at the minimum frequency

as programmed by an external resistor, on pin RMIN

(as show in Fig 4). The minimum frequency should

be set below the High-Q resonance frequency of the

ballast output stage to ensure that the frequency

ramps through resonance for lamp Ignition

.The desired preheat time can be set by adjusting

the slope of the VCPH ramp with the external

capacitor on pin CPH. The relation of LCC tank

frequency and Pin CPH voltage VCPH as show in

Fig5.

WS21351

Run Mode

TheWS21351 enters RUN mode when the voltage

on pin CPH exceeds 5V . The lamp has ignited and

the ballast output stage becomes a low-Q, series-L,

parallel-RC circuit. The voltage on the CPH pin

continues to increase but the frequency don't change

as the minimum frequency is reached. The resonant

inductor, resonant capacitor, DC bus voltage and

minimum frequency determine the running lamp

power. The relation of minimum run frequency and

the setting resistor RRMIN as show in Fig 6. The IC

stays at this minimum frequency unless VDD

decreases below the VDDTH– threshold

5/7

Steady, keep you advance

Share Link: