UM0527 datasheet(14/66 Pages) STMICROELECTRONICS

14 / 66 page

General description

UM0527

14/66

The battery charger is used as a battery charger for the mains mode or as a reactive power

recirculation circuit for the inverter mode. For both modes the charger output power is

accepted by the battery. The charger power converter is built in quasi-resonant flyback

mode based on the controller L6565 with external power switch Q1 and output diode D1.

The PWM controller is powered from the main UPS supply module and from the auxiliary

winding on the flyback transformer. The transformer is designed with the ETD29 core. The

CHOFF signal is used to switch (Q2 and Q3 STP80PF55) charging modes by the

microcontroller. An additional output voltage loop limits open output charger voltage. The

charger module also contains a battery overvoltage protection circuit with SCR TYN608 and

voltage reference TL431.

Table 3.

Battery charger specifications

AC/DC converter

120 Vac version

230 Vac version

Max output voltage

29 Vdc ± 5%

Max output power

50 W

Efficiency

>80%

Minimal switching frequency

100kHz ± 10%

Controller U1

L6565

Power switch Q11

STP5NK90Z

Transformer core

ETD29

Rectifier diode D1

STPS8H100

Clamp diode D3

STTA106

UM0527 Datasheet(PDF) 14 Page - STMicroelectronics