ST ISA013V1 User Manual

STEVAL-ISA013V1

Dual output off-line wide range 24W power supply evaluation board

for VIPer53

Data Brief

Features

■ Switch mode general purpose power supply

■ Input: 85 to 264Vac @ 50/60Hz

■ Output: 12V @ 1A & 5V @ 2.4A

■ Output power (peak) : 24W

■ Switching frequency 100kHz

■ Current mode control

■ 75% efficiency

■ Auxiliary undervoltage lockout with hysteresis

■ Output short circuit protection

■ Thermal shutdown protection

■ Meets EN55022 Class B EMI specification

■ Meets Blue Angels

Description

This evaluation board is an off-line wide range
dual output general-purpose power supply
capable of delivering up to 24W through two
outputs, +5V and +12V. The board is configured
for secondary regulation with optocoupler
feedback.

ST components

■ VIPer53

■ STTA106

■ BYW98-200

■ TL431A

■ STPS5L40

■ 1.5KE220A

STEVAL-ISA013V1

Other output voltages can easily be achieved by
changing the transformer and a few components
on the board, as shown in the application note.

Transformers are readily available for the
following configurations:

■ 5V/12V

■ 5V/15V

■ 5V/24V

July 2007 Rev 1 1/5

For further information contact your local STMicroelectronics sales office

www.st.com

5

General circuit description STEVAL-ISA013V1

1 General circuit description

The evaluation board operates from 90 to 264Vac input with an output power peak of 24W
through two output voltages of +5V and +12V.

The AC input is rectified and filtered by the bridge BR1 and the bulk capacitor C2 to generate
the high voltage DC bus applied to the primary winding of the transformer, T1.

The switching frequency is set at 100kHz through R3 and C5.

Secondary regulation is provided by an optocoupler and a programmable voltage reference
(TL431).

The transformer is designed and manufactured by Cramer Coil and Transformer Company, Inc.

This evaluation board has an efficiency of 78% at 115Vac at full load for both outputs.

The evaluation board consumes less than 1W total power consumption when working in burst
mode during standby operation and therefore, meets Blue Angel norm.

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