The UC3827 family of controller devices provides an integrated control solution for cascaded buck and push-pull converters. These converters are known as current fed or voltage fed push-pull converters and are ideally suited for multiple output and/or high voltage output applications. In both current fed and voltage fed modes, the push-pull switches are driven at 50% nominal duty cycles and at one half the switching frequency of the buck stage. In the current fed mode, the two switches are driven with a specified over-lap period to prevent ringing and voltage stress on the devices.
The UC3827 family of controller devices provides an integrated control solution for cascaded buck and push-pull converters, known as current fed or voltage fed push-pull converters. These converters are ideally suited for multiple output and/or high voltage output applications. The devices support both current fed and voltage fed modes, with specific driver configurations to prevent ringing, voltage stress, or shorting of the transformer.
Key features include high voltage and high current floating drivers for the buck converter stage, with options for overlapping or nonoverlapping conduction periods. The controllers support average current mode, peak current mode, or voltage mode with input voltage feedforward control. Additional features include a wide bandwidth, low offset differential current sense amplifier, precise short circuit current control, and soft start circuitry.
| Operating Frequency | Up to 500 kHz |
|---|---|
| Supply Voltage | 20 V |
| Input Voltage Range | 90 V |
| BUCK Driver VO Continuous | +250 mA |
| BUCK Driver VO Peak | +1 A |
| PUSH/PULL Driver VO Continuous | +200 mA |
| PUSH/PULL Driver VO Peak | +1 A |
| Storage Temperature | -65 to 150 °C |
| Junction Temperature | -55 to 150 °C |
| Reference Voltage | +5 V |
They are ideally suited for multiple output and/or high voltage output applications using cascaded buck and push-pull converters.
The maximum practical discharge current is 20 mA.