PMP30934

IGBT and SiC gate drive auxiliary PSU reference design

PMP30934

Design files

Overview

This reference design introduces a tiny auxiliary power supply unit (PSU) used to supply automotive insulated-gate bipolar transistor (IGBT) or automotive silicon carbide (SiC) transistor gate drive.. The isolated outputs support three gate controls. Each is supplied with +17 V and -4 V. For transformer windings simplicity, a virtual ground by ZENER diodes has been implemented for symmetrical loading.

The LM25184 controller supports primary-side regulation just by controlling the flyback voltage from the secondary side. There is no need for an additional auxiliary winding. Valley switching is beneficial for efficiency. To reduce reflected ripple to source, a differential input filter has been added to the PSR flyback converter.

Features

Two-stage differential input filter to prevent conducted emissions
Three outputs (+17 V and -4 V ) with efficiency of 86% at full load and temperature rise of +15 K at full load
Simple transformer windings by using virtual output return provides isolation voltage of 2500 V_RMS
No opto-isolator design, primary side regulation
Two-layer board, single-side assembly and high-power density by using integrated FET and circuit geometry of 70 mm x 35 mm
Maximum height of 7.4 mm by low profile transformer

Output voltage options	PMP30934.1	PMP30934.2	PMP30934.3	PMP30934.4	PMP30934.5	PMP30934.6
Vin (Min) (V)	6	6	6	6	6	6
Vin (Max) (V)	27	27	27	27	27	27
Vout (Nom) (V)	17	-4	17	-4	17	-4
Iout (Max) (A)	.05	.05	.05	.05	.05	.05
Output Power (W)	.85	.2	.85	.2	.85	.2
Isolated/Non-Isolated	Isolated	Isolated	Isolated	Isolated	Isolated	Isolated
Input Type	DC	DC	DC	DC	DC	DC
Topology	Flyback- Integrated Switch^Flyback- Non Sync	Flyback- Integrated Switch^Flyback- Non Sync	Flyback- Integrated Switch^Flyback- Non Sync	Flyback- Integrated Switch^Flyback- Non Sync	Flyback- Integrated Switch^Flyback- Non Sync	Flyback- Integrated Switch^Flyback- Non Sync