6 Low-Voltage Bias Supplies

In traction inverters, the low-voltage bias supplies usually connect to a low-voltage source such as the 12-V battery and power the gate driver. TI provides various solutions: including converters with integrated field-effect transistors (FETs) and integrated magnetics, converters with integrated FETs and external magnetics, and controllers with external FETs and external magnetics.

The UCC14240-Q1 isolated DC/DC converter module delivers 1.5 W of output power at ambient temperatures of 105°C, and provides ±1.3% output voltage regulation. The device has basic and reinforced isolation versions and greater than 150 V/ns common-mode transient immunity performance. #FIG_Z3D_BDZ_N5B shows the image of (EVM) board of UCC14240-Q1 which is in a low-profile, 3.5-mm, wide body SOIC integrated package.

The UCC25800-Q1 device is an inductor-inductor-capacitor resonant converter with ultra-low EMI emission. This device allows the design to utilize a transformer with higher leakage inductance, but much smaller parasitic primary-to-secondary capacitance and protection features such as adjustable overcurrent protection, input overvoltage protection, overtemperature protection, and protection from pin faults.

The SN6507-Q1 is a high-frequency push-pull transformer driver with integrated MOSFETs, and duty cycle control which enables wide input voltage range. The device integrates a controller and two 0.5-A NMOS power switches that switch out of phase. This device also includes programmable soft start, spread spectrum clocking and pin-configurable slew rate control.

The LM2518x-Q1 family are primary-side regulated (PSR) flyback converters with integrated power switches and the ability to operate over a wide input voltage range of 4.5 V to 42 V. The isolated output voltage is sampled from the primary-side flyback voltage, eliminating the need for an optocoupler, voltage reference, or third winding from the transformer for output voltage regulation. Boundary conduction mode (BCM) switching enables a compact magnetic design and better than ±1.5% load and line regulation performance.