Maxim's 1 A spread-spectrum, push-pull transformer driver for isolated power supplies
The MAX13253 is a 1 A push-pull transformer driver designed to provide a simple solution for low-EMI isolated power supplies. The MAX13253 has an internal oscillator and operates from a single +3.0V to +5.5V supply. The transformer’s secondary-to-primary winding ratio defines the output voltage, allowing selection of virtually any isolated output voltage with galvanic isolation. The MAX13253 features an integrated oscillator driving a pair of N-channel power switches. The driver includes pin-selectable spread-spectrum oscillation and a well-controlled slew rate to reduce EMI. The MAX13253 can optionally be driven by an external clock to further manage EMI. Internal circuitry guarantees a fixed 50% duty cycle to prevent DC current flow through the transformer, regardless of which clock source is used. The MAX13253 operates with up to 1 A of continuous current and features integrated protection including fault detection, overcurrent protection, and thermal shutdown. The MAX13253 includes a low-current shutdown mode to reduce the overall supply current to less than 5 µA (max) when the driver is disabled. The MAX13253 is available in a small, 10-pin, (3 mm x 3 mm) TDFN package and is specified over the -40°C to +125°C temperature range.