MAX258ATA+T

The MAX258 is a 500mA, push-pull transformer driver designed to provide a simple solution for isolated power supplies. The IC 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 device features an integrated oscillator driving a pair of n-channel power switches. Internal circuitry guarantees a fixed 50% duty cycle to prevent DC current flow through the transformer.

The IC operates with up to 500mA of continuous current and features undervoltage lockout and thermal shutdown.

The IC includes a low-current shutdown mode to reduce the overall supply current to less than 5μA (max) when the driver is disabled.

The MAX258 is available in a small 8-pin (2mm×3mm) TDFN package and is specified over the -40°C to +125°C temperature range.

The MAX258 is an integrated primary-side transformer driver for isolated power-supply circuits. An on-board oscillator and internal MOSFETs provide up to 500mA of drive current to the primary windings of a centertapped transformer. The IC features an internal oscillator for autonomous operation. An internal flip-flop stage guarantees a fixed 50% duty cycle to prevent DC current flow in the transformer.

The device operates from a single +3.0V to +5.5V supply and includes undervoltage lockout for controlled startup. Thermal shutdown circuitry provides additional protection against excessive power dissipation.

The IC allows a versatile range of secondary-side rectification circuits. The primary-to-secondary transformer winding ratio can be chosen to adjust the isolated output voltage. The device allows up to 500mA of current into the primary transformer winding with a supply voltage up to +5.5V.