Space-grade QMLV, 40-V input, 1.5-A dual-output 1-MHz PWM controller

The UC1856 is a high-performance version of the popular UC1846 series of current-mode controllers, and is intended for both design upgrades and new applications where speed and accuracy are important. All input-to-output delays have been minimized, and the current sense output is slew-rate limited to reduce noise sensitivity. Fast 1.5-A peak output stages have been added to allow rapid switching of power FETs.

A low-impedance TTL-compatible sync output has been implemented with a TRI-STATE function when used as a sync input.

Internal-chip grounding has been improved to minimize internal noise caused when driving large capacitive loads. This improvement, in conjunction with the improved differential current-sense amplifier, results in enhanced noise immunity.

Other features include a trimmed oscillator current (8%) for accurate frequency and dead-time control; a 1-V 5% shutdown threshold; and 4-kV minimum electrostatic discharge (ESD) protection on all pins.