The UC2856DW is a current-mode Pulse Width Modulation (PWM) Controller 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 1.5A 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, 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 1V 5% shutdown threshold and 4kV minimum ESD protection on all pins.
Pin-for-pin compatible with the UC3846
65ns Typical delay from shutdown to outputs
50ns Typical delay from sync to outputs
Improved current sense amplifier with reduced noise sensitivity
Differential current sense with 3V common mode range
Trimmed oscillator discharge current for accurate deadband control
