UC2965

The UC3965 is suitable for applications needing greater precision and more functionality than the TL431 type shunt regulators. The wide range VCC input capability enables the device to be biased from the secondary side output voltage rail, resulting in closed loop soft start.

The UC3965 includes an accessible 2.5V precision reference which offers 0.4% initial and 1% reference accuracy over line, load, and full temperature range with a low offset error amplifier, a 2X inverting amplifier/buffer, and an undervoltage lockout circuit. The IC is ideally suited for applications where high precision PWM power supply regulation is required. Typically, the error amplifier is configured to compare a fraction of the to be regulated power supply voltage to the on-chip 2.5V reference. The 2X amplifier/buffer output is then used to drive a PWM controller or regulator. The UC3965 is also capable of driving an optocoupler diode for isolated applications.