VPC28C45

VPCx8C4x is a high-performance current mode universal PMW controller designed using advanced BCD semiconductor technology, which has excellent characteristics such as low power consumption, fast current sampling, and high programmable maximum operating frequency. The internally implemented circuit includes: an undervoltage lockout (UVLO) with a starting current as low as tens of microamperes; A pulse width modulation (PWM) fast comparator that provides current limiting control, with a total delay from comparison to output as low as 30nS; A fast comparison oscillator that can achieve a programmable maximum frequency of 1MHz; An error amplifier with a precision reference of ± 1% calibrated through tuning at its forward input end; A push-pull output composed of NMOS and PMOS transistors, which can output a high level of the same magnitude as the device's power supply voltage; Other internal circuits also include logic to ensure latch operation. Specifically, the VPCx8C4x series also features a clamp circuit internally. When the VDD voltage rises to approximately 19V, its current gradually increases with the increase of its voltage until it reaches its maximum value of 14mA (typical value) at 24.7V. Under normal circumstances, the device operates below 19V with low power consumption and is suitable for a wider temperature range; When the auxiliary power supply is too high, it can prevent the VDD voltage from rising and avoid exceeding the rated voltage of the power transistor gate. VPCx8C4x offers a variety of packaging options, temperature range options, maximum duty cycle options, as well as options for opening and closing thresholds and hysteresis ranges. Devices with high on or off hysteresis are ideal choices for offline power supplies, while devices with a narrow hysteresis range are suitable for DC-DC applications. The working temperature range of VPC28C4x is -40 ° C to 105 ° C, and the working temperature range of VPC38C4x is -25 ° C to 85 ° C.