VPC2842

VPCx84x 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 VPCx84x series also features a clamp circuit internally. When the VDD voltage of the device VPCx842/4 rises to approximately 19V (VPCx843/5 is 13V), its current gradually increases with its voltage until it reaches its maximum value of 14mA (typical value) at 24.7V (VPCx843/5 is 19V). Proper design of current limiting resistors for auxiliary power supply can prevent the increase of VDD voltage and avoid exceeding the rated voltage of the power transistor gate when the auxiliary power supply is too high. VPCx84x offers multiple models, with the main differences being temperature range, maximum duty cycle, and different threshold voltages for opening and closing. 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 VPC284x is -40 ° 125 ° C, and the working temperature range of VPC384x is -25 ° C to 85 ° C.