1 Features
Ultra-low start-up current (5uA maximum)
Current mode control
Integrated 1.5A peak current gate driver
Programmable switching frequency
Light load step-by-step analog frequency reduction optimization efficiency curve
No-load intermittent operation to achieve low no-load power consumption
Cycle-by-cycle current limiting protection, short circuit protection, over temperature protection
No need for feed-forward to achieve consistency of over-current point
Direct optocoupler interface
Optional built-in or external soft start
Built-in slope compensation
Maximum duty cycle 80% limit
MSOP8 ultra-small package
2 Fields of application
Discontinuous (DCM)/continuous (
CCM) mode flyback converter
Industrial power conversion
POE power supply
Isolated communication power supply
Switch-mode power supplies for smart meters and audio amplifiers (
SMPS）
Building automation and white goods SMPS
3 Description
VPC5021 offline pulse width modulation (
PWM) controller using electric
Flow-Mode Control Enables High Efficiency Offline Single-Ended Flyback/Forward Power Converter
Applications. VIN high-voltage power supply port achieves ultra-low start-up current (less than
5uA), start-up voltage 20V, under-voltage lockout voltage 7.6V, at a certain start-up
Minimize the power consumption of starting the network under the active time, which can achieve low standby
ACDC power converter for machine power consumption. VDD low voltage power supply port start
The voltage is as low as 7.4V, which can also meet the DCDC of low input voltage
application of switching power supplies .
The VPC5021 controller works fixedly at the set
PWM modulation is performed at the maximum operating frequency, as the load is reduced to a
To a certain extent, the controller optimizes the full-duty
load range efficiency while achieving lower light load ripple voltage and no-load power
consumption, and there is no audio noise, which better solves the no-load power consumption, light
The contradictory relationship between load ripple and audio noise.
VPC5021 also integrates output short-circuit protection, over-current protection, output
The output overvoltage protection and other functions ensure the high reliability of the switching power supply in the whole range.
