The MAX5021/MAX5022EUT current-mode PWM controllers contain all the control circuitry required for the design of wide input voltage range isolated power supplies. These devices are well suited for use in universal input (85VAC to 265VAC) off-line or telecom (-36VDC to -72VDC) power supplies.An undervoltage lockout (UVLO) circuit with large hysteresis coupled with low startup and operating current reduce power dissipation in the startup resistor and allow use of ceramic bypass capacitors. The 262kHz switching frequency is internally trimmed to }12% accuracy; this allows the optimization of the magnetic and filter components resulting in compact, cost-effective power supplies. The MAX5021 with 50% maximum duty cycle and MAX5022EUT with 75% maximum duty cycle are recommended for forward converters and flyback converters, respectively. The MAX5021/MAX5022EUT are available in 6-pin SOT23, 8-pin μMAX, and 8-pin DIP packages and are rated for operation over the -40C to +85C temperature range.
Feature
- Available in a Tiny 6-Pin SOT23 Package
- 50μA Typical Startup Current
- 1.2mA Typical Operating Current
- Large UVLO Hysteresis of 14V
- Fixed Switching Frequency of 262kHz ±12%
- 50% Maximum Duty Cycle Limit (MAX5021)
- 75% Maximum Duty Cycle Limit (MAX5022)
- 60ns Cycle-by-Cycle Current-Limit Response Time
Applications
- Isolated Power Supplies
- Low-Power Telecom Power Supplies
- Mobile Phone Chargers
- Standby Power Supplies
- Universal Offline Power Supplies