The MAX5021/MAX5022 are current-mode PWM controllers suitable for wide input voltage range isolated power supply design. They feature large undervoltage lockout circuit, low startup and operating current, and fixed switching frequency.
The MAX5021 and MAX5022 are current‑mode PWM controllers designed for isolated power‑supply applications with universal input ranges (85 VAC‑265 VAC or –36 VDC‑–72 VDC). They feature low startup current, large UVLO hysteresis, and internally trimmed 262 kHz switching frequency, making them suitable for forward‑converter and fly‑back designs.
The document includes electrical characteristics, absolute maximum ratings, pin configurations for SOT‑23, UMAX and PDIP packages, and layout recommendations for high‑voltage off‑line circuits. Application examples such as universal off‑line supplies, standby supplies, and telecom power supplies are described.
| Switching Frequency | 262 kHz ±12 % |
|---|---|
| Maximum Duty Cycle (MAX5021) | 50 % |
| Maximum Duty Cycle (MAX5022) | 75 % |
| Typical Operating Current | 1.2 mA |
| UVLO Hysteresis | 14 V |
| Operating Temperature Range | -40 °C to +85 °C |
| Package Types | 6‑pin SOT23, 8‑pin UMAX, 8‑pin PDIP |
The internal switching frequency is 262 kHz, trimmed to ±12 % accuracy.
MAX5021 supports a maximum duty cycle of 50 %, while MAX5022 supports 75 %.
They are offered in 6‑pin SOT23, 8‑pin UMAX, and 8‑pin PDIP packages.