The MT7812 is a high‑efficiency, high‑precision, non‑isolated buck LED constant‑current driver chip with built‑in 500 V MOSFET and multiple protection features.
The MT7812 LED driver chip from Maxictech integrates a 500 V high‑voltage MOSFET, enabling a simple external circuit and low system cost. It operates in Critical Conduction Mode, turning the power switch on only when the inductor current reaches zero, which yields over 95 % peak efficiency and high current accuracy.
Key features include built‑in over‑current, short‑circuit, open‑circuit, and over‑temperature protection, as well as UVLO and front‑edge blanking control. The device is supplied in an SOP‑8 package and is suited for a wide range of LED lighting applications such as bulbs, floodlights, signal lights, and stage lighting. This manual is written in Chinese.
| Maximum VCC absorption current | 5 mA |
|---|---|
| VOVP pin voltage range | -0.3 V to 6 V |
| DRAIN voltage range | -0.3 V to 500 V |
| SOURCE voltage range | -0.3 V to 40 V |
| CS pin voltage range | -0.3 V to 6 V |
| Maximum power dissipation | 0.8 W |
| Storage temperature range | -55 °C to 150 °C |
| Operating temperature range | -40 °C to 105 °C |
| Maximum output LED current | <200 mA |
| Peak current detection threshold (VCS‑TH) | 400 mV |
| Minimum turn‑off time (TOFF_MIN) | 5 µs |
| Maximum turn‑off time (TOFF_MAX) | 400 µs |
| Maximum turn‑on time (TON_MAX) | 55 µs |
The device can drive an LED current of less than 200 mA.
It monitors the CS pin voltage and shuts off the internal switch when the voltage exceeds 400 mV, providing per‑cycle over‑current protection.
The chip operates from –40 °C to 105 °C ambient temperature.