MAX6977 is one of the MAX697x series. The MAX697x series is an 8-channel LED driver that uses an industry standard 4-wire serial interface and supports PWM control.
The MAX6977 is a serial‑interfaced LED driver that provides eight open‑drain, constant‑current sinking outputs rated at 5.5 V. It operates from a 3 V to 5.5 V supply and uses a 25 Mb, industry‑standard 4‑wire serial interface to program output current and read status.
Key features include programmable output current up to 55 mA per channel via a single external resistor, 3 % current matching between outputs, automatic open‑circuit LED fault detection, and a wide operating temperature range of –40 °C to +125 °C. The device is offered in TSSOP‑16, PDIP‑16, and SSOP‑16 packages and can be cascaded for larger LED arrays.
| Supply Voltage Range | 3 V to 5.5 V |
|---|---|
| Number of LED Outputs | 8 |
| Output Voltage Rating | 5.5 V |
| Maximum Output Current per Channel | 55 mA |
| Operating Temperature Range | -40 °C to +125 °C |
| Serial Interface Speed | 25 Mb, 4‑wire |
The device operates from a 3 V to 5.5 V supply.
Output current is programmed by an external resistor RSET; a 360 Ω resistor sets about 50 mA, while the minimum 307.6 Ω sets the maximum 55 mA.
It automatically detects open‑circuit LEDs and reports the fault in bits D6 and D5 of the shift register, which are shifted out on the next data transmission.
The device is specified for operation from –40 °C up to +125 °C.