The MAX6971 is a serial-interfaced LED driver that provides 16 open-drain, constant-current-sinking LED driver outputs rated at 36V. The MAX6971 operates from a 3V to 5.5V supply. The MAX6971 supply and the LEDs’ supply or supplies can power up in any order. The constant-current outputs are programmed together to up to 55mA using a single external resistor. The MAX6971 operates with a 25Mb, industry-standard, 4-wire serial interface. The MAX6971 uses the industry-standard, shift-register-plus-latch-type serial interface. The driver accepts data shifted into a 16-bit shift register using data input DIN and clock input CLK. Input data appears at the DOUT output 16 clock cycles later to allow cascading of multi- ple MAX6971s. The latch-enable input, LE, loads the 16 bits of shift register data into a 16-bit output latch to set which LEDs are on and which are off. The output- enable, OE, gates all 16 outputs on and off, and is fast enough to be used as a PWM input for LED intensity control. For applications requiring LED fault detection, refer to the MAX6983, which automatically detects open-circuit LEDs. For safety-related applications requiring a watchdog timer, refer to the MAX6983, which includes a fail-safe feature that blanks the display if the serial interface becomes inactive for more than 1s. The MAX6971 is one of a family of 12 shift-register-plus- latch-type LED drivers. The family includes 8-port and 16-port types, with 5.5V- or 36V-rated LED outputs.
The MAX6971 is a 16‑port, 36 V constant‑current LED driver that operates from a 3 V to 5.5 V supply. It uses a 4‑wire, shift‑register‑plus‑latch serial interface (DIN, CLK, LE, OE, DOUT) allowing cascading of multiple devices. Each output is an open‑drain, constant‑current sink capable of up to 55 mA per channel, set by a single external resistor.
The datasheet provides absolute maximum ratings, electrical characteristics, timing diagrams, pin descriptions, and package dimensions for the 24‑pin TSSOP and PDIP versions. It also includes typical application circuits and ordering information.
| Operating Supply Voltage (V+) | 3.0 V – 5.5 V |
|---|---|
| Output Voltage (Vout) | 36 V |
| Continuous Current per Output | Up to 55 mA |
| Operating Temperature Range | -40 °C to +125 °C |
| Package Types | 24‑pin TSSOP, 24‑pin PDIP |
Each output can sink up to 55 mA of LED current.
The device operates from a 3 V to 5.5 V supply.
The MAX6971 provides 16 constant‑current sinking LED outputs.