The MAX6968 is a serial-interface LED driver that provides eight open-drain, constant-current sinking LED driver outputs rated at 5.5V. It operates from a 3V to 5.5V supply and allows the supply and the LEDs' supply to power up in any order. The constant-current outputs can be programmed together to up to 55mA using a single external resistor. The MAX6968 uses a 25Mb, industry-standard, 4-wire serial interface with a shift-register-plus-latch-type serial interface. It accepts data shifted into an 8-bit shift register and outputs the data eight clock cycles later, allowing cascading of multiple MAX6968s. The output latch is loaded with the data from the shift register using the latch-enable input, determining which LEDs are on and off. The output-enable input gates all eight outputs on and off and can be used as a PWM input for LED intensity control. For LED fault detection, the MAX6977 data sheet can be referred to, which automatically detects open-circuit LEDs. For safety-related applications with a watchdog timer, the MAX6978 data sheet can be referred to, which includes a fail-safe feature that blanks the display if the serial interface becomes inactive for more than 1s. The MAX6968 is part of a family of 12 shift-register-plus-latch-type LED drivers, including 8-port and 16-port types, with 5.5V- or...
The MAX6968 is an 8‑port, open‑drain, constant‑current LED driver that operates from a 3 V to 5.5 V supply and supports a 5.5 V output rating. It uses a 4‑wire serial interface to shift data into an 8‑bit register and latch the output states, allowing cascading of multiple devices.
Key features include up to 55 mA continuous current per output, 3 % current matching between outputs, and operation over a temperature range of –40 °C to +125 °C. The device is supplied in TSSOP, PDIP, and SSOP packages and is intended for applications such as signage, architectural lighting, and multiplexed LED displays.
| Supply Voltage (V+) | 3.0 – 5.5 V |
|---|---|
| Output Voltage Rating | 5.5 V |
| Maximum Continuous Current per Output | 55 mA |
| Operating Temperature Range | -40 °C to +125 °C |
| Number of LED Output Ports | 8 |
| Interface Type | 4‑wire serial |
Each output can sink up to 55 mA of continuous current.
The device operates from –40 °C to +125 °C.