The PCA9621 is an 8-channel programmable open-drain output driver with a 2-wire bus interface (including I2C bus, SMBus bus, PMBus bus and other systems based on similar principles). Output ports have a 65 mA sink capability, making them ideal for driving LEDs. The state of the outputs is determined by a programmable 8-bit register which can be read and written via signals from the 2-wire bus (e.g., I2C bus or similar). The 2-wire bus interface also has 30 mA Fast-mode Plus (Fm+) capability, and consequently can be run in excess of 1 MHz or up to 4000 pF capacitance. As such, the PCA9621 can be connected to other 2-wire devices across long cable connections. It can be mixed with other Fast-mode Plus slaves in systems driven by Fm+ buffers or by the PCA9646 (fully buffered 4-channel bus switch) to build large scale systems with high-speed or high-capacitance drive capability, for example large scale LED displays or controlled lighting.
The PCA9621 is a monolithic CMOS integrated circuit that provides eight individually selectable open‑drain output ports. Each port can sink up to 65 mA, making the device suitable for driving LEDs and other general‑purpose loads. The outputs are programmed via a 2‑wire bus (I²C/SMBus/PMBus) using an 8‑bit control register.
The device operates from 2.7 V to 5.5 V, supports Fast‑mode Plus (up to 80 mA and 4000 pF) and can run at bus speeds exceeding 1 MHz. It is offered in SO‑16 and TSSOP‑16 packages and includes ESD protection on all I/Os.
| Sink capability per output | 65 mA |
|---|---|
| Operating voltage range | 2.7 V to 5.5 V |
| Number of output ports | 8 open‑drain ports |
| Fast‑mode Plus bus capability | 80 mA, 4000 pF, >1 MHz |
| Maximum total output drive (paralleled) | 500 mA |
Each output port can sink up to 65 mA.
The device operates from 2.7 V to 5.5 V.
It provides eight open‑drain output ports.
The 2‑wire bus can operate in excess of 1 MHz.