GPIO expander is a useful tool for applications that lack IO ports. It can control GPIO output states using the I2C write protocol and detect GPIO input states using the I2C read protocol. Additionally, it has an interrupt function that frees the CPU from polling the registers in the GPIO expander. GPIO expanders also feature built-in power on reset, 3V tolerant input, and NMOS open-drain output.
The BU8272GUW is a GPIO expander IC from ROHM that adds up to 20 general‑purpose I/O pins via a 2‑Wire (I²C) serial interface. It supports 400 kbps fast‑mode operation, includes an interrupt output, built‑in power‑on reset, 3 V‑tolerant inputs and NMOS open‑drain outputs, making it suitable for designs with limited I/O resources.
The document details absolute maximum ratings, recommended operating conditions, package specifications (VBGA035W040), pin diagrams, functional block diagrams, electrical characteristics, and ordering information. It also includes legal notices and handling guidelines for the device.
| Supply voltage (VDD) range | 1.65 V – 1.95 V (typical) |
|---|---|
| 2‑Wire (I²C) interface speed | 400 kbps (Fast‑mode) |
| Number of GPIO pins | 20‑bit general‑purpose I/O |
| Package type | VBGA035W040 |
| Operating temperature range | -55 °C – +125 °C |
| Standby current | 3.0 pA |
The device supports up to 400 kHz I²C clock frequency.
It provides a 20‑bit general‑purpose I/O interface.
The IC is supplied in a VBGA035W040 ball‑grid array package.