BU21023GUL, BU21023MUV, BU21024FV-M are 4-wire resistive touch screen controller ICs produced by ROHM. They support dual-touch detection and gesture recognition. These intelligent controllers expose a set of registers to a host processor and are software configurable. The controllers can detect single point coordinates, dual coordinates, pinch, spread, rotate left and rotate right gestures, enabling pan and zoom operations in applications that previously had to rely exclusively on capacitive touch technology. Resistive touch does not require custom panel development which reduces development cost and results in faster time to market across a family of products.
The BU21024FV-M is a 4‑wire resistive touch screen controller IC that supports single‑touch, dual‑touch and gesture recognition, offering up to two simultaneous touch points and a 10‑bit ADC for high‑resolution coordinate measurement. It operates from a single 3 V supply and includes programmable interrupt polarity, filtering, and calibration features.
This technical note describes the device's features, electrical characteristics, recommended operating conditions, SPI and 2‑wire serial host interfaces, EEPROM programming options, mechanical packaging, ordering information, and legal notices. It also provides a line‑up matrix comparing the BU21024FV-M with related parts.
| Supply voltage range | 2.7 V – 3.6 V |
|---|---|
| Maximum detection points | 2 |
| ADC resolution | 10‑bit |
| Power dissipation | 850 mW |
| Operating current | 4 mA – 6 mA |
| Oscillation frequency | 20 MHz |
| Package type | SSOP‑B28 |
The BU21024FV-M operates from 2.7 V to 3.6 V.
It can detect up to two touch points at the same time.
The device supports a 4‑wire SPI interface and a 2‑wire I²C‑like serial interface.
The BU21024FV-M is supplied in an SSOP‑B28 package.