The MXB7843 is an industry-standard 4-wire touch-screen controller. It contains a 12-bit sampling analog-to-digital converter (ADC) with a synchronous serial interface and low on-resistance switches for driving resistive touch screens. The MXB7843 uses an external reference. The MXB7843 can make absolute or ratiometric measurements. The MXB7843 has two auxiliary ADC inputs. All analog inputs are fully ESD protected, eliminating the need for external TransZorb™ devices. The MXB7843 is guaranteed to operate with a single 2.375V to 5.25V supply voltage. In shutdown mode, the typical power consumption is reduced to under 0.5µW, while the typical power consumption at 125ksps throughput and a 2.7V supply is 650µW. Low-power operation makes the MXB7843 ideal for battery-operated systems, such as personal digital assistants with resistive touch screens and other portable equipment. The MXB7843 is available in 16-pin QSOP and TSSOP packages, and is guaranteed over the -40°C to +85°C temperature range.
The MXB7843 is an industry‑standard 4‑wire touch‑screen controller that integrates a 12‑bit successive‑approximation ADC, SPI/QSPI serial interface, and low‑on‑resistance switches for driving resistive touch screens. It operates from a single supply of 2.375 V to 5.25 V and is qualified for the –40 °C to +85 °C temperature range, making it suitable for portable devices such as PDAs, point‑of‑sale terminals, and cellular phones.
Key features include ESD‑protected analog inputs (±15 kV air‑gap, ±8 kV contact discharge), two auxiliary ADC channels, automatic shutdown between conversions, and configurable resolution (8‑ or 12‑bit). The device is offered in 16‑pin QSOP and TSSOP packages and provides both single‑ended and differential (ratiometric) measurement modes.
| Supply Voltage Range | 2.375 V to 5.25 V |
|---|---|
| ADC Resolution | 12 bits |
| Typical Power Consumption at 125 kS/s | 270 µA |
| Operating Temperature Range | –40 °C to +85 °C |
| ESD Protection (Air‑Gap) | ±15 kV IEC 61000‑4‑2 |
| Number of Pins / Packages | 16‑pin QSOP or TSSOP |
| Auxiliary ADC Inputs | 2 |
It operates from a single supply voltage between 2.375 V and 5.25 V.
The device includes two auxiliary ADC inputs (IN3 and IN4).
At 125 kS/s and a 2.7 V supply the typical power consumption is about 270 µA (650 µW).
The analog inputs are protected to ±15 kV air‑gap discharge and ±8 kV contact discharge per IEC 61000‑4‑2.