General Description

The MXB7843 is an industry-standard 4-wire touchscreen controller. It contains a 12-bit sampling analogto-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 ratio metric measurements. The MXB7843 has two auxiliary ADC inputs. All analog inputs are fully ESD protected, eliminating the need for external TransZorb™ devices.

Features

♦ ESD-Protected ADC Inputs

    ±15kV IEC 61000-4-2 Air-Gap Discharge

    ±8kV IEC 61000-4-2 Contact Discharge

♦ Pin Compatible with MXB7846

♦ +2.375V to +5.25V Single Supply

♦ 4-Wire Touch-Screen Interface

♦ Ratiometric Conversion

♦ SPI™/QSPI™, 3-Wire Serial Interface

♦ Programmable 8-/12-Bit Resolution

♦ Two Auxiliary Analog Inputs

♦ Automatic Shutdown Between Conversions

♦ Low Power

    270µA at 125ksps

    115µA at 50ksps

    25µA at 10ksps

    5µA at 1ksps

    2µA Shutdown Current

Applications

    Personal Digital Assistants

    Portable Instruments

    Point-of-Sales Terminals

    Pagers

    Touch-Screen Monitors

    Cellular Phones