Touch Screen Controller 16-Pin QSOP

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.

• 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