Sensor Controller Resistive 4-CH SPI/QSPI/3-Wire 16-Pin QSOP T/R

The MXB7846 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 MXB7846 uses an internal +2.5V reference or an external reference. The MXB7846 can make absolute or ratiometric measurements. In addition, this device has an on-chip temperature sensor, a battery-monitoring channel, and has the ability to perform touch-pressure measurements without external components. The MXB7846 has one auxiliary ADC input. All analog inputs are fully ESD protected, eliminating the need for external TransZorb devices. The MXB7846 is guaranteed to operate with a supply voltage down to +2.375V when used with an external reference or +2.7V with an internal reference. In shut-down 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 MXB7846 ideal for battery-operated systems, such as personal digital assistants with resistive touch screens and other portable equipment. The MXB7846 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 MXB7843

+2.375V to +5.25V Single Supply

Internal +2.5V Reference

Direct Battery Measurement (0 to 6V)

On-Chip Temperature Measurement

Touch-Pressure Measurement

4-Wire Touch-Screen Interface

Ratiometric Conversion

SPI™/QSPI™, 3-Wire Serial Interface

Programmable 8-/12-Bit Resolution

Auxiliary Analog Input

Automatic Shutdown Between Conversions

Low Power (External Reference)

• 270µA at 125ksps
• 115µA at 50ksps
• 25µA at 10ksps
• 5µA at 1ksps
• 2µA Shutdown Current