Texas Instruments ADS7846IRGVR

Overview

ADS7846IRGVR from Texas Instruments is a 12-bit successive-approximation ADC touch screen controller with integrated 2.5V reference, battery monitoring (0V to 6V), on-chip temperature sensing, and touch-pressure measurement capability. It operates from 2.2V to 5.25V, supports QSPI/SPI 3-wire interface, and delivers up to 125kHz throughput in TSSOP-16 package for resistive touch systems.

For engineers reviewing the ADS7846IRGVR datasheet, ADS7846IRGVR pinout, ADS7846IRGVR application, or ADS7846IRGVR equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters, real-world use cases in portable instrumentation and handheld devices, and two rigorously cross-checked alternative parts for design continuity.

Technical Context

The ADS7846IRGVR implements a capacitive redistribution SAR architecture with integrated sample-and-hold, enabling ratiometric differential measurements for X/Y position via internal switch drivers (X+/X–/Y+/Y–) and supporting both single-ended and differential reference modes. Its internal 2.5V reference (±2.5mV accuracy, 15ppm/°C drift) powers auxiliary, battery, and temperature channels while remaining disableable for ADS7843 compatibility.

It features dedicated PENIRQ open-drain interrupt output, BUSY status flag, and configurable 8- or 12-bit conversion modes. The device uses a 24-clock-cycle SPI protocol with 8-bit control byte followed by 12-bit result, and supports auto power-down (3µA) when CS/DCLK/DIN are high.

Key Specifications

Pinout & Package

TSSOP-16 package (RGV suffix), 4.4mm × 5mm body, 0.65mm pitch, exposed thermal pad (not electrically connected). Pin 1 marked by dot; pin numbering counterclockwise from top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar touch screen controller applications.

Compared with ADS7846IRGVR, ADS7843E omits all auxiliary sensing and requires external components for battery/temperature functions, while MAX11803A replaces SPI with I²C and removes dedicated VBAT/PENIRQ hardware - making ADS7846IRGVR uniquely suited for cost-sensitive, feature-complete resistive touch upgrades.

Availability

ADS7846IRGVR is available at Aetrix Electronics and suitable for personal digital assistants, point-of-sale terminals, and portable medical instruments requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for ADS7846IRGVR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with over 90 years of innovation in precision data conversion and power management.

The ADS7846IRGVR belongs to TI's precision analog touch controller product line, designed specifically to replace legacy ADS7843 systems with enhanced functionality while maintaining mechanical and electrical compatibility for seamless integration into portable human-interface applications.

FAQ

What is the function of the PENIRQ pin on the ADS7846IRGVR?

The PENIRQ pin on the ADS7846IRGVR is an open-drain, active-low interrupt output that signals touch detection. It requires an external 10kΩ to 100kΩ pull-up resistor to +VCC. When a touch closes the resistive panel, ADS7846IRGVR asserts PENIRQ low within 10µs, allowing the host processor to initiate coordinate acquisition without polling. This pin remains high-impedance when CS is high, enabling clean power-down behavior.

Does the ADS7846IRGVR require an external reference voltage?

No - the ADS7846IRGVR includes an internal 2.5V reference (2.45–2.55V, 15ppm/°C drift) usable for battery monitoring, temperature measurement, and AUX input. However, for optimal touch screen linearity, the device supports differential reference mode (SER/DFR = 0) where +REF/–REF connect directly to Y+/Y– or X+/X–, eliminating dependency on any reference voltage. External reference is optional and only needed for non-ratiometric precision measurements.

How does the ADS7846IRGVR measure battery voltage up to 6V while operating from a 2.7V supply?

The ADS7846IRGVR measures battery voltage via the VBAT pin using an internal 4:1 resistor divider. When configured (A2A1A0 = 010), the 0.5–6.0V input is scaled to 0.125–1.5V for the ADC, staying within the 2.5V reference range. Input impedance is 10kΩ during sampling and 1GΩ otherwise, minimizing load on the battery. This allows direct monitoring of raw battery voltage pre-regulation - a capability not present in the ADS7843 and critical for accurate state-of-charge estimation in ADS7846IRGVR designs.

Can the ADS7846IRGVR perform temperature measurements without calibration?

Yes - the ADS7846IRGVR supports two temperature measurement modes. The differential method (TEMP0/TEMP1) requires no factory calibration and achieves ±2°C accuracy across –40°C to +85°C by measuring voltage delta between two diode currents (1× and 91×). The single-point method (TEMP0 only) achieves ±3°C accuracy but requires storing one 25°C calibration value in system memory. Both methods use the same PENIRQ diode and internal ADC path, and neither requires external components - a key differentiator of the ADS7846IRGVR versus earlier controllers.

What is the maximum sampling rate of the ADS7846IRGVR and what limits it?

The ADS7846IRGVR supports a maximum throughput rate of 125kHz, limited by its internal SAR conversion time (12 DCLK cycles) and acquisition time (3 DCLK cycles), totaling 15 cycles per sample. At 2MHz DCLK, this yields 133ksps theoretical maximum; however, the datasheet specifies 125kHz as the guaranteed maximum due to timing margins across voltage/temperature. Performance degrades below 2.7V supply or above +85°C, and the device automatically throttles in high-temperature conditions to maintain ±2 LSB integral linearity - a hard limit enforced by the ADS7846IRGVR's internal timing architecture.