AD7889-1ACBZ-RL7

Overview

The AD7889-1ACBZ-RL7 is a 12-bit successive approximation analog-to-digital converter (SAR ADC) designed for resistive touch screen applications. It operates on a single 1.6 V to 3.6 V supply and supports an I²C interface, indicated by the '-1' suffix in the model number. The device features a throughput rate of 105 kSPS and includes a preprocessing block with median and averaging filters to reduce noise. Key specifications include a shutdown mode consuming less than 6 μA, auxiliary input/battery monitoring capabilities, and integrated temperature sensing. It is housed in a 12-ball WLCSP package.

Feature Summary

• 12-bit SAR ADC with 105 kSPS throughput rate
• I²C serial interface (AD7889-1 variant)
• Median and averaging filter for noise reduction
• Auxiliary analog input and battery monitor (0.5 V to 5 V)
• Shutdown mode with maximum current consumption of 6 μA

Applications

• Personal digital assistants
• Smart handheld devices
• Touch screen monitors
• Point-of-sale terminals
• Medical devices

Procurement Notes

Verify that the specific ordering suffix matches the required interface configuration. The '-1' designation confirms I²C compatibility, whereas non-suffixed or other variants may utilize SPI. Confirm the package type corresponds to the design requirements, as the AD7889 family includes both WLCSP and LFCSP options. Ensure the ambient operating temperature range aligns with the specified -40°C to +85°C limits for reliable performance.

Selection Notes

Select this component when an I²C interface is preferred over SPI for system integration. The AD7889-1 variant is suitable for low-voltage systems requiring operation between 1.6 V and 3.6 V. Consider the integrated filtering capabilities if the application environment has significant LCD noise. Verify that the 12-ball WLCSP package fits within the available PCB area constraints.

Part Context

The AD7889-1ACBZ-RL7 belongs to the AD7879/AD7889 family of touch screen controllers manufactured by Analog Devices. This family provides complete data acquisition solutions for digitizing positional inputs from 4-wire resistive touch screens. The AD7889 specifically offers a backside-coated WLCSP option for enhanced reliability compared to standard versions.

Replacement Considerations

The AD7879-1ACPZ-RL7 serves as a functional equivalent within the same family but utilizes an SPI interface instead of I²C. Direct substitution requires verifying that the host controller supports the SPI protocol or that the pinout differences for CS/DIN/DOUT versus ADD0/ADD1/SDA are accommodated.