AD7148ACPZ-1500RL7

Overview

The AD7148ACPZ-1500RL7 is a programmable capacitance-to-digital converter (CDC) designed for single-electrode capacitive sensors. It features eight sensor inputs, a 16-bit sigma-delta architecture, and an I2C-compatible serial interface with a separate VDRIVE level. The device operates on a 2.6 V to 3.6 V supply, drawing 1 mA in full power mode and 21.5 μA in low power mode. It includes on-chip automatic calibration logic, environmental compensation, and adaptive thresholds. Packaged in a 16-lead, 4 mm × 4 mm LFCSP, it supports update rates of approximately 25 ms across all channels.

Feature Summary

• Integrated capacitance-to-digital conversion with femtofarad resolution
• On-chip automatic calibration and environmental change compensation
• I2C-compatible serial interface with independent VDRIVE voltage level
• Programmable touch controller supporting buttons, scroll bars, and wheels

Applications

• Cell phones
• Personal music and multimedia players
• Smart handheld devices
• Television, A/V, and remote controls
• Gaming consoles

Procurement Notes

Verify the specific ordering suffix against official Analog Devices documentation to confirm package type and reel specifications. Ensure compatibility with the host processor's I2C voltage levels by checking the VDRIVE pin requirements. Confirm that the application environment falls within the specified operating temperature range and supply voltage limits before finalizing procurement.

Selection Notes

Select this component when designing systems requiring high-resolution user input methods like sliders or wheels. It is suitable for applications needing minimal software overhead due to its on-chip calibration and threshold logic. Consider the 16-lead LFCSP package constraints and ensure adequate PCB space for the required external components, such as the BIAS capacitor.

Part Context

This part belongs to the AD714x series of CapTouch controllers from Analog Devices. It shares register map compatibility with the AD7143 but differs in channel count and interface capabilities. The AD7148 specifically targets single-electrode grounded sensors, distinguishing it from models designed for floating or two-electrode configurations.

Replacement Considerations

The AD7143 is noted as register map compatible. Verify if the target application requires fewer than eight channels or utilizes floating sensors, which might necessitate alternative parts. Cross-reference pinouts and electrical characteristics carefully when substituting.