CAP1293-1-AC3-TR

Overview

The CAP1293-1-AC3-TR is a three-channel capacitive touch sensor controller manufactured by Microchip Technology. It features an SMBus/I2C interface and operates within a supply voltage range of 3.0V to 5.5V. The device draws 500µA during active sensing and 5µA in Deep Sleep mode. It supports proximity detection, signal guarding, and multiple pattern touch recognition. The component is housed in an 8-TDFN (2x3) package with exposed pad and functions across a temperature range of -40°C to 125°C.

Feature Summary

• Three individual capacitive touch sensor inputs with programmable sensitivity and automatic recalibration for parasitic capacitance compensation.
• Proximity detection capability with optional signal guard output to isolate antennas from noise and conductive surface attenuation.
• Multiple Pattern Touch recognition allowing simultaneous button sets to trigger specific status bits and interrupts.
• Low power operation with Active, Standby, Combo, and Deep Sleep states, including 8kV ESD rating on all pins.

Applications

• Desktop and Notebook PCs
• LCD Monitors
• Consumer Electronics
• Appliances

Procurement Notes

Verify the complete part number against official Microchip documentation to ensure correct suffix alignment. Confirm that the AC3 designation corresponds to the specified 8-TDFN package variant. Cross-reference the datasheet revision history to validate current manufacturing status and any potential design changes affecting pinout or electrical characteristics.

Selection Notes

Select this component when a low-pin-count solution for multi-touch interfaces is required. Ensure the host system supports SMBus or I2C protocols at frequencies up to 400kHz. Verify that the application environment stays within the specified operating temperature range and that the 5V tolerant digital pins align with the host logic levels.

Part Context

This part belongs to the CAP1293 family of capacitive touch controllers. The base model provides three channels with proximity detection. Variations exist in packaging options, such as SOIC, but the TDFN form factor offers a compact footprint suitable for space-constrained consumer electronics and portable devices requiring robust touch input.

Replacement Considerations

Direct substitutes include other Microchip capacitive touch sensors like the CAP1203 series for single-channel needs or the CAP1298 for higher channel counts. Verify interface compatibility and pinout differences before swapping. Alternative vendors may offer functionally similar ICs, but register-level code migration will likely be necessary.

FAQ

Can the CS2 pin function as both a touch sensor and a signal guard?

Yes, the CS2/SG pin is multifunctional. It can serve as Capacitive Touch Sensor Input 2 or act as the Signal Guard output, depending on the configuration settings in the control registers.

How does the device handle environmental drift?

The CAP1293 automatically recalibrates to compensate for gradual environmental changes. Calibration occurs after power-on reset, when sample time or gain changes, or when a sensor input is newly enabled.

What is the default I2C address for the CAP1293?

The CAP1293 responds to the SMBus address 0101_000 (7-bit address). This address is fixed for standard operation unless modified by specific hardware configurations not detailed in the general description.