Texas Instruments FDC2112QDNTTQ1

Overview

FDC2112QDNTTQ1 from Texas Instruments is a 2-channel, AEC-Q100 Grade 1 automotive-qualified capacitance-to-digital converter (CDC) for high-resolution capacitive sensing. It delivers up to 28-bit resolution, 13.3 kSPS maximum output rate per active channel, and 0.3 fF RMS noise at 100 SPS with 5 MHz sensor excitation - enabling precise proximity and gesture detection in harsh environments.

For engineers reviewing the FDC2112QDNTTQ1 datasheet, FDC2112QDNTTQ1 pinout, FDC2112QDNTTQ1 application, or FDC2112QDNTTQ1 equivalent, key selection criteria include its resonant L-C tank architecture, I²C interface, 2.7–3.6 V supply, –40°C to +125°C operation, and WSON-12 (4 mm × 4 mm) package with integrated ground DAP.

Technical Context

The FDC2112QDNTTQ1 employs a narrow-band resonant sensing architecture that measures sensor capacitance via frequency shift of an external L-C tank, not switched-capacitor sampling. Its core digitizes the ratio f_SENSOR/f_REF, where f_REF is derived from either an internal 43.4 MHz oscillator or an external clock (2–40 MHz).

It supports programmable sensor excitation (10 kHz–10 MHz), configurable settling time per channel, and dual-channel sequential conversion. The device uses differential input pairs (IN0A/IN0B, IN1A/IN1B) to reject common-mode noise and includes EMI-resistant design validated under AEC-Q100 HBM ±2 kV and CDM ±750 V.

Key Specifications

Pinout & Package

The FDC2112QDNTTQ1 is housed in a 12-pin WSON (DNT) package measuring 4 mm × 4 mm with an exposed die attach pad (DAP) that must be connected to ground for optimal thermal and EMI performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar capacitance-to-digital conversion applications.

Compared with FDC2112QDNTTQ1, the FDC2114QDSGRQ1 adds two channels in a larger package for expanded sensing coverage, while the FDC2212QDNTTQ1 guarantees full 28-bit output at the expense of higher noise - making FDC2112QDNTTQ1 optimal for high-SNR, dual-zone automotive proximity systems.

Availability

FDC2112QDNTTQ1 is available at Aetrix Electronics and suitable for automotive proximity sensing, gesture interface, and conductive liquid level monitoring requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for FDC2112QDNTTQ1 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 automotive ICs, with decades of expertise in precision sensing and automotive-grade reliability.

The FDC2x1x-Q1 product line was designed specifically for robust, high-resolution capacitive sensing in automotive interiors and exteriors - addressing EMI resilience, temperature drift, and functional safety requirements from the silicon level.

FAQ

What is the maximum sensor capacitance supported by the FDC2112QDNTTQ1?

The FDC2112QDNTTQ1 supports up to 250 nF maximum sensor capacitance when paired with a 1 mH inductor at 10 kHz oscillation frequency. This specification is measured under defined test conditions and enables use with large-area or long-probe capacitive sensors in automotive and industrial applications. Exceeding this value may reduce measurement stability or dynamic range. The FDC2112QDNTTQ1 achieves this via its resonant L-C tank architecture, which differs fundamentally from switched-capacitor CDCs.

Does the FDC2112QDNTTQ1 require an external crystal or oscillator?

No, the FDC2112QDNTTQ1 does not require an external crystal. It integrates a factory-trimmed 43.4 MHz internal oscillator usable as the controller clock source (f_CLK). Alternatively, an external clock (2–40 MHz) can be applied to CLKIN for higher precision. When using the internal oscillator, CLKIN must be tied to GND. The FDC2112QDNTTQ1's clocking architecture allows flexible trade-offs between cost, board space, and timing accuracy depending on system requirements.

How many capacitive sensing channels does the FDC2112QDNTTQ1 provide?

The FDC2112QDNTTQ1 provides two fully independent capacitive sensing channels, each with differential input pairs (IN0A/IN0B and IN1A/IN1B). Both channels support programmable excitation frequency, settling time, and reference clock division. The device operates in either single-channel mode (one channel continuously sampled) or dual-channel auto-scan mode (sequentially cycling between both), enabling temperature drift compensation using one channel as a reference. This matches the "2112" designation in the FDC2112QDNTTQ1 part number.

What package type and dimensions does the FDC2112QDNTTQ1 use?

The FDC2112QDNTTQ1 uses a 12-pin WSON package (Texas Instruments designation: DNT), with nominal dimensions of 4 mm × 4 mm and an exposed die attach pad (DAP) on the bottom. The DAP must be soldered to a PCB ground plane for thermal management and EMI suppression. Pin pitch is 0.5 mm. This compact, leadless package supports high-density automotive PCB layouts while maintaining AEC-Q100 thermal and mechanical robustness - confirmed by R_θJA = 36.7°C/W and qualified operation from –40°C to +125°C.

Is the FDC2112QDNTTQ1 qualified for automotive applications?

Yes, the FDC2112QDNTTQ1 is explicitly qualified for automotive applications under AEC-Q100 with Grade 1 temperature rating (–40°C to +125°C ambient), HBM ESD level 2 (±2 kV), and CDM level C5 (±750 V). It is manufactured and tested to meet stringent automotive reliability, traceability, and process control standards. The "Q1" suffix in FDC2112QDNTTQ1 denotes this automotive qualification, distinguishing it from commercial-grade variants. All electrical, thermal, and stress test data in the official datasheet reflect AEC-Q100-compliant characterization.