Renesas ZSSC3123AI7T

Overview

ZSSC3123AI7T from Renesas Electronics is a CMOS capacitive sensor signal conditioner IC performing capacitance-to-digital conversion with on-chip digital compensation for offset, sensitivity, and temperature drift. It supports single or differential capacitive sensors up to 260 pF, delivers ±0.25% FSO accuracy from –40°C to +125°C, and outputs corrected values via I²C, SPI, or PDM-enabling high-precision industrial pressure and level sensing.

For engineers reviewing the ZSSC3123AI7T datasheet, ZSSC3123AI7T pinout, ZSSC3123AI7T application, or ZSSC3123AI7T equivalent, key selection considerations include its 14-TSSOP package, programmable resolution (8–14 bit), dual alarm outputs, internal temperature reference, and low-power sleep mode (≤1 μA at 85°C).

Technical Context

The ZSSC3123AI7T integrates a capacitance-to-digital converter (CDC) with configurable multiplier settings (Mult1–Mult8) to match sensor capacitance ranges from 2 pF to 260 pF, and a dedicated temperature sensor with digital 1st/2nd-order gain and offset drift compensation. Its DSP executes sensor-specific correction algorithms using calibration coefficients stored in on-chip EEPROM.

It operates across 2.3 V to 5.5 V supply, supports both update and sleep modes, and provides three output modalities: digital (I²C/SPI), pulse density modulation (PDM) for ratiometric analog-like signals, and two independent alarm outputs configurable as push-pull or open-drain switches.

Key Specifications

Pinout & Package

Package: 4.4 × 5.0 mm 14-pin TSSOP (JEDEC MO-153), lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar capacitive sensor signal conditioning applications.

Compared with ICM-42688-P and AD7745, the ZSSC3123AI7T uniquely integrates sensor-specific digital correction, dual PDM outputs, and alarm logic in a single 14-TSSOP package - reducing firmware development, PCB area, and total calibration cost for volume capacitive sensor deployments.

Availability

ZSSC3123AI7T is available at Aetrix Electronics and suitable for industrial pressure transducers, automotive HVAC sensors, medical disposable flow meters, and smart home water leak detectors requiring stable component supply and long-term manufacturability.

Supply support for ZSSC3123AI7T 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

Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog, power, and SoC solutions for automotive, industrial, infrastructure, and IoT applications.

The ZSSC3123AI7T belongs to Renesas' cLite™ family of highly integrated capacitive signal conditioners, designed specifically for cost-sensitive, high-volume capacitive sensing applications demanding factory-calibrated accuracy and minimal external components.

FAQ

What is the maximum sensor capacitance supported by the ZSSC3123AI7T?

The ZSSC3123AI7T supports capacitive sensors up to 260 pF using the Mult8 configuration setting. This is achieved via an internal capacitance-to-digital converter with selectable multiplier factors (Mult1–Mult8), each optimized for specific capacitance ranges - for example, Mult1 covers 2–10 pF, while Mult8 covers 130–260 pF. The ZSSC3123AI7T automatically scales resolution and conversion time based on the selected multiplier.

Does the ZSSC3123AI7T require an external temperature sensor for compensation?

No, the ZSSC3123AI7T includes an on-die temperature sensor with internal reference - no external thermistor or sensor is needed. It performs digital 1st- and 2nd-order temperature compensation for both sensor offset and sensitivity drift using coefficients stored in on-chip EEPROM. This eliminates component count, layout complexity, and thermal mismatch errors inherent in discrete solutions.

Can the ZSSC3123AI7T operate with a 1.8 V supply?

No, the ZSSC3123AI7T requires a minimum supply voltage of 2.3 V and operates up to 5.5 V. Operation below 2.3 V is outside specification and may result in undefined behavior, including failure of the EEPROM programming, CDC conversion, or alarm functionality. For 1.8 V systems, level-shifting or a compatible alternative signal conditioner is required.

How is calibration performed for the ZSSC3123AI7T?

Calibration is performed digitally via the I²C interface using the ZSSC3123AI7T Evaluation Kit and Renesas-provided software. A PC-controlled procedure measures sensor response across temperature and pressure points, computes correction coefficients, and writes them to the on-chip EEPROM. Once programmed, the ZSSC3123AI7T and sensor form a digitally mated pair - eliminating laser trimming, hardware adjustments, or post-assembly calibration steps.

What output formats does the ZSSC3123AI7T support besides I²C and SPI?

In addition to I²C and SPI, the ZSSC3123AI7T supports Pulse Density Modulation (PDM) outputs for both capacitance (PDM_C) and temperature (PDM_T). These are filtered, ratiometric digital streams that emulate analog behavior - enabling simple RC filtering to recover DC-equivalent voltages without requiring a separate ADC. PDM outputs are especially useful in EMI-prone environments or where microcontroller ADC resources are constrained.