Microchip Technology TC7109ACLW713

Overview

TC7109ACLW713 from Microchip Technology is a 12-bit plus sign dual-slope integrating analog-to-digital converter (ADC) with true differential input and reference, 15 μV_P-P typical input noise, 1 pA typical input bias current, and zero-integrator cycle for fast overload recovery. It operates with ±5 V supplies and is used in precision bridge-based sensor interfaces such as load cells and strain gauges.

For engineers reviewing the TC7109ACLW713 datasheet, TC7109ACLW713 pinout, TC7109ACLW713 application, or TC7109ACLW713 equivalent, key selection considerations include its differential measurement capability, auto-zero architecture, UART handshake mode for serial data logging, and compatibility with 40-pin PLCC packaging and industrial temperature range (0°C to +70°C).

Technical Context

The TC7109ACLW713 implements a four-phase dual-slope conversion cycle: Auto-Zero (AZ), Signal Integrate (INT), Reference De-integrate (DE), and Zero Integrator (ZI). Its AZ phase achieves <10 μV input-referred offset via closed-loop compensation of buffer, integrator, and comparator offsets.

ZI phase activation eliminates residual integrator charge after over-range inputs-preventing cross-talk in multiplexed systems and enabling reliable thermocouple monitoring. The device supports both Direct parallel interface (via CE/LOAD, HBEN, LBEN) and UART Handshake mode (MODE HIGH, SEND-controlled), with buffered oscillator output (BUFF OSC OUT) usable for RUN/HOLD synchronization.

Key Specifications

Pinout & Package

TC7109ACLW713 is housed in a 44-pin PLCC (Plastic Leaded Chip Carrier) package with gull-wing leads, rated for 0°C to +70°C operation. Pin assignments follow the standard 40-pin DIP functional mapping, with NC (no internal connection) on pins 33 and 34 per PLCC layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar integrating ADC applications.

Compared with MAX134ACPP, TC7109ACLW713 offers deterministic 8192-clock-cycle timing and built-in overload recovery at lower cost and power, while ICL7109CPLZ lacks the enhanced output drive and ZI phase critical for multiplexed industrial sensing.

Availability

TC7109ACLW713 is available at Aetrix Electronics and suitable for industrial weigh scales, thermocouple data loggers, strain gauge test benches, and portable multimeters requiring stable component supply across extended production lifecycles.

Supply support for TC7109ACLW713 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

Microchip Technology is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and interface ICs for industrial, automotive, and consumer applications.

The TC7109A product line was designed specifically for high-accuracy, low-drift, dual-slope integrating ADC applications in sensor signal conditioning - emphasizing robustness in noisy environments and minimal external component count.

FAQ

What is the operating temperature range for the TC7109ACLW713?

The TC7109ACLW713 is specified for 0°C to +70°C operation, consistent with its PLCC packaging and industrial-grade qualification. This range supports deployment in factory automation equipment, test instruments, and commercial-grade data acquisition modules where ambient temperatures remain within standard office or controlled industrial environments. The device's drift specifications (e.g., TCZS < 1 μV/°C) are guaranteed across this full range.

Does the TC7109ACLW713 require external zero adjustment?

No, the TC7109ACLW713 does not require external zero adjustment. Its auto-zero architecture actively compensates for offset voltage in the buffer amplifier, integrator, and comparator during each conversion cycle, achieving <10 μV input-referred offset without manual trimming. This eliminates production calibration steps and ensures long-term stability - a key advantage over non-auto-zeroing ADCs like the original ICL7109.

How does the UART handshake mode work on the TC7109ACLW713?

In UART handshake mode, the TC7109ACLW713 configures CE/LOAD, HBEN, and LBEN as TTL-compatible outputs that sequence high- and low-byte data transfers to industry-standard UARTs (e.g., HD6403). The SEND input monitors the UART's TBRE (transmitter buffer register empty) signal, pausing transmission until the UART is ready - eliminating data loss without CPU intervention. This mode is activated by holding MODE high or pulsing it high during conversion.

What is the purpose of the Zero Integrator (ZI) phase in the TC7109ACLW713?

The Zero Integrator (ZI) phase in the TC7109ACLW713 clears residual charge from the integrator capacitor after an over-range input event. Without ZI, this charge would transfer to the auto-zero capacitor and corrupt the next conversion - causing measurable crosstalk in multiplexed systems. ZI activates automatically post-overload and lasts ≤1024 clock cycles, ensuring accurate subsequent readings even with broken thermocouples or saturated bridge sensors.

Can the TC7109ACLW713 operate with a single supply?

No, the TC7109ACLW713 requires dual supplies: V+ nominally +5 V and V− nominally −5 V relative to GND. Its analog section relies on symmetric rails to support ±4 V integrator swing and true differential input operation. Attempting single-supply operation violates absolute maximum ratings (e.g., V− must be ≤ −9 V) and will cause functional failure or permanent damage. A charge pump or isolated DC/DC converter is required for bipolar supply generation.