Microchip Technology TC7109CKW713

Overview

TC7109CKW713 from Microchip Technology is a 12-bit plus sign CMOS 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 TC7109CKW713 datasheet, TC7109CKW713 pinout, TC7109CKW713 application, or TC7109CKW713 equivalent, key selection considerations include its differential architecture, auto-zero stability, UART handshake mode compatibility, and PQFP-44 package integration into industrial data acquisition systems.

Technical Context

The TC7109CKW713 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.

Conversion timing is fixed at 8192 clock periods per cycle, with INT phase lasting exactly 2048 counts. The ZI phase activates only after over-range detection and lasts up to 1024 counts to eliminate residual integrator charge-critical for eliminating crosstalk in multiplexed thermocouple or sensor arrays.

Key Specifications

Pinout & Package

TC7109CKW713 is housed in a 44-pin plastic quad flat pack (PQFP) with 0.8 mm lead pitch, rated for 0°C to +70°C operation. Pin functions are identical to the 40-pin PDIP variant per Microchip DS21456D, with NC (no internal connection) assigned to pins 1–4, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, and 44 per pin map alignment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX134ACPP and ICL7135CPLZ, TC7109CKW713 uniquely combines differential bridge interface capability, zero integrator cycle for crosstalk suppression, and hardware UART handshake - making it the only option supporting both high-accuracy multiplexed sensor arrays and low-overhead remote data logging in a single IC.

Availability

TC7109CKW713 is available at Aetrix Electronics and suitable for industrial weigh scales, thermocouple data loggers, strain gauge test benches, portable multimeters, and precision bridge-based sensor interfaces requiring stable component supply across long-lifecycle instrumentation programs.

Supply support for TC7109CKW713 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 TC7109 family was designed specifically for high-stability, low-drift integrating ADC applications in precision measurement equipment - emphasizing ratiometric bridge sensing, multiplexed channel integrity, and minimal external component count.

FAQ

What is the operating temperature range for the TC7109CKW713?

The TC7109CKW713 is specified for 0°C to +70°C operation, consistent with its "C" grade designation and 44-pin PQFP packaging. This range supports deployment in commercial and industrial control cabinets where ambient temperatures remain within standard environmental specifications. The device's auto-zero drift of ≤1 µV/°C ensures stable performance across this full span without recalibration.

Does the TC7109CKW713 require external zero adjustment?

No, the TC7109CKW713 does not require external zero adjustment. Its integrated auto-zero architecture continuously compensates for offset voltage in the buffer amplifier, integrator, and comparator, achieving <10 µV input-referred offset. This eliminates manual trimming components and improves long-term stability in field-deployed TC7109CKW713-based instruments.

How does the UART handshake mode function on the TC7109CKW713?

In UART handshake mode, the TC7109CKW713 configures CE/LOAD, HBEN, and LBEN as TTL-compatible outputs to directly control industry-standard UARTs like the HD6403. When MODE is held high, the TC7109CKW713 sequences high- and low-byte transfers using SEND input feedback - enabling robust serial data transmission without external glue logic or firmware polling.

Can the TC7109CKW713 interface with bridge sensors without external amplification?

Yes, the TC7109CKW713 can directly interface with low-output bridge sensors such as 350 Ω load cells. Its true differential input (IN HI/IN LO) and differential reference (REF IN+/REF IN−), combined with 1 pA input bias current and 15 µV_P-P noise, allow direct ratiometric digitization of mV-level bridge outputs - eliminating the need for external instrumentation amplifiers in most precision weighing applications.

What is the purpose of the Zero Integrator (ZI) phase in the TC7109CKW713?

The Zero Integrator (ZI) phase in the TC7109CKW713 activates only after an over-range condition to discharge residual charge from the integrator capacitor. This prevents error carryover into subsequent conversions - a critical feature for multiplexed systems where open thermocouple inputs or transient overloads would otherwise corrupt adjacent channel readings in TC7109CKW713-based data acquisition units.