Microchip Technology TC7109IJL

Overview

TC7109IJL from Microchip Technology is a 12-bit plus sign dual-slope integrating analog-to-digital converter (ADC) with true differential input and reference, auto-zero architecture, zero integrator cycle for overload recovery, and UART handshake mode. It delivers ±0.2 count non-linearity, 15 µV_P-P input noise, 1 pA typical input bias current, and operates across –25°C to +85°C in a 40-pin CERDIP package - used in precision bridge-based transducer measurement systems including load cells and strain gauges.

For engineers reviewing the TC7109IJL datasheet, TC7109IJL pinout, TC7109IJL application, or TC7109IJL equivalent, key selection considerations include its differential input common-mode range (V_– +1.5 V to V₊ –1.5 V), 8192-clock-cycle conversion timing, buffered oscillator output capability, and dual-mode digital interface (Direct parallel or UART Handshake) - all critical for industrial data acquisition and remote sensor logging designs.

Technical Context

The TC7109IJL implements a four-phase dual-slope integration 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 using CAZ.

ZI phase activation eliminates residual integrator charge after over-range inputs, preventing cross-talk in multiplexed systems. The device supports both crystal (OSC IN/OUT) and RC (BUFF OSC OUT + OSC SEL) clock configurations, with internal 12-bit binary counter, output latches, and TTL-compatible three-state drivers for B1–B12, POL, and OR signals.

Key Specifications

Pinout & Package

TC7109IJL is housed in a hermetically sealed 40-pin CERDIP (Ceramic Dual In-line Package) with 0.6-inch body width and 0.1-inch lead pitch, rated for –25°C to +85°C operation and suitable for high-reliability industrial and aerospace environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TC7107CPL, TC7109IJL adds zero integrator recovery and UART handshake for robust multiplexed systems; compared with MAX133ACPI+, it trades resolution for inherent drift cancellation, integrated reference, and deterministic dual-slope timing - making it superior for industrial bridge sensor interfacing where long-term stability matters more than bit count.

Availability

TC7109IJL is available at Aetrix Electronics and suitable for industrial instrumentation, precision transducer interfaces, and remote data loggers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for TC7109IJL 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 Inc. is a U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and interface ICs, with emphasis on reliability, longevity, and industrial-grade qualification.

The TC7109IJL belongs to Microchip's legacy precision analog converter family designed specifically for high-stability, low-drift, dual-slope ADC applications in test equipment, weigh scales, and sensor signal conditioning - prioritizing accuracy retention over speed or integration density.

FAQ

What is the operating temperature range of the TC7109IJL?

The TC7109IJL is specified for operation from –25°C to +85°C. This extended industrial temperature range is enabled by its 40-pin CERDIP package, which provides hermetic sealing and superior thermal stability versus plastic DIP variants. The TC7109IJL maintains ±0.2 count non-linearity and <1 µV/°C zero drift across this full range - critical for outdoor or factory-floor deployments where ambient temperature fluctuates widely. All electrical specifications in the DS21456D datasheet apply within this interval.

Does the TC7109IJL require external zero adjustment?

No, the TC7109IJL does not require external zero adjustment. Its auto-zero architecture continuously compensates for offset voltages in the buffer amplifier, integrator, and comparator using an internal CAZ capacitor. This results in <10 µV input-referred offset and zero drift of only 0.2 µV/°C - eliminating manual trim pots and improving long-term calibration stability. The TC7109IJL achieves this with no user intervention, unlike earlier generations such as the TC7107.

How does the Zero Integrator (ZI) phase improve performance in multiplexed systems?

When an over-range condition occurs, the TC7109IJL activates its Zero Integrator (ZI) phase to discharge residual charge on the integrator capacitor before entering the next auto-zero cycle. This prevents charge carryover that would otherwise corrupt the next conversion - a phenomenon known as "cross-talk." In multiplexed thermocouple or load-cell arrays, ZI ensures that an overdriven channel does not induce errors in subsequent channels, enabling reliable unattended operation in automated test systems.

Can the TC7109IJL interface directly with a UART without a microcontroller?

Yes, the TC7109IJL supports UART Handshake mode where MODE (Pin 21) is held HIGH. In this mode, CE/LOAD, HBEN, and LBEN become active outputs synchronized to the SEND input - allowing direct connection to industry-standard UARTs like the HD6403 or CDP1854. The TC7109IJL handles byte sequencing, timing, and handshaking autonomously; no firmware or external logic is needed. This reduces BOM count and improves reliability in remote sensor nodes.

What are the power supply requirements for the TC7109IJL?

The TC7109IJL requires dual analog supplies: V+ = +5 V and V– = –5 V, with GND (Pin 1) as the 0 V reference. These rails support a ±4 V integrator swing, maximizing dynamic range and SNR. Supply current is 700–1500 µA depending on oscillator configuration and load. Digital outputs are TTL-compatible and referenced to GND. Input voltages may exceed supply rails only if current is limited to ±100 µA - exceeding this risks latch-up.