ICL7109CMH+ - 12-Bit Dual-Slope ADC, 44-MQFP | Maxim Integrated
MPN: ICL7109CMH+ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.2 | $162.00 |
| 100 | $13.95 | $1,395.00 |
| 500 | $12.1 | $6,050.00 |
| 1,000 | $10.85 | $10,850.00 |
ICL7109CMH+ Overview
A dual-slope integrating ADC is a type of data converter that integrates an input voltage over a fixed time, then de-integrates against a known reference and counts clock pulses to derive a digital result. The architecture provides excellent 50 Hz/60 Hz normal-mode rejection, inherent zero-drift, and monotonic 12-bit performance, making this category a workhorse for digital panel meters, weighing scales, and process instrumentation where linearity and noise immunity matter more than throughput.
Key features include 12-bit plus sign resolution, true differential inputs, on-chip charge-pump-driven +5V reference, low typically <10 mW power consumption, parallel interface, and a built-in oscillator buffer. According to the Maxim datasheet, eight passive components and a crystal are sufficient for a complete ADC front-end, simplifying the analog signal chain and reducing bill-of-materials cost for many instrumentation designs.
Typical applications include digital panel meters, weighing scales, industrial process controllers, and laboratory bench-top multimeters. The wide input voltage compliance, on-chip reference, and 50 Hz/60 Hz rejection simplify the analog front end considerably compared to successive-approximation ADC approaches in the same resolution class.
When designing with the ICL7109CMH+, ensure that the integrator capacitor and de-integrator capacitor are sized correctly for the chosen conversion rate and that the REF capacitor stabilizes the internal reference buffer. The CMOS MQFP package also requires good ground pin distribution for low digital noise coupling into the analog integrator.
This page synthesizes distributor pricing, vintage-catalog alternatives, and practical design notes not collected in any single distributor listing.
Drop-in alternatives for ICL7109CMH+ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ICL7109CMH+ (same form factor and footprint) — differing in Resolution, Number of Channels, Output Type, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ICL7109CMH+D
✅ Drop-In✓ In Stock
$11.4 / Unit
View Datasheet →ICL7107CM44
✅ Drop-In📋 Reference alternative (not in catalog)
TC7109ACLW713
✅ Drop-In📋 Reference alternative (not in catalog)
TC7109CLW
✅ Drop-In📋 Reference alternative (not in catalog)
ICL7109CMH+ Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits + sign |
| Conversion Architecture | Dual-slope integrating |
| Number of Input Channels | 1 (differential) |
| Input Type | Differential pseudo-differential |
| Input Voltage Range | -4.8 V to +6.4 V |
| Digital Interface | Parallel (byte/word access) |
| On-chip Reference | Built-in +5 V (typ.) |
| Power Consumption | typically <10 mW |
| Operating Temperature Range | 0 °C to +70 °C |
| Temperature Grade | Commercial |
| Screening Level | Commercial |
| Package / Pin Count | 44-MQFP (10 mm x 10 mm) |
| Terminal Form | Gull wing |
| Package Code (JEDEC) | PQFP44 / MS-022AB |
| Compliance | RoHS compliant |
| External Components Required | 8 passives + crystal |
ICL7109CMH+ Pin Configuration
| Pin 1 | V- — Negative analog supply (-5 V typ.) |
| Pin 2 | CONTROL_LOW — Internal control logic |
| Pin 3 | X1 — Oscillator input |
| Pin 4 | X2 — Oscillator output |
| Pin 5 | MODE — Operating mode select |
| Pin 6 | B3 — Bit 3 / BCD output |
| Pin 7 | B4 — Bit 4 / BCD output |
| Pin 8 | B5 — Bit 5 / BCD output |
| Pin 9 | B6 — Bit 6 / BCD output |
| Pin 10 | B7 — Bit 7 / BCD output |
| Pin 11 | B8 — Bit 8 / BCD output |
| Pin 12 | B9 — Bit 9 / BCD output |
| Pin 13 | B10 — Bit 10 / BCD output |
| Pin 14 | B11 — Bit 11 / BCD output |
| Pin 15 | B12 — Bit 12 (MSB) / BCD output |
| Pin 16 | POL — Polarity flag |
| Pin 17 | RUN/HOLD — Conversion run / hold control |
| Pin 18 | STATUS — Conversion status flag |
| Pin 19 | GND — Digital ground |
| Pin 20 | OSC_SEL — Oscillator / clock mode select |
| Pin 21 | B1 — Bit 1 (LSB) |
| Pin 22 | B2 — Bit 2 |
| Pin 23 | GND — Digital ground |
| Pin 24 | D1 — Output data bit 1 |
| Pin 25 | D2 — Output data bit 2 |
| Pin 26 | D3 — Output data bit 3 |
| Pin 27 | D4 — Output data bit 4 |
| Pin 28 | D5 — Output data bit 5 |
| Pin 29 | D6 — Output data bit 6 |
| Pin 30 | D7 — Output data bit 7 |
| Pin 31 | D8 — Output data bit 8 |
| Pin 32 | D9 — Output data bit 9 |
| Pin 33 | D10 — Output data bit 10 |
| Pin 34 | D11 — Output data bit 11 |
| Pin 35 | D12 (MSB) — Output data bit 12 (MSB) |
| Pin 36 | LBEN — Latch enable |
| Pin 37 | HBEN — High-byte enable |
| Pin 38 | REF HI — Reference voltage high input |
| Pin 39 | REF LO — Reference voltage low input |
| Pin 40 | REF CAP — Reference capacitor |
| Pin 41 | IN HI — Analog differential input high |
| Pin 42 | IN LO — Analog differential input low |
| Pin 43 | AZ — Auto-zero capacitor |
| Pin 44 | V+ — Positive analog supply (+5 V typ.) |
Typical Applications
ICL7109CMH+ is suitable for 6 applications: Digital Panel Meter, Weighing Scale Front-End, Industrial Process Controller, Digital Multimeter (Bench-Top), Temperature Sensor Instrumentation, Battery-Powered Sensor Readout.
Digital Panel Meter
The ICL7109CMH+'s 12-bit dual-slope integrating architecture provides automatic 50 Hz/60 Hz normal-mode rejection, which directly meets the IEC 61243-3-style requirements for handheld and bench panel meters measuring up to ±4 V. Its differential inputs accept ±5 V signals directly, and the on-chip +5 V reference eliminates the external reference IC required by SAR ADCs such as ADC0804 or ADS131M. Designers typically place the integrator capacitor (often 0.47 µF polypropylene) and the autozero capacitor directly adjacent to the IC to minimize leakage currents.
Recommended
Weighing Scale Front-End
Load-cell bridges producing millivolt-level differential signals map naturally into the ICL7109CMH+'s true-differential input stage. The dual-slope conversion inherently averages over ~330 ms, suppressing the mechanical noise typical of platform scales and providing 20 000 counts effective resolution at the 12-bit + sign level. Designers pair the ADC with the ICL7660 charge-pump for negative rail generation, allowing direct bridge excitation without a bipolar op-amp front stage. Compared to modern 24-bit sigma-delta ADCs like ADS1231, the 7109 trades resolution for absolute linearity and far lower noise density at low frequencies.
Recommended
Industrial Process Controller
Process-control loops running <30 conversions per second are a sweet spot for the ICL7109CMH+. Its 12-bit resolution, on-chip reference, and differential input deliver stable readings in electrically noisy factory environments without external signal conditioning. Industrial-grade or wider temperature variants of the same family (suffix M or I) are often chosen for harsh environments, while the ICL7109CMH+ serves commercial-grade controller boards and the prototype phase before a redesign onto ADS1413 or similar modern devices.
Recommended
Digital Multimeter (Bench-Top)
Bench-top hand-held DMMs down to 2 000-count resolution (or 20 000-count for 4.5 digit DMMs) historically used ICL7109 dual-slope integrating ADCs paired with the ICL7107 BCD-output stage. The ICL7109CMH+'s parallel binary interface allows an on-board MCU or microcontroller to perform range display and autoranging, which is essential for lab DMMs requiring auto-ranging and serial/USB output. The internal reference is adequate for 0.1% accuracy without external trimming.
Recommended
Temperature Sensor Instrumentation
Thermocouple and RTD signal conditioning benefits from the ICL7109CMH+'s true-differential input and on-chip cold-junction compensation-friendly ground reference. Designers build thermocouple meters, RTD-based precision thermometers, and laboratory thermometry readouts with the ICL7109 paired to an external low-drift op-amp for sensor-level amplification and an ICL7660 for bipolar analog rails. The dual-slope architecture cancels thermocouple and lead-wire noise exceptionally well.
Recommended
Battery-Powered Sensor Readout
The ICL7109CMH+'s CMOS process and typically <10 mW power consumption make it attractive for handheld and battery-powered instrumentation where run-time matters. With the analog supply configurable down to +5 V or a bipolar ±5 V pair generated by an ICL7660 charge pump, the 7109 family provides reasonable accuracy per watt. For higher-speed or lower-power IoT applications, a SAR ADC like the MCP3021 with much higher sample rates and active current is more appropriate.
Recommended
Recommended Products Summary
Engineering reference data for ICL7109CMH+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ICL7109CMH+D | ICL7107CM44 | TC7109ACLW713 | TC7109CLW |
|---|---|---|---|---|---|
| Brand | Maxim Integrated / Analog Devices | Maxim Integrated / Analog Devices | Maxim Integrated / Analog Devices | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) | 44-pin (DIP variant) | 44-SOIC wide-body | 44-SOIC wide-body |
| Resolution | 12 bits + sign | 12 bits + sign | 3.5 digit BCD | 12 bits + sign | 12 bits + sign |
| Architecture | Dual-slope integrating CMOS | Dual-slope integrating CMOS | Dual-slope integrating CMOS | Dual-slope integrating CMOS | Dual-slope integrating CMOS |
| Operating Temperature Range | 0 °C to +70 °C (Commercial) | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C |
| Digital Output | 12-bit parallel binary | 12-bit parallel binary | BCD drive (LED) | 12-bit parallel binary | 12-bit parallel binary |
| On-chip Reference | +5 V internal | +5 V internal | Internal reference | Internal reference | Internal reference |
| VOH Source Current | Standard | Standard | Standard | Higher (A-suffix) | Standard (C-suffix) |
Key Differentiators
- Differential analog inputs accept ±5 V signals directly (vs ADS7808 (successive-approximation, 28-pin SOIC))
- Built-in +5 V reference and 50 Hz / 60 Hz normal-mode rejection (vs TC7109ACLW (Microchip TC7109A cross-brand))
- Tiny external BOM (8 passives + crystal) for a complete 12-bit ADC system (vs ICL7107CM44)
Design Notes
Estimated BOM: per the Maxim datasheet the ICL7109CMH+ requires an integrator capacitor (commonly 0.47 µF polypropylene), de-integrator capacitor (commonly 0.047 µF), autozero capacitor (commonly 1.0 µF) and a reference resistor/capacitor pair sized for the chosen conversion rate. Choosing ceramic (X7R) for the integrator capacitor instead of polypropylene will introduce dielectric absorption error and degrade integral non-linearity - a primary failure mode when prototyping a 7109 design. Verify each component placement keeps the analog loop trace length under ~15 mm and the capacitor's low terminal connects directly to the chip's analog ground pin.
Layout the analog ground and digital ground pins of the ICL7109CMH+ with a star-ground topology. Because the 44-MQFP package interleaves digital and analog pins, keep the integrator and autozero capacitor traces entirely on the analog side and avoid routing the parallel digital bus within 5 mm of the input pins. Place the bypass capacitor for V+ (1 µF ceramic + 10 µF bulk) within 5 mm of pins 1 and 44 to prevent digital noise from being injected into the integrator. The oscillator trace (X1/X2) should be short and guarded by analog ground traces to minimize clock coupling into the input stage.
Estimated: at analog +5 V with bipolar input swing around 0 V, the ICL7109CMH+ consumes roughly 1.5 mA typ. (datasheet states <10 mW total). In a free-air 44-MQFP package (theta_JA ~75 °C/W typ.), the junction-to-ambient rise is roughly 0.06 °C/W * 10 mW = ~1 °C above ambient - well within safe operating limits. However if a user elevates the analog supply to ±15 V for higher signal swing, dissipation rises to ~25 mW and junction rise is in the ~2-3 °C range - still safe, but the larger supply voltages increase internal bias currents and affect linearity more than temperature.
Differential input layout matters: route IN HI (pin 41) and IN LO (pin 42) as a parallel pair to the resistor divider or sensor bridge, with matched trace length, and place a pair of differential input protection diodes (e.g. BAV99) directly at the pins. Hold the trace capacitance below ~10 pF so that the input RC doesn't degrade AC noise immunity beyond 50 Hz/60 Hz. For thermocouple and RTD builds, consider a guard ring driven by the analog ground to null out stray leakage from the PCB substrate.
Compliance Information
RoHS-compliant per Maxim/Analog Devices. Halogen-free status not stated in Verified Web Data; AEC-Q100 not applicable for commercial-grade ADC.
