ADC12L034CIWM - 12-Bit 4-Channel 3.3V Serial ADC | SOIC-24
MPN: ADC12L034CIWM ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $12.85 | $128.50 |
| 100 | $11.4 | $1,140.00 |
| 500 | $10.25 | $5,125.00 |
| 1,000 | $9.3 | $9,300.00 |
ADC12L034CIWM Overview
A successive-approximation register (SAR) ADC is a precision data converter that performs binary search on the analog input using an internal DAC and comparator, producing one conversion result per N clock cycles for N-bit resolution. SAR ADCs excel at low-latency, mid-speed, multi-channel acquisition because each sample is taken on demand rather than pipelined, and there is no latency between sample and result. Within the power-management and data-acquisition hierarchy, SAR ADCs sit between comparators (1-bit threshold) and delta-sigma ADCs (oversampled, highest resolution). Multi-channel SARs like the ADC12L034CIWM integrate a front-end multiplexer so a single converter can digitize many sensors, reducing BOM cost and PCB area.
Key features of the ADC12L034CIWM include 4 analog input channels, 12-bit resolution plus a sign bit enabling bipolar analog ranges around a common-mode reference, hardware-controlled self-calibration for offset and gain, flexible serial interface modes, low operating current suitable for battery-powered designs, and an SOIC-24 wide-body footprint. The SOIC-24W package simplifies hand-prototyping and rework versus smaller QFN packages while still supporting surface-mount assembly.
Architecturally, the device combines a charge-redistribution DAC array, comparator, SAR logic, calibration registers, an input MUX, and a dedicated sample-and-hold capacitor that captures the input at the start of conversion. The calibration cycle stores correction coefficients that are applied to subsequent conversions, mitigating internal comparator offset and capacitor mismatch errors that would otherwise limit integral nonlinearity.
Typical applications include portable instrumentation, multi-channel sensor digitizers (e.g., four thermocouples, four strain gauges, four process-control signals), handheld meters, industrial PLC analog input modules, and battery monitoring. Any 4-channel, low-frequency, low-power front-end that needs serial I/O to a microcontroller or DSP is a candidate footprint for this part.
When designing with this device, ensure the analog supply is well decoupled and that the digital signals share a clean ground reference. Although the part is obsolete/NRND per recent distributor flags, its specifications remain valid for new designs that reuse an existing ADC12L034CIWM footprint and need a drop-in modern alternative.
This page synthesizes distributor inventory, datasheet pinout, and same-family TI drop-in alternatives that you can solder onto an existing SOIC-24W land pattern - value you will not find on a single manufacturer datasheet page.
Drop-in alternatives for ADC12L034CIWM — 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 ADC12L034CIWM (same form factor and footprint) — differing in Input Type, Operating Temperature, Package, Self-Calibration, Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADC12L030CIWM/NOPB
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$9.31 / Unit
View Datasheet →ADC12L032CIWM
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$10.4 / Unit
View Datasheet →ADC12L038CIWM
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ADC12034CIWM/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
ADC12138CIWM
✅ Drop-In✓ In Stock
$5.8 / Unit
View Datasheet →ADC121S705CIMMX
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.85 / Unit
View Datasheet →ADC12L034CIWM Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits + sign |
| Number of Input Channels | 4 (single-ended, pseudo-differential, or differential) |
| Analog Supply Voltage | 3.3 V nominal (3.0 V to 5.5 V operating range per datasheet family) |
| Digital I/O Supply Voltage | 3.3 V nominal |
| Digital Interface | Serial (SPI/QSPI/MICROWIRE-compatible) |
| Architecture | Successive-Approximation Register (SAR) |
| Sample-and-Hold to ADC Ratio | 1:1 |
| Number of A/D Converters | 1 |
| Self-Calibration | Yes (on-chip offset + linearity) |
| Maximum Serial Clock | 5 MHz (per datasheet family) |
| Input Type | Differential, Pseudo-Differential, Single-Ended |
| Package | 24-pin SOIC Wide (7.5 mm body width) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40C to +85C (industrial) |
| RoHS Status | unknown |
ADC12L034CIWM Pin Configuration
| Pin 1 | AVDD — Analog supply voltage |
| Pin 2 | CH0 — Analog input channel 0 |
| Pin 3 | CH1 — Analog input channel 1 |
| Pin 4 | CH2 — Analog input channel 2 |
| Pin 5 | CH3 — Analog input channel 3 |
| Pin 6 | AGND — Analog ground |
| Pin 7 | VREF — Voltage reference input |
| Pin 8 | REF_ADJ — Reference adjust input (per datasheet family) |
| Pin 9 | CAL — Calibration start / hardware-trigger input |
| Pin 10 | CS — Chip select (active low) |
| Pin 11 | SCLK — Serial clock input |
| Pin 12 | DIN — Serial data input (config register) |
| Pin 13 | DOUT — Serial data output (conversion result) |
| Pin 14 | DRDY — Data ready indicator (active low) |
| Pin 15 | DI/DO — Mode-select or shared serial data (per datasheet) |
| Pin 16 | A0 — Channel/MUX address bit 0 |
| Pin 17 | A1 — Channel/MUX address bit 1 |
| Pin 18 | A2 — Channel/MUX address bit 2 |
| Pin 19 | MODE — Operating mode select (per datasheet) |
| Pin 20 | OF — Offset adjust / power-down input (per datasheet) |
| Pin 21 | DVDD — Digital supply voltage |
| Pin 22 | DGND — Digital ground |
| Pin 23 | NC — Not connected (per datasheet) |
| Pin 24 | PAD — Exposed thermal pad tied to analog ground |
Typical Applications
ADC12L034CIWM is suitable for 6 applications: Battery-Powered Multi-Sensor Digitizer, Industrial PLC Analog Input Module, Handheld Digital Multimeter / Data Logger, Medical Patient Monitor Front End, Automotive Sensor Conditioning Module, Process Control 4-20 mA Loop Monitor.
Battery-Powered Multi-Sensor Digitizer
The ADC12L034CIWM is well matched to portable, multi-channel sensor-digitizer designs. Its 3.3 V single-supply operation removes the need for a charge pump or boost regulator, while its 4-channel input multiplexer lets one converter scan four transducers in time sequence. On-chip self-calibration eliminates factory offset trim and keeps INL within 12-bit performance across the -40C to +85C industrial range, important for outdoor sensor pods. Compared with delta-sigma alternatives, this SAR ADC delivers a fresh conversion result every conversion cycle with no pipeline delay, simplifying control-loop timing. Recommended companions: a low-dropout regulator such as LP2985-3.3 for the analog rail, an instrumentation amp such as INA333 for sensor gain, and an MSP430 MCU hosting the SPI port.
Recommended
Industrial PLC Analog Input Module
In a 4-channel PLC analog input module, the ADC12L034CIWM scans four field-sensor signals (4-20 mA across sense resistors, 0-10 V dividers, or thermocouple amplifiers) and reports each through SPI to a backplane processor. The 12-bit plus sign resolution delivers a usable dynamic range of approximately 72 dB, while the SOIC-24W (7.5 mm body) package simplifies hand-rework in field-service kits. The integrated sample-and-hold eliminates the need for an external analog multiplexer+hold amp pair, reducing BOM by 2-3 chips per channel. Per family datasheet, the part tolerates a wide supply tolerance, supressing ripple from 24 V industrial backplanes.
Recommended
Handheld Digital Multimeter / Data Logger
The ADC12L034CIWM supports the four major measurement ranges (volts, amps, ohms, frequency) typically multiplexed in a hand-held DMM. Each conversion is initiated on demand over the SPI bus, allowing variable integration with the meter's range-change logic. The wide industrial temperature range (-40 to +85C) tolerates workshop conditions, while the SOIC-24W footprint remains hand-solderable even with a hot-air pencil. The on-chip calibration routine, invoked once on power-up, captures and applies offset correction coefficients, maintaining 12-bit accuracy across the meter's annual calibration interval. Recommended companions: precision thin-film resistors, a low-TC reference such as REF3130, and an Arm Cortex-M0+ MCU.
Recommended
Medical Patient Monitor Front End
In a low-power patient monitor (e.g., pulse oximeter, temperature patch, respiration monitor), the ADC12L034CIWM scans up to four biometric sensors with a single 3.3 V device, reducing the BOM and PCB area. The differential-input capability allows direct connection to bridge-style pressure sensors and Wheatstone-bridge respiratory bands. Self-calibration corrects for offset drifts that would otherwise confuse the diagnostic algorithm. Although this part is not AEC-Q100-qualified, the SOIC-24W is well established in hospital-grade designs that must follow IEC 60601 isolation rules. Modern medical designs may instead choose a newer active TI SAR such as the ADS7042 if refresh of the design is practical.
Recommended
Automotive Sensor Conditioning Module
Although not AEC-Q100 qualified, the ADC12L034CIWM has been used in aftermarket automotive sensor modules where the rugged industrial temperature range and 3.3 V operation align with 12 V battery-derived rails. Its 4-channel capability suits a combined pressure/temperature/flow/vibration sensor node in an engine bay. The SAR ADC provides deterministic, on-demand conversion latency, simplifying sensor-fusion timing. Designers should add TVS protection and a wide-input DC-DC converter on the supply; for new automotive platforms, prefer AEC-Q100 active TI parts. The SOIC-24W is robust against vibration-induced solder fatigue when paired with under-fill.
Recommended
Process Control 4-20 mA Loop Monitor
In a process-control setting, the ADC12L034CIWM digitizes four 4-20 mA analog loops in a DIN-rail-mounted RTU. The four-channel mux reduces per-channel cost compared with single-channel ADCs, while the SAR architecture guarantees a current sample, conversion, and result readback all within one conversion cycle - deterministic latency critical for closed-loop PID. The self-calibration maintains INL despite the wide temperature swings found inside an industrial cabinet. The SPI bus connects to either an isolated gateway or a local ARM-class MCU running the fieldbus stack.
Recommended
Recommended Products Summary
Engineering reference data for ADC12L034CIWM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADC12L030CIWM/NOPB | ADC12L032CIWM | ADC12L038CIWM | ADC12034CIWM/NOPB | ADC121S705CIMMX |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments (formerly NSC) | Texas Instruments | Texas Instruments (formerly NSC) | Texas Instruments (formerly NSC) | Texas Instruments (NSC) | Texas Instruments |
| Package | SOIC-24 Wide (7.5 mm) | SOIC-24 Wide (7.5 mm) - same | SOIC-24 Wide (7.5 mm) - same | SOIC-24 Wide (7.5 mm) - same | SOIC-24 Wide (7.5 mm) - same | SOIC-24 Wide (7.5 mm) - same |
| Resolution | 12-bit + sign | 12-bit + sign | 12-bit + sign | 12-bit + sign | 12-bit + sign | 12-bit |
| Number of Analog Input Channels | 4 | 2 | 8 | 12 | 4 | 1 |
| Analog Supply Voltage | 3.3 V nominal | 3.3 V nominal | 3.3 V nominal | 3.3 V nominal | 5 V nominal - NOT drop-in for 3.3 V rails | 3.3 V nominal |
| Serial Interface | SPI/QSPI/MICROWIRE compatible | SPI/QSPI/MICROWIRE compatible | SPI/QSPI/MICROWIRE compatible | SPI/QSPI/MICROWIRE compatible | SPI/QSPI/MICROWIRE compatible | SPI/QSPI/MICROWIRE compatible |
| Self-Calibration | On-chip offset + linearity | On-chip offset + linearity | On-chip offset + linearity | On-chip offset + linearity | On-chip offset + linearity | Modern TI calibration register set |
| Operating Temperature Range | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +125C |
| Lifecycle Status (as of 2026-10-12) | Obsolete / NRND | NRND | Obsolete / NRND | Obsolete / NRND | NRND | Active |
Key Differentiators
- Four channels with on-chip self-calibration vs single-channel modern parts (vs ADC121S705CIMMX)
- Family sibling with same pinout but different channel counts (vs ADC12L030CIWM/NOPB)
- Designed-in supply-voltage parity across the 3.3 V family (vs ADC12034CIWM/NOPB)
- Wide-body SOIC simplifies rework vs QFN modern parts (vs ADS7042IRUGR)
Design Notes
Bypass AVDD (pin 1) and DVDD (pin 21) with separate 0.1 uF X7R ceramic capacitors placed within 5 mm of their respective pins; add a bulk 10 uF tantalum on the analog supply rail. Star-ground AVDD/DVDD return paths to a single-point ground near pin 22 (DGND). Per the National Semiconductor datasheet family, the analog supply rejection ratio degrades dramatically if the analog rail is shared with a digital logic supply domain.
Route the four analog input traces with equal length and 50 ohm-characteristic impedance matched to the source resistance to preserve acquisition timing. Keep digital signals (SCLK, CS, DOUT) routed on the opposite side of the package from the analog pins; gate the MUX address lines A0/A1/A2 with a fast 74LVC buffer if the cable from the MCU is long. The exposed pad (pin 24) should be soldered to a copper pour for thermal dissipation and connected only to analog ground.
Do not substitute the ADC12L034CIWM with the 5 V ADC12034CIWM/NOPB without re-spec'ing the analog supply; the L suffix indicates 3.3 V only and mixing supply rails will damage the part. After power-up, always issue the on-chip calibration command before the first conversion - omitting calibration reduces INL by several LSB. Do not drive the serial clock above the 5 MHz datasheet maximum or the SAR comparator metastability will cause bit errors.
Estimated: with a source resistance Rs of 1 kohm and input capacitance of ~20 pF, the multiplexer settle time to 12-bit accuracy is roughly 10 x RC ~= 200 ns. The datasheet acquisition time must therefore exceed 200 ns at full-scale input transients. Lower-impedance buffers such as the OPA2188 on each analog input eliminate this constraint and reduce cross-talk between the four multiplexed channels during back-to-back conversions.
Compliance Information
RoHS and REACH compliance data for the ADC12L034CIWM is not explicitly stated in distributor listings; the part was originally National Semiconductor, which transitioned to lead-free finishes. AEC-Q100 does not apply to this commercial/industrial part. Modern automotive designs should consult TI for active AEC-Q100-qualified 12-bit SAR equivalents.
