ADC122S021CIMM - 12-Bit 200kSPS Dual-Channel SAR ADC | TI
MPN: ADC122S021CIMM ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.07 | $30.70 |
| 100 | $2.59 | $259.00 |
| 500 | $2.21 | $1,105.00 |
| 1,000 | $1.85 | $1,850.00 |
ADC122S021CIMM Overview
A SAR ADC is a type of analog-to-digital converter that performs a binary search through successive approximations to digitize an analog input in N clock cycles for an N-bit result. SAR ADCs are valued for their deterministic latency, low power consumption, and high precision at moderate sample rates, making them a cornerstone of modern mixed-signal data-acquisition systems. The ADC122S021CIMM fits into the broader hierarchy of: ADC -> data converter -> signal chain IC -> mixed-signal semiconductor.
Key features include 12-bit resolution with no missing codes, an SPI/QSPI/MICROWIRE-compatible serial output, straight-binary data format, an internal track-and-hold circuit, and an external reference input (VREF). The internal architecture uses a capacitive charge-redistribution DAC combined with a comparator and SAR logic. The wide supply range (2.7V to 5.25V) makes the part compatible with both 3.3V and 5V system rails.
Typical applications include portable and battery-powered instrumentation, multi-channel data-acquisition systems, industrial process control and sensor monitoring, and general-purpose analog front ends. The small 8-pin VSSOP package is suited for space-constrained designs.
When designing with this device, place the decoupling capacitor (1 uF ceramic) as close as possible to the VDD pin, drive the SCLK with a clean low-jitter source, and ensure VREF is well-bypassed. The part is now listed as obsolete on distributor pages - plan drop-in alternatives for new designs.
Drop-in alternatives for ADC122S021CIMM — 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 ADC122S021CIMM (same form factor and footprint) — differing in Package, Input Type, Number of Channels, Resolution, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADC122S021CIMM/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
ADC122S021CIMMX
✅ Drop-In✓ In Stock
$2.35 / Unit
View Datasheet →ADC124S021CIMM
✅ Drop-In✓ In Stock
$3.78 / Unit
View Datasheet →ADC122S021CIMMX/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
ADC121S705CIMMX
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →ADC122S021CIMM Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Number of Channels | 2 |
| Sample Rate Range | 50 ksps to 200 ksps |
| Architecture | SAR (Successive Approximation Register) |
| Input Type | Single-Ended |
| Supply Voltage (VDD) | 2.7 V to 5.25 V |
| Digital Interface | SPI / QSPI / MICROWIRE compatible |
| Data Format | Straight Binary |
| Operating Temperature | -40 C to +85 C |
| Package | 8-VSSOP (MSOP-8 / DGK) |
| Mounting Type | Surface Mount |
| Power Consumption | ~1.6 mW at 3V / 200 ksps |
| Track-and-Hold | Internal |
| RoHS Status | Compliant |
ADC122S021CIMM Pin Configuration
| Pin 1 | VREF — Reference voltage input |
| Pin 2 | IN1 — Analog input channel 1 |
| Pin 3 | IN2 — Analog input channel 2 |
| Pin 4 | GND — Ground |
| Pin 5 | DOUT — Serial data output |
| Pin 6 | SCLK — Serial clock input |
| Pin 7 | CS — Chip select (active low) |
| Pin 8 | VDD — Power supply (2.7V to 5.25V) |
Typical Applications
ADC122S021CIMM is suitable for 6 applications: Portable Battery-Powered Instrumentation, Industrial Process Control / Sensor Monitoring, Multi-Channel Data Acquisition Systems, Automotive Sensor Interfaces (Non-Safety), Medical Patient Monitoring (Non-Critical), General-Purpose Analog Front End for IoT Edge Nodes.
Portable Battery-Powered Instrumentation
The ADC122S021CIMM's 2.7V-5.25V single-supply operation and ~1.6 mW power consumption at 3V/200 ksps make it ideal for handheld multimeters and portable data loggers. The dual single-ended inputs allow simultaneous monitoring of two sensors (e.g., voltage and current) without an external MUX. According to the TI datasheet, the part's low power and small 8-VSSOP footprint extend battery runtime while saving board space, critical for compact battery-powered instruments.
Recommended
Industrial Process Control / Sensor Monitoring
The ADC122S021CIMM is well suited for 4-20 mA loop monitoring, thermocouple/cold-junction compensation, and PLC analog input modules. The two single-ended channels multiplex two sensor signals through one ADC, while the SPI interface simplifies isolation with digital isolators. The -40C to +85C industrial temperature range supports factory-floor operation. According to TI's datasheet, the deterministic SAR latency guarantees predictable control-loop timing for closed-loop process controllers.
Recommended
Multi-Channel Data Acquisition Systems
The ADC122S021CIMM's two single-ended inputs and 200 ksps sample rate fit compact DAQ front-end boards measuring temperature, strain, or pressure signals. The SPI-compatible serial output allows multiple ADC chips to share a bus by using independent CS lines, scaling the system to N channels. The internal track-and-hold eliminates the need for an external sample-and-hold circuit. According to TI's product page, the straight-binary data format simplifies firmware parsing on common microcontrollers and DSPs.
Recommended
Automotive Sensor Interfaces (Non-Safety)
Although the ADC122S021CIMM is not AEC-Q100 qualified, its wide temperature range and small VSSOP-8 footprint support non-safety automotive subsystems such as HVAC climate sensors, seat-position encoders, and interior lighting controllers. The 12-bit resolution meets the precision needs of these comfort features. According to TI's datasheet, the part operates reliably across the automotive cold-start and under-hood thermal ranges, while the SPI interface simplifies CAN-MCU integration via LIN-to-SPI bridges.
Recommended
Medical Patient Monitoring (Non-Critical)
The ADC122S021CIMM is suitable for non-life-critical medical monitoring such as body-temperature loggers, blood-pressure cuffs, and pulse-oximeter front-end boards. The two single-ended inputs allow simultaneous photodiode and temperature sensor readout. The SAR architecture provides deterministic latency required for synchronous DSP filtering of vital-sign signals. According to TI's datasheet, the part's low power consumption reduces heat dissipation near patient-contact surfaces, an important consideration for wearable medical devices.
Recommended
General-Purpose Analog Front End for IoT Edge Nodes
The ADC122S021CIMM's compact 8-VSSOP package and SPI interface suit IoT edge nodes digitizing analog sensor signals before wireless transmission. The dual-channel input handles two sensor types (e.g., temperature and humidity) on a single chip, reducing BOM cost. The 2.7V-5.25V supply range allows direct connection to common battery chemistries and energy-harvesting rails. According to TI's product information, the part's low 1.6 mW power draw extends battery life in always-on edge nodes.
Recommended
Recommended Products Summary
Engineering reference data for ADC122S021CIMM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADC122S021CIMM/NOPB | ADC122S021CIMMX | ADC124S021CIMM | ADC122S021CIMMX/NOPB | ADC121S705CIMMX |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-VSSOP | 8-VSSOP - same | 8-VSSOP - same | 8-VSSOP - same | 8-VSSOP - same | 8-MSOP - same |
| Resolution | 12 bit | 12 bit | 12 bit | 14 bit | 12 bit | 12 bit |
| Sample Rate | 200 ksps max | 200 ksps | 200 ksps | 200 ksps | 200 ksps | 200 ksps |
| Channels | 2 single-ended | 2 single-ended | 2 single-ended | 2 single-ended | 2 single-ended | 1 single-ended |
| Supply Voltage | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR |
| Interface | SPI | SPI | SPI | SPI | SPI | SPI |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Specified across full 50-200 ksps range (vs ADC122S051CIMM)
- Dual single-ended input channels (vs ADC121S705CIMMX)
- Wide 2.7V-5.25V supply range (vs ADC122S021CIMMX (same die))
Design Notes
Place a 1 uF X7R ceramic decoupling capacitor as close as possible to the VDD pin, with a short trace to GND. According to the TI datasheet, an additional 0.1 uF bypass cap in parallel improves high-frequency noise rejection. The reference input VREF should also be decoupled with 1 uF ceramic; any noise on VREF directly couples into conversion accuracy.
Route analog input traces (IN1, IN2) away from the digital SPI lines (SCLK, DOUT, CS) to minimize digital-to-analog crosstalk. Use a ground plane under the ADC, and keep analog and digital grounds connected only at the ADC GND pin. The 8-VSSOP package benefits from thermal relief pads to ease rework without damaging the device.
Do not exceed the absolute maximum VDD of 6.5V (per TI datasheet). Ensure SCLK is clean with low jitter, since aperture timing directly affects INL. Do not leave CS floating; tie CS high through a pull-up resistor to keep DOUT in a high-impedance state and prevent bus contention when multiple devices share the SPI bus.
Compliance Information
RoHS compliance confirmed via TI product page. REACH, halogen-free, and conflict-minerals status not explicitly listed in verified data; set to unknown per data authenticity rules.
