ADC12138CIN/NOPB - 12-bit+Sign 8-ch SAR ADC 114ksps | TI DIP-28
MPN: ADC12138CIN/NOPB ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.2 | $112.00 |
| 100 | $9.85 | $985.00 |
| 500 | $8.9 | $4,450.00 |
| 1,000 | $8.1 | $8,100.00 |
| 3,000 | $7.45 | $22,350.00 |
ADC12138CIN/NOPB Overview
What is a SAR ADC? A successive-approximation-register analog-to-digital converter is a low-latency ADC architecture that uses an internal binary-search algorithm against a precision DAC to converge on the input voltage within N clock cycles, where N is the resolution. SAR ADCs sit hierarchically under analog-to-digital converters, data converters, signal chain ICs, and finally power management and signal-chain semiconductors. They are the dominant choice when designers need deterministic acquisition latency, no pipeline delay, and excellent DC linearity - contrast them with sigma-delta ADCs (higher resolution but heavier digital filtering) and pipeline ADCs (faster throughput at higher cost).
Key features of this part include 12-bit resolution plus sign (effectively 13-bit dynamic range bipolar), a configurable 4 or 8 input channel multiplexer (part of the ADC12130/12132/12138 family), 0.0488% linearity error (about 1 LSB), 8.8 µs typical conversion time at a 114 ksps throughput, and built-in self-calibration that corrects offset and linearity errors on demand, eliminating manual trimming in production. The MICROWIRE serial interface reduces MCU pin count to three (CS, SCLK, DOUT), simplifying PCB routing in space-constrained designs.
The architecture combines a charge-redistribution DAC, a high-speed comparator, and an SAR control register that performs binary-weighted approximations. Built-in self-calibration measures internal errors and applies digital correction on each conversion cycle, enabling the part to maintain 12-bit accuracy across the -40°C to +85°C industrial temperature range without user intervention.
Typical applications include portable instrumentation, multi-channel sensor monitoring systems, industrial process control loops with 4-20 mA front ends, and embedded data acquisition boards that need an 8-channel analog front end behind a microcontroller. The 8.8 µs conversion time is suitable for control-loop bandwidths in the low kilohertz range.
When designing with this converter, allocate ample settling time for the multiplexer stage at the analog input and add a small RC filter to attenuate broadband noise - the integrated sample-and-hold handles acquisition but a high-impedance source can introduce gain error. The single-supply operation simplifies power-rail design relative to bipolar-input ADCs that need ±5 V rails.
This page synthesizes pricing tiers across authorized distributors, validated drop-in alternatives in the same PDIP-28 footprint, and practical design notes beyond the manufacturer datasheet to accelerate your evaluation of the ADC12138CIN/NOPB.
Drop-in alternatives for ADC12138CIN/NOPB — 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 ADC12138CIN/NOPB (same form factor and footprint) — differing in Resolution, Package, Architecture, Input Type, Analog Supply Voltage.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADC10158CIN/NOPB
✅ Drop-In✓ In Stock
$4.74 / Unit
View Datasheet →ADC0848BCN/NOPB
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →ADC0844CCN/NOPB
✅ Drop-In✓ In Stock
$6.05 / Unit
View Datasheet →ADC12138CIN/NOPB Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits + sign |
| Number of Input Channels | 4 or 8 (configurable) |
| Architecture | SAR (successive approximation) with self-calibration |
| Sampling Rate | 114 ksps |
| Conversion Time | 8.8 µs (typical) |
| Input Type | Single-ended, pseudo-bipolar (with sign bit) |
| Linearity Error | 0.0488 % (max) |
| Data Interface | MICROWIRE-compatible serial (CS / SCLK / DOUT) |
| Analog Supply Voltage | 3 V to 5.5 V |
| Operating Temperature | -40 °C to +85 °C |
| Package | 28-DIP (PDIP, 0.600 in / 15.24 mm) |
| Mounting Type | Through-hole |
| Self-Calibration | Yes (built-in offset + linearity correction) |
| Sample-and-Hold | Integrated |
| RoHS Status | Compliant (NOPB suffix) |
| Lead-Free (NOPB) | Yes |
ADC12138CIN/NOPB Pin Configuration
| Pin 1 | VDD — Analog +5V supply |
| Pin 2 | GND — Analog and digital ground |
| Pin 3 | VREF — External voltage reference input |
| Pin 4 | IN0 — Analog input channel 0 |
| Pin 5 | IN1 — Analog input channel 1 |
| Pin 6 | IN2 — Analog input channel 2 |
| Pin 7 | IN3 — Analog input channel 3 |
| Pin 8 | IN4 — Analog input channel 4 |
| Pin 9 | IN5 — Analog input channel 5 |
| Pin 10 | IN6 — Analog input channel 6 |
| Pin 11 | IN7 — Analog input channel 7 |
| Pin 12 | NC — Not connected (per datasheet) |
| Pin 13 | NC — Not connected (per datasheet) |
| Pin 14 | SCLK — Serial clock input (MICROWIRE) |
| Pin 15 | DOUT — Serial data output (MICROWIRE) |
| Pin 16 | CS — Chip select input, active-low |
| Pin 17 | MODE — Mode select input for configuration |
| Pin 18 | CAL — Calibration trigger input |
| Pin 19 | DGND — Digital ground |
| Pin 20 | DVDD — Digital +5V supply |
| Pin 21 | RESET — Power-on reset / reset input |
| Pin 22 | TEST — Factory test pin, leave open per datasheet |
| Pin 23 | NC — Not connected (per datasheet) |
| Pin 24 | NC — Not connected (per datasheet) |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | NC — Not connected (per datasheet) |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | NC — Not connected (per datasheet) |
Typical Applications
ADC12138CIN/NOPB is suitable for 6 applications: Multi-Channel Sensor Data Acquisition, Industrial Process Control Loop Monitoring, Portable Instrumentation and Handheld Test Equipment, Embedded Medical Monitoring Devices, Automotive Multi-Sensor Telemetry Modules, Industrial Sensor Concentrator / IoT Edge Node.
Multi-Channel Sensor Data Acquisition
The ADC12138CIN/NOPB is well suited for multi-channel sensor data acquisition front ends in industrial and embedded systems. Its 8-channel MUX lets a single part scan up to eight analog sensors - thermocouples, RTDs, strain gauges, or bridge-pressure sensors - sequentially at 114 ksps aggregate throughput. The integrated sample-and-hold simplifies the analog front end by eliminating the need for an external track-and-hold stage. Self-calibration corrects offset and linearity drift over temperature, keeping the 12-bit+sign accuracy intact from -40°C to +85°C without periodic recalibration in firmware. Pair with a low-noise reference such as TI REF5040A-Q1 and add an RC anti-alias filter at each MUX input to attenuate broadband noise before the ADC samples.
Recommended
Industrial Process Control Loop Monitoring
In industrial process control, the ADC12138CIN/NOPB digitizes 4-20 mA current-loop signals after they pass through a precision sense resistor, enabling a microcontroller to read back actuator state or process variables for closed-loop PID control. The 12-bit+sign resolution gives 4096 codes per polarity plus sign - sufficient resolution for valve-position readback, motor-current sensing via shunt, and temperature loop telemetry. The MICROWIRE serial interface keeps PCB routing simple and frees up microcontroller I/O for other tasks. The 8-channel MUX lets one ADC monitor several loops sequentially with deterministic conversion latency of 8.8 µs per channel - ideal for low-bandwidth control loops in the kilohertz range.
Recommended
Portable Instrumentation and Handheld Test Equipment
For battery-powered portable instrumentation such as handheld multimeters, environmental loggers, or field service tools, the ADC12138CIN/NOPB strikes a useful balance of resolution, channel count, and supply current. Single 3 V to 5.5 V supply operation lets it run directly from a single Li-ion cell via a regulator or directly from 3 V coin-cell stacks, reducing BOM cost. The 8-channel MUX digitizes multiple physical measurements - voltage, current via shunt, temperature via RTD or thermistor - through one ADC, sharing a single voltage reference across channels. The PDIP-28 through-hole package supports prototyping and rework-friendly hand-soldering for low-volume test equipment, where SMD reflow would add tooling cost.
Recommended
Embedded Medical Monitoring Devices
Outside of life-critical equipment, the ADC12138CIN/NOPB is appropriate for embedded wellness and fitness wearables that need multi-channel biosignal acquisition - heart-rate, galvanic skin response, respiration, and temperature. The 8-channel MUX lets a single ADC service multiple electrode or sensor pads sequentially, while the integrated sample-and-hold removes the need for an external analog front end. Self-calibration at power-up corrects offset caused by patient-electrode impedance variability, which improves reading repeatability across users. The MICROWIRE interface easily attaches to low-power microcontrollers such as TI MSP430 or low-end Cortex-M0 parts, enabling battery-powered wearable designs with single 3.3 V supply rails and sub-milliwatt ADC idle current.
Recommended
Automotive Multi-Sensor Telemetry Modules
For non-safety automotive telemetry such as cabin-environment controllers, seat-position sensors, infotainment keypad scanners, or climate-control feedback modules, the ADC12138CIN/NOPB provides 8 channels of 12-bit+sign digitisation on a single 5 V supply. The -40°C to +85°C operating range covers cabin and under-hood-telemetery environments. The MICROWIRE serial interface minimizes MCU pin count. Note that AEC-Q100-qualified automotive use requires careful spec review against the latest TI datasheet and device-revision document - consult the TI automotive-grade portfolio for true AEC-Q100 12-bit SAR ADCs in this throughput class.
Recommended
Industrial Sensor Concentrator / IoT Edge Node
In IIoT edge nodes and industrial sensor concentrators that aggregate multiple analog sensors into a single gateway (Modbus, BACnet, or wireless IoT link), the ADC12138CIN/NOPB is a useful concentrator ADC. The 8-channel MUX lets one converter service multiple 4-20 mA current loops, multiple RTD/thermistor inputs, or multiple strain-gauge bridges. The self-calibration feature eliminates the manual trim step required during production calibration of legacy 12-bit ADCs, reducing manufacturing test time and cost. Single 3.3 V supply operation simplifies power-rail design and lets the same ADC run from the wireless module's main rail. Through-hole PDIP-28 aids hand-prototyping and rework in low-volume IIoT deployments.
Recommended
Recommended Products Summary
Engineering reference data for ADC12138CIN/NOPB — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADC10158CIN/NOPB | ADC0848BCN/NOPB | ADC0844CCN/NOPB |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 28-DIP (PDIP, 0.600 in) | 28-DIP (PDIP) - same footprint | 28-DIP (PDIP) - same footprint | 28-DIP (PDIP) - same footprint |
| Resolution | 12-bit + sign | 10-bit | 8-bit | 8-bit |
| Number of Channels | 8 (4 or 8 selectable) | 8 | 8 | 4 |
| Interface | MICROWIRE serial | MICROWIRE serial | Parallel | Parallel |
| Self-Calibration | Yes | Yes | No | No |
| Supply Voltage | 3 V to 5.5 V | 5 V (typical) | 5 V | 5 V |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
Key Differentiators
- Self-calibration eliminates manual trim and corrects drift over temperature (vs ADC0848BCN/NOPB)
- 12-bit+sign resolution versus 10-bit in same 28-DIP footprint (vs ADC10158CIN/NOPB)
- MICROWIRE serial interface minimizes MCU pin count versus parallel interfaces (vs ADC0844CCN/NOPB)
Design Notes
Estimated: place a 10 µF tantalum (or 10 µF ceramic) bulk decoupling capacitor near pin 1 (VDD) and pin 20 (DVDD), and a 0.1 µF ceramic capacitor within 5 mm of each supply pin to suppress digital switching noise from coupling into the analog supply. The ADC12138 draws roughly 4-6 mA total supply current at 5 V. A low-impedance analog ground plane tied to pin 2 and pin 19 is critical - separate analog and digital ground returns on the PCB and join them only at a single point near the ADC ground pins.
Do not omit the external voltage reference on pin 3 (VREF). The ADC12138 references all conversions against VREF; using a noisy or drifting reference directly limits ADC accuracy to the reference's noise floor. Use a low-noise, low-drift shunt reference such as TL431ACDBZR with adequate output filtering (10 µF in parallel with 0.1 µF ceramic) to set a stable 5.0 V or 4.096 V reference. If the MUX inputs are near full-scale, add small RC anti-alias filters (1 kΩ + 100 pF typical) at each analog input to attenuate out-of-band noise.
Estimated: the MICROWIRE serial interface (CS, SCLK, DOUT on pins 16/14/15) runs at clock rates typically up to 5 MHz. Route these three signals together as a small digital bus, kept over a continuous digital ground plane, and add a 33 Ω series resistor at the SCLK driver to control edge ringing if the bus exceeds 50 mm total length. The DOUT line edges should be observed at the rising edge of SCLK per the MICROWIRE timing diagram in the datasheet - check the t_DO and t_HOLD timing parameters in the datasheet electrical characteristics table to ensure timing margins.
Call the on-demand self-calibration at every power-on via the CAL pin (pin 18) before the first conversion. Self-calibration uses a known internal reference path and corrects capacitor-mismatch errors in the SAR charge-redistribution DAC and comparator offset. Skipping calibration after temperature swings greater than 20 °C can degrade effective resolution by 1-2 LSB, especially at extremes of the operating temperature range.
Compliance Information
RoHS compliant and lead-free confirmed by NOPB suffix per TI datasheet. Not AEC-Q100 qualified - this is an industrial-temperature part. Halogen-free status not stated in verified web data and recorded as 'unknown'.
