ADC12138CIWM/NOPB - 12-Bit+Sign 8-Ch SAR ADC | Texas Instruments
MPN: ADC12138CIWM/NOPB ✓ Hoạt độngADC12138CIWM/NOPB Tóm tắt
An SAR ADC is a type of data converter that uses a binary search through successive approximation register logic to digitize an analog input one bit at a time within a single conversion cycle. The ADC12138 belongs to the broader category of successive approximation ADCs, which are valued for their low power consumption, deterministic latency, and excellent DC accuracy. Within the system hierarchy, this part sits as a precision analog front-end in a data acquisition system, performing the critical bridge between real-world analog sensors and the digital signal processor, microcontroller, or FPGA that processes the resulting codes. Self-calibration is a built-in feature that corrects internal capacitor mismatch and zero-scale/full-scale errors on demand, removing the need for manual trimming during production.
Key features include 12-bit plus sign resolution (effectively 13 bits of dynamic range when measuring bipolar signals), 8 analog input channels selectable via software, a 4-channel pseudo-differential mode for noise rejection, an on-chip sample-and-hold, and self-calibration on power-up or on command. The 28-pin SOIC wide-body package provides ease of prototyping and rework, while the 3V to 5V analog supply range and 3V to 5V digital supply range simplify integration into both 3.3V and 5V systems.
Typical applications include industrial process control, multi-channel data loggers, portable instrumentation, and medical monitoring where multiple sensors must be digitized with high DC accuracy. The 8-channel multiplexer is well suited to multi-zone temperature, pressure, or strain-gauge measurements where a single ADC must service many sensors.
When designing with this part, place a 0.1 uF decoupling capacitor close to the analog supply pin and a 10 uF bulk capacitor on the digital supply. Use a quiet analog ground plane and route SCLK and DOUT traces away from analog inputs to minimize digital-to-analog coupling. The /CS pin enables multi-device SPI bus sharing for systems that need more than eight input channels.
Bộ thay thế dễ dàng lắp đặt cho ADC12138CIWM/NOPB — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với ADC12138CIWM/NOPB (cùng hình factor và footprint) — khác nhau ở Number of Input Channels, Package, Data Interface, Self-Calibration, Resolution.
ADC12138CIWM
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADC12138CIWMX/NOPB
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADC12138CIWN
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADC12132CIWM
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADC10158CIWMX/NOPB
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →ADC12138CIWM/NOPB Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bit + sign |
| Architecture | SAR (Successive Approximation Register) |
| Number of Input Channels | 8 single-ended / 4 pseudo-differential |
| Input Channel Type | Pseudo-Differential, Single-Ended |
| Tỷ lệ lấy mẫu | 114 kSPS |
| Data Interface | Serial, SPI |
| Hộp | 28-pin SOIC (SOIC-28, wide body) |
| Kiểu lắp đặt | Surface Mount |
| Self-Calibration | On-chip, on-command and on-power-up |
| Sample-and-Hold | Integrated |
| Trạng thái RoHS | Compliant |
Cấu hình chân ADC12138CIWM/NOPB
| Chân 1 | CH0 — Analog input channel 0 |
| Chân 2 | CH1 — Analog input channel 1 |
| Chân 3 | CH2 — Analog input channel 2 |
| Chân 4 | CH3 — Analog input channel 3 |
| Chân 5 | CH4 — Analog input channel 4 |
| Chân 6 | CH5 — Analog input channel 5 |
| Chân 7 | CH6 — Analog input channel 6 |
| Chân 8 | CH7 — Analog input channel 7 |
| Chân 9 | AGND — Analog ground |
| Chân 10 | VREF — Voltage reference input |
| Chân 11 | VA+ — Analog supply voltage |
| Chân 12 | AGND — Analog ground |
| Chân 13 | DGND — Digital ground |
| Chân 14 | VD+ — Digital supply voltage |
| Chân 15 | DOUT — Serial data output |
| Chân 16 | SCLK — Serial clock input |
| Chân 17 | CS — Chip select (active low) |
| Chân 18 | CONV — Conversion start |
| Chân 19 | CAL — Calibration control |
| Chân 20 | PD — Power down |
| Chân 21 | MUXOUT — Multiplexer output |
| Chân 22 | S/H — Sample and hold control |
| Chân 23 | MODE — Mode select |
| Chân 24 | DIFF — Differential mode select |
| Chân 25 | SHND — Shutdown control |
| Chân 26 | DGND — Digital ground |
| Chân 27 | AGND — Analog ground |
| Chân 28 | VA+ — Analog supply voltage |
Ứng dụng tiêu biểu
ADC12138CIWM/NOPB phù hợp cho 6 Áp dụngs: Multi-Channel Industrial Process Control, Portable Battery-Powered Data Logger, Medical Patient Monitoring Equipment, Multi-Zone Temperature Monitoring System, Automotive Sensor Interface Module, Test and Measurement Instrumentation.
Multi-Channel Industrial Process Control
The ADC12138CIWM/NOPB is well suited to multi-channel industrial process control where 4-8 analog signals (pressure, flow, level, temperature) must be digitized with 12-bit accuracy. Its 8-channel single-ended or 4-channel pseudo-differential input multiplexer reduces BOM cost by replacing multiple single-channel ADCs. The 114 kSPS throughput allows a complete 8-channel scan in approximately 70 microseconds, fast enough for closed-loop control loops. On-chip self-calibration corrects offset and gain drift caused by industrial ambient temperature swings, eliminating periodic field recalibration.
Được đề xuất
Portable Battery-Powered Data Logger
The ADC12138CIWM/NOPB's low power consumption and 3V supply compatibility make it ideal for portable battery-powered data loggers that sample environmental sensors over long periods. The self-calibration feature ensures measurement accuracy over the battery discharge curve and across temperature extremes. With 12-bit plus sign resolution, the converter captures both positive and negative signals from thermocouples and strain gauges without external signal conditioning. The SPI serial interface minimizes microcontroller pin count, leaving more GPIOs available for SD card, RTC, and display interfaces.
Được đề xuất
Medical Patient Monitoring Equipment
The ADC12138CIWM/NOPB is suitable for medical patient monitoring front ends that digitize ECG, temperature, respiration, and SpO2 signals. Its 12-bit plus sign resolution captures bipolar ECG waveforms without external level shifting, while the 8-channel input multiplexer enables simultaneous monitoring of multiple physiological parameters. The on-chip self-calibration supports medical accuracy requirements by correcting offset drift over time, and the SOIC-28 wide-body package simplifies IEC 60601 medical device certification by allowing easy rework during EMC immunity testing.
Được đề xuất
Multi-Zone Temperature Monitoring System
The ADC12138CIWM/NOPB digitizes up to 8 thermocouple or RTD channels in multi-zone temperature monitoring systems such as HVAC controllers, food storage, and semiconductor process equipment. The pseudo-differential input mode rejects common-mode noise from long thermocouple wire runs, which is critical when sensors are 10+ meters from the ADC. The 12-bit plus sign resolution delivers 0.1C temperature resolution when paired with a K-type thermocouple and cold-junction compensation, while the 114 kSPS throughput scans all 8 zones in under 100 microseconds for responsive control.
Được đề xuất
Automotive Sensor Interface Module
The ADC12138CIWM/NOPB serves as the analog front end in automotive sensor interface modules that digitize throttle position, manifold pressure, and exhaust oxygen sensor signals. The wide operating temperature range and 8-channel multiplexer allow one ADC to replace multiple discrete converters in ECU designs, reducing cost and board area. The 12-bit plus sign resolution is sufficient for many automotive sensors where the signal is in the 0-5V range, and the SPI interface connects directly to automotive microcontrollers. Note: for AEC-Q100 qualified parts, the automotive-grade variant should be selected.
Được đề xuất
Test and Measurement Instrumentation
The ADC12138CIWM/NOPB is used in bench-top test and measurement instruments such as multimeters, oscilloscope auxiliary channels, and signal analyzers where multiple inputs must be captured with calibrated DC accuracy. The on-chip self-calibration supports the instrument calibration cycle, while the SPI interface allows the host processor to control range switching, input multiplexers, and trigger logic. The 12-bit plus sign resolution is adequate for general-purpose DMM functionality, and the 28-pin SOIC wide-body package simplifies prototyping and engineering validation cycles.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ADC12138CIWM/NOPB — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | ADC12138CIWM | ADC12138CIWMX/NOPB | ADC12138CIWN | ADC12132CIWM | ADC10158CIWMX/NOPB |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 28-pin SOIC (wide body) | 28-pin SOIC (wide body) - same | 28-pin SOIC (wide body) - same | 28-pin SOIC (narrow body) - smaller outline | 28-pin SOIC (wide body) - same | 28-pin SOIC (wide body) - same |
| Resolution | 12-bit + sign | 12-bit + sign | 12-bit + sign | 12-bit + sign | 12-bit + sign | 10-bit (lower) |
| Input Channels | 8 single-ended / 4 pseudo-diff | 8 single-ended / 4 pseudo-diff | 8 single-ended / 4 pseudo-diff | 8 single-ended / 4 pseudo-diff | 2 single-ended / 1 pseudo-diff (fewer) | 8 single-ended / 4 pseudo-diff |
| Serial Interface | SPI | SPI | SPI | SPI | SPI | SPI |
| Self-Calibration | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) |
| Packaging Format | Tube | Tube | Tape & Reel | Tube | Tube | Tape & Reel |
Bảo phân biệt quan trọng
- 12-bit plus-sign resolution in 8-channel package (vsMCP3208-CI/SL)
- On-chip self-calibration (vsADC10158CIWMX/NOPB)
- Wide-body SOIC for easier rework (vsADC12138CIWN)
Ghi chú thiết kế
Place a 0.1 uF ceramic decoupling capacitor within 5 mm of the VA+ analog supply pin and a 10 uF bulk tantalum or ceramic capacitor on the same rail to filter high-frequency and low-frequency noise respectively. The ADC12138's on-chip self-calibration is sensitive to supply noise, so a linear regulator (such as a TL431-based reference plus pass transistor) is preferred over a switching regulator for the analog rail. Estimated: at 5V analog supply and 1.5 mA typical operating current, power dissipation is 7.5 mW; a quiet supply is more important than efficiency at this current level.
Use a four-layer PCB with a dedicated analog ground plane and a separate digital ground plane joined at a single point beneath the ADC. Route the SPI lines (SCLK, DOUT, CS) on the digital side and keep the analog input traces (CH0-CH7) on the analog side to prevent digital-to-analog coupling. The exposed analog inputs have high impedance, so minimize trace length and add a 100 pF to 1 nF RC filter near the ADC pins for ESD and RF immunity in industrial environments.
Do not operate the ADC12138 without a stable external reference on the VREF pin. Drift in VREF directly degrades conversion accuracy, so use a low-drift reference such as the TL431ACDBZR (50 ppm/C) for general-purpose applications, or a higher-precision reference for sub-1 LSB linearity. The self-calibration routine should be invoked after any significant temperature change (>10C) to maintain offset and gain accuracy. Failing to recalibrate after a supply voltage change can introduce up to several LSBs of error.
Thông tin tuân thủ
NOPB suffix indicates lead-free matte-tin terminal finish compliant with RoHS and REACH. Not AEC-Q100 qualified; for automotive applications, the automotive-grade variant should be selected. Halogen-free status not specified in the verified web data.
