AD7888BR-REEL7 - 12-Bit 125kSPS 8-Ch ADC SOIC-16 | ADI
MPN： AD7888BR-REEL7 ✓ 啟用中AD7888BR-REEL7 概覽
An ADC (Analog-to-Digital Converter) is a data-conversion IC that samples continuous analog voltage levels and translates them into discrete digital codes for microcontrollers, DSPs, or FPGAs. Within the converter hierarchy, the AD7888 sits in the SAR (successive-approximation register) sub-family of ADCs, characterized by deterministic latency and low power consumption compared to delta-sigma or pipeline architectures; it is itself part of the larger data-converter domain of mixed-signal ICs.
Key features include a 500 ns input track-and-hold acquisition time, eight single-ended channels multiplexed to a single ADC core, a true analog input range of 0 V to VREF on each channel, daisy-chainable serial interface, and a hardware shutdown pin. The internal reference and channel sequencer reduce external component count, which is valuable in space-constrained sensor-interface PCBs.
Technically, the AD7888 uses a charge-balancing DAC and a high-speed comparator inside its SAR loop to deliver 12-bit resolution without pipeline delay, making it well-suited to multiplexed applications that need deterministic per-channel conversion timing. Its low-power CMOS process keeps active current around 1 mA typical at full throughput.
Typical applications include portable instrumentation, multi-channel sensor monitoring (temperature, pressure, strain-gauge bridges), battery-powered data loggers, and industrial process-control front ends where multiple slow-moving analog signals must be digitized by a single MCU.
When designing with this device, ensure that the analog input pins are not driven above VDD or below GND, and add a 0.1 µF decoupling capacitor close to the supply pin to reduce digital-coupling noise on the analog sampling instant.
This page synthesizes ADI-authorized datasheet data, current distributor pricing, and drop-in SOIC-16 cross-references so engineers can compare the AD7888 against modern pin-compatible ADCs in one place.
直接替換替代品，適用於 AD7888BR-REEL7 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： AD7888BR-REEL7 （相同外形與佔位） — 差異在於 Number of Channels, Package, Reference Voltage.
AD7888BRZ-REEL7
✅ 直接替換📋 參考替代品（不在目錄中）
AD7888AR-REEL7
✅ 直接替換📋 參考替代品（不在目錄中）
AD7888ARZ-REEL7
✅ 直接替換📋 參考替代品（不在目錄中）
AD7888BR
✅ 直接替換📋 參考替代品（不在目錄中）
AD7888AR
✅ 直接替換📋 參考替代品（不在目錄中）
AD7888BR-REEL7 最大額定值與電氣特性
| 解析度 | 12 bits |
| Number of Channels | 8 single-ended |
| 取樣率 | 125 kSPS |
| 供應電壓 | 2.7 V to 5.25 V (single) |
| Supply Current (shutdown) | < 1 µA (power-down mode) |
| Input Track-and-Hold Acquisition | 500 ns |
| Analog Input Range | 0 V to VREF |
| 參考電壓 | 2.5 V internal (external REF supported) |
| 介面 | SPI, MICROWIRE, QSPI, DSP-compatible serial |
| Architecture | SAR (Successive Approximation) |
| 封裝 | 16-SOIC_N (SOIC-16, 0.154 inch / 3.90 mm body width) |
| 安裝類型 | Surface Mount |
AD7888BR-REEL7 腳位配置
| 腳位 1 | AIN1 — Analog input channel 1 (single-ended, 0-VREF) |
| 腳位 2 | AIN2 — Analog input channel 2 (single-ended, 0-VREF) |
| 腳位 3 | AIN3 — Analog input channel 3 (single-ended, 0-VREF) |
| 腳位 4 | AIN4 — Analog input channel 4 (single-ended, 0-VREF) |
| 腳位 5 | AIN5 — Analog input channel 5 (single-ended, 0-VREF) |
| 腳位 6 | AIN6 — Analog input channel 6 (single-ended, 0-VREF) |
| 腳位 7 | AIN7 — Analog input channel 7 (single-ended, 0-VREF) |
| 腳位 8 | AIN8 — Analog input channel 8 (single-ended, 0-VREF) |
| 腳位 9 | GND — Analog/digital ground |
| 腳位 10 | REF — Reference input/output (2.5 V internal, or external drive) |
| 腳位 11 | SCLK — Serial clock input |
| 腳位 12 | DIN — Serial data input (MISO control word) |
| 腳位 13 | DOUT — Serial data output (conversion result) |
| 腳位 14 | CONVST — Conversion start input |
| 腳位 15 | PD — Power-down (active low) input |
| 腳位 16 | VDD — Analog/digital supply (2.7-5.25 V) |
典型應用
AD7888BR-REEL7 適用於 6 應用s: Multi-Channel Sensor Data Acquisition, Portable Battery-Powered Instrumentation, Industrial Process Control Front-Ends, Battery Management System Telemetry, Data Logging and Environmental Monitoring, Medical Patient Monitoring Peripherals.
Multi-Channel Sensor Data Acquisition
The AD7888BR-REEL7 is well-matched to multiplexed sensor-front-ends where 4-8 slowly varying analog channels (temperature, pressure, strain-gauge bridges, photocurrents) need to be digitised by a single 3.3 V or 5 V MCU. Its 125 kSPS throughput supports polling all eight AIN1-AIN8 channels at over 10 kSPS per channel when averaging is acceptable, while the integrated 2.5 V reference removes an external reference IC. Designers use the daisy-chain feature to cascade two AD7888s for 16-channel systems without additional chip-select lines, keeping BOM cost low in industrial PLCs and environmental monitors.
推薦
Portable Battery-Powered Instrumentation
The AD7888BR-REEL7's single 2.7-5.25 V supply, internal reference, and sub-1 µA power-down current make it ideal for handheld multimeters, portable medical monitors, and battery-pack fuel-gauges that digitize voltage, current, and temperature channels. Its low active supply current (single-digit mA class) preserves battery life, and the shutdown pin lets the host MCU switch the ADC off between conversions. Engineers place the AD7888 upstream of a low-power MCU such as an MSP430 or an ADuCM302x for sub-mW sleep profiles while still retaining 12-bit measurement resolution across multiple sensor inputs.
推薦
Industrial Process Control Front-Ends
In 4-20 mA loop-monitor PLCs, motor controllers, and SCADA remote-terminal-units (RTUs), the AD7888BR-REEL7 digitizes analog transducer outputs (pressure, flow, level) and reports them to a host DSP or PLC over a shared SPI bus. The 500 ns track-and-hold acquisition provides accurate sampling of multiplexed channels even when the source impedance is in the kilo-ohm range, and the SOIC-16 footprint suits ruggedized through-hole reflow designs. Pair with a 16-bit ADC such as the AD7708BRU-REEL on the same PCB when a slow-but-precision companion channel is required alongside the AD7888's faster multiplexed channels.
推薦
Battery Management System Telemetry
Battery-management systems (BMS) for UPS, e-bike, and small-EV packs need to monitor 8+ individual cell voltages and pack temperatures; the AD7888BR-REEL7 handles eight analog inputs in one SOIC-16 IC, simplifying the analog-front-end of the BMS MCU. Its 0 V to VREF input range naturally matches resistor-divider-scaled cell voltages when the internal 2.5 V reference is used. The daisy-chain option lets designers stack two AD7888s for 16-cell packs without additional GPIO pins, and the SPI interface ties directly into common BMS controllers from TI, NXP, and ST.
推薦
Data Logging and Environmental Monitoring
Environmental data loggers for greenhouse gas, weather-station, and cold-chain applications require digitisation of multiple slow analog sensors (temperature, humidity, soil moisture, light) at low power. The AD7888BR-REEL8-series' low active supply current and <1 µA shutdown draw keep idle power low while the device wakes every few seconds to scan all eight channels. The internal 2.5 V reference simplifies calibration, and the deterministic SAR latency simplifies time-stamping of sensor events. A host low-power MCU can keep the rest of the system in deep sleep between conversions.
推薦
Medical Patient Monitoring Peripherals
Although not AEC-Q100 qualified, the AD7888BR-REEL7 is widely used in non-life-critical medical peripherals (sleep-study sensors, fitness ECG leads, pulse-oximeter front-ends) where 8 channels of slow analog input need to be digitised at modest speed. The integrated multiplexer and reference shrink PCB area in wearable form factors, while the SPI interface suits low-power ARM Cortex-M hosts. Designers should always add front-end protection (ESD diodes, current-limiting resistors) and verify compliance with IEC 60601 for any device that contacts patients.
推薦
推薦產品摘要
工程參考資料，適用於 AD7888BR-REEL7 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | AD7888BRZ-REEL7 | AD7888AR-REEL7 | AD7888ARZ-REEL7 | AD7888BR | AD7888AR |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 16-SOIC_N | 16-SOIC_N (same) | 16-SOIC_N (same) | 16-SOIC_N (same) | 16-SOIC_N (same, tube) | 16-SOIC_N (same, tube) |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Channels | 8 single-ended | 8 single-ended | 8 single-ended | 8 single-ended | 8 single-ended | 8 single-ended |
| Sampling Rate | 125 kSPS | 125 kSPS | 125 kSPS | 125 kSPS | 125 kSPS | 125 kSPS |
| Linearity Grade | B-grade (tight INL/DNL) | B-grade | A-grade (looser by ~0.5 LSB) | A-grade | B-grade | A-grade |
| Lead-Free / RoHS | Not specified by suffix | Yes (Z suffix) | Not specified | Yes (Z suffix) | Tube (legacy) | Tube (legacy) |
| Packaging Format | Tape & Reel, 7-inch (-REEL7) | Tape & Reel, 7-inch (-REEL7) | Tape & Reel, 7-inch | Tape & Reel, 7-inch | Tube | Tube |
主要差異化特點
- Integrated 8-channel multiplexer in a single SOIC-16 footprint (對比Multiple discrete AD7478 single-channel ADCs)
- B-grade linearity specification (對比AD7888AR-REEL7 (A-grade))
- True sub-1 µA hardware power-down mode (對比Software-shutdown ADCs without a dedicated PD pin)
- Daisy-chaining capability doubles channel count (對比Discrete muxed ADCs without daisy-chain mode)
設計說明
Power the AD7888BR-REEL7 from a clean 2.7-5.25 V rail that is well-decoupled at the VDD pin with a 0.1 µF ceramic plus a 1 µF tantalum or ceramic bulk capacitor. Drive the PD (power-down) pin LOW when the host MCU wants the ADC to draw < 1 µA between conversions; the pin is logically inverted, so a HIGH keeps the part powered. Estimated: average supply current at 10 kSPS aggregate throughput is roughly 0.3 mA when PD is exercised between conversion bursts.
Place all eight AINx trace inputs away from the SCLK/DOUT/DIN digital lines and route them over a continuous analog ground pour to keep digital switching transients from coupling into the analog front-end. The REF pin decoupling capacitor (typically 0.1 µF) should be placed within 2-3 mm of the REF pin to suppress reference-noise folding into the conversion result. Keep the SOIC-16 thermal pad area free of heavy copper to avoid inducing ground loops near sensitive AIN pins.
Do not drive any AIN pin above VDD or below GND - even transient overdrive can corrupt the conversion result and forward-bias the input ESD structures. Ensure the host SPI controller toggles CONVST correctly: a falling edge on CONVST starts a conversion, and SCLK should remain idle until the EOC bit appears on DOUT. Daisy-chain mode requires that the host MISO line be reconfigured between the first and second devices, which is a common firmware bug.
For the B-grade (tighter linearity) variant, use the internal 2.5 V reference only when the supply is well-regulated; for precision measurements, drive an external low-noise reference such as the ADR441 or ADR01 onto the REF pin. Estimated: at full 125 kSPS throughput the SINAD typically falls by 0.5-1 dB if the reference pin sees more than a few microamps of high-frequency load, which a properly placed 0.1 µF cap mitigates.
合規資訊
B-grade and A-grade lead-free RoHS compliance requires the Z-suffix variant (e.g. AD7888BRZ-REEL7 or AD7888ARZ-REEL7); the AD7888BR-REEL7 itself does not carry the Z suffix and RoHS status is unknown from verified data. AEC-Q100 qualification is not applicable for a generic industrial 12-bit SAR ADC - confirm with ADI directly for automotive-grade needs.
