AD7887ARZ-REEL - 12-Bit 125kSPS 2-Ch SAR ADC | Analog Devices
料号： AD7887ARZ-REEL ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $6.84 | $6.84 |
| 10 | $6.15 | $61.50 |
| 100 | $5.45 | $545.00 |
| 500 | $4.82 | $2,410.00 |
| 1,000 | $4.25 | $4,250.00 |
AD7887ARZ-REEL 概述
An ADC is a data converter that maps a continuous analog input voltage onto a discrete binary codeword. The 12-bit resolution means each LSB equals the full-scale range divided by 4096 - giving ~0.024% of FS step size and enabling precise measurement of low-bandwidth signals such as sensor outputs, motor currents, and instrumentation front-ends. Within the broader converter family, SAR ADCs excel where low latency, deterministic sampling, and excellent DC linearity are required, sitting between flash (fastest, lowest resolution) and sigma-delta (highest resolution, slowest) architectures.
Key features of the AD7887 include a 500 ns input track-and-hold acquisition window, single-ended sampling architecture, straight-binary output coding, and a low-power CMOS process that consumes only a few milliwatts at full throughput. The serial interface can be operated from a single 3 V or 5 V supply, and dual-/single-channel mode is selectable through the on-chip control register. Power-down modes between conversions further reduce quiescent current to microamp levels, making the device attractive for battery and portable designs.
Architecture-wise, the AD7887 combines a charge-redistribution DAC, a high-speed comparator, and an internal 2.5 V bandgap reference. The internal reference can be applied externally via the AIN1/VREF pin in single-channel mode, eliminating the need for an external reference IC and saving both cost and PCB area.
Typical applications include industrial process control loops, portable and battery-powered instrumentation, motor-control current sense, optical sensor front-ends (e.g., photodiode signal conditioning), and general-purpose data acquisition in PLC and embedded systems.
When designing with this device, bypass VDD with a 0.1 uF ceramic capacitor placed within 5 mm of the pin and keep the analog input trace short and guarded from digital switching nodes. The internal reference needs at least a 1 uF external decoupling capacitor on the REFCAP pin for the 2.5 V reference to settle within datasheet limits.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives, and practical PCB/thermal notes that go beyond the AD7887 datasheet standalone.
直接替换替代料： AD7887ARZ-REEL ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： AD7887ARZ-REEL （相同外形与封装尺寸） ——差异在于 Architecture, Data Interface, Number of Channels, Package, Packaging.
快速对比工具——选择替代料号进行并排对比：
AD7887ARZ-REEL7
✅ 直接替换📋 参考替代料（不在目录中）
AD7887BRZ-REEL
✅ 直接替换📋 参考替代料（不在目录中）
AD7887CRZ-REEL
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
AD7887ARMZ-REEL
✅ 直接替换📋 参考替代料（不在目录中）
MAX1241ACSA+
✅ 直接替换📋 参考替代料（不在目录中）
MCP3201-BI/SN
✅ 直接替换📋 参考替代料（不在目录中）
LTC1865LCS8#PBF
✅ 直接替换📋 参考替代料（不在目录中）
TLC2543IDW
✅ 直接替换📋 参考替代料（不在目录中）
AD7887ARZ-REEL 最大额定值与电气特性
| 分辨率 | 12 bit |
| Architecture | SAR (Successive Approximation) |
| Number of Analog Inputs | 1 or 2 (single-ended) |
| 采样率 | 125 kSPS |
| Input Track-and-Hold Acquisition | 500 ns |
| Supply Voltage (Single) | 2.7 V to 5.25 V |
| Internal Reference Voltage | 2.5 V |
| Digital Interface | SPI, QSPI, MICROWIRE, DSP-compatible serial |
| Output Coding | Straight binary |
| Input Sampling Scheme | Single-ended |
| Channel Configuration | Dual-channel or read-only single-channel |
| 封装 / 外壳 | 8-SOIC (0.154 inch, 3.90 mm width) |
| 安装类型 | Surface Mount |
| Packaging | Tape & Reel (REEL), 2,500 pcs |
| RoHS 状态 | Compliant (Z suffix) |
| Lead Free | Yes |
AD7887ARZ-REEL 引脚配置
| 引脚 1 | AIN1 / VREF — Analog input 1 in dual-channel mode; 2.5 V internal reference output in single-channel mode |
| 引脚 2 | AIN0 / IN — Analog input 0 (primary input in single-channel mode) |
| 引脚 3 | GND — Ground reference |
| 引脚 4 | REFCAP — Reference bypass capacitor (external 1 uF minimum) |
| 引脚 5 | SCLK — Serial clock input for SPI/QSPI/MICROWIRE/DSP interface |
| 引脚 6 | DOUT — Serial data output (conversion result) |
| 引脚 7 | DIN — Serial data input (control register write in dual-channel mode) |
| 引脚 8 | VDD — Power supply, 2.7 V to 5.25 V |
典型应用
AD7887ARZ-REEL 适用于 8 应用s: Industrial Process Control Loops, Portable and Battery-Powered Instrumentation, Motor Control Current Sensing, Optical Sensor Front-Ends, General-Purpose Data Acquisition Boards, Power Supply Voltage and Current Monitoring, IoT Edge Sensor Nodes, Audio Signal Chain Digitization.
Industrial Process Control Loops
The AD7887ARZ-REEL fits 4-20 mA current-loop digitization with its 12-bit resolution and 125 kSPS throughput, sampling analog signals from thermocouples, RTDs, and pressure transducers faster than typical 10 Hz control loops. The internal 2.5 V reference eliminates the need for an external reference, dropping BOM cost and saving PCB area inside PLC analog input modules. Single-ended sampling against ground works with industrial 0-10 V signal-conditioning front-ends that drive both inputs differentially.
推荐
Portable and Battery-Powered Instrumentation
For handheld multimeters and battery-powered data loggers, the AD7887ARZ-REEL operates from a single 2.7 V to 5.25 V rail, so a Li-ion or 3.3 V system can power the ADC directly without level shifting. Power-down modes drop quiescent current to the microamp range between conversions, extending battery life in duty-cycled measurements. With only 1 or 2 analog inputs, the device is well suited to single- or dual-sensor handhelds measuring voltage or temperature.
推荐
Motor Control Current Sensing
In brushless DC or stepper motor drives, the AD7887ARZ-REEL digitizes the output of a current-sense amplifier measuring phase currents up to 100 kHz. The 125 kSPS throughput gives 5-10 samples per PWM period at 20 kHz switching, capturing ripple and transient events for FOC algorithms. The 8-SOIC footprint is small enough for the compact control PCBs used in drone ESCs and robotic joint controllers.
推荐
Optical Sensor Front-Ends
Photodiodes in light meters, smoke detectors, and pulse oximeters generate microamp currents that need digitization with low offset and adequate dynamic range. The AD7887ARZ-REEL's 12-bit resolution gives 4,096 levels over the 2.5 V internal reference, suitable for accurate lux or absorbance measurement in consumer optical sensors. At 125 kSPS, it can track rapid LED-driven pulse-oximeter waveforms faster than the device's 1 kHz heartbeat signal.
推荐
General-Purpose Data Acquisition Boards
The AD7887ARZ-REEL is a workhorse for hobbyist and OEM DAQ boards that need 1-2 channels of 12-bit analog sampling with a compact SPI interface. Two analog inputs allow simultaneous monitoring of two sensor channels (e.g., accelerometer and temperature), while 125 kSPS handles audio-band signals up to ~60 kHz. The 8-SOIC package is breadboard-friendly and compatible with virtually every ARM Cortex-M and PIC microcontroller.
推荐
Power Supply Voltage and Current Monitoring
In AC-DC and DC-DC converters, the AD7887ARZ-REEL digitizes output voltage and current for telemetry, OVP, and OCP feedback. The internal 2.5 V reference yields 0.6 mV LSB at 12 bits, enough resolution for tight regulation loops in telecom and server PSUs. Sampling at 125 kSPS allows 4 updates per 30 kHz switching cycle, enabling cycle-by-cycle monitoring of output ripple in digitally controlled power converters.
推荐
IoT Edge Sensor Nodes
Battery-powered IoT nodes need a low-power ADC with reasonable speed - the AD7887ARZ-REEL fits with its 2.7 V to 5.25 V supply range and micropower consumption. Two analog inputs are sufficient for most edge sensors (temperature + humidity, pressure + temperature, light + voltage), and the integrated reference avoids the cost of a separate precision IC. The part drops into ESP32, nRF52, or SAMD-based sensor boards via a single SPI bus.
推荐
Audio Signal Chain Digitization
Although primarily a DC SAR ADC, the AD7887ARZ-REEL's 125 kSPS throughput is sufficient to digitize baseband audio up to ~50 kHz, covering most voice-band and ultrasonic applications. The integrated 2.5 V reference and single-ended inputs simplify microphone preamp design for industrial acoustic monitoring, ultrasonic ranging, and consumer voice assistants. Its SPI interface directly drives audio DSPs and FPGA-based signal-processing engines.
推荐
推荐产品汇总
工程参考数据： AD7887ARZ-REEL ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | AD7887ARZ-REEL7 | AD7887BRZ-REEL | MAX1241ACSA+ | MCP3201-BI/SN |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Maxim Integrated | Microchip Technology |
| Package | 8-SOIC (0.154 inch) | 8-SOIC (0.154 inch) | 8-SOIC (0.154 inch) | 8-SOIC | 8-SOIC |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Throughput | 125 kSPS | 125 kSPS | 125 kSPS | 73 kSPS | 100 kSPS |
| Number of Inputs | 1 or 2 | 1 or 2 | 1 or 2 | 1 | 1 |
| Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.5 V |
| Internal Reference | 2.5 V (integrated) | 2.5 V (integrated) | 2.5 V (integrated) | External required | External required |
| Digital Interface | SPI/QSPI/MICROWIRE/DSP | SPI/QSPI/MICROWIRE/DSP | SPI/QSPI/MICROWIRE/DSP | SPI | SPI |
| Approx. Unit Price (Oct 2026) | $6.84 | $6.84 | $7.10 | $5.95 | $4.20 |
关键差异点
- Highest throughput at 12 bits in the AD7887 family for this grade （对比 MAX1241ACSA+)
- Integrated 2.5 V reference eliminates external reference IC （对比 MCP3201-BI/SN)
- Dual-channel sampling in a single 8-SOIC （对比 MAX1241ACSA+)
设计说明
The AD7887ARZ-REEL operates from a single 2.7 V to 5.25 V supply; bypass VDD with a 0.1 uF X7R ceramic capacitor within 5 mm of pin 8. Add a 10 uF tantalum or aluminum-polymer bulk capacitor for systems where the supply rail is shared with digital switching loads. Power-down mode (entered via the control register) drops quiescent current to microamp levels and is recommended for battery-powered instrumentation to maximize runtime.
Route the analog input traces (AIN0, AIN1) with a guard ring tied to GND or to a driven guard potential, kept short and away from the SCLK/DOUT digital lines. Place the 1 uF REFCAP capacitor as close to pin 4 as possible with a wide ground return via under the device. The exposed copper area beneath the 8-SOIC body can be tied to GND to provide thermal relief and shielding - a 2 mm × 2 mm footprint pour is sufficient for typical 25 mW dissipation.
The input track-and-hold acquisition time is 500 ns; ensure the source impedance is below 500 ohm to settle within that window to datasheet-specified INL and DNL. If higher source impedance is unavoidable (e.g., a 10 kohm sensor divider), add a wideband buffer such as the AD8628ARZ at the analog input. Avoid driving the analog input with a current-source output amplifier - the single-ended architecture assumes a low-impedance voltage source at the ADC pin.
Estimated: at a 5 V supply and 1 mA quiescent current, the AD7887ARZ-REEL dissipates approximately 5 mW; with thermal resistance theta_JA around 156 C/W for the 8-SOIC, junction rises only 0.8 C above ambient - no heatsink required. However, omitting the REFCAP capacitor causes the internal 2.5 V reference to drift, degrading last-code linearity - the 1 uF REFCAP is mandatory for spec compliance.
合规信息
RoHS compliance indicated by the Z suffix per Analog Devices part numbering convention. REACH, halogen-free, and conflict-mineral status were not explicitly listed in the provided distributor data and should be confirmed via the AD7887 datasheet Rev. E material declaration section.