AD7887ARZ-REEL - 12-Bit 125kSPS 2-Ch SAR ADC | Analog Devices
MPN: AD7887ARZ-REEL ✓ Hoạt độngAD7887ARZ-REEL Tóm tắt
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.
Bộ thay thế dễ dàng lắp đặt cho AD7887ARZ-REEL — 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 AD7887ARZ-REEL (cùng hình factor và footprint) — khác nhau ở Architecture, Data Interface, Number of Channels, Package, Packaging.
AD7887ARZ-REEL7
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7887BRZ-REEL
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7887CRZ-REEL
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
AD7887ARMZ-REEL
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX1241ACSA+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MCP3201-BI/SN
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC1865LCS8#PBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
TLC2543IDW
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7887ARZ-REEL Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bit |
| Architecture | SAR (Successive Approximation) |
| Number of Analog Inputs | 1 or 2 (single-ended) |
| Tỷ lệ lấy mẫu | 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 |
| Hộp / Vỏ | 8-SOIC (0.154 inch, 3.90 mm width) |
| Kiểu lắp đặt | Surface Mount |
| Packaging | Tape & Reel (REEL), 2,500 pcs |
| Trạng thái RoHS | Compliant (Z suffix) |
| Lead Free | Yes |
Cấu hình chân AD7887ARZ-REEL
| Chân 1 | AIN1 / VREF — Analog input 1 in dual-channel mode; 2.5 V internal reference output in single-channel mode |
| Chân 2 | AIN0 / IN — Analog input 0 (primary input in single-channel mode) |
| Chân 3 | GND — Ground reference |
| Chân 4 | REFCAP — Reference bypass capacitor (external 1 uF minimum) |
| Chân 5 | SCLK — Serial clock input for SPI/QSPI/MICROWIRE/DSP interface |
| Chân 6 | DOUT — Serial data output (conversion result) |
| Chân 7 | DIN — Serial data input (control register write in dual-channel mode) |
| Chân 8 | VDD — Power supply, 2.7 V to 5.25 V |
Ứng dụng tiêu biểu
AD7887ARZ-REEL phù hợp cho 8 Áp dụngs: 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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho AD7887ARZ-REEL — 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 | 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 |
Bảo phân biệt quan trọng
- Highest throughput at 12 bits in the AD7887 family for this grade (vsMAX1241ACSA+)
- Integrated 2.5 V reference eliminates external reference IC (vsMCP3201-BI/SN)
- Dual-channel sampling in a single 8-SOIC (vsMAX1241ACSA+)
Ghi chú thiết kế
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.
Thông tin tuân thủ
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.