AD7894BRZ-10REEL - 14-Bit 200kSPS 5V Serial ADC | Analog Devices
부품 번호: AD7894BRZ-10REEL ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $26.5 | $26.50 |
| 10 | $23.85 | $238.50 |
| 100 | $19.4 | $1,940.00 |
| 500 | $16.95 | $8,475.00 |
| 1,000 | $14.2 | $14,200.00 |
AD7894BRZ-10REEL 개요
A successive-approximation ADC is a precision data converter type that uses an internal binary-search register to compare the sampled input against a precisely scaled DAC reference voltage, achieving one conversion step per clock cycle on the DAC side. This topology sits one level above flash converters in speed and one level below sigma-delta converters in resolution, occupying the middle ground where 12-16-bit accuracy at tens-to-hundreds of kSPS is required. The AD7894 is a classic member of this category, well-suited to industrial process control, instrumentation, and motor-control feedback loops.
Key specifications distinguishing the AD7894BRZ-10 include a 4.5 microsecond conversion time (approximately 200 kSPS throughput), an on-chip track-and-hold amplifier, an on-chip clock, and a high-speed serial interface that reduces external pin count. The bipolar -10 V to +10 V input range eliminates external signal conditioning for many industrial signals. Single-supply +5 V operation simplifies board-level power tree design, and the ADC draws its bias from the same rail that powers the host microcontroller or DSP.
Architecturally, the AD7894 integrates the input multiplexer-free front end, charge-redistribution DAC array, comparator, and SAR logic onto a single BiCMOS die. Dynamic performance parameters include harmonic distortion and signal-to-noise ratio specified for the audio and precision-DC measurement bands. Standalone through-pin serial control (RFS, SCLK, SDATA) means the part can be driven from the SPI or DSP-serial port of most microcontrollers without external logic.
Typical applications include industrial process control (4-20 mA loop digitization), motor control current/voltage feedback, instrumentation sensors, and data-acquisition front-ends where a bipolar input range and serial interface reduce opto-isolation cost. The wide input common-mode range also simplifies protection circuitry in line-powered installations.
When designing with this ADC, allocate the host microcontroller a DMA or interrupt-driven SPI handler because a 200 kSPS throughput demands bus availability roughly every 5 microseconds. Use a low-impedance input buffer (such as the AD8021) if the source impedance exceeds 1 kohm and decouple the +5 V supply with both a 10 microfarad tantalum and a 0.1 microfarate ceramic placed within 5 millimeters of the pin.
This page synthesizes distributor pricing, drop-in alternatives in the same SOIC-8 footprint, and practical design notes not found in the manufacturer datasheet alone, helping engineers source and qualify the AD7894BRZ-10REEL quickly for production designs.
드롭인 대체품: AD7894BRZ-10REEL — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
AD7894BRZ-10REEL7
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
AD7894BRZ-10
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
AD7894ARZ-10REEL
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
AD7894BRZ-3REEL
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
AD7894BRZ-10REEL 최대 정격 & 전기적 특성
| 분해능 | 14 bits |
| Architecture | SAR (Successive Approximation) |
| Number of Channels | 1 |
| 샘플링 속도 | 200 kSPS |
| Conversion Time | 4.5 us |
| Input Type | Single-Ended, Bipolar |
| Analog Input Range | -10 V to +10 V |
| 공급 전압 | 5 V single supply |
| Output Interface | Serial (SPI-compatible) |
| On-Chip Track/Hold | Yes |
| On-Chip Clock | Yes |
| 동작 온도 범위 | -40 C to +85 C |
| 패키지 | SOIC-8 (R-8 / 150 mil) |
| 실장 유형 | Surface Mount |
| Packaging | Tape & Reel (REEL, 2500 pcs) |
| RoHS 상태 | Compliant (Z suffix) |
| Lead-Free | Yes |
AD7894BRZ-10REEL 핀 구성
| 핀 1 | VREF — External 2.5V reference input |
| 핀 2 | VDD — +5V analog and digital supply |
| 핀 3 | GND — Common ground (analog and digital) |
| 핀 4 | SCLK — Serial clock input |
| 핀 5 | RFS — Receive-frame-sync input (chip-select) |
| 핀 6 | SDATA — Serial data output |
| 핀 7 | NC — Not connected (pin reserved) |
| 핀 8 | VIN — Analog input (BIP -10V to +10V for the -10 suffix) |
일반적인 애플리케이션
AD7894BRZ-10REEL 적합 용도: 6 애플리케이션s: Industrial Process Control / 4-20 mA Loop Digitization, Motor Control Current/Voltage Feedback, Instrumentation & Sensor Digitization, Data Acquisition Front End / Portable Measurement, Audio Signal Processing / Precision DC Measurement, Power Quality / Energy Metering.
Industrial Process Control / 4-20 mA Loop Digitization
The AD7894BRZ-10REEL's bipolar -10 V to +10 V input range directly digitizes 4-20 mA current-loop voltages when paired with a 250 ohm sense resistor (giving 1-5 V), eliminating external signal-conditioning amplifiers. Its 200 kSPS throughput captures the 4 kHz Nyquist bandwidth required for closed-loop process control, while its -40 C to +85 C industrial operating range handles factory-floor temperatures. The serial interface is also easy to galvanically isolate through low-cost digital optocouplers, providing 1.5 kV field-side isolation in the same BOM cost as a typical PLC analog front-end.
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Motor Control Current/Voltage Feedback
Three-phase motor drives require ADC feedback of phase currents up to 25 kHz, well within the 200 kSPS capability of the AD7894BRZ-10REEL. With its bipolar -10 V to +10 V input window, the part directly digitizes shunt-resistor voltages (typically +/- 100 mV) after a small gain stage, simplifying PCB layout by reducing analog signal-chain components. The 14-bit resolution provides high dynamic-range feedback for FOC algorithms, and the SOIC-8 footprint is small enough to sit adjacent to each phase leg of a compact motor-drive PCB.
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Instrumentation & Sensor Digitization
The AD7894BRZ-10REEL's bipolar input and 14-bit resolution suit precision instrumentation designs digitizing strain-gauge bridges, load cells, and thermocouple-amplified signals. Its on-chip track-and-hold simplifies high-impedance source handling, and the serial interface avoids bus contention in multi-channel data-acquisition modules where multiple ADCs share an SPI bus via individual RFS lines. Designers appreciate the deterministic 4.5 microsecond conversion time for synchronous sampling schemes across multiple converter banks.
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Data Acquisition Front End / Portable Measurement
When a system requires up to 200 kHz per-channel sampling with 14-bit precision, the AD7894BRZ-10REEL provides a compact SOIC-8 footprint solution in a single +5 V rail. Its on-chip clock eliminates external crystal or oscillator components, saving BOM cost in portable measurement devices, while the serial interface reduces PCB trace count. Designers pair it with a low-power host MCU such as an MSP430 to implement low-power battery-data-loggers; the bipolar input window accepts both differential transducer outputs and single-ended sensor signals without reconfiguration.
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Audio Signal Processing / Precision DC Measurement
Although optimized for DC-style industrial signals, the AD7894BRZ-10REEL's 200 kSPS throughput covers the full audio band (Nyquist to 100 kHz), and Analog Devices specifies harmonic distortion and SNR for audio-frequency input content. The part is therefore also used in precision audio-metering applications such as broadcast-level measurement and transducer-loop test equipment. Its bipolar input accepts balanced audio up to 7 Vrms without external attenuation, simplifying the front end.
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Power Quality / Energy Metering
In three-phase power-quality analyzers, the AD7894BRZ-10REEL digitizes voltage and current waveforms at 200 kSPS with 14-bit accuracy, supporting IEC 61000-4-30 Class A measurement of voltage dips, swells, and harmonics. Its bipolar input accommodates the +/- 300 V scaled-down mains voltage when routed through a 30:1 divider plus a bias shift, and its serial interface simplifies multi-unit synchronization to a single host processor. The industrial temperature rating handles smart-meter outdoor enclosures from -40 C to +85 C.
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추천 제품 요약
엔지니어링 참조 데이터: AD7894BRZ-10REEL — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | AD7894BRZ-10REEL7 | AD7894BRZ-10 | AD7894ARZ-10REEL | AD7894BRZ-3REEL |
|---|---|---|---|---|---|
| Package | SOIC-8 (150 mil, R-8) | SOIC-8 (150 mil) | SOIC-8 (150 mil) | SOIC-8 (150 mil) | SOIC-8 (150 mil) |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 14 bits | 14 bits | 14 bits | 14 bits | 14 bits |
| Sampling Rate | 200 kSPS | 200 kSPS | 200 kSPS | 200 kSPS | 200 kSPS |
| Analog Input Range | -10 V to +10 V bipolar | -10 V to +10 V bipolar | -10 V to +10 V bipolar | -10 V to +10 V bipolar | 0 V to +2.5 V unipolar |
| Conversion Time | 4.5 us | 4.5 us | 4.5 us | 4.5 us | 4.5 us |
| Output Interface | Serial (SPI-compatible) | Serial (SPI-compatible) | Serial (SPI-compatible) | Serial (SPI-compatible) | Serial (SPI-compatible) |
| Packaging | Tape & Reel (2500 pcs) | Tape & Reel (7-inch) | Tray | Tape & Reel | Tape & Reel |
주요 차별점
- Bipolar -10 V to +10 V input without external signal conditioning (vs AD7894BRZ-3REEL (0 V to +2.5 V unipolar))
- 200 kSPS throughput with on-chip track/hold and clock (vs AD7890ARZ-10REEL (~100 kSPS, 8-channel))
- Industry-standard SOIC-8 footprint and SPI-compatible serial interface (vs Other 14-bit SAR ADCs with parallel/byte-wide interfaces)
설계 노트
Decouple the +5 V supply (pin 2) with a 10 microfarad tantalum capacitor and a 0.1 microfarade ceramic capacitor placed within 5 mm of the device. The AD7894 datasheet specifies decoupling requirements and recommends placing the capacitors between VDD and GND with minimum trace inductance.
When driving the analog input (pin 8), ensure the source impedance is less than 1 kohm to avoid throughput-dependent gain error. For higher-impedance sources (such as a strain-gage bridge above 1 kohm), buffer the input with a low-offset amplifier like the AD8021. Add a small RC network (typically 50 ohms + 1 nF) at the ADC input pin to absorb amplifier switching kickback.
The serial interface lines (SCLK, RFS, SDATA) should be routed as short, matched-length traces (< 25 mm) to avoid reflections. Place the AD7894 close to the host MCU or DSP to minimize digital coupling. Keep digital return currents (from serial line transients) physically separated from the analog ground return path around the VIN pin using a star-ground or wide-trace split plane.
규정 준수 정보
Z suffix on the MPN denotes RoHS-compliant lead-free terminal finish. Not AEC-Q100 qualified; the AD7894 family is targeted at industrial process control rather than automotive.
