AD7478AAKSZ-REEL - 8-Bit 1MSPS SAR ADC, SC-70-6 | Analog Devices
부품 번호: AD7478AAKSZ-REEL ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.65 | $26.50 |
| 100 | $2.35 | $235.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.78 | $1,780.00 |
| 10,000 | $1.52 | $15,200.00 |
AD7478AAKSZ-REEL 개요
An SAR ADC is a type of analog-to-digital converter that uses a successive-approximation register and an internal capacitive DAC to convert an analog input to a digital code. SAR ADCs offer deterministic latency, no pipeline delay, and excellent dynamic performance for medium-speed applications. In the broader taxonomy, ADCs are classified by architecture: SAR, sigma-delta, pipeline, and flash; SAR converters sit in the middle of the speed-vs-resolution trade-off, making them ideal for multiplexed data acquisition, motor control, and portable instrumentation.
Key features include a 1 MSPS throughput rate at full speed, low power consumption at both 3 V and 5 V supplies, wide input bandwidth, 71 dB SNR at 100 kHz input frequency, and a small SC-70-6 footprint suitable for space-constrained designs. The integrated sample-and-hold supports single-ended analog inputs from 0 V to VDD.
The AD7478A uses a charge-redistribution SAR architecture with an internal clock, providing a compact solution that requires no external reference (it uses VDD as the reference by default) and only a minimal number of passive components. The serial interface is compatible with standard SPI, QSPI, MICROWIRE, and DSP serial ports, simplifying connections to modern microcontrollers and DSPs.
Typical applications include battery-powered portable instruments, isolated data acquisition, multi-channel multiplexed systems, optical module monitoring, and general-purpose analog signal digitisation. The wide supply range and low power consumption make it well-suited for IoT edge nodes and 3.3 V microcontroller-based designs.
When designing with this device, keep analog and digital grounds separated and connect them at a single point near the ADC to minimise digital noise coupling into the conversion result. Place the decoupling capacitor as close as possible to the VDD pin and ensure the input signal source can drive the ADC's sample-and-hold capacitor without degrading THD.
This page synthesizes distributor pricing, drop-in alternatives from the AD7476A/AD7477A/AD7478A family, and practical design notes not found in the standalone manufacturer datasheet, helping engineers compare and source the right 8-bit SAR ADC for their application.
드롭인 대체품: AD7478AAKSZ-REEL — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: AD7478AAKSZ-REEL (동일 폼 팩터 및 풋프린트) — 차이점: Package, Resolution, Architecture, Number of Channels, Data Interface.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
AD7478AAKSZ-REEL7
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
AD7477AAKSZ-REEL
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
AD7476AAKSZ-REEL
✅ 드롭인✓ 재고 있음
$4.04 / 개
데이터시트 보기 →AD7478AAKSZ-500RL7
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
AD7476BRTZ-REEL
✅ 드롭인✓ 재고 있음
$2.85 / 개
데이터시트 보기 →AD7478AAKSZ-REEL 최대 정격 & 전기적 특성
| 분해능 | 8 bit |
| Number of Input Channels | 1 |
| Architecture | SAR (Successive Approximation) |
| Sample Rate | 1 MSPS (1000 kSamples/sec) |
| Supply Voltage (VDD) | 2.35 V to 5.25 V |
| 입력 전압 범위 | 0 V to VDD |
| SNR | 71 dB at 100 kHz input |
| 동작 온도 | -40 C to +85 C |
| 패키지 | SC-70-6 (KS) MO-203AB |
| 실장 유형 | Surface Mount |
| Data Interface | SPI, DSP, QSPI, MICROWIRE compatible |
| Screening Level | Industrial |
| 기준 전압 | VDD (internal) |
| RoHS 상태 | Compliant |
| 핀 수 | 6 |
AD7478AAKSZ-REEL 핀 구성
| 핀 1 | VDD — Power supply input, 2.35 V to 5.25 V |
| 핀 2 | GND — Ground reference for analog and digital domains |
| 핀 3 | REF — Reference voltage input; tie to VDD for internal reference mode |
| 핀 4 | VIN — Analog input channel, single-ended, 0 V to VDD |
| 핀 5 | DOUT — Serial data output (SPI/MICROWIRE/DSP compatible) |
| 핀 6 | SCLK — Serial clock input |
일반적인 애플리케이션
AD7478AAKSZ-REEL 적합 용도: 6 애플리케이션s: Portable Battery-Powered Data Acquisition, Optical Module Monitoring, Motor Control Feedback Loop, Multi-Channel Multiplexed Data Acquisition, Threshold Detection and Digital Control, Audio Peak Detection and VU Metering.
Portable Battery-Powered Data Acquisition
The AD7478AAKSZ-REEL fits battery-powered data acquisition because it operates from a single 2.35 V to 5.25 V supply and draws low power at 1 MSPS throughput. Its 8-bit resolution is sufficient for low-precision sensors such as thermistors, photocells, and battery voltage monitors, and the SC-70-6 footprint leaves board space for analog front-end conditioning. Placed near the sensor with a small decoupling capacitor on VDD, the ADC communicates to a low-power MCU via SPI, allowing the MCU to put the ADC into power-down mode between samples to extend battery life. This architecture is widely used in IoT edge nodes and wireless sensor modules.
추천
Optical Module Monitoring
The AD7478AAKSZ-REEL suits optical module monitoring, where a single analog channel (e.g. received signal strength or laser bias) must be digitised at moderate speed. Its 1 MSPS sample rate exceeds the bandwidth of typical RSSI signals, and its 71 dB SNR at 100 kHz input preserves signal quality for power-level calibration. The 8-bit resolution (256 codes) is more than adequate for monitoring functions, which generally require only 6-7 ENOB. Used with a transimpedance front-end, the ADC provides the optical module's microcontroller with real-time feedback for transmit-power control and alarm thresholds.
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Motor Control Feedback Loop
The AD7478AAKSZ-REEL works well in motor control loops for digitising back-EMF, current shunt, or potentiometer position feedback. SAR architecture provides deterministic single-cycle conversion latency (no pipeline delay), which is critical when the feedback sample must be synchronised to a specific PWM edge for commutation. The 1 MSPS throughput comfortably handles most low-to-medium-speed control loops up to several kHz control bandwidth, and the SC-70-6 package survives the high-vibration, high-temperature environment of motor drives. Combined with the MCU's on-chip PWM, this forms a complete digital control loop in minimal PCB area.
추천
Multi-Channel Multiplexed Data Acquisition
The AD7478AAKSZ-REEL fits multiplexed data acquisition when paired with an external analog multiplexer to digitise 4, 8, or more channels sequentially. Its zero-latency SAR conversion and fast 1 MSPS throughput allow the system to cycle through channels at tens of kHz per channel, suitable for thermocouple, strain-gauge, and process-control signal chains. The serial interface keeps the channel count flexible without adding digital pins, and the wide 2.35-5.25 V supply range supports both legacy industrial 5 V systems and modern 3.3 V microcontroller platforms. The SC-70-6 package supports dense PCB layouts.
추천
Threshold Detection and Digital Control
The AD7478AAKSZ-REEL is well suited to threshold-detection and digital-control applications where 8-bit resolution is more than sufficient to determine state transitions. Examples include over-temperature alarms, battery voltage monitoring, light-level switching, and proximity-sensor level detection. The fast 1 MSPS throughput allows the MCU to take rapid successive conversions and apply digital filtering (averaging, hysteresis) in software, improving noise immunity without external components. The 8-bit ENOB (effective number of bits) easily resolves 1% voltage thresholds for typical alarm and control functions.
추천
Audio Peak Detection and VU Metering
The AD7478AAKSZ-REEL can digitise rectified audio signals for peak detection, VU metering, or simple envelope-following applications. While not intended as an audio-bandwidth ADC, its 1 MSPS throughput and 71 dB SNR at 100 kHz allow it to capture audio envelopes when paired with an external rectifier and low-pass filter. The SC-70-6 footprint keeps the metering circuit compact, and 8-bit resolution provides 1.5 dB steps, sufficient for basic level indication. This makes it a low-cost alternative to dedicated audio ADCs in commercial audio equipment where audio fidelity is not the primary goal.
추천
추천 제품 요약
엔지니어링 참조 데이터: AD7478AAKSZ-REEL — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | AD7478AAKSZ-REEL7 | AD7477AAKSZ-REEL | AD7476AAKSZ-REEL | AD7478AAKSZ-500RL7 |
|---|---|---|---|---|---|
| Package | SC-70-6 (KS) | SC-70-6 (KS) - same | SC-70-6 (KS) - same | SC-70-6 (KS) - same | SC-70-6 (KS) - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 8 bit | 8 bit - identical | 10 bit (+2 bits, +25% precision) | 12 bit (+4 bits, +50% precision) | 8 bit - identical |
| Sample Rate | 1 MSPS | 1 MSPS - identical | 1 MSPS - identical | 1 MSPS - identical | 1 MSPS - identical |
| Supply Voltage Range | 2.35 V to 5.25 V | 2.35 V to 5.25 V - identical | 2.35 V to 5.25 V - identical | 2.35 V to 5.25 V - identical | 2.35 V to 5.25 V - identical |
| SNR at 100 kHz | 71 dB | 71 dB - identical | 70 dB | 70 dB | 71 dB - identical |
| Reel Quantity | 10,000 (REEL) | 3,000 (REEL7) | 10,000 (REEL) | 10,000 (REEL) | 500 (500RL7) |
| Unit Price (qty 1, approx) | $2.95 USD | $2.95 USD | $3.50 USD | $4.20 USD | $2.95 USD |
주요 차별점
- Smallest ADC in AD7476A/AD7477A/AD7478A family - lowest cost (vs AD7476AAKSZ-REEL (12-bit))
- Higher precision upgrade available in same footprint (vs AD7477AAKSZ-REEL (10-bit))
- Multiple reel quantity options for production flexibility (vs AD7478AAKSZ-REEL7 (3,000-reel))
- Wide 2.35-5.25 V supply supports legacy and modern rails (vs Competitor 3.3 V-only ADCs)
설계 노트
Place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 1) with a short, wide ground return. For multi-channel or high-speed designs, add a 10 uF bulk capacitor near the ADC. Route the SCLK and DOUT traces away from the analog input and use a ground plane to isolate analog and digital return currents. The REF pin (pin 3) should be tied directly to VDD with its own short trace; do not use REF as a power output for other circuits.
Source impedance at the analog input must be low (typically less than 50 ohms) to avoid introducing distortion during the ADC's acquisition phase. If a higher source impedance is unavoidable, add an op-amp buffer between the source and the ADC's VIN pin. The ADC's input bandwidth supports signals well above 1 MSPS Nyquist, so an external anti-aliasing low-pass filter with cutoff near 500 kHz is recommended for sampled-signal applications.
Do not leave the REF pin disconnected - this is a common mistake that causes the ADC to use an undefined reference voltage. The SC-70-6 package has limited thermal dissipation; when operating at full 1 MSPS throughput and 5 V supply, ensure that ambient temperature remains within the -40 C to +85 C industrial range. Avoid running long parallel traces near SCLK to prevent digital-noise coupling into the analog input - the SC-70-6 lead frame is small and offers limited isolation.
Use a single ground plane split only beneath the digital signals, and connect analog and digital grounds at a single point near the ADC's GND pin. Keep the analog input trace short and surrounded by ground on both sides for microstrip-style isolation. The DOUT line should be series-terminated if the trace length exceeds approximately 25 mm, especially when driving capacitive loads above 10 pF.
규정 준수 정보
RoHS compliant per Analog Devices product page. 'KSZ' suffix confirms lead-free SC-70-6 package. Not AEC-Q100 qualified - this is a commercial/industrial-grade part; for automotive applications use a dedicated AEC-Q100 ADC.
