MAX157ACUA - 10-Bit 108ksps 2-Ch SAR ADC | Maxim Integrated
부품 번호: MAX157ACUA ✗ 단종| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $6.92 | $6.92 |
| 10 | $6.18 | $61.80 |
| 100 | $5.42 | $542.00 |
| 500 | $4.78 | $2,390.00 |
| 1,000 | $4.15 | $4,150.00 |
MAX157ACUA 개요
An SAR ADC (Successive-Approximation Register Analog-to-Digital Converter) is a type of data converter that uses a binary search algorithm combined with an internal DAC to convert an analog input to a digital code, typically one sample at a time with no pipeline latency. SAR ADCs sit within the broader hierarchy of analog-to-digital converters, alongside delta-sigma, pipeline, and flash architectures; they are valued for low power consumption, deterministic latency, and good DC accuracy at moderate sampling rates, making them well-suited for instrumentation, sensor read-out, and embedded data-acquisition designs.
Key differentiating features of the MAX157ACUA include a 2-channel input mux (2 analog inputs selectable through software), an integrated +2.5V reference (factory-trimmed, with REF option on select variants), an external reference input for flexibility, low operating supply current, and hardware/software shutdown mode that drops the supply current to < 1 µA in standby. The wide 2.7V-5.25V supply range permits operation directly from a single-cell Li-ion battery or a 3.3V/5V regulated rail.
Architecturally, the MAX157ACUA employs a charge-redistribution DAC with a built-in sample-and-hold, controlled by an SAR logic core that produces 10-bit results over four internal clock cycles. The device supports both unipolar (0-VREF) and pseudo-bipolar (VREF/2 offset) input ranges when driven in two's-complement mode, providing flexibility for single-supply signal-chain applications.
Typical applications for the MAX157ACUA include portable data loggers, battery-powered sensor read-out boards, industrial process-control loops, panel meters, and embedded system front-ends where low power and small footprint matter more than extreme sampling speed. This page synthesizes distributor pricing, drop-in alternatives, and practical design guidance not found in the manufacturer datasheet alone.
When designing with this device, place a 0.1 µF decoupling capacitor close to the VDD pin and a 10 µF bypass on the reference output if the internal reference is used. Operating at the higher 5 V supply yields the best dynamic range, but always observe the absolute-maximum VDD rating from the datasheet.
드롭인 대체품: MAX157ACUA — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: MAX157ACUA (동일 폼 팩터 및 풋프린트).
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MAX157AEUA+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX157ACUA+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX157BCUA+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX157BEUA+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX157CCUA+
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
MAX157ACUA 최대 정격 & 전기적 특성
| 분해능 | 10 bits |
| 샘플링 속도 | 108 ksps |
| Number of Input Channels | 2 (single-ended) |
| Conversion Time | 7.4 us |
| Supply Voltage (VDD) | +2.7 V to +5.25 V |
| Supply Current (power-down) | < 1 uA |
| 기준 전압 | Internal +2.5 V (external reference option) |
| Input Voltage Range (unipolar) | 0 V to VREF |
| Data Interface | SPI / QSPI / MICROWIRE compatible, serial |
| 패키지 | 8-pin uMAX (UMAX) |
| 동작 온도 범위 | 0 C to +70 C (commercial, AC suffix) |
| 실장 유형 | Surface Mount |
| MSL 레벨 | 1 (unlimited floor life at <30 C / 85% RH) |
MAX157ACUA 핀 구성
| 핀 1 | AIN1 — Analog input channel 1 (single-ended) |
| 핀 2 | GND — Ground |
| 핀 3 | AIN2/REF- — Analog input channel 2 / reference negative |
| 핀 4 | REF/VREF — Internal +2.5V reference output or external reference input |
| 핀 5 | VDD — Positive supply, +2.7V to +5.25V |
| 핀 6 | DOUT — Serial data output (tri-state, SPI-compatible) |
| 핀 7 | CS/SHDN — Active-low chip select / shutdown (combined function) |
| 핀 8 | SCLK — Serial clock input (Schmitt trigger) |
일반적인 애플리케이션
MAX157ACUA 적합 용도: 6 애플리케이션s: Portable Data Logger, Industrial Process-Control Sensor Read-Out, Panel Meter / Digital Voltmeter Front-End, Embedded System Sensor Hub, Battery-Powered Medical Monitor, Consumer Touch-Panel Controller.
Portable Data Logger
The MAX157ACUA fits portable data loggers thanks to its 10-bit / 108 ksps throughput, 2-channel mux, and sub-1 uA power-down current. The Maxim datasheet cites automatic shutdown between conversions as the key power-saving feature for battery-driven designs. With a 3.6 V Li-ion supply the device draws only milliamps during conversion and drops to <1 uA in standby. Two ADC inputs can sample a sensor pair (temperature + pressure, for example) without external multiplexing. Pin-compatible and footprint-compatible with modern replacements, the MAX157ACUA remains a reference design choice for low-power logging.
추천
Industrial Process-Control Sensor Read-Out
The MAX157ACUA handles 4-20 mA or 0-10 V sensor signals through its 0-VREF input range and 2.7V-5.25V supply. In a typical 3.3V industrial loop, AIN1 samples a voltage-clamped transducer signal while AIN2 reads a reference, allowing software calibration. The integrated +2.5 V reference and external reference option simplify ratiometric or absolute measurements. The 8-pin uMAX package keeps the analog front-end within a 6 mm footprint, suitable for distributed I/O cards where each channel needs its own ADC.
추천
Panel Meter / Digital Voltmeter Front-End
The MAX157ACUA suits handheld DVMs and panel meters that need a 10-bit reading across two ranges (e.g., voltage and current). The internal +2.5 V reference of the MAX157ACUA establishes a 2.5 V full-scale that pairs naturally with a 4:1 resistive divider for a 10 V range. SPI/QSPI/MICROWIRE-compatible serial output reads as a 10-bit code, easily scaled in firmware to display voltage on an LCD. Low operating current and standby < 1 uA extend battery life in pocket meters.
추천
Embedded System Sensor Hub
The MAX157ACUA acts as a secondary ADC for microcontrollers lacking an internal SAR ADC or needing an extra channel. With SCLK, DOUT, and CS pins, the device mates directly to an MCU's SPI peripheral at speeds up to its 108 ksps maximum. Two analog inputs feed sensors (light, temperature, accelerometer analog outputs) into a 10-bit stream the MCU consumes without DMA overload. The 2.7V-5.25V range suits both 3.3V and 5V MCUs from PIC, AVR, STM32, and MAX32 families.
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Battery-Powered Medical Monitor
The MAX157ACUA is well suited to personal medical devices that monitor two vitals (e.g., SpO2 and respiration) from a single MCU. Battery life hinges on average current draw, and the MAX157ACUA's < 1 uA power-down mode means the ADC spends >99 percent of the time in standby between conversions. Operation from a 3 V primary cell is supported down to 2.7 V. The 8-pin uMAX footprint keeps the analog section under 5 mm square, ideal for wearable patches or wrist-worn monitors.
추천
Consumer Touch-Panel Controller
The MAX157ACUA reads 4-wire resistive touch-panel voltages on its two analog inputs while the host drives the panel through GPIO. The internal +2.5 V reference of the MAX157ACUA ensures stable measurements even as supply varies, and the 10-bit resolution yields touch coordinates with ~100 LSB per axis after a 2:1 resistive divider. The serial output goes to the panel's microcontroller over three wires (SCLK, DOUT, CS), saving pins versus parallel ADCs.
추천
추천 제품 요약
엔지니어링 참조 데이터: MAX157ACUA — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MAX157AEUA+ | MAX157ACUA+ | MAX157BCUA+ | MAX157BEUA+ | MAX157CCUA+ |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 8-uMAX | 8-uMAX (same) | 8-uMAX (same) | 8-uMAX (same) | 8-uMAX (same) | 8-uMAX (same) |
| Resolution | 10 bits | 10 bits | 10 bits | 10 bits | 10 bits | 10 bits |
| Sampling Rate | 108 ksps | 108 ksps | 108 ksps | 108 ksps | 108 ksps | 108 ksps |
| Number of Channels | 2 | 2 | 2 | 2 | 2 | 2 |
| Operating Temperature Range | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) |
| Supply Voltage | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V |
| Internal Reference | +2.5V | +2.5V | +2.5V | +2.5V | +2.5V | +2.5V |
| Serial Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
| RoHS Compliance | Depends on date code | Yes (lead-free finish) | Yes (lead-free finish) | Yes (lead-free finish) | Yes (lead-free finish) | Yes (lead-free finish) |
주요 차별점
- Wider operating temperature range (vs MAX157ACUA (base part))
- Lead-free and RoHS-compliant finishes (vs MAX157ACUA (original))
- Firmware-transparent pin-compatible replacement (vs MAX157AEUA / MAX157BCUA / MAX157BEUA / MAX157CCUA)
설계 노트
Estimated: At a 3.3V supply and a typical ADC operating current of about 1.5 mA active / < 1 uA power-down per the Maxim datasheet, the average current draw is dominated by the duty cycle of conversion. For a 1 ksps sample rate, averaging across time yields well under 100 uA average draw, making the MAX157ACUA compatible with coin-cell and primary-cell designs. Decouple VDD with a 0.1 uF ceramic capacitor placed within 5 mm of pin 5.
Use a star-ground or single-point ground tie for the ADC ground (pin 2) and the digital ground to avoid return-current disturbances from the SPI bus. Route DOUT traces away from analog input traces, and keep the reference bypass capacitor (typically 4.7 uF or 10 uF) close to the REF/VREF pin. Avoid running high-speed digital lines parallel to AIN traces; if you must, place a guard ground between them.
Per the Maxim datasheet, the CS/SHDN pin combines chip-select and shutdown functions. Driving this pin high (inactive) between conversions puts the device into power-down automatically; driving it low wakes the part for the next conversion. Some first-time users forget that CS must return high to start a new conversion. Also note: the input voltage should not exceed VDD+300mV or fall below -0.3V (ESD diodes), and VDD should never exceed +6.0V absolute max.
규정 준수 정보
Compliance status depends on date code of MAX157ACUA base part. The '+' suffix variants (MAX157ACUA+) are lead-free and RoHS-compliant per the Maxim datasheet. AEC-Q100 testing was not performed; the part is not automotive-qualified.
