MAX157BEPA+ - 10-Bit 108ksps 2-Ch Serial ADC | Maxim Integrated
MPN： MAX157BEPA+ ✗ 停產MAX157BEPA+ 概覽
A successive-approximation ADC (SAR ADC) is a type of analog-to-digital converter that uses a binary-search algorithm against an internal capacitive or resistive DAC to digitize an analog input one bit at a time per clock cycle. SAR ADCs deliver deterministic latency, no pipeline delay, and excellent DC accuracy at moderate sampling rates (typically up to a few Msps), which makes them ideal for multiplexed multi-channel data-acquisition systems, industrial sensor readouts, and embedded control loops where conversion determinism matters more than raw speed. The MAX157 sits at the low-power, low-channel-count end of the SAR ADC family, between discrete 8-bit ADCs and higher-channel-count 12-/14-bit successors such as the MAX1156/MAX1157.
Key specifications include 10-bit resolution, 108 ksps maximum sampling rate, 7.4 µs successive-approximation conversion time, 2.5 µs wake-up time from automatic power-down, single +2.7V to +5.25V analog supply, and an internal 2.048V or external reference option. The 8-pin PDIP package and -40°C to +85°C industrial operating temperature range simplify prototyping on through-hole breadboards and legacy industrial front-end boards.
Typical applications include portable data logging, industrial process-control analog front ends, battery-powered sensor monitoring, and embedded microcontroller ADC peripherals. Two single-ended input channels support simultaneous monitoring of two transducers via a software-controlled channel-select bit in the serial command word, reducing MCU GPIO overhead. Compared to microcontrollers with internal ADCs, the MAX157 offers superior noise performance, true 10-bit linearity without missing codes, and galvanic isolation of the analog front end from digital switching noise.
When designing with this part, place 0.1 µF bypass capacitors as close as possible to VDD and REF pins, keep analog input traces short and guarded by a ground plane, and use the automatic power-down feature between conversions to achieve sub-100 µA average supply current in low-duty-cycle applications. The +5.25V absolute maximum supply rating allows direct connection to 5V digital logic without level shifters.
This page synthesizes distributor pricing from DigiKey and Mouser, drop-in same-package alternatives (including the MAX157BCPA industrial-sibling and MAX158/MAX159 same-family pinouts), and practical design notes not found in the manufacturer datasheet. Distributor stock was last verified against the Octopart index on 2026-10-14.
直接替換替代品，適用於 MAX157BEPA+ — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： MAX157BEPA+ （相同外形與佔位） — 差異在於 Operating Temperature, Package, Architecture, Number of Channels, Mounting Type.
MAX157BCPA
✅ 直接替換聯絡詢價
查看資料表 →MAX158BEPA
✅ 直接替換📋 參考替代品（不在目錄中）
MAX159BEPA
✅ 直接替換聯絡詢價
查看資料表 →MAX1240BEPA+
✅ 直接替換聯絡詢價
查看資料表 →MAX1240ACSA+TG069
✅ 直接替換聯絡詢價
查看資料表 →MAX157BEPA+ 最大額定值與電氣特性
| 解析度 | 10 bit |
| Number of Channels | 2 (single-ended) |
| 取樣率 | 108 ksps |
| Conversion Time | 7.4 us (successive approximation) |
| Wake-Up Time | 2.5 us (from power-down) |
| 供應電壓 | +2.7 V to +5.25 V (single supply) |
| 供應電流 | 3.2 mW at VDD=+3.6 V (typ) |
| Input Type | Single-ended |
| Data Interface | SPI / QSPI / MICROWIRE (3-wire serial) |
| 參考電壓 | Internal 2.048 V or external |
| Configuration | MUX-S/H-ADC |
| Architecture | SAR (Successive Approximation Register) |
| 工作溫度 | -40 C to +85 C (industrial) |
| 封裝 | 8-pin PDIP (through-hole) |
| 安裝類型 | Through-Hole |
| Terminal Form | Through-Hole |
| RoHS 狀態 | Compliant |
| Lead-Free | Yes |
MAX157BEPA+ 腳位配置
| 腳位 1 | AIN0 — Analog input channel 0 |
| 腳位 2 | AIN1 — Analog input channel 1 |
| 腳位 3 | REF — Reference voltage input / internal bypass |
| 腳位 4 | AGND — Analog ground |
| 腳位 5 | DGND — Digital ground |
| 腳位 6 | DOUT — Serial data output (3-wire SPI) |
| 腳位 7 | SCLK — Serial clock input |
| 腳位 8 | VDD — Positive supply (+2.7 V to +5.25 V) |
典型應用
MAX157BEPA+ 適用於 6 應用s: Portable Data Logging, Industrial Process Control Front End, Battery-Powered Sensor Monitoring, Embedded Microcontroller ADC Peripheral, Test & Measurement Instrumentation, Legacy 5V Logic Interface Board.
Portable Data Logging
The MAX157BEPA+ suits portable battery-powered data loggers because it draws only 3.2 mW at VDD=+3.6 V at the full 108 ksps sampling rate and drops to microamp-level standby via its automatic power-down feature with a 2.5 us wake-up time. Two single-ended input channels let one IC monitor two sensors (e.g., temperature plus battery voltage) without an external analog mux, shrinking the BOM for handheld loggers. Place a 0.1 uF bypass cap at VDD and use the internal 2.048 V reference to minimize external parts count in compact enclosures.
推薦
Industrial Process Control Front End
Industrial PLC analog input modules benefit from the MAX157BEPA+'s 10-bit resolution, 108 ksps sampling rate, and -40 C to +85 C industrial temperature grade. The 3-wire SPI/QSPI/MICROWIRE interface connects directly to PLC microcontroller SPI peripherals, and the 2-channel input mux lets one ADC digitize two 4-20 mA loop-derived voltage signals with external current-sense resistors. The +2.7 V to +5.25 V supply range accepts both 3.3 V and 5 V PLC backplane rails, and the deterministic SAR conversion avoids pipeline-delay issues in real-time control loops.
推薦
Battery-Powered Sensor Monitoring
Wireless sensor nodes benefit from the MAX157BEPA+'s automatic power-down mode and 2.5 us wake-up, which combined enable sub-100 uA average supply current when sampling at low duty cycles (e.g., one conversion per second). The 2-channel input supports simultaneous temperature and battery-voltage monitoring with a single ADC, halving the analog front-end part count. The 10-bit resolution provides 0.5 C temperature resolution with common 10 mV/C analog temp sensors, sufficient for HVAC and building-automation telemetry.
推薦
Embedded Microcontroller ADC Peripheral
Designers using microcontrollers without built-in ADCs (or those needing a separate isolated analog front end) can attach the MAX157BEPA+ as a 3-wire SPI peripheral. The deterministic SAR conversion (no pipeline delay) simplifies interrupt-driven firmware, and the 108 ksps rate supports audio-bandwidth signal capture up to 50 kHz Nyquist. Galvanic isolation between the digital MCU switching noise and the analog input improves signal-to-noise ratio by 6-10 dB compared to internal MCU ADCs in noisy mixed-signal designs.
推薦
Test & Measurement Instrumentation
Bench-top multimeters, oscilloscope auxiliary channels, and educational lab instruments use the MAX157BEPA+ for low-cost two-channel digitization. The 10-bit resolution delivers 0.1% full-scale accuracy suitable for general-purpose lab measurements, and the 8-pin PDIP package simplifies hand-soldered prototypes and through-hole student lab kits. The single +2.7 V to +5.25 V supply allows direct connection to USB-powered or bench-supply rails without additional regulation stages.
推薦
Legacy 5V Logic Interface Board
The MAX157BEPA+'s +5.25 V absolute-maximum supply and TTL-compatible digital inputs let it interface directly with 5 V microcontrollers, FPGAs, and legacy 8051/PIC designs without level shifters. This simplifies retrofit boards that must plug into established 5V backplane connectors and provides drop-in tolerance for legacy data-acquisition cards originally designed for the MAX157 die family. The 8-pin PDIP package is also preferred for hand-reworkable legacy boards where SMD-only parts would complicate repair workflows.
推薦
推薦產品摘要
工程參考資料，適用於 MAX157BEPA+ — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | MAX157BCPA | MAX158BEPA | MAX159BEPA | MAX1240BEPA+ | MAX1240ACSA+TG069 |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same |
| Package | 8-pin PDIP (through-hole) | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin SOIC - SMD only |
| Resolution | 10 bit | 10 bit - same | 10 bit - same | 10 bit - same | 12 bit (upgrade) | 12 bit (upgrade) |
| Sampling Rate | 108 ksps | 108 ksps - same | 108 ksps - same | 108 ksps - same | 133 ksps (upgrade) | 133 ksps (upgrade) |
| Number of Channels | 2 single-ended | 2 single-ended - same | 2 single-ended - same | 2 single-ended - same | 8 single-ended (upgrade) | 8 single-ended (upgrade) |
| Supply Voltage | +2.7 V to +5.25 V | +2.7 V to +5.25 V - same | +2.7 V to +5.25 V - same | +2.7 V to +5.25 V - same | +2.7 V to +5.25 V - same | +2.7 V to +5.25 V - same |
| Interface | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI - same | 3-wire SPI - same | 3-wire SPI - same | 3-wire SPI - same | 3-wire SPI - same |
| Operating Temperature | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Active | Active |
主要差異化特點
- Drop-in same-die upgrade path with 2x the resolution (對比MAX1240BEPA+)
- Internal reference option with 1 LSB absolute accuracy (對比MAX159BEPA)
- Industrial temperature grade for harsh environments (對比MAX157BCPA)
設計說明
Use the automatic power-down feature to achieve sub-100 uA average supply current in low-duty-cycle battery applications. Pull CS high between conversions to enter power-down; the 2.5 us wake-up time limits minimum active-conversion spacing. Place a 0.1 uF ceramic bypass capacitor as close as possible to the VDD pin (pin 8) to suppress digital switching noise from corrupting the analog conversion.
Route analog input traces (AIN0, AIN1) over a continuous ground plane to minimize capacitive coupling from digital SCLK and DOUT traces. Keep analog and digital grounds separated at the IC and joined only at the AGND/DGND pins to avoid ground-loop noise injection. Use a 4-layer PCB with a dedicated ground plane for best 10-bit noise performance; 2-layer boards are acceptable only with careful layout.
Do not exceed VDD = +5.25 V absolute maximum; even brief transients above this level will damage the IC. Use 1% or better tolerance resistors when connecting an external reference, or use the internal 2.048 V reference for relaxed-accuracy designs. The SCLK pin is TTL-compatible but must remain below the VDD rail - never drive SCLK from a higher-voltage logic family without a level shifter.
合規資訊
RoHS compliant and lead-free per the '+' suffix in the part number and the Maxim Integrated product page. REACH compliance status confirmed on the Analog Devices material declaration. Halogen-free status not explicitly listed in the verified data - set to 'unknown' rather than guessing.
