MAX157BCPA - 10-Bit 108ksps 2-Ch Serial ADC | Maxim Integrated
MPN: MAX157BCPA ✗ Cuối đờiMAX157BCPA Tóm tắt
An SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a type of data converter that uses a binary-search algorithm and an internal capacitive DAC to resolve an analog input to N bits in N clock cycles. SAR ADCs sit within the broader data-converter family alongside flash, sigma-delta, and pipeline ADCs, and are valued for low power consumption, deterministic latency, and excellent DC accuracy - making them the standard choice for multiplexed low-frequency multi-channel measurement, instrumentation, and portable/battery-powered systems.
Key specifications include 108 ksps sampling rate, 7.4 µs successive-approximation conversion time, 2 analog input channels with channel-select input, ±1 LSB INL (max), and an 8-pin PDIP through-hole footprint. The MAX157 also features a dedicated shutdown pin that drops supply current to a few microamps between samples, which is critical for handheld or duty-cycled designs where average power dominates battery life.
Architecturally, the device uses a charge-redistribution capacitive DAC with an on-chip sample/hold, an internal 2.5 MHz oscillator for conversions, and a straight binary output code. The 3-wire serial interface (CS, SCLK, DOUT) allows direct connection to most microcontrollers and DSPs without glue logic, and the SPI/QSPI/MICROWIRE compatibility simplifies firmware porting from one host to another.
Typical applications include portable data loggers, battery-powered sensor read-out, pen-tablet digitizers, hand-held instruments, loop-powered 4-20 mA transmitters, and isolated multi-channel measurement front-ends. The wide +2.7V to +5.25V supply range supports both 3.3V and 5V MCU rails, and the two-channel mux allows dual-sensor sampling (e.g., temperature + pressure) with a single ADC.
When designing with the MAX157BCPA, ensure the analog input bandwidth (input RC) is limited appropriately for full-scale settling, and place 0.1 µF bypass capacitors close to the supply pin. Use the shutdown pin aggressively between conversions in low-duty-cycle applications - this is where the part earns its low-power reputation.
This page synthesizes distributor pricing, drop-in alternatives within the MAX157/MAX159 family, and practical design notes not collated in the manufacturer datasheet alone.
Bộ thay thế dễ dàng lắp đặt cho MAX157BCPA — 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 MAX157BCPA (cùng hình factor và footprint) — khác nhau ở Package, Operating Temperature, Architecture, Conversion Time, Number of Channels.
MAX157BCPA+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX159BCPA
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MAX159BCPA+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX157BCPA Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 10 bit |
| Number of Channels | 2 |
| Tỷ lệ lấy mẫu | 108 ksps |
| Conversion Time | 7.4 µs |
| Điện áp cung cấp | +2.7 V to +5.25 V |
| Supply Current (active at 3.6V) | 3.2 mW (typ) |
| Wake-Up Time | 2.5 µs |
| INL (max) | ±1 LSB |
| Architecture | SAR (Successive Approximation) |
| Giao diện | 3-wire SPI/QSPI/MICROWIRE-compatible serial |
| Shutdown Mode | Yes - auto power-down + SHDN pin |
| On-Chip Clock | Yes (internal oscillator) |
| Hộp | 8-pin PDIP |
| Kiểu lắp đặt | Through-Hole |
| Nhiệt độ hoạt động | 0°C to +70°C (commercial) |
| Trạng thái RoHS | Compliant (Pb-free '+' suffix versions) |
Cấu hình chân MAX157BCPA
| Chân 1 | AIN — Analog input (channel 1 / 2 selected by channel-select pin per MAX157/MAX159 datasheet) |
| Chân 2 | GND — Ground |
| Chân 3 | REF — External reference voltage input |
| Chân 4 | VDD — Positive supply, +2.7V to +5.25V |
| Chân 5 | DOUT — Serial data output (3-wire SPI/QSPI/MICROWIRE) |
| Chân 6 | SCLK — Serial clock input |
| Chân 7 | CS — Chip select (active low) |
| Chân 8 | SHDN — Shutdown control input (active high = shutdown) |
Ứng dụng tiêu biểu
MAX157BCPA phù hợp cho 7 Áp dụngs: Portable Data Loggers, Battery-Powered Sensor Read-Out, Hand-Held Instrumentation, Pen-Tablet / Digitizer Systems, Loop-Powered 4-20 mA Transmitters, Isolated Multi-Channel Measurement, Industrial Process Monitor.
Portable Data Loggers
The MAX157BCPA's 3.2 mW active power at 3.6V and automatic power-down between samples make it well suited to battery-powered multi-channel data loggers. With 108 ksps sampling and 10-bit resolution it is fast enough for vibration and temperature profiling while staying below the 5 mW budget of coin-cell designs. Place a 0.1 µF bypass on VDD and drive SHDN between conversions to drop average current below 100 µA at 1 kHz sample rate.
Được đề xuất
Battery-Powered Sensor Read-Out
The wide +2.7V to +5.25V supply of the MAX157BCPA lets it sit directly on a 3.3V or 5V MCU rail in handheld sensor modules. Its 2-channel input mux handles a sensor pair (e.g., temperature + humidity) with deterministic 7.4 µs conversion latency, ideal for time-stamped wireless telemetry packets. Combined with 2.5 µs wake-up, the part draws negligible current between samples, preserving battery life across long idle periods.
Được đề xuất
Hand-Held Instrumentation
The MAX157BCPA's small 8-pin PDIP footprint and integrated SPI/QSPI/MICROWIRE interface minimize MCU glue logic in handheld multimeters and probes. The 10-bit resolution is sufficient for bar-graph and digit-style readouts where 0.5% accuracy is acceptable, and the 108 ksps rate supports smooth auto-zero routines. Its ±1 LSB INL delivers consistent linearity across the operating temperature range required for laboratory-grade instruments.
Được đề xuất
Pen-Tablet / Digitizer Systems
The MAX157BCPA's 108 ksps throughput and dual-channel input make it a natural fit for digitizer pen-position read-out where a host MCU needs to sample two sensors at high rate. Its small 8-pin PDIP footprint simplifies hand-routed prototypes and its deterministic SAR latency simplifies stylus-timing calibration. The 3-wire serial interface shares an SPI bus with other peripherals without arbitration logic.
Được đề xuất
Loop-Powered 4-20 mA Transmitters
The MAX157BCPA's low 3.2 mW active consumption and single +2.7V supply make it well-suited to 4-20 mA loop-powered industrial transmitters where the entire sensor node must operate below 3.6 mA. Its automatic power-down keeps idle current below 100 µA so the loop's 3.6 mA budget can power the sensor, ADC, and a low-power MCU. Its robust SPI interface survives the long cable runs typical of industrial instrumentation.
Được đề xuất
Isolated Multi-Channel Measurement
The MAX157BCPA's serial interface minimizes the number of signals crossing an isolation barrier, a major cost saver in multi-channel isolated measurement modules. Only CS, SCLK, and DOUT must cross the isolator, and the ADC's deterministic SAR timing simplifies latency budgeting across the isolation latency. The +2.7V to +5.25V supply range lets the ADC run from either side of the barrier.
Được đề xuất
Industrial Process Monitor
The MAX157BCPA's deterministic SAR architecture and 108 ksps throughput let a process monitor digitize two transducer channels at fixed, predictable intervals - critical for closed-loop control loops. Its ±1 LSB INL provides repeatable linearity across the industrial temperature range, and its 3-wire SPI interface minimizes isolator cost when the front-end must be galvanically isolated from the controller.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MAX157BCPA — 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 | MAX157BCPA+ | MAX159BCPA | MAX159BCPA+ | MAX157BCUA | MAX159BCUA |
|---|---|---|---|---|---|---|
| Package | 8-pin PDIP | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin PDIP - same | 8-pin µMAX - different (SMD) | 8-pin µMAX - different (SMD) |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 10 bit | 10 bit | 10 bit | 10 bit | 10 bit | 10 bit |
| Sampling Rate | 108 ksps | 108 ksps | 108 ksps | 108 ksps | 108 ksps | 108 ksps |
| Number of Channels | 2 | 2 | 2 | 2 | 2 | 2 |
| 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 |
| Interface | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE |
| RoHS / Lead Finish | Tin-lead (non-RoHS) | Pb-free RoHS | Tin-lead (non-RoHS) | Pb-free RoHS | Pb-free RoHS | Pb-free RoHS |
| Lifecycle Status | Obsolete | Obsolete (RoHS variant) | Obsolete | Obsolete (RoHS variant) | Obsolete (SMD variant) | Obsolete (SMD variant) |
Bảo phân biệt quan trọng
- Pb-free RoHS upgrade without layout change (vsMAX157BCPA+)
- Same package, inverse channel-select for second-source flexibility (vsMAX159BCPA / MAX159BCPA+)
- Surface-mount option in same die family (vsMAX157BCUA / MAX159BCUA)
Ghi chú thiết kế
Drive the SHDN pin high between conversions to put the device into its few-microamp shutdown state; pull SHDN low only while CS is active or a conversion is in progress. According to the Maxim datasheet, this is how the part achieves its low average-current reputation in duty-cycled battery applications. A 0.1 µF ceramic bypass capacitor must be placed within 5 mm of the VDD pin to keep digital noise out of the analog reference.
The analog input pin should be driven from a low-impedance source with the input RC settled within the 7.4 µs acquisition window. Add an external RC if your sensor cannot settle in time, or oversample to average out the residual. Place REF bypass capacitor (typically 0.1 µF ceramic + 10 µF electrolytic) close to the REF pin - reference noise directly determines INL and DNL of the conversion result.
Do not drive SHDN high while CS is low or the conversion will be aborted and DOUT will return an invalid code per the Maxim MAX157/MAX159 datasheet. Also, do not operate below the 2.7 V minimum supply - the internal oscillator can mis-trigger at lower voltages and produce noisy conversions. When migrating from MAX157 to MAX159, remember that the channel-select logic is inverted; check the firmware if swapping between the two.
Thông tin tuân thủ
MAX157BCPA (without '+' suffix) is tin-lead finish and is non-RoHS. The '+' suffix variants MAX157BCPA+, MAX159BCPA+ are Pb-free and RoHS compliant. AEC-Q100 is not applicable for this commercial-grade part.