Analog Devices Inc./Maxim Integrated MAX157BCPA+

Overview

MAX157BCPA+ from Maxim Integrated is a low-power, 10-bit successive-approximation analog-to-digital converter (SAR ADC) with two single-ended input channels, 108ksps sampling rate, ±0.5 LSB differential nonlinearity, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface - designed for battery-powered instrumentation and portable data logging systems.

For engineers reviewing the MAX157BCPA+ datasheet, MAX157BCPA+ pinout, MAX157BCPA+ application, or MAX157BCPA+ equivalent, key selection criteria include its 2.7V–5.25V single-supply operation, 0.9mA active current at 108ksps, 2.5µs wake-up time from shutdown, internal track/hold, and 8-pin plastic DIP package with 0°C to +70°C temperature range.

Technical Context

The MAX157BCPA+ implements a SAR architecture with integrated track/hold, enabling precise sampling of single-ended analog inputs (CH0 and CH1) referenced to GND. It supports both internal clock mode (laser-trimmed ~2MHz oscillator) and external clock mode (100kHz–2.17MHz), with conversion initiated on CS/SHDN falling edge.

Its analog front-end features 16pF input capacitance, 9kΩ input resistance, and internal protection diodes allowing input swing from GND−300mV to VDD+300mV. The 3-wire serial interface outputs 16-bit frames including EOC bit, channel ID, 10-bit data (MSB-first), and two sub-LSB bits, with DOUT transitioning on SCLK falling edge.

Key Specifications

Pinout & Package

MAX157BCPA+ is housed in an 8-pin plastic DIP package (0.300" wide), suitable for through-hole prototyping and industrial PCB assembly. Pin spacing complies with JEDEC MS-001 standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with MAX144ACPA+ and ADS7822U, the MAX157BCPA+ offers optimal balance of low power (0.9mA), fast wake-up (2.5µs), integrated track/hold, and proven reliability in battery-critical portable instrumentation - making it preferred for cost-sensitive, space-constrained, and ultra-low-power dual-channel applications.

Availability

MAX157BCPA+ is available at Aetrix Electronics and suitable for battery-powered data loggers, medical patient monitors, industrial process sensors, and portable test equipment requiring stable component supply across extended production lifecycles.

Supply support for MAX157BCPA+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The MAX157/MAX159 family was engineered for ultra-low-power, space-constrained data acquisition - delivering 10-bit precision with integrated serial interface and shutdown in sub-20mm² packages for portable and remote sensing systems.

FAQ

What is the operating temperature range for MAX157BCPA+?

The MAX157BCPA+ is specified for 0°C to +70°C ambient operation. This commercial-grade temperature range aligns with its plastic DIP packaging and targets applications such as portable instruments, consumer test gear, and non-military industrial controls where extended thermal extremes are not required. Full electrical performance - including ±0.5 LSB DNL and 108ksps sampling - is guaranteed across this range.

Does MAX157BCPA+ require an external reference voltage?

Yes, MAX157BCPA+ requires an external reference voltage applied to the REF pin. The device accepts 0V to (VDD + 50mV), with typical use at 2.5V. A 0.1µF ceramic capacitor must be placed directly at the REF pin for stability. The reference must source up to 250µA DC current during conversion and exhibit ≤10Ω output impedance to maintain specified INL and gain error performance.

How does the MAX157BCPA+ handle channel selection between CH0 and CH1?

The MAX157BCPA+ automatically alternates between CH0 and CH1 after each conversion when CS/SHDN is toggled. Following power-on reset, CH0 is sampled first; subsequent conversions cycle CH0 → CH1 → CH0. To sample only one channel, tie CH0 and CH1 together - though the output stream retains the channel ID bit. Channel selection is hardware-controlled via CS/SHDN edge timing, requiring no register writes or configuration overhead.

What is the wake-up time from shutdown for MAX157BCPA+?

The MAX157BCPA+ wakes up from shutdown in 2.5µs after CS/SHDN falls, assuming the external reference is stable within 1 LSB. If the reference requires additional settling time, the wake-up interval must be extended accordingly. This fast recovery enables burst-mode sampling strategies - for example, waking every 1ms to acquire 10 samples at 108ksps before returning to shutdown - minimizing average current draw.

Is MAX157BCPA+ compatible with standard SPI microcontrollers?

Yes, MAX157BCPA+ is fully compatible with standard SPI interfaces when configured with CPOL = 0 and CPHA = 0. It supports 100kHz–2.17MHz SCLK in external clock mode and outputs a 16-bit frame (EOC + CHID + 10-bit data + 2 sub-LSB bits) MSB-first on DOUT, with data valid on the falling edge of SCLK. No special timing adjustments or glue logic are needed for integration with PIC, ARM, or MSP430 microcontrollers.