Analog Devices Inc./Maxim Integrated MAX148BCAP+

Overview

MAX148BCAP+ from Maxim Integrated is a 10-bit, 8-channel serial analog-to-digital converter (ADC) with software-configurable unipolar/bipolar and single-ended/differential inputs, operating from +2.7V to +5.25V, achieving 133ksps sampling rate and ±1 LSB INL at 0°C to +70°C, used in portable data loggers and battery-powered medical instruments.

For engineers reviewing the MAX148BCAP+ datasheet, MAX148BCAP+ pinout, MAX148BCAP+ application, or MAX148BCAP+ equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated SSOP-20 pin functions, confirmed alternative parts with documented differences, and supply support for industrial embedded and low-power sensing designs.

Technical Context

The MAX148BCAP+ implements successive-approximation (SAR) architecture with integrated track/hold, supporting both internal clock mode (1.8MHz typical) and external serial clock mode (up to 2.0MHz). Its analog front-end allows flexible input configuration: 8 single-ended or 4 pseudo-differential channels, with COM pin serving as zero-reference in single-ended mode and common-mode node in differential mode.

It features a reference-buffer amplifier (gain = 2.00) requiring external VREF (1.0V to VDD+50mV), with REFADJ enabling ±1.5% voltage adjustment. The 4-wire SPI/QSPI/MICROWIRE-compatible interface operates with CS, SCLK, DIN, and DOUT, while SSTRB provides timing strobe for TMS320-family DSPs - all without external logic.

Key Specifications

Pinout & Package

MAX148BCAP+ is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, RoHS-compliant and lead-free, rated for 640mW continuous power dissipation at +70°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit, serial, multi-channel ADC applications.

Compared with MAX149BCAP+, MAX148BCAP+ trades integrated reference for external reference flexibility and tighter gain control; compared with ADS7822U, it offers true 8-channel multiplexing, bipolar support, and lower power at equivalent speed - making it superior for portable multi-sensor systems requiring design reuse and calibration headroom.

Availability

MAX148BCAP+ is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MAX148BCAP+ 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 precision analog, mixed-signal, and power-management ICs for industrial, medical, and communications applications.

The MAX148/MAX149 family was designed for low-power, multi-channel data acquisition in space- and energy-constrained systems - emphasizing flexible input configuration, minimal external components, and seamless microcontroller integration.

FAQ

What is the reference voltage requirement for MAX148BCAP+?

MAX148BCAP+ requires an external reference voltage applied to the VREF pin, ranging from 1.0V to VDD+50mV. It uses an internal reference buffer with 2.00× gain, so a 2.500V source yields a 5.000V effective reference at the ADC core. The REFADJ pin allows ±1.5% adjustment of the buffered reference, and must be tied to VDD to disable the buffer - essential for accurate operation with precision external references.

Does MAX148BCAP+ support differential input mode?

Yes, MAX148BCAP+ supports pseudo-differential input mode via software configuration. When SGL/DIF = 0 in the control byte, it measures the voltage difference between four predefined channel pairs: CH0–CH1, CH2–CH3, CH4–CH5, and CH6–CH7. The negative input (IN−) must remain stable within ±0.5 LSB relative to AGND during conversion - achieved by placing a 0.1µF capacitor from the selected IN− channel to AGND.

What is the maximum sampling rate of MAX148BCAP+ and how is it achieved?

MAX148BCAP+ achieves a maximum sampling rate of 133ksps using an external 2.0MHz serial clock in external clock mode, with 15 clock cycles per conversion. In internal clock mode, it operates at ~1.8MHz and still achieves 133ksps, but requires the SHDN pin unconnected. Conversion time is 5.5–7.5µs depending on SHDN state - enabling high-throughput data acquisition without sacrificing low-power operation.

How does the power-down functionality work on MAX148BCAP+?

MAX148BCAP+ offers three power-down states controlled by PD1/PD0 bits in the control byte: full power-down (1µA), fast power-down (not supported - MAX149 only), and internal/external clock modes. Full power-down halts all analog and digital circuitry except the SHDN detection logic. Accessing the serial interface automatically wakes the device, and quick turn-on (<10µs) allows powering down between every conversion - reducing average current to <60µA at reduced sampling rates.

Is MAX148BCAP+ pin-compatible with other devices in the MAX148/MAX149 family?

Yes, MAX148BCAP+ is pin-compatible with all MAX148 variants (e.g., MAX148ACAP+, MAX148BCPP+) and MAX149 variants in the same package type (SSOP-20 or PDIP-20). Pin functions, layout, and electrical characteristics are identical across grades; only performance parameters differ - e.g., MAX148ACAP+ has ±0.5 LSB INL vs. ±1 LSB for MAX148BCAP+, and MAX149 includes internal reference while MAX148 requires external reference.