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 integral nonlinearity 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 electrical parameters, SSOP-20 package mapping, SPI/QSPI/MICROWIRE-compatible interface behavior, and real-world design implications for low-power, multi-channel signal acquisition systems.

Technical Context

The MAX148BCAP implements a successive-approximation register (SAR) architecture with integrated track/hold circuitry, supporting both internal clock mode (1.8MHz typical) and external clock mode (up to 2.0MHz), enabling flexible timing control without external logic. Its analog front-end allows channel selection via 3-bit address plus SGL/DIF and UNI/BIP configuration bits in an 8-bit control byte.

It features a reference-buffer amplifier with ±1.5% voltage-adjustment range at REFADJ, requiring external reference (VREF = 2.500V applied), and supports power-down modes yielding 1µA shutdown current. The 4-wire serial interface drives DOUT on SCLK falling edge and provides SSTRB strobe synchronized to conversion start/end.

Key Specifications

Pinout & Package

MAX148BCAP is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm pitch, JEDEC MO-153 compliant, footprint compatible with industry-standard 20-lead SSOP layouts and reflow soldering profiles.

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 internal reference simplicity for external reference precision and lower quiescent current in reference buffer path; versus ADS7822U, it offers wider supply range, bipolar/differential configurability, and better low-voltage performance at the cost of 2-bit resolution.

Availability

MAX148BCAP is available at Aetrix Electronics and suitable for portable data logging, battery-powered medical devices, and industrial process monitoring requiring stable component supply, long-term lifecycle assurance, 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) designs precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX148/MAX149 product line targets low-power, multi-channel data acquisition in space- and energy-constrained systems, emphasizing flexible input configuration, serial interface compatibility, and robust performance across extended temperature ranges.

FAQ

What is the reference configuration requirement for MAX148BCAP?

MAX148BCAP requires an external 2.500V reference applied to the VREF pin. The internal reference buffer must be disabled by tying REFADJ to VDD. This configuration ensures optimal INL performance and avoids reliance on internal reference drift, making MAX148BCAP suitable for ratiometric or high-stability measurement systems where external reference accuracy dominates overall error budget.

Does MAX148BCAP support differential input mode, and how is it configured?

Yes, MAX148BCAP supports pseudo-differential input mode across four channel pairs: CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7. Configuration is performed via the 3-bit SEL field and SGL/DIF bit (bit 2) in the 8-bit control byte. In differential mode, the device samples the voltage difference while maintaining stability on the IN– input within ±0.5 LSB relative to AGND - achieved using a 0.1µF capacitor from selected IN– channel to AGND.

What are the power-down capabilities of MAX148BCAP, and how is shutdown initiated?

MAX148BCAP offers full power-down (1µA typical) and fast power-down (not applicable - MAX149 only). Shutdown is initiated either by pulling SHDN pin low or by programming PD1/PD0 = 00 in the control byte. Accessing the serial interface automatically powers up the device, and its quick turn-on time enables cycling between conversions to reduce average supply current - critical for battery-operated MAX148BCAP implementations.

Which microcontroller interfaces are directly compatible with MAX148BCAP's serial interface?

MAX148BCAP's 4-wire serial interface is directly compatible with SPI (CPOL = 0, CPHA = 0), QSPI, and MICROWIRE controllers without external logic. It accepts control bytes on DIN at SCLK rising edge and outputs conversion results on DOUT at SCLK falling edge. The SSTRB strobe provides hardware synchronization for DMA-triggered reads, and CS enables standard chip-select arbitration in multi-peripheral systems using MAX148BCAP.

How does the track/hold acquisition time affect signal source impedance in MAX148BCAP designs?

MAX148BCAP specifies a maximum acquisition time (tACQ) of 1.5µs, calculated as tACQ = 7 × (RS + 9kΩ) × 16pF. For source impedances ≤4kΩ, tACQ remains near minimum and AC performance is unaffected. Above 4kΩ, acquisition time increases linearly - requiring longer inter-conversion delays or addition of a 0.01µF capacitor at each analog input to maintain accuracy, as confirmed in the MAX148BCAP datasheet Figure 4 and Table 1.