Analog Devices Inc./Maxim Integrated MAX148BEAP

Overview

MAX148BEAP 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, sampling at up to 133ksps, and featuring internal track/hold, SPI/QSPI/MICROWIRE-compatible 4-wire interface, and programmable power-down - used in portable data loggers and battery-powered medical instruments.

For engineers reviewing the MAX148BEAP datasheet, MAX148BEAP pinout, MAX148BEAP application, or MAX148BEAP equivalent, this page delivers verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternative parts with functional distinctions, and supply support for industrial embedded and low-power sensing systems.

Technical Context

The MAX148BEAP implements successive-approximation (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 across microcontroller interfaces. Its analog front-end allows channel selection via 3-bit address (CH0–CH7), configurable input polarity (unipolar/bipolar), and input topology (single-ended or pseudo-differential).

It uses a reference-buffer amplifier with ±1.5% adjustment range at REFADJ, requiring external VREF (2.500V typical) - unlike the MAX149 which integrates a 2.5V reference. The device supports full power-down (≤1µA) and fast power-down (not applicable to MAX148), with automatic wake-on-CS assertion and sub-µs acquisition time (1.5µs typical).

Key Specifications

Pinout & Package

MAX148BEAP is housed in a 20-pin plastic SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, JEDEC MO-153 compliant, suitable for automated SMT assembly and moderate-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX148BEAP, MAX149BCAP removes external reference dependency while retaining full compatibility, whereas ADS7822U trades configurability for higher resolution - making MAX148BEAP optimal for adaptable, trimmable, low-power 10-bit systems.

Availability

MAX148BEAP is available at Aetrix Electronics and suitable for portable data logging, battery-powered medical instruments, and industrial process monitoring requiring stable component supply, long-lifecycle availability, and consistent parametric performance across production batches.

Supply support for MAX148BEAP 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 MAX148BEAP belongs to Maxim's precision data-acquisition product line, designed specifically for low-power, multi-channel, serial-interface ADC applications in space- and energy-constrained embedded systems.

FAQ

What is the maximum sampling rate of the MAX148BEAP?

The MAX148BEAP achieves a maximum sampling rate of 133ksps when using an external 2.0MHz clock and 15 clock cycles per conversion. This rate is maintained across its full operating temperature range (0°C to +70°C) and supply range (+2.7V to +5.25V). At lower clock frequencies or in internal clock mode, the effective throughput decreases accordingly - for example, internal clock mode yields ~130ksps typical. The MAX148BEAP datasheet specifies tCONV ≤ 7.5µs (internal clock) and ≤6µs (external clock), confirming this performance ceiling.

Does the MAX148BEAP include an internal voltage reference?

No, the MAX148BEAP does not include an internal voltage reference. It requires an external 2.500V reference applied to the VREF pin, with input current of 100–150µA and input resistance of 18–25kΩ. The internal reference buffer must be disabled by tying REFADJ to VDD. This distinguishes it from the pin-compatible MAX149, which integrates a 2.5V reference with ±30ppm/°C temperature coefficient. The MAX148BEAP's external-reference architecture enables system-level calibration via the REFADJ pin's ±1.5% adjustment range.

What package type is used for the MAX148BEAP?

The MAX148BEAP is supplied in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, designated by the "AP" suffix in the part number. This surface-mount package measures 7.2mm × 5.3mm and complies with JEDEC MO-153 standards. It is distinct from the through-hole 20-pin plastic DIP ("PP") variants like MAX148BCPP. The SSOP offers superior thermal performance and board-space efficiency compared to DIP, and is fully compatible with standard reflow soldering processes.

How does the MAX148BEAP handle analog input protection?

The MAX148BEAP includes internal clamping diodes that protect analog inputs (CH0–CH7, COM) from voltages between AGND − 0.3V and VDD + 0.3V, preventing damage during overvoltage events. However, for accurate conversions near full scale, inputs must remain within AGND + 50mV to VDD − 50mV. Exceeding these limits risks forward-biasing protection diodes on inactive channels, which must be limited to <2mA. To enhance robustness, designers should add external series resistors and RC filters - especially when source impedance exceeds 4kΩ, as acquisition time degrades linearly with RS per tACQ = 7 × (RS + 9kΩ) × 16pF.

Can the MAX148BEAP operate in differential input mode?

Yes, the MAX148BEAP supports pseudo-differential input mode via software configuration. Setting SGL/DIF = 0 in the 8-bit control byte selects differential operation, pairing CH0/CH1, CH2/CH3, CH4/CH5, or CH6/CH7. In this mode, only the positive input (IN+) is actively sampled; the negative input (IN−) must remain stable to ±0.5 LSB relative to AGND during conversion. A 0.1µF capacitor from IN− to AGND is recommended to maintain stability. Differential mode provides common-mode rejection but does not offer true fully differential input architecture - it is functionally equivalent to measuring |IN+ − IN−| with COM referenced to IN−.