Analog Devices Inc./Maxim Integrated MAX146AEAP

Overview

MAX146AEAP from Maxim Integrated is a 12-bit, 8-channel serial analog-to-digital converter (ADC) with integrated track/hold, software-configurable unipolar/bipolar and single-ended/differential inputs, internal 2.5V reference, and SPI/QSPI/MICROWIRE-compatible 4-wire serial interface. It operates from a single +2.7V to +3.6V supply, consumes 1.2mA at 133ksps, and supports portable data logging and battery-powered medical instrumentation.

For engineers reviewing the MAX146AEAP datasheet, MAX146AEAP pinout, MAX146AEAP application, or MAX146AEAP equivalent, key selection considerations include its internal reference accuracy (±0.5% initial, ±30ppm/°C), 1.5µs acquisition time, 12-bit no-missing-codes performance, and SSOP-20 package compatibility with space-constrained embedded sensor interfaces.

Technical Context

The MAX146AEAP uses successive-approximation architecture with an on-chip track/hold circuit that acquires input signals within 1.5µs and supports pseudo-differential sampling across eight analog inputs. Its serial interface operates in external clock mode (up to 2MHz SCLK) or internal clock mode, with control-byte–driven configuration of channel, polarity, and power-down state.

It features a hard-wired SHDN pin for three-level shutdown control (full power-down, fast power-down, or operational), automatic wake-up on serial access, and reference-buffer amplifier with ±1.5% REFADJ adjustment range. The device maintains ±0.5 LSB INL and ±0.5 LSB DNL over 0°C to +70°C, with 73dB SINAD and 90dB SFDR at 10kHz input.

Key Specifications

Pinout & Package

MAX146AEAP is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, optimized for compact PCB layouts in portable and medical devices.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit serial ADC applications.

Compared with ADS7822U and MAX11131ETE+, the MAX146AEAP uniquely combines internal reference, bipolar/differential configurability, and TMS320-compatible SSTRB output in a 20-pin SSOP - making it optimal for portable, low-power, multi-sensor systems requiring flexible analog front-end control.

Availability

MAX146AEAP is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered instruments requiring stable component supply with long-term industrial availability.

Supply support for MAX146AEAP 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 MAX146AEAP belongs to Maxim's precision data-acquisition product line, designed specifically for low-power, multi-channel, battery-operated measurement systems where integration, accuracy, and small footprint are critical.

FAQ

What is the operating temperature range for the MAX146AEAP?

The MAX146AEAP is specified for 0°C to +70°C ambient operation, as indicated by the "E" grade suffix in its ordering code. This commercial-grade temperature range aligns with its intended use in portable and non-military industrial equipment. The device maintains ±0.5 LSB INL and ±0.5 LSB DNL across this full range, with VREF drift limited to ±30ppm/°C. For extended temperature applications, engineers should consider the MAX146BCAP (-40°C to +85°C) variant instead of the MAX146AEAP.

Does the MAX146AEAP require an external reference voltage?

No, the MAX146AEAP does not require an external reference voltage because it integrates a precision 2.500V ±0.5% internal reference with ±1.5% adjustment range via the REFADJ pin. This internal reference is enabled by default and bypassed with a 4.7µF capacitor on the VREF pin. In contrast, the MAX147 variant requires an external reference. Using the internal reference simplifies layout, reduces BOM cost, and improves long-term stability - all confirmed in the MAX146AEAP's Electrical Characteristics table under "INTERNAL REFERENCE (MAX146 only)".

How many analog input channels does the MAX146AEAP support, and how are they configured?

The MAX146AEAP supports eight analog input channels (CH0–CH7), configurable either as eight single-ended inputs referenced to COM or as four differential pairs (CH0/CH1, CH2/CH3, CH4/CH5, CH6/CH7). Configuration is performed entirely in software via an 8-bit control byte written to DIN, with bits SGL/DIF (bit 2) and UNI/BIP (bit 3) selecting mode, and SEL2–SEL0 (bits 6–4) selecting channel. This flexibility is documented in Tables 2 and 3 of the MAX146AEAP datasheet and requires no hardware changes.

What serial interface protocols is the MAX146AEAP compatible with?

The MAX146AEAP supports SPI™, QSPI™, and MICROWIRE™ protocols through its 4-wire serial interface (CS, DIN, DOUT, SCLK), with additional TMS320-family DSP compatibility via the SSTRB strobe output. It operates with CPOL = 0 and CPHA = 0 for standard SPI, and supports clock frequencies up to 2MHz. The interface is electrically and timing-compatible - no protocol translation or external logic is required. This interoperability is explicitly verified in the "Features" section and Figure 6 timing diagram of the MAX146AEAP datasheet.

What power-saving modes does the MAX146AEAP offer, and how are they controlled?

The MAX146AEAP offers three power-saving states: full power-down (1µA), fast power-down (54µA), and active operation (1.2mA at 133ksps). These are controlled via the SHDN pin (hardware) and PD1/PD0 bits in the control byte (software). Pulling SHDN low forces full shutdown; letting it float enables fast wake-up; pulling it high configures reference buffer mode. Software power-down is triggered automatically after conversion when PD1/PD0 = 00. All modes are validated in the "Power Requirements" section and Figure 5 typical operating circuit.