Analog Devices Inc./Maxim Integrated MAX146AEAP+T

Overview

MAX146AEAP+T 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 shutdown current as low as 1µA - ideal for portable data loggers and battery-powered medical instruments.

For engineers reviewing the MAX146AEAP+T datasheet, MAX146AEAP+T pinout, MAX146AEAP+T application, or MAX146AEAP+T equivalent, key selection criteria include its 12-bit resolution with ±0.5 LSB INL, 2.25MHz small-signal bandwidth, 1.5µs acquisition time, internal reference stability (±30 ppm/°C), and SSOP-20 package compatibility with space-constrained embedded systems.

Technical Context

The MAX146AEAP+T uses successive-approximation architecture with an on-chip track/hold circuit that acquires input signals over three SCLK cycles and holds during conversion. Its pseudo-differential sampling allows flexible channel pairing (e.g., CH0/CH1, CH2/CH3) while maintaining stable COM reference within ±0.5 LSB.

It supports dual clock modes: internal clock (programmed via PD1/PD0 = 10) or external serial clock (PD1/PD0 = 11), with conversion timing fully synchronized to SCLK falling edges. The 4-wire serial interface requires no external logic for SPI/QSPI/MICROWIRE interfacing and includes SSTRB strobe for TMS320-family DSP synchronization.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and AD7490BRUZ, MAX146AEAP+T uniquely combines internal reference, bipolar/single-ended configurability, SSTRB strobe, and 2.7V operation in SSOP-20 - making it optimal for space- and power-constrained portable instrumentation where signal flexibility matters more than raw speed or channel count.

Availability

MAX146AEAP+T is available at Aetrix Electronics and suitable for portable data logging, battery-powered medical instruments, and industrial process monitoring requiring stable component supply and long-term obsolescence support.

Supply support for MAX146AEAP+T 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 leader in precision analog, mixed-signal, and power management ICs, serving industrial, medical, and communications markets since 1983.

The MAX146AEAP+T belongs to Maxim's low-power, high-accuracy data-acquisition product line, designed specifically for portable and energy-conscious systems needing integrated signal conditioning without sacrificing resolution or interface simplicity.

FAQ

What is the operating temperature range for MAX146AEAP+T?

The MAX146AEAP+T is specified for 0°C to +70°C ambient operation, matching the 'A' grade temperature rating. This range covers commercial and industrial indoor applications including handheld test equipment and portable medical monitors. Its internal reference maintains ±30 ppm/°C drift across this span, ensuring stable full-scale accuracy without external calibration. The SSOP-20 package supports reflow soldering per JEDEC J-STD-020 standards.

Does MAX146AEAP+T support differential input mode, and how is it configured?

Yes, MAX146AEAP+T supports 4-channel differential input mode (CH0/CH1, CH2/CH3, CH4/CH5, CH6/CH7) via the SGL/DIF bit (bit 2) in the 8-bit control byte. When SGL/DIF = 0, the ADC performs pseudo-differential sampling where IN− is held stable at COM, and only IN+ is actively sampled. This architecture reduces component count versus true differential ADCs while preserving channel matching - critical for applications like bridge sensor readout where common-mode rejection is needed but full differential drivers are impractical.

How does the internal reference of MAX146AEAP+T differ from the MAX147 variant?

MAX146AEAP+T integrates a factory-trimmed 2.500V ±0.8% internal reference buffer with ±1.5% external adjustment via REFADJ, eliminating need for external reference components. In contrast, the MAX147 requires an external reference applied to VREF and lacks internal buffering - making MAX146AEAP+T the preferred choice for cost-sensitive, space-constrained designs where reference integration reduces BOM count and improves long-term stability without external trimming.

Can MAX146AEAP+T be interfaced directly with a TMS320C54x DSP?

Yes, MAX146AEAP+T supports direct connection to TMS320-family DSPs via its SSTRB (serial strobe) output, which pulses high for one SCLK period before the MSB is clocked out - enabling precise frame synchronization without additional logic. The 4-wire SPI-compatible interface (DIN, DOUT, SCLK, CS) matches standard McBSP or HPI configurations. No level-shifting is required for 3.3V TMS320 devices, and the 2MHz max SCLK aligns with typical C54x serial port timing budgets.

What is the minimum acquisition time for MAX146AEAP+T, and how does source impedance affect it?

The guaranteed minimum acquisition time (tACQ) for MAX146AEAP+T is 1.5µs, calculated as tACQ = 9 × (RS + RIN) × 16pF, where RIN = 9kΩ and RS is the analog source impedance. For RS ≤1kΩ, tACQ remains near 1.5µs with negligible AC performance impact. Higher source impedances require longer acquisition intervals or local 0.01µF input capacitors to maintain accuracy - a design consideration explicitly called out in the datasheet to prevent hold-mode droop and code-dependent errors.