Analog Devices Inc./Maxim Integrated MAX1112CAP

Overview

MAX1112CAP from Maxim Integrated is an 8-bit, 8-channel successive-approximation analog-to-digital converter (ADC) with integrated track/hold, 4.096V internal reference, SPI/QSPI/MICROWIRE-compatible serial interface, and software-configurable unipolar/bipolar and single-ended/differential input modes. It operates from a single 4.5V–5.5V supply, draws 135µA at 50ksps, and targets portable data logging and hand-held measurement systems.

For engineers reviewing the MAX1112CAP datasheet, MAX1112CAP pinout, MAX1112CAP application, or MAX1112CAP equivalent, this page delivers verified electrical specs, package mapping to 20-pin SSOP, confirmed timing behavior (e.g., 25µs conversion time in internal clock mode), real-world acquisition constraints (t_ACQ ≥ 1µs), and validated alternative options for low-power, multi-channel 8-bit ADC selection.

Technical Context

The MAX1112CAP implements a capacitive DAC-based successive-approximation architecture with an internal track/hold circuit that acquires input signals over two SCLK cycles before conversion. Its analog front-end supports pseudo-differential sampling via configurable channel pairs (CH0/CH1, CH2/CH3, etc.) and requires stable COM reference within ±0.5 LSB.

Conversion timing is governed by either internal clock (25µs typical conversion time, SSTRB active-low pulse) or external serial clock (500kHz max, 10 clocks/conversion). The 4-wire serial interface uses MSB-first, falling-edge data output (DOUT) and rising-edge data input (DIN), with CS-controlled three-state outputs and SSTRB as end-of-conversion strobe.

Key Specifications

Pinout & Package

The MAX1112CAP is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, JEDEC MO-153 compliant, and specified for 0°C to +70°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit multi-channel ADC applications.

Compared with ADS7822U and MAX1110CAP, the MAX1112CAP uniquely combines 8 analog inputs, integrated track/hold, internal reference, and software-configurable modes in a single 20-pin SSOP-reducing component count and layout complexity for portable and diagnostic systems requiring ≥4 channels.

Availability

MAX1112CAP is available at Aetrix Electronics and suitable for portable data logging, hand-held instrumentation, and industrial diagnostics requiring stable component supply, long-term lifecycle support, and guaranteed 0°C to +70°C performance.

Supply support for MAX1112CAP 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 consumer applications.

The MAX1112CAP belongs to Maxim's precision low-power ADC product line, designed specifically for battery-operated and space-constrained systems needing integrated signal conditioning, minimal external components, and flexible input configuration.

FAQ

What is the maximum sampling rate of the MAX1112CAP, and under what conditions is it achieved?

The MAX1112CAP achieves a maximum sampling rate of 50ksps when using the external clock mode with a 500kHz SCLK and 10 clocks per conversion cycle. This requires strict adherence to the 45–55% duty cycle specification for SCLK and proper bypassing of REFOUT with a 1µF capacitor. At this rate, supply current is 135µA, and acquisition time must be ≥1µs. The MAX1112CAP cannot exceed 50ksps due to internal SAR timing constraints.

How does the MAX1112CAP handle differential input configurations, and which channel pairs are supported?

The MAX1112CAP supports pseudo-differential input via four fixed channel pairs: CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7. In differential mode, the positive input (IN+) is sampled while the negative input (IN−) serves as a stable reference; IN− must remain within ±0.5 LSB of AGND. Configuration is controlled by bits SGL/DIF and SEL[2:0] in the 8-bit control byte, with Tables 1a/1b in the datasheet defining valid combinations for the MAX1112CAP.

Can the MAX1112CAP operate with an external reference, and what is the acceptable voltage range?

Yes, the MAX1112CAP accepts an external reference voltage applied to the REFIN pin over the range of 1V to VDD (4.5V–5.5V). When using an external reference, the internal 4.096V reference is disabled, and full-scale input range becomes equal to the applied reference voltage. The device maintains ±1 LSB total unadjusted error across this range, and REFIN must be low-noise and stable to ensure accuracy-no additional buffering is required.

What is the function of the SHDN pin on the MAX1112CAP, and what are its three logic states?

The SHDN pin on the MAX1112CAP provides three-level shutdown control: open-circuit (high-impedance) enables normal operation; connection to DGND reduces supply current to ≤10µA; connection to VDD disables the internal reference while keeping digital logic active. This flexibility allows selective power gating-e.g., disabling the reference during sleep while retaining register state-without requiring a full reset sequence upon wake-up.

Does the MAX1112CAP require external passive components for stable operation, and if so, which ones?

Yes, the MAX1112CAP requires three mandatory external components: a 0.1µF ceramic capacitor and a 1µF tantalum or ceramic capacitor from VDD to AGND (placed as close as possible to the pins), and a 1µF capacitor from REFOUT to AGND. These ensure stable power delivery, low-noise reference generation, and 0.5 LSB settling of the 4.096V reference. Omitting the REFOUT capacitor degrades DC accuracy and increases conversion noise beyond datasheet specifications.