Analog Devices Inc./Maxim Integrated MAX1112CPP+

Overview

MAX1112CPP+ 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 only 135µA at 50ksps, and delivers ±1 LSB total unadjusted error over temperature. It is used in portable data loggers and hand-held measurement devices requiring low-power, multi-channel signal digitization.

For engineers reviewing the MAX1112CPP+ datasheet, MAX1112CPP+ pinout, MAX1112CPP+ application, or MAX1112CPP+ equivalent, key selection considerations include its 8-channel single-ended / 4-channel differential input flexibility, 50ksps sampling rate with internal clock, 1µs minimum acquisition time, 1.5MHz small-signal bandwidth, and 20-pin SSOP package compatibility with space-constrained embedded systems.

Technical Context

The MAX1112CPP+ implements a capacitive DAC-based successive-approximation architecture with an internal track/hold circuit that acquires input signals in ≤1µs and holds them during conversion. Its analog front-end supports pseudo-differential sampling via channel-pair selection (CH0/CH1, CH2/CH3, etc.) and configurable common-mode reference (COM) for bipolar operation.

Conversion timing is governed by either the internal 400kHz clock or an external serial clock up to 500kHz (external mode) or 2MHz (internal mode). The 8-bit control byte-programmed via DIN-configures channel selection, input polarity, single-ended/differential mode, and power-down state, enabling full software control without external logic.

Key Specifications

Pinout & Package

The MAX1112CPP+ is housed in a 20-pin shrink small-outline package (SSOP) 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 8-bit multi-channel ADC applications.

Compared with ADS7822U and TLV2548IPW, the MAX1112CPP+ uniquely combines 8-channel flexibility, bipolar input capability, integrated 4.096V reference, and ultra-low 13µA shutdown current - making it optimal for battery-constrained, multi-sensor systems needing configurability without external support components.

Availability

MAX1112CPP+ is available at Aetrix Electronics and suitable for portable data logging, hand-held instrumentation, and solar-powered remote sensing requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MAX1112CPP+ 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 MAX1112CPP+ belongs to Maxim's precision data-acquisition product line, designed specifically for low-power, multi-channel digitization in space- and energy-constrained embedded systems where integration, accuracy, and ease of interface are critical.

FAQ

What is the maximum sampling rate achievable with the MAX1112CPP+?

The MAX1112CPP+ achieves up to 50ksps when using the internal clock or an external serial clock of 500kHz in external clock mode. In internal clock mode, the conversion completes in 25µs (typ), allowing the host processor to read results at its own pace - up to 2MHz serial clock rate - while maintaining full 8-bit accuracy. The MAX1112CPP+ does not support rates beyond 50ksps due to SAR architecture and internal timing constraints.

Does the MAX1112CPP+ support true differential input mode?

The MAX1112CPP+ implements pseudo-differential input mode: it samples the voltage difference between two selected channels (e.g., CH0 and CH1), but only the positive input (IN+) is actively tracked; the negative input (IN−) must remain stable within ±0.5 LSB relative to AGND. It does not provide fully isolated differential input stages like dedicated delta-sigma ADCs, but this architecture enables effective noise rejection in bridge and sensor applications when properly decoupled.

Can the MAX1112CPP+ operate with a 3.3V supply?

No, the MAX1112CPP+ requires a minimum supply voltage of 4.5V and operates only within the 4.5V to 5.5V range. Attempting to power it from 3.3V will result in improper internal reference generation, failed conversions, and undefined behavior on digital outputs. For 3.3V systems, a level-shifting supply or alternative ADC such as the ADS7822U (2.7–5.25V) should be considered instead of the MAX1112CPP+.

How is bipolar operation implemented on the MAX1112CPP+?

Bipolar operation on the MAX1112CPP+ is achieved by setting the COM pin to VREFIN/2 (i.e., 2.048V) and selecting the bipolar mode bit (UNI/BIP = 0) in the 8-bit control byte. This configures the full-scale range to ±2.048V, with output codes in two's-complement format. The internal 4.096V reference remains active, and COM must be driven by a low-impedance source stable to ±0.5 LSB to maintain accuracy - typically using a precision resistor divider buffered by an op-amp.

What is the purpose of the SSTRB pin on the MAX1112CPP+?

The SSTRB (Serial Strobe) pin on the MAX1112CPP+ provides hardware notification of conversion completion: in internal clock mode, it asserts low for ~25µs during conversion and goes high upon completion; in external clock mode, it pulses high for two SCLK periods before the MSB appears on DOUT. This signal enables interrupt-driven firmware handling, eliminating polling overhead and ensuring precise timing alignment between conversion end and data readout in the MAX1112CPP+.