Analog Devices Inc./Maxim Integrated MAX188DEPP

Overview

MAX188DEPP from Maxim Integrated is a 12-bit, 8-channel serial analog-to-digital converter (ADC) with software-configurable unipolar/bipolar and single-ended/differential inputs, internal track/hold, and SPI/QSPI/MICROWIRE-compatible 4-wire serial interface. It operates from a single +5V or dual ±5V supply and achieves 133ksps sampling rate with 1.5mA operating current and <10µA power-down current. It is used in portable data loggers and battery-powered instrumentation requiring precision, low power, and compact integration.

For engineers reviewing the MAX188DEPP datasheet, MAX188DEPP pinout, MAX188DEPP application, or MAX188DEPP equivalent, key selection considerations include external reference dependency (4.096V), 20-pin PDIP package, 12-bit resolution with ±1.0 LSB relative accuracy, bipolar input support down to –VREF/2, and compatibility with TMS320 DSPs via SSTRB strobe output.

Technical Context

The MAX188DEPP implements successive-approximation (SAR) conversion with an integrated track/hold circuit enabling 1.5µs acquisition time and 4.5MHz small-signal bandwidth. Its analog front-end supports pseudo-differential sampling across eight channels, with channel selection and input mode (unipolar/bipolar, single-ended/differential) fully controlled via an 8-bit serial command byte.

It uses either an internal clock (1.7–10MHz) or external serial clock (up to 4MHz in internal-clock mode, beyond 4MHz when using internal clock) for conversion timing. The device requires an external 4.096V reference applied at VREF and includes a reference-buffer amplifier with REFADJ input for gain adjustment (1.638×REFADJ), distinguishing it from the internally referenced MAX186.

Key Specifications

Pinout & Package

MAX188DEPP is housed in a 20-pin plastic DIP (PDIP) package with 0.3-inch body width and through-hole mounting. Pin spacing is 0.1 inch; lead finish is lead(Pb)-free/RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX186DEPP, MAX188DEPP trades internal reference convenience for external reference flexibility and gain trim via REFADJ; compared with ADS7822U, it offers TMS320 strobe support and superior channel crosstalk (–85dB vs typical –70dB), at the cost of larger PDIP packaging.

Availability

MAX188DEPP is available at Aetrix Electronics and suitable for portable instrumentation, medical devices, and industrial process monitoring requiring stable component supply, long-term lifecycle support, and RoHS-compliant through-hole assembly.

Supply support for MAX188DEPP 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 systems.

The MAX186/MAX188 product line was designed for low-power, high-accuracy data acquisition in space- and energy-constrained environments-emphasizing integrated track/hold, flexible serial interfacing, and robust analog front-end performance.

FAQ

What reference voltage does the MAX188DEPP require?

The MAX188DEPP requires an external 4.096V reference applied to the VREF pin. Unlike the MAX186DEPP, it lacks an internal reference. The device includes a reference-buffer amplifier with REFADJ input, allowing gain adjustment (1.638×REFADJ) for precision scaling. A 4.7µF capacitor is recommended at VREF for external compensation mode to ensure stability during conversion.

How does the MAX188DEPP handle differential input configurations?

The MAX188DEPP supports pseudo-differential inputs using four channel pairs: CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7. In differential mode, only the positive input (IN+) is actively sampled; the negative input (IN–) must remain stable within ±0.5LSB of AGND. This is achieved by placing a 0.1µF capacitor from the selected IN– channel to AGND. The control byte's SGL/DIF bit selects this mode, and Tables 3–4 define valid channel mappings.

What are the power-down modes available on the MAX188DEPP?

The MAX188DEPP provides two software-selectable power-down modes via bits PD1/PD0 in the control byte: fast power-down (30µA typical) and full power-down (≤10µA). Additionally, the SHDN pin offers hardware-controlled shutdown (<10µA). All modes retain register state and allow immediate wake-up on CS assertion or serial activity-enabling per-conversion power gating without reinitialization overhead.

Can the MAX188DEPP interface directly with TMS320 DSPs?

Yes, the MAX188DEPP features a dedicated SSTRB (serial strobe) output that directly interfaces with TMS320 family digital signal processors. In internal clock mode, SSTRB goes low at conversion start and high upon completion; in external clock mode, it pulses high for one clock period before the MSB appears on DOUT. This eliminates polling or timer-based synchronization, enabling deterministic real-time data capture in DSP-based control loops.

What is the maximum sampling rate and associated timing constraint for the MAX188DEPP?

The MAX188DEPP achieves a maximum sampling rate of 133ksps with a 2MHz external clock and 15 clock cycles per conversion. Total conversion time must not exceed 120µs to prevent track/hold droop-induced error. When using the internal clock, conversion completes within 10µs, and SCLK may run up to 10MHz for data readout-decoupling conversion timing from serial interface speed and improving system-level timing predictability.