Analog Devices Inc./Maxim Integrated MAX3100CPD+

Overview

MAX3100CPD+ from Maxim Integrated is a SPI/MICROWIRE-compatible universal asynchronous receiver/transmitter (UART) optimized for microcontroller-based systems. It integrates an on-chip crystal oscillator, 8-word FIFO, software-programmable baud-rate generator (300–230 kbaud), IrDA timing mode, and shutdown current of 10 µA. It drives opto-couplers directly via TX/RTS outputs (25 mA sink) and supports RS-232/RS-485/IR isolated links in handheld instrumentation and building control networks.

For engineers reviewing the MAX3100CPD+ datasheet, MAX3100CPD+ pinout, MAX3100CPD+ application, or MAX3100CPD+ equivalent, this page delivers verified technical context, real-world interface constraints (e.g., Schmitt-trigger inputs, open-drain IRQ), power behavior across temperature, and validated alternatives for UART-in-SPI system design.

Technical Context

The MAX3100CPD+ implements a full UART core with independent transmit/receive shift registers, 16× oversampling for start-bit detection, and majority-sampled data recovery. Its baud-rate generator uses B0–B3 bits to select 16 division ratios, enabling precise rates from 300 to 230 kbaud with 1.8432 MHz or 3.6864 MHz crystals.

It features dual shutdown modes-hardware (SHDN pin) and software (SHDNi bit)-both disabling the oscillator while preserving register access and enabling RX activity wake-up. The interrupt logic supports four maskable sources (R, T, PM, RAM), with IRQ asserted low and open-drain output compatible with 5 V or 3.3 V µC systems.

Key Specifications

Pinout & Package

MAX3100CPD+ is housed in a 14-pin plastic DIP package rated for 0°C to +70°C operation. Pin functions are electrically identical to the QSOP variant but mapped to DIP layout per Maxim's ordering table.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar UART bridging applications.

Compared with SC16IS750IPW and TL16C550CP, the MAX3100CPD+ uniquely combines sub-10 µA shutdown, direct opto-coupler drive, and IrDA SIR timing in a 14-pin DIP-making it the only choice for battery-operated handheld tools and space-constrained isolated UART bridges.

Availability

MAX3100CPD+ is available at Aetrix Electronics and suitable for handheld instrumentation, intelligent building control systems, and isolated RS-232/RS-485 interfaces requiring stable component supply across commercial temperature range (0°C to +70°C).

Supply support for MAX3100CPD+ 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) designs precision analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The MAX3100 product line delivers SPI/MICROWIRE-compatible UARTs optimized for microcontroller-based systems with tight power and board-space constraints-enabling robust serial connectivity in portable and isolated equipment.

FAQ

What is the operating temperature range for MAX3100CPD+?

The MAX3100CPD+ is specified for commercial temperature operation from 0°C to +70°C. This range aligns with its "C" grade suffix and makes it suitable for indoor instrumentation, consumer-grade test equipment, and non-automotive embedded systems where ambient thermal stress is moderate. It does not support extended industrial (-40°C to +85°C) operation like the MAX3100EPD+ variant.

Does MAX3100CPD+ require an external crystal to operate?

Yes, the MAX3100CPD+ requires either a 1.8432 MHz or 3.6864 MHz crystal connected between X1 and X2 pins for accurate baud-rate generation. Alternatively, an external square-wave clock (45–55% duty cycle) can be applied to X1 with X2 left unconnected. No internal RC oscillator is present-the crystal or external clock is mandatory for UART timing.

Can MAX3100CPD+ drive RS-232 line drivers directly?

No, MAX3100CPD+ outputs are CMOS-level (0 V to VCC) and cannot meet RS-232 voltage requirements (±3 V to ±15 V). However, it directly drives opto-couplers (e.g., 6N136) and RS-485 transceivers via RTS/TE control. For true RS-232, a level-shifter such as MAX3222 or MAX232 must be used between MAX3100CPD+ TX/RX and the connector.

How does the MAX3100CPD+ handle wake-up from shutdown mode?

The MAX3100CPD+ wakes from shutdown upon any transition on the RX pin, setting the RA (receive activity) bit and asserting IRQ if RAM is enabled. This occurs even with the oscillator disabled, allowing ultra-low-power monitoring of serial bus activity. The wake-up event is latched until cleared by reading the RA/FE register or exiting shutdown.

What is the maximum SPI clock frequency supported by MAX3100CPD+?

The MAX3100CPD+ supports SPI clock (SCLK) frequencies up to 10 MHz, as confirmed by timing parameters tCL (100 ns min), tCH (100 ns min), and tCP (238 ns min). At 10 MHz, setup/hold times are met with typical PCB routing; for robust operation across voltage/temperature, 8 MHz is recommended in production designs.