Analog Devices Inc./Maxim Integrated MAX318CPA+

Overview

MAX318CPA+ from Maxim Integrated is a precision CMOS single-pole single-throw (SPST) analog switch with normally open (NO) configuration, 35Ω maximum on-resistance, <10pC charge injection, and ±2000V ESD rating. It operates from ±4.5V to ±20V bipolar or +10V to +30V single supply, enabling rail-to-rail signal switching in test equipment and military radios.

For engineers reviewing the MAX318CPA+ datasheet, MAX318CPA+ pinout, MAX318CPA+ application, or MAX318CPA+ equivalent, key selection criteria include guaranteed on-resistance matching (<2Ω), leakage current (<6nA at +85°C), fast switching (t_ON <175ns), and 8-pin plastic DIP package compatibility with legacy through-hole layouts.

Technical Context

The MAX318CPA+ uses Maxim's silicon-gate CMOS process to achieve low distortion and high channel isolation. Its SPST NO topology provides unidirectional signal path control with TTL/CMOS-compatible logic input (IN) referenced to VL, while COM, NO, V+, V−, and GND define the analog signal path and dual-supply interface.

Operation requires independent analog (V+/V−) and logic (VL) supplies; V− must be connected to ground for single-supply use. The device guarantees flat on-resistance (∆3Ω max) and matched R_ON between channels only under bipolar-supply conditions, with off-isolation of 68dB at 1MHz.

Key Specifications

Pinout & Package

MAX318CPA+ is housed in an 8-pin plastic DIP (dual in-line package) with 0.300-inch width, compatible with standard through-hole PCB assembly and socketing. Pin 1 is COM (analog common terminal); pin 2 is N.C. (no internal connection); pin 3 is GND (logic ground); pin 4 is V+ (positive analog supply); pin 5 is VL (logic supply); pin 6 is IN (digital control input); pin 7 is V− (negative analog supply); pin 8 is NO (normally open analog terminal).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog switch applications.

Compared with ADG1419BRZ and TS5A23157DGSR, the MAX318CPA+ uniquely combines 8-pin DIP packaging, ±44V breakdown, bipolar/single-supply flexibility, and guaranteed parameter matching - making it irreplaceable in legacy military, test, and industrial analog signal routing where layout stability and voltage headroom are mandatory.

Availability

MAX318CPA+ is available at Aetrix Electronics and suitable for test equipment, military radios, sample-and-hold circuits, and battery-powered systems requiring stable component supply, long-term obsolescence management, and through-hole manufacturing compatibility.

Supply support for MAX318CPA+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and defense applications.

The MAX317/MAX318/MAX319 family was designed specifically for precision analog signal routing in environments demanding low distortion, high reliability, and wide supply voltage tolerance - targeting military, aerospace, and automated test equipment markets.

FAQ

What is the maximum allowable supply voltage for MAX318CPA+?

The MAX318CPA+ has an absolute maximum V+ to V− rating of +44V. Operation beyond this risks permanent damage. For reliable long-term use, bipolar supplies should stay within ±4.5V to ±20V, and single supplies within +10V to +30V. Exceeding these ranges degrades on-resistance flatness and increases leakage - verified in the Electrical Characteristics tables on pages 2–4 of the MAX318CPA+ datasheet.

Does MAX318CPA+ support single-supply operation?

Yes, MAX318CPA+ supports single-supply operation from +10V to +30V. In this mode, V− must be tied to ground, and VL should be set to +5V for TTL compatibility or to V+ for CMOS logic levels. Note that on-resistance matching and flatness specifications are guaranteed only under bipolar-supply conditions, as stated in Note 4 of the datasheet's Electrical Characteristics section.

What is the function of pin 2 (N.C.) on MAX318CPA+?

Pin 2 on MAX318CPA+ is labeled N.C. (No Connect) and is not internally bonded - it serves no electrical function. The datasheet explicitly states "N.C. = No Connect" and warns against connecting this pin to any net, including ground or supply rails. Leaving it unconnected avoids parasitic coupling and ensures compliance with the device's validated thermal and electrical performance.

How does charge injection affect MAX318CPA+ performance in sample-and-hold circuits?

MAX318CPA+ guarantees ≤10pC charge injection, directly limiting voltage error on hold capacitors. For example, with a 10nF capacitor, 10pC injection causes only 1mV step error - critical for maintaining 12-bit+ accuracy. This value is measured per Figure 5 in the datasheet and remains stable across temperature and supply voltage, making MAX318CPA+ suitable for precision acquisition stages where hold-step fidelity is essential.

Is MAX318CPA+ pin-compatible with other devices in the MAX317/MAX318/MAX319 family?

Yes, MAX318CPA+ shares identical pinout and package with MAX317CPA+ and MAX319CPA+ (all 8-pin DIP). However, internal switch configuration differs: MAX317CPA+ is NC, MAX318CPA+ is NO, and MAX319CPA+ is SPDT. Swapping them requires logic inversion or circuit redesign - they are footprint-compatible but not functionally interchangeable without validation.