Analog Devices Inc./Maxim Integrated MAX14778EETP+T

Overview

MAX14778EETP+T from Maxim Integrated is a dual ±25V above- and below-the-rails 4:1 analog multiplexer IC supporting bidirectional signal switching up to ±25V with a single 3.0–5.5V supply, 1.5Ω max on-resistance, 75MHz bandwidth, and ±6kV HBM ESD protection on A_/B_ pins - deployed in RS-485/USB 1.1 connector-sharing systems.

For engineers reviewing the MAX14778EETP+T datasheet, MAX14778EETP+T pinout, MAX14778EETP+T application, or MAX14778EETP+T equivalent, this page delivers verified electrical parameters, thermal limits, break-before-make timing (840µs), leakage specs (±250nA off-leakage), and real-world multiprotocol interface use cases without generic assumptions.

Technical Context

The MAX14778EETP+T integrates three charge pumps (5V regulated, +35V, –27V) to enable ±25V rail-to-rail analog operation from a single 3.0–5.5V supply; VDD > 4.64V disables the 5V pump to reduce supply current. It implements independent digital control for each 4:1 mux via SA0/SA1/ENA and SB0/SB1/ENB, with break-before-make switching enforced by internal logic.

Each channel supports ±300mA continuous bidirectional current, 78pF input capacitance, and maintains ≤3mΩ on-resistance flatness across –25V to +25V common-mode range. Off-isolation exceeds –80dB at 100kHz, crosstalk is –103dB, and THD+N is 0.003% (20Hz–20kHz), confirming high-fidelity analog routing capability.

Key Specifications

Pinout & Package

MAX14778EETP+T uses a 20-pin TQFN package (5mm × 5mm, outline 21-0140) with exposed pad (EP) electrically tied to VN. The package supports JEDEC-standard reflow (260°C) and soldering (300°C, 10s), with θJA = 30°C/W on four-layer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX14778EETP+T, MAX14777EETP+T offers half the channel count but identical high-voltage performance and footprint, while ADG1419BRUZ demands external rails and lacks system-level protections - making MAX14778EETP+T uniquely suited for rugged, multi-protocol embedded interfaces.

Availability

MAX14778EETP+T is available at Aetrix Electronics and suitable for RS-485/USB 1.1 connector sharing, POS peripheral consolidation, and industrial handheld communication systems requiring stable component supply across extended temperature and high-reliability production cycles.

Supply support for MAX14778EETP+T 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, automotive, and communications applications - emphasizing robustness, integration, and high-voltage tolerance.

The MAX14778EETP+T belongs to Maxim's high-voltage analog switch family, engineered specifically to eliminate negative supplies in multi-protocol interface systems while maintaining signal integrity, ESD resilience, and thermal safety.

FAQ

What is the maximum continuous current rating for MAX14778EETP+T?

The MAX14778EETP+T supports ±300mA continuous bidirectional current through each multiplexer channel (A0–A3 or B0–B3). This rating applies across the full –25V to +25V signal range and is validated over the –40°C to +125°C operating temperature range. Exceeding ±300mA risks thermal shutdown activation or long-term reliability degradation.

Does MAX14778EETP+T require external capacitors, and if so, what values?

Yes, MAX14778EETP+T requires three external capacitors: a 1µF ceramic capacitor from VDD to GND, and 100nF ceramic capacitors from VP to GND and VN to GND. These are mandatory for stable charge-pump operation, full ±6kV HBM ESD protection on A_/B_ pins, and thermal performance - omission compromises both signal integrity and device reliability.

Can MAX14778EETP+T operate with VDD = 0V while analog signals are present?

Yes, MAX14778EETP+T tolerates ±25V on A_, B_, ACOM, and BCOM pins with VDD = 0V. Input leakage remains typically <1µA, though transient charging currents may flow into VP/VN capacitors. To avoid exceeding the ±500mA absolute maximum rating, dv/dt on analog inputs must be limited to ≤3V/µs once VP/VN capacitors reach steady state.

What is the purpose of the exposed pad (EP) on MAX14778EETP+T?

The exposed pad (EP) on MAX14778EETP+T must be electrically connected to VN, not GND or VDD. This connection provides a low-impedance thermal path for heat dissipation (θJC = 2°C/W) and establishes a stable reference for the negative charge pump. Leaving EP floating or connecting it incorrectly degrades thermal performance and may cause ESD protection failure.

How does MAX14778EETP+T achieve ±25V operation from a single 3.0–5.5V supply?

MAX14778EETP+T achieves ±25V operation using three integrated charge pumps: a 5V-regulated pump (bypassed when VDD > 4.64V), a +35V pump, and a –27V pump. These generate internal bias voltages that extend the analog switch's control range beyond the supply rails - enabling true above-and-below-the-rails signal handling without external high-voltage supplies.