Analog Devices Inc./Maxim Integrated MAX4643ETA+

Overview

MAX4643ETA+ from Maxim Integrated is a dual SPST analog switch IC with one normally open (NO) and one normally closed (NC) channel, operating from +1.8V to +5.5V single supply. It delivers 4Ω max on-resistance at +5V, 0.6Ω R_ON matching between channels, 1Ω R_ON flatness, <20ns switching times, and <0.35nA leakage over –40°C to +85°C - enabling precision signal routing in battery-powered audio and data-acquisition systems.

For engineers reviewing the MAX4643ETA+ datasheet, MAX4643ETA+ pinout, MAX4643ETA+ application, or MAX4643ETA+ equivalent, key selection criteria include guaranteed break-before-make timing (7ns typ), rail-to-rail analog signal range, low charge injection (2pC), high off-isolation (–80dB at 1MHz), and µMAX package compatibility for space-constrained PCB layouts.

Technical Context

The MAX4643ETA+ integrates two independent CMOS SPST switches with complementary control logic: IN1 drives NO1 (OFF/ON), while IN2 drives NC2 (ON/OFF), enforcing inherent break-before-make behavior during state transitions. Its internal level translators ensure TTL/CMOS-compatible logic thresholds only at +5V supply, while analog paths support bidirectional rail-to-rail signals up to V+.

ESD protection diodes are embedded between each analog pin (NO1, NC2, COM1, COM2) and both V+ and GND, limiting absolute voltage to –0.3V to (V+ + 0.3V). Leakage current originates solely from reverse-biased ESD diodes - not inter-channel conduction - and is specified at <±0.35nA across full temperature range.

Key Specifications

Pinout & Package

MAX4643ETA+ is housed in an 8-pin µMAX package (3mm × 3mm, 0.8mm height), pin-compatible with industry-standard SO-8 footprints but with 50% smaller area. Thermal resistance θ_JA = 222°C/W enables operation at full rating up to +70°C ambient without heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADG741BRMZ and TS5A23157DCUR, the MAX4643ETA+ uniquely provides verified break-before-make timing, tighter R_ON matching (0.6Ω), and lower leakage (<0.35nA), making it optimal for fail-safe, high-precision, low-power analog multiplexing where channel interaction must be strictly controlled.

Availability

MAX4643ETA+ is available at Aetrix Electronics and suitable for battery-operated equipment, low-voltage data-acquisition systems, and sample-and-hold circuits requiring stable component supply across industrial temperature ranges.

Supply support for MAX4643ETA+ 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 MAX464x family targets low-voltage, high-speed analog switching in space- and power-constrained systems - emphasizing guaranteed R_ON performance, rail-to-rail signal handling, and robust leakage control across temperature.

FAQ

What is the maximum supply voltage rating for MAX4643ETA+?

The MAX4643ETA+ has an absolute maximum supply voltage (V+) of +6V, but its operational specification guarantees functionality only from +1.8V to +5.5V. Exceeding +5.5V may cause parametric degradation or permanent damage. The device's internal ESD diodes clamp analog pins to –0.3V to (V+ + 0.3V), so applying signals beyond this range - even briefly - risks latch-up or increased leakage. Always use external blocking diodes if overvoltage transients are expected in the system.

Does MAX4643ETA+ support true bidirectional analog signal flow?

Yes, MAX4643ETA+ supports fully bidirectional analog signal routing on all NO1, NC2, COM1, and COM2 pins. The CMOS switch architecture imposes no intrinsic directionality - signal paths function identically whether driven from COM1 to NO1 or NO1 to COM1. However, off-capacitance differs slightly between NO1 and NC2 terminals (7pF each), and charge injection (2pC) is measured with COM grounded. For symmetric AC coupling, place series capacitors on both sides of the switch to balance impedance.

How is break-before-make timing enforced in MAX4643ETA+?

Break-before-make timing in MAX4643ETA+ is inherent to its internal logic design: when IN1 and IN2 transition simultaneously, the NC2 channel turns OFF ~7ns before NO1 turns ON, preventing momentary shorting between COM1 and COM2. This behavior is guaranteed by design (not just typical) and verified across –40°C to +85°C. Unlike externally controlled dual switches, no external timing circuitry or delay elements are needed - the timing is fixed and process-insensitive within the monolithic die.

Can MAX4643ETA+ operate reliably from a 1.8V supply?

Yes, MAX4643ETA+ is fully specified down to +1.8V supply, with R_ON = 30Ω typical at +1.8V and full temperature range. Logic inputs remain functional, though VIH/VIL thresholds scale with V+ (VIH ≈ 0.7×V+, VIL ≈ 0.3×V+). At 1.8V, t_ON/t_OFF increase to ~22ns/11ns, and THD rises slightly to 0.025%. All leakage specs (<±0.35nA) and R_ON flatness (1Ω) remain guaranteed - making it viable for ultra-low-power wake-up signal routing in energy-harvesting systems.

What decoupling capacitance is recommended for MAX4643ETA+ V+ pin?

A 0.1µF X7R ceramic capacitor placed within 2mm of the MAX4643ETA+ V+ pin and GND is mandatory for stable operation. This capacitor suppresses high-frequency noise generated during switching transitions and prevents supply droop that could modulate R_ON or induce logic glitches. For systems with heavy digital activity nearby, add a second 1µF tantalum or polymer capacitor in parallel. Avoid electrolytic or high-ESR capacitors - their inductance degrades high-frequency bypassing and may cause oscillation in the analog signal path.