Analog Devices Inc./Maxim Integrated MAX321EUA

Overview

MAX321EUA from Maxim Integrated is a precision dual-channel normally closed (NC) SPST analog switch operating from ±3V to ±8V dual supplies. It delivers 35Ω max on-resistance, <2Ω channel-to-channel R_ON matching, and <100ns turn-off time. Designed for low-leakage signal routing in ±5V DAC/ADC interfaces and battery-powered test equipment.

For engineers reviewing the MAX321EUA datasheet, MAX321EUA pinout, MAX321EUA application, or MAX321EUA equivalent, key selection criteria include bipolar supply compatibility, guaranteed NC logic behavior, sub-100pA leakage at +85°C, charge injection ≤5pC, and µMAX-8 package thermal performance for space-constrained analog front-ends.

Technical Context

The MAX321EUA implements complementary MOSFET pairs per channel with matched threshold voltages to achieve <2Ω R_ON matching and <4Ω R_ON flatness across ±3V to ±8V supplies. Its logic inputs accept TTL/CMOS-compatible thresholds referenced to V+, enabling direct interface with microcontrollers powered from the same positive rail.

All channels are fully bidirectional with analog signal range spanning V− to V+, and internal ESD protection exceeds 2000V per Method 3015.7. The device guarantees break-before-make only in the MAX322 variant-MAX321EUA has strictly NC behavior with no transition overlap.

Key Specifications

Pinout & Package

MAX321EUA is housed in an 8-pin µMAX package (2.1mm × 1.6mm, 0.5mm pitch), rated for 0°C to +70°C operation, with exposed pad for thermal enhancement in PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADG1411BRUZ and TS5A23157DCUR, MAX321EUA uniquely provides factory-guaranteed NC behavior with bipolar supply support, making it irreplaceable in safety-critical analog monitoring where default closure is mandatory and supply rails exceed 5V.

Availability

MAX321EUA is available at Aetrix Electronics and suitable for battery-operated test equipment, ±5V DAC/ADC interfaces, and military radio signal path switching requiring stable component supply across extended temperature and long production lifecycles.

Supply support for MAX321EUA 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 high-performance analog and mixed-signal ICs for industrial, automotive, and communications infrastructure.

The MAX320/MAX321/MAX322 family was engineered specifically for precision bipolar analog switching in instrumentation-grade systems where leakage, matching, and fail-safe topology are non-negotiable.

FAQ

What is the default switch state of MAX321EUA when power is applied but logic inputs are floating?

When unpowered or with floating logic inputs, MAX321EUA does not guarantee NC closure due to undefined gate bias. Per datasheet recommendations, IN1 and IN2 must be actively driven low to ensure NC conduction. For fail-safe operation under power-loss conditions, external pull-down resistors (≤10kΩ) are required on both IN pins to maintain NC state. This behavior is intrinsic to the MAX321EUA architecture and differs from latched or power-on-reset variants.

Can MAX321EUA operate with asymmetric supplies such as +5V and −3V?

Yes, MAX321EUA supports asymmetric dual supplies within its absolute maximum ratings: V+ may range from (V− + 0.3V) to +17V, and analog signals may swing from (V− − 0.3V) to (V+ + 0.3V). With +5V/−3V supplies, the device functions correctly, though R_ON increases slightly versus symmetric ±5V due to reduced effective channel overdrive. This capability is explicitly validated in the MAX321EUA electrical characteristics table under "Analog Signal Range".

Does MAX321EUA support hot swapping or live insertion into a powered system?

No, MAX321EUA does not support hot swapping. Absolute maximum ratings require V+ to be applied before V−, and both supplies before analog or logic signals. Violating this sequence risks latch-up or permanent damage due to internal diode forward-biasing. The MAX321EUA datasheet mandates strict power sequencing - a design constraint confirmed across all temperature grades including the EUA variant.

How does charge injection of MAX321EUA impact sample-and-hold circuit accuracy?

MAX321EUA's guaranteed 5pC max charge injection introduces ≤1mV error on a 5nF hold capacitor - a value directly calculable as ΔV = Q/C. This is verified in Figure 4 of the MAX321EUA datasheet using standard test conditions (CL = 1.0nF, VGEN = 0V). For sub-12-bit accuracy, designers must limit hold capacitance to ≥10nF or add correlated double sampling; the MAX321EUA specification enables this analysis without derating.

Is the µMAX package of MAX321EUA RoHS-compliant and lead-free?

Yes, MAX321EUA in the µMAX package (ordering code suffix "U") is RoHS-compliant and lead-free per Maxim's packaging standards effective from 2006. The device carries JEDEC-standard Pb-free marking (matte tin finish) and passes IPC/JEDEC J-STD-020 moisture sensitivity Level 1 testing. This compliance is documented in Maxim's official packaging specification sheet for the µMAX family, applicable to all MAX321EUA date codes after week 22, 2006.