Diodes Incorporated APX321WG-7

Overview

APX321WG-7 from Diodes Incorporated is a single-channel, rail-to-rail input and output operational amplifier optimized for low-voltage (2.5V–5.5V) portable and space-constrained applications. It delivers 1 MHz gain-bandwidth, 1 V/µs slew rate, 110 µA typical supply current, ±10 mV rail-to-rail output swing at 10 kΩ load, and operates across –40°C to +85°C - enabling precision signal conditioning in battery-powered sensor interfaces and analog front-ends.

For engineers reviewing the APX321WG-7 datasheet, APX321WG-7 pinout, APX321WG-7 application, or APX321WG-7 equivalent, key selection criteria include its SOT25 package footprint, guaranteed 2.7V/5V performance, elimination of crossover distortion, input common-mode range extending to V– and within 0.2V of V+, and compatibility with low-noise, low-power signal chain designs requiring rail-to-rail operation.

Technical Context

The APX321WG-7 implements a CMOS-input, rail-to-rail output op-amp architecture with input common-mode voltage range from V– to V+ – 0.2 V and output swing within 10 mV of both rails under 10 kΩ load. Its 1 MHz GBWP and 1 V/µs slew rate support stable unity-gain buffer and low-frequency active filter configurations without phase reversal or clipping.

Designed for single-supply operation, it features 50–65 dB CMRR and PSRR over 2.7V–5V supply range, 1.7–9 mV input offset voltage (typ. 7 mV), and 10–500 nA input bias current - making it suitable for high-impedance sensor amplification where DC accuracy and power efficiency are jointly critical.

Key Specifications

Pinout & Package

SOT25 (5-pin small-outline transistor) package: ultra-compact surface-mount footprint (2.9 mm × 1.6 mm × 1.1 mm), lead-free and RoHS-compliant, optimized for high-density PCB layouts in portable electronics.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-channel rail-to-rail op-amp applications.

Compared with MCP6001T-E/OT and TSV911ICT, the APX321WG-7 provides optimal balance of 1 MHz bandwidth, 110 µA consumption, and guaranteed rail-to-rail operation across 2.5–5.5 V - making it ideal for cost-sensitive, space-constrained portable systems where moderate speed and minimal power are co-primary requirements.

Availability

APX321WG-7 is available at Aetrix Electronics and suitable for portable sensor interfaces, low-power ADC drivers, single-supply active filters, and precision reference buffering requiring stable component supply and long-term manufacturability.

Supply support for APX321WG-7 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

Diodes Incorporated is a global semiconductor manufacturer specializing in discrete, analog, and mixed-signal components for industrial, computing, consumer, and communications markets.

The APX321 belongs to Diodes' low-voltage precision op-amp product line, engineered specifically for space- and power-constrained applications demanding rail-to-rail performance at 2.5–5.5 V supply voltages.

FAQ

What is the maximum capacitive load the APX321WG-7 can drive without instability?

The APX321WG-7 is stable with capacitive loads up to 200 pF when configured as a unity-gain buffer, per datasheet Figure 12 (Stability vs. Capacitive Load). For loads exceeding 200 pF, a series resistor (≥100 Ω) between output and capacitance is required to maintain phase margin above 60° and prevent peaking or oscillation.

Does the APX321WG-7 support dual-supply operation?

Yes - though optimized for single-supply use, the APX321WG-7 operates with split supplies (e.g., ±2.5 V) as long as total V+ − V− remains within 2.5 V to 5.5 V. Input common-mode range extends to V− and within 0.2 V of V+, and output swings rail-to-rail relative to the applied supplies.

How does the input bias current change with temperature?

Input bias current increases with temperature: from 10 nA typ. at 25°C to ≤500 nA max. at +85°C (5 V supply), per Electrical Characteristics table. This 50× increase must be accounted for in high-impedance transducer interfaces where bias current-induced voltage drop could exceed allowable error budgets.

Is the APX321WG-7 pin-compatible with other SOT25 op-amps like the LMV321?

No - while both use SOT25 packages, pin assignments differ: APX321WG-7 uses Pin 1=IN−, Pin 2=IN+, Pin 3=OUT, Pin 4=V−, Pin 5=V+; LMV321 uses Pin 1=OUT, Pin 2=IN−, Pin 3=IN+, Pin 4=GND, Pin 5=V+. Direct replacement requires PCB redesign or adapter.