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Home > Products > Integrated Circuits (ICs) > Linear > Instrumentation, Op Amps, Buffer Amps

Diodes Incorporated AS321KTR-G1

Name: AS321KTR-G1
Brand: Diodes Incorporated
SKU: AS321KTR-G1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AS321KTR-G1

Manufacturer:: Diodes Incorporated

Category:: Instrumentation, Op Amps, Buffer Amps

Package:: SC-74A, SOT-753

Datasheet:: AS321KTR-G1.pdf

Description:: IC OPAMP GP 1 CIRCUIT SOT25

Quantity:: RFQ Add To RFQ list

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Inventory:662,577

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Product details

Overview

AS321KTR-G1 from Diodes Incorporated is a low-power, single-supply operational amplifier with 100 dB typical open-loop gain, 60° phase margin, and rail-to-rail input common-mode range (0 V to V_CC−1.5 V). It operates from 3 V to 36 V single supply (or ±1.5 V to ±18 V dual supply), draws only 0.35 mA at 5 V, and is housed in a RoHS-compliant, halogen-free SOT25 package. It serves as a drop-in replacement for industry-standard LM321 in battery-powered instrumentation and active filter circuits.

For engineers reviewing the AS321KTR-G1 datasheet, AS321KTR-G1 pinout, AS321KTR-G1 application, or AS321KTR-G1 equivalent, key selection criteria include its wide supply voltage range, low input bias current (20 nA typ), input offset voltage (2 mV typ), and compatibility with legacy 321-based designs requiring green, lead-free packaging.

Technical Context

The AS321KTR-G1 integrates internal frequency compensation for stable unity-gain operation and delivers high DC precision with 7 µV/°C input offset drift and 70 dB typical CMRR over its full input common-mode range. Its output can source up to 40 mA and sink 15 mA while maintaining 26 V swing into 2 kΩ at 30 V supply.

Designed for single-supply operation, it supports true 0 V input capability and tolerates input voltages up to 36 V independent of V_CC. The amplifier's thermal resistance (θ_JA = 260 °C/W) and junction temperature rating (T_J = +150 °C) enable reliable use in industrial ambient conditions up to +85 °C.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage Range	3 V to 36 V single supply - enables direct interface with Li-ion batteries, 24 V industrial rails, and legacy 5 V logic systems.
Input Offset Voltage	2 mV typical - ensures ≤20 mV output error in unity-gain buffer configurations at room temperature.
Input Bias Current	20 nA typical - minimizes voltage error across high-impedance sensor networks and RC timing elements.
Phase Margin	60° - guarantees stable step response without external compensation in closed-loop gains ≥1.
Supply Current	0.35 mA at 5 V - supports >1-year battery life in always-on sensor signal conditioning nodes.
Common-Mode Input Range	0 V to V_CC−1.5 V - allows direct sensing of ground-referenced signals in single-supply data acquisition.
Output Voltage Swing	26 V into 2 kΩ at 30 V supply - delivers >86% rail utilization for analog front-end drivers.

Pinout & Package

AS321KTR-G1 is packaged in a 5-pin SOT25 (SC-74A) surface-mount outline measuring 2.82 mm × 1.70 mm × 1.30 mm, with gull-wing leads and exposed pad thermal path (θ_JC = 101 °C/W).

Pin/Terminal	Circuit Role	Design Meaning
1	Inverting Input (−)	High-impedance node accepting feedback or reference signals; supports common-mode down to 0 V.
2	Non-Inverting Input (+)	High-impedance node for sensor or signal source connection; same common-mode range as Pin 1.
3	V_EE / Ground	Power return for single-supply operation; must be tied to system ground or negative rail in dual-supply mode.
4	V_CC	Positive supply input; accepts 3–36 V; decoupling capacitor required within 1 cm for stability.
5	Output	Class-AB push-pull stage capable of sourcing 40 mA and sinking 15 mA into resistive loads.

Key Features

Feature	Design Value
Lead-Free & Green Packaging	SOT25 package fully compliant with RoHS 3 (2015/863/EU), <900 ppm Br/Cl, <1000 ppm Sb - meets automotive and medical environmental mandates.
Single-Supply Operation	0 V input common-mode capability eliminates need for level-shifting circuitry in battery-powered sensors and portable instruments.
Low Power Consumption	0.35 mA supply current at 5 V enables integration into energy-constrained IoT edge nodes without compromising DC accuracy.
Industry-Standard Pinout	Pin-compatible with LM321, TLC321, and other 321-series op-amps - simplifies drop-in replacement in existing PCB layouts.

Applications

Battery Charger Monitoring

Active Low-Pass Filter

Use Scenario: Real-time voltage and current sensing in 3-cell Li-ion charger IC feedback loops.

IC Role / Device Role / Timing Role: Precision DC amplifier buffering cell voltage to ADC input, rejecting common-mode ripple from switching regulators.

Use Value: 2 mV offset and 70 dB CMRR ensure ≤0.5% measurement error across −40°C to +85°C operating range.

Use Scenario: Anti-aliasing and noise suppression in 12-bit SAR ADC front-ends for industrial PLC analog inputs.

IC Role / Device Role / Timing Role: Unity-gain Sallen-Key topology amplifier with 60° phase margin ensuring monotonic step response and no peaking.

Use Value: Stable 100 dB gain and 0.015% THD at 1 kHz allow clean 10 kHz bandwidth without external compensation.

General-Purpose Controller

DC Summing Amplifier

Use Scenario: Error amplification in PID-based temperature control loop using thermistor and DAC setpoint.

IC Role / Device Role / Timing Role: High-gain transconductance stage converting ΔV between sensor and reference into proportional drive signal.

Use Value: 100 dB open-loop gain maintains <0.1% linearity over 4-decade dynamic range in closed-loop configuration.

Use Scenario: Combining multiple sensor outputs (e.g., pressure, humidity, temp) into single analog bus for microcontroller ADC sampling.

IC Role / Device Role / Timing Role: Inverting summing node with matched input resistors and low input bias current minimizing offset accumulation.

Use Value: 20 nA input bias current limits summation error to <10 µV per 100 kΩ input impedance, preserving multi-sensor accuracy.

Equivalent & Alternatives

The following parts are listed as comparable options for similar operational amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM321DR	Higher supply current (0.8 mA typ), wider offset range (±7 mV max), non-green package	Lacks halogen-free compliance; not suitable for EU medical or automotive programs requiring RoHS 3	Select when legacy qualification or cost sensitivity outweighs environmental compliance requirements
TLC321CDR	Lower input bias current (1 pA typ), but narrower supply range (3–16 V), higher cost	Unsuitable for 24 V industrial rails or 30 V battery systems due to 16 V absolute max supply rating	Select only for ultra-high-impedance pH or photodiode sensor interfaces where bias current dominates error budget

Compared with LM321DR and TLC321CDR, AS321KTR-G1 uniquely balances green compliance, 36 V operation, and sub-1 mA quiescent current-making it optimal for next-generation industrial and portable equipment where regulatory alignment and supply flexibility are co-primary constraints.

Availability

AS321KTR-G1 is available at Aetrix Electronics and suitable for battery-powered instrumentation, active filter design, and general-purpose controller circuits requiring stable component supply across automotive, industrial, and medical OEM programs.

Supply support for AS321KTR-G1 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The AS321 belongs to Diodes' precision analog amplifier product line, engineered specifically for cost-sensitive, environmentally regulated applications demanding single-supply operation, low power, and drop-in compatibility with legacy 321 footprints.

FAQ

Is AS321KTR-G1 pin-compatible with LM321?

Yes, AS321KTR-G1 uses the identical SOT25 pinout as LM321: Pin 1 (−IN), Pin 2 (+IN), Pin 3 (GND), Pin 4 (V_CC), Pin 5 (OUT). No PCB redesign is needed for drop-in replacement, and both share identical footprint and thermal pad layout recommendations per Diodes' SOT25 datasheet.

What is the maximum output current capability of AS321KTR-G1?

AS321KTR-G1 can source up to 40 mA and sink up to 15 mA under recommended operating conditions (V_CC = 15 V, T_A = +25°C). At elevated temperatures or lower supply voltages, output current decreases linearly; full 40 mA sourcing is guaranteed only above 10 V supply and below +70°C ambient.

Does AS321KTR-G1 require external compensation capacitors?

No. AS321KTR-G1 is internally frequency-compensated for unity-gain stability. External compensation is unnecessary for standard inverting, non-inverting, or voltage-follower configurations. Stability testing per Figure 12 in DS36976 confirms 60° phase margin across all gains ≥1 with no added components.

Can AS321KTR-G1 operate with input voltages exceeding V_CC?

Yes - the absolute maximum rating permits input voltages up to +40 V regardless of V_CC, and the input structure tolerates −0.3 V below ground. However, normal operation requires input common-mode voltage between 0 V and V_CC−1.5 V for specified CMRR and offset performance; inputs beyond that range degrade accuracy but do not damage the device.

AS321KTR-G1 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: SC-74A, SOT-753

Packaging:: Tape & Reel (TR)

Product Status:: Active

Amplifier Type:: General Purpose

Number of Circuits:: 1

Output Type:: -

Slew Rate:: -

Gain Bandwidth Product:: -

-3db Bandwidth:: -

Current - Input Bias:: 20 nA

Voltage - Input Offset:: 2 mV

Current - Supply:: 450µA

Current - Output / Channel:: 40 mA

Voltage - Supply Span (Min):: 3 V

Voltage - Supply Span (Max):: 36 V

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-25

AS321KTR-G1 FAQ

1.How can I place an order for AS321KTR-G1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AS321KTR-G1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for AS321KTR-G1 reliable?

The price and inventory of AS321KTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AS321KTR-G1 is usually 5 days.

3.What payment methods are accepted for AS321KTR-G1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AS321KTR-G1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AS321KTR-G1?

AS321KTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AS321KTR-G1 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for AS321KTR-G1?

For technical support, including AS321KTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AS321KTR-G1 requirements.

6.How does Aetrix verify that AS321KTR-G1 is sourced from the original manufacturer or authorized distributors?

All AS321KTR-G1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AS321KTR-G1 meets industry standards.

7.What is the process for return or replacement of AS321KTR-G1?

All AS321KTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AS321KTR-G1, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The AS321KTR-G1 part is unused and in its original packaging.

Return procedure for AS321KTR-G1:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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