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Texas Instruments OPA345NA/3KG4
- Part No.:
- OPA345NA/3KG4
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- SC-74A, SOT-753
- Datasheet:
-
OPA345NA/3KG4.pdf
- Description:
- IC OPAMP GP 1 CIRCUIT SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,467
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Product details
Overview
OPA345NA/3KG4 from Texas Instruments is a single, rail-to-rail input/output CMOS operational amplifier optimized for gain ≥ 5, featuring 3 MHz gain-bandwidth product, 2 V/µs slew rate, 150 µA typical quiescent current, and operation from 2.7 V to 5.5 V single supply - ideal for precision signal conditioning in low-power data acquisition systems.
For engineers reviewing the OPA345NA/3KG4 datasheet, OPA345NA/3KG4 pinout, OPA345NA/3KG4 application, or OPA345NA/3KG4 equivalent, key selection criteria include its minimum stable gain requirement (G ≥ 5), rail-to-rail output swing within 1 mV of rails (RL = 100 kΩ), THD+N of 0.006% at 1 kHz, and SOT23-5 package compatibility with space-constrained PCB layouts.
Technical Context
The OPA345NA/3KG4 employs a complementary differential input stage enabling rail-to-rail common-mode input range extending 300 mV beyond both supply rails, with a defined transition region near (V+) – 1.3 V where PSRR and CMRR degrade. Its class AB output stage delivers true rail-to-rail output swing while maintaining >96 dB open-loop gain into 100 kΩ loads.
Designed for closed-loop gains ≥ 5, the device uses internal compensation optimized for 3 MHz GBW and 2 V/µs slew rate - not unity-gain stable. It supports capacitive load drive up to 250 pF at G ≥ 5 and features ultra-low input bias current (±0.2 pA typ) and 30 nV/√Hz input voltage noise density at 10 kHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain-Bandwidth Product | 3 MHz - enables stable amplification at G ≥ 5 up to ~600 kHz full-power bandwidth |
| Slew Rate | 2 V/µs - supports clean 100 kHz, 2 VPP output signals without distortion |
| Input Offset Voltage | ±0.2 mV (typ) - ensures ≤ 1 mV error in G = 5 configurations with 5 V supply |
| Quiescent Current | 150 µA (typ) - allows battery-powered operation for >1 year with 10 mA·h coin cell |
| THD + Noise | 0.006% at 1 kHz, G = 5 - meets audio-grade signal fidelity requirements |
| Rail-to-Rail Output Swing | Within 1 mV of rails (RL = 100 kΩ) - maximizes dynamic range in 3.3 V or 5 V systems |
| Common-Mode Input Range | –0.3 V to (V+) + 0.3 V - accepts inputs below ground or above V+ in single-supply setups |
Pinout & Package
SOT23-5 surface-mount package (DBV drawing), 5-pin, moisture sensitivity level 2, RoHS-compliant, rated for –40°C to +85°C operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - V– | Negative supply / ground reference | Connect to system ground or negative rail; supports single-supply operation down to 2.7 V |
| 2 - –In | Inverting input | Differential input node; high-impedance (1013 Ω || 6 pF) CMOS input |
| 3 - Out | Amplifier output | Class AB rail-to-rail stage capable of sourcing/sinking ±15 mA; drives 600 Ω loads |
| 4 - +In | Non-inverting input | Differential input node; matched to –In for <±3 µV/°C drift and low offset |
| 5 - V+ | Positive supply | Accepts 2.7 V to 5.5 V single supply; bypass with 0.01 µF ceramic capacitor to V– |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-rail input and output | Enables full-scale signal handling in low-voltage systems (e.g., 3.3 V ADC drivers) without level-shifting circuitry |
| Gain ≥ 5 optimization | Guarantees stability and specified AC performance only when configured for closed-loop gain of five or higher |
| 150 µA quiescent current | Reduces power budget impact in multi-channel sensor front-ends or portable instrumentation |
| 0.006% THD+N at 1 kHz | Supports high-fidelity analog signal paths in audio processing and precision measurement applications |
| 30 nV/√Hz input voltage noise | Maintains SNR > 90 dB in 20 kHz bandwidth systems with 10 kΩ source impedance |
Applications
| PCMCIA Data Acquisition Card | Industrial Process Control Loop |
|---|---|
|
Use Scenario: Signal conditioning of thermocouple or RTD outputs before 12-bit SAR ADC sampling in compact PCMCIA-format data loggers. IC Role / Device Role / Timing Role: Precision non-inverting amplifier (G = 5) driving ADS7822 input capacitance while rejecting supply ripple and common-mode noise. Use Value: Rail-to-rail output swing preserves full 0–5 V ADC input range; 150 µA IQ extends battery life in field-deployed units. |
Use Scenario: Isolated current-to-voltage conversion and filtering in 4–20 mA loop-powered transmitters. IC Role / Device Role / Timing Role: Low-drift I/V converter with active low-pass filtering (G = 5, fc = 100 Hz) preceding microcontroller ADC. Use Value: ±0.2 mV VOS ensures <0.01% span error over temperature; 3 MHz GBW supports fast step response to process transients. |
| Audio Line-Level Buffer | Communications Baseband Filter |
|
Use Scenario: Single-supply headphone driver or line-out buffer in portable voice recorders using electret microphones. IC Role / Device Role / Timing Role: Unity-gain follower replaced by G = 5 configuration to meet stability requirements while providing headroom for clipping margin. Use Value: 0.006% THD+N maintains CD-quality audio fidelity; rail-to-rail input accepts microphone preamp outputs near ground. |
Use Scenario: Active bandpass filtering of baseband signals in narrowband IoT modems (e.g., LoRa, NB-IoT). IC Role / Device Role / Timing Role: Second-order Sallen-Key filter stage (G = 5, Q = 2) shaping 10–100 kHz channel response. Use Value: 2 V/µs slew rate prevents distortion on 50 kHz sinusoidal carriers; low noise preserves SNR in weak-signal reception. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar rail-to-rail, low-power op amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA344NA/3KG4 | Unity-gain stable; 1 MHz GBW; 0.8 V/µs slew rate; same SOT23-5 package and pinout | Preferred for G = 1 buffers or wideband applications requiring lower speed but unconditional stability | Select OPA344NA/3KG4 when gain is unity or variable, or when driving highly capacitive loads without isolation resistor |
| MCP6001T-E/OT | 1 MHz GBW; 0.6 V/µs slew rate; 100 µA IQ; rail-to-rail I/O; different pinout (V+, –In, Out, +In, V–) | Lower power but reduced speed and noise performance; suitable for cost-sensitive, non-precision applications | Choose MCP6001T-E/OT for sub-100 µA power budgets where 3 MHz bandwidth and 0.006% THD+N are not required |
Compared with OPA344NA/3KG4, the OPA345NA/3KG4 trades unity-gain stability for 3× higher bandwidth and 2.5× faster slew rate - critical for G ≥ 5 signal chains. Against MCP6001T-E/OT, it delivers superior AC performance and lower distortion at modest IQ increase, justifying use in precision data acquisition.
Availability
OPA345NA/3KG4 is available at Aetrix Electronics and suitable for data acquisition, industrial process control, audio processing, and communications applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant SOT23-5 packaging.
Supply support for OPA345NA/3KG4 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
Texas Instruments is a global semiconductor leader delivering analog and embedded processing solutions, with over 90 years of innovation in precision analog design and manufacturing excellence.
The OPA345NA/3KG4 belongs to TI's MicroAmplifier™ series, engineered specifically for low-power, miniature, rail-to-rail signal conditioning in battery-operated and space-constrained systems - emphasizing precision, speed, and supply flexibility.
FAQ
Is OPA345NA/3KG4 unity-gain stable?
No, the OPA345NA/3KG4 is not unity-gain stable. It is internally compensated for minimum closed-loop gain of 5. Using it at G = 1 risks oscillation and degraded phase margin. For unity-gain applications, select the pin-compatible OPA344NA/3KG4 instead, which shares the same SOT23-5 package and operating voltage range.
What is the maximum capacitive load OPA345NA/3KG4 can drive?
The OPA345NA/3KG4 can directly drive up to 250 pF of pure capacitive load when configured for gain ≥ 5. At lower gains, stability margins decrease - do not use below G = 5. For loads exceeding 250 pF or for unity-gain configurations, add a 10–20 Ω series resistor between output and load to maintain stability without significant DC error.
Does OPA345NA/3KG4 support rail-to-rail input below ground?
Yes - the OPA345NA/3KG4 accepts input voltages down to –0.3 V relative to V– (ground), enabling true rail-to-rail input operation in single-supply systems. However, inputs below –0.3 V may cause output lockup; if such excursions are possible, add a Schottky diode clamp to V– with a current-limiting resistor as shown in TI's SBOS107A Figure 4.
What is the thermal resistance (θJA) of OPA345NA/3KG4 in SOT23-5 package?
The junction-to-ambient thermal resistance (θJA) for OPA345NA/3KG4 in the SOT23-5 (DBV) package is 200°C/W under standard JEDEC test conditions. This value assumes a 1-inch² copper pad on the board; actual thermal performance improves with larger copper areas or thermal vias to inner layers.
Can OPA345NA/3KG4 operate from a 2.5 V supply?
While the OPA345NA/3KG4 is fully specified from 2.7 V to 5.5 V, it functions down to 2.5 V per absolute maximum ratings. However, parameters like GBW, slew rate, and output swing degrade below 2.7 V - for guaranteed performance across temperature, maintain VS ≥ 2.7 V. The 2.5 V figure applies only to survival, not specification compliance.
OPA345NA/3KG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- MicroAmplifier™
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Amplifier Type:
- General Purpose
- Number of Circuits:
- 1
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 2V/µs
- Gain Bandwidth Product:
- 3 MHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 0.2 pA
- Voltage - Input Offset:
- 200 µV
- Current - Supply:
- 150µA
- Current - Output / Channel:
- 15 mA
- Voltage - Supply Span (Min):
- 2.5 V
- Voltage - Supply Span (Max):
- 5.5 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
OPA345NA/3KG4 FAQ
1.How can I place an order for OPA345NA/3KG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA345NA/3KG4 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 OPA345NA/3KG4 reliable?
The price and inventory of OPA345NA/3KG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA345NA/3KG4 is usually 5 days.
3.What payment methods are accepted for OPA345NA/3KG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA345NA/3KG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA345NA/3KG4?
OPA345NA/3KG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA345NA/3KG4 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 OPA345NA/3KG4?
For technical support, including OPA345NA/3KG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA345NA/3KG4 requirements.
6.How does Aetrix verify that OPA345NA/3KG4 is sourced from the original manufacturer or authorized distributors?
All OPA345NA/3KG4 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 OPA345NA/3KG4 meets industry standards.
7.What is the process for return or replacement of OPA345NA/3KG4?
All OPA345NA/3KG4 units undergo pre-shipment inspection (PSI). If there is an issue with OPA345NA/3KG4, 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 OPA345NA/3KG4 part is unused and in its original packaging.
Return procedure for OPA345NA/3KG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
OPA345NA/3KG4 Tags
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LM358DT
STMicroelectronics
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LM358DR
Texas Instruments
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LM2904DR
Texas Instruments
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LM358ADR
Texas Instruments
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LM2904DGKR
Texas Instruments
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LM324DR
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MCP6006T-E/OT
Microchip Technology
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MCP6006UT-E/OT
Microchip Technology
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LM324PWR
Texas Instruments
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LM2902PWR
Texas Instruments
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LM2902DR
Texas Instruments
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LM358P
Texas Instruments
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