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Texas Instruments OPA4345UA
- Part No.:
- OPA4345UA
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
OPA4345UA.pdf
- Description:
- IC CMOS 4 CIRCUIT 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,119
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Product details
Overview
OPA4345UA from Texas Instruments is a quad, rail-to-rail input/output CMOS operational amplifier optimized for gains ≥5, featuring 3MHz gain-bandwidth product, 2V/µs slew rate, and 150µA typical quiescent current per amplifier. It operates from a single 2.7V to 5.5V supply and delivers 1mV output swing from rails into high-impedance loads-ideal for precision signal conditioning in space-constrained, low-power data acquisition systems.
For engineers reviewing the OPA4345UA datasheet, OPA4345UA pinout, OPA4345UA application, or OPA4345UA equivalent, this page provides verified technical context, package-specific pin functions, real-world application mappings, and two validated alternative parts with documented functional and application-level differences.
Technical Context
The OPA4345UA implements a complementary CMOS input stage enabling rail-to-rail common-mode input range extending 300mV beyond both supply rails, with a defined transition region where both N- and P-channel pairs operate. Its unity-gain unstable architecture requires minimum gain ≥5 for stability, supported by 3MHz GBW and 2V/µs slew rate.
It features ultra-low input bias current (±0.2pA typ), 8µVrms integrated input voltage noise (0.1–50kHz), and 0.006% THD+N at 1kHz with G=5-enabling high-fidelity buffering of ADC inputs and precision I/V conversion without degrading SNR in battery-powered instrumentation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain-Bandwidth Product | 3MHz - supports stable closed-loop operation at G≥5 up to ~600kHz signal bandwidth |
| Slew Rate | 2V/µs - enables full-scale settling of 2V output steps in ≤1.5µs (0.1%) for fast data acquisition |
| Quiescent Current (per amp) | 150µA typ - allows four amplifiers to operate under 600µA total, critical for micro-power systems |
| Input Offset Voltage | ±0.2mV typ - ensures <1LSB error when driving 12-bit ADCs with 5V full-scale range |
| Output Swing from Rail | 1mV into 100kΩ - preserves >99.9% dynamic range in 3.3V or 5V single-supply systems |
| THD + Noise | 0.006% at 1kHz, G=5 - meets audio-grade linearity requirements without external trimming |
| Common-Mode Range | –0.3V to (V+) + 0.3V - accepts inputs below ground or above V+, simplifying level-shifting circuits |
Pinout & Package
OPA4345UA is packaged in SO-14 (D package), a 14-pin small-outline integrated circuit with standard 1.27mm pitch, rated for –40°C to +85°C operation and RoHS-compliant lead finish (NIPDAU).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Out A) | Amplifier A output | Drives external load; rail-to-rail swing enables direct interface to SAR ADC reference inputs |
| 2 (–In A) | Amplifier A inverting input | High-impedance node (10¹³Ω); sensitive to PCB leakage-requires guard ring in high-Z designs |
| 3 (+In A) | Amplifier A non-inverting input | Accepts signals from –0.3V to V+ + 0.3V; enables true single-supply sensor interfacing |
| 4 (V–) | Negative supply / ground | Reference for all four amplifiers; must be low-impedance with local 0.01µF ceramic bypass |
| 5 (+In B) | Amplifier B non-inverting input | Independent input for second channel; identical specs enable matched dual-path signal chains |
| 6 (–In B) | Amplifier B inverting input | Shares no internal nodes with Channel A-ensures >130dB dc channel separation |
| 7 (Out B) | Amplifier B output | Capable of driving 600Ω loads; maintains rail-to-rail swing even under moderate load |
| 8 (Out C) | Amplifier C output | Third independent output; supports multi-channel filtering or simultaneous signal conditioning |
| 9 (–In C) | Amplifier C inverting input | Same ultra-low IB as other channels-critical for high-precision integrators or charge amplifiers |
| 10 (+In C) | Amplifier C non-inverting input | Enables three independent buffer/gain stages on one IC, reducing board area and component count |
| 11 (+V) | Positive supply | Accepts 2.7V–5.5V; PSRR >130dB at 1kHz minimizes supply noise coupling into signal path |
| 12 (–In D) | Amplifier D inverting input | Fourth channel input; fully specified across temperature-supports redundant or calibration paths |
| 13 (+In D) | Amplifier D non-inverting input | Allows independent biasing per channel; enables programmable gain arrays using external resistors |
| 14 (Out D) | Amplifier D output | Final output stage; matches performance of Channels A–C-no derating required for layout symmetry |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-rail input and output | Extends usable input range to –0.3V to V+ + 0.3V and output swing to within 1mV of rails-maximizes dynamic range in low-voltage systems |
| 3MHz gain-bandwidth at G ≥ 5 | Enables stable amplification of kHz-range sensor signals (e.g., strain gauges, thermocouples) without phase margin loss |
| 150µA quiescent current per amplifier | Supports always-on monitoring circuits with four active channels drawing <600µA total-extends battery life in portable DAQ |
| 0.006% THD + noise at 1kHz | Preserves signal fidelity in audio preprocessing and communications front-ends without post-amplifier filtering |
| ±0.2pA input bias current | Minimizes offset drift in high-impedance transducer interfaces (e.g., pH electrodes, piezoelectric sensors) |
| SO-14 package with industry-standard footprint | Enables drop-in replacement for legacy quad op amps (e.g., LM324, TL074) while delivering superior AC performance |
Applications
| PCMCIA Data Acquisition Card | Industrial Process Control Loop |
|---|---|
|
Use Scenario: Signal conditioning for 12-bit SAR ADCs in compact PCMCIA cards with strict power and area budgets. IC Role / Device Role / Timing Role: Quad buffer/gain stage driving ADS7822 ADC inputs; provides rail-to-rail drive capability and charge injection immunity. Use Value: Enables full-scale 0–5V input range with <1LSB error and <600µA total supply current-meeting PCMCIA Class A power limits. |
Use Scenario: Isolated analog input module for 4–20mA current loop receivers in PLC backplanes. IC Role / Device Role / Timing Role: Precision I/V conversion and filtering stage; converts loop current to voltage while rejecting common-mode noise. Use Value: ±0.2mV offset and 130dB CMRR ensure <0.1% accuracy over –40°C to +85°C-meeting SIL-2 functional safety requirements. |
| Audio Processing Front-End | Communications Baseband Filter |
|
Use Scenario: Electret microphone preamplifier and bandpass filter in voice-enabled IoT edge devices. IC Role / Device Role / Timing Role: First-stage gain (G=100) and 300Hz–3kHz bandpass filter; operates from 2.7V supply with <500µA total system current. Use Value: 0.006% THD+N and 3MHz GBW preserve speech intelligibility without clipping or harmonic distortion. |
Use Scenario: Low-pass and anti-alias filtering before high-speed ADC in cellular base station receiver chains. IC Role / Device Role / Timing Role: Active filter stage implementing 2nd-order Butterworth response; drives ADC sample-and-hold capacitance directly. Use Value: 2V/µs slew rate and 1mV output swing ensure <0.1% settling error for 1Msps sampling-reducing aperture jitter. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad rail-to-rail operational amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA4344UA | Unity-gain stable; 1MHz GBW, 0.8V/µs slew rate, same pinout and quiescent current | Better suited for G=1 buffers and low-frequency (<100kHz) applications; not recommended for G≥5 signal chains | Select OPA4344UA when stability at unity gain is required and bandwidth demands are ≤100kHz |
| MCP6004-E/SL | 1MHz GBW, 0.6V/µs slew rate, 100µA IQ, wider supply range (1.8–6.0V), but only 65dB CMRR min | Lower cost for consumer-grade applications; insufficient CMRR for precision industrial sensing | Select MCP6004-E/SL for cost-sensitive, non-critical applications where 65dB CMRR and 1MHz BW suffice |
Compared with OPA4345UA, OPA4344UA trades bandwidth and slew rate for guaranteed unity-gain stability, while MCP6004-E/SL reduces cost and supply voltage floor at the expense of precision-making OPA4345UA the optimal choice for high-fidelity, medium-speed signal conditioning where G≥5 is acceptable.
Availability
OPA4345UA is available at Aetrix Electronics and suitable for industrial process control, portable data acquisition, and audio front-end applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.
Supply support for OPA4345UA 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 specializing in analog and embedded processing technologies, with decades of expertise in precision op amp design and high-volume manufacturing.
The OPA4345UA belongs to TI's MicroAmplifier™ series-engineered specifically for low-power, miniature, rail-to-rail signal conditioning in battery-operated and space-constrained instrumentation systems.
FAQ
What is the minimum stable gain for OPA4345UA?
The OPA4345UA is optimized for closed-loop gains of 5 or greater and is not unity-gain stable. Attempting to use it at G=1 may cause oscillation or excessive overshoot. For unity-gain applications, TI recommends the pin-compatible OPA4344UA instead. Always verify stability with load and layout parasitics using the OPA4345UA SPICE model available on ti.com.
Does OPA4345UA support true single-supply operation down to 2.5V?
Yes-OPA4345UA is fully specified from 2.7V to 5.5V and functional down to 2.5V. At 2.5V, key parameters including input common-mode range (–0.3V to 2.8V), output swing (within 10mV of rails into 5kΩ), and THD+N (0.006%) remain valid per the datasheet. Operation below 2.7V is allowed but not production-tested.
Can OPA4345UA drive capacitive loads directly?
OPA4345UA can directly drive up to 250pF in gains ≥5 without external compensation. At G=5, its phase margin remains >60° with 250pF. For larger loads or lower gains, add a 10Ω–20Ω series resistor at the output (as shown in Figure 5 of SBOS107A) to maintain stability while preserving DC accuracy.
What is the thermal resistance (θJA) of the OPA4345UA in SO-14 package?
The OPA4345UA in SO-14 (D package) has a thermal resistance θJA of 100°C/W, measured under JEDEC JESD51-7 standard conditions (single-layer 1-in² copper pad). This value assumes proper PCB layout with thermal vias and adequate copper pour-actual junction temperature rise depends on board-level heatsinking.
Is OPA4345UA pin-compatible with legacy quad op amps like LM324?
No-OPA4345UA uses a different pinout than LM324. While both are 14-pin SOIC packages, OPA4345UA assigns pins 1/7/8/14 to outputs (A/B/C/D), whereas LM324 uses pins 1/7/8/14 for outputs A/B/C/D *plus* internal compensation. Direct replacement requires PCB redesign. However, OPA4345UA is pin-compatible with OPA4344UA and OPA4345EA (TSSOP-14).
OPA4345UA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- MicroAmplifier™
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Active
- Amplifier Type:
- CMOS
- Number of Circuits:
- 4
- 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 (x4 Channels)
- 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:
- 14-SOIC
OPA4345UA FAQ
1.How can I place an order for OPA4345UA through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA4345UA 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 OPA4345UA reliable?
The price and inventory of OPA4345UA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA4345UA is usually 5 days.
3.What payment methods are accepted for OPA4345UA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA4345UA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA4345UA?
OPA4345UA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA4345UA 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 OPA4345UA?
For technical support, including OPA4345UA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA4345UA requirements.
6.How does Aetrix verify that OPA4345UA is sourced from the original manufacturer or authorized distributors?
All OPA4345UA 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 OPA4345UA meets industry standards.
7.What is the process for return or replacement of OPA4345UA?
All OPA4345UA units undergo pre-shipment inspection (PSI). If there is an issue with OPA4345UA, 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 OPA4345UA part is unused and in its original packaging.
Return procedure for OPA4345UA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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