My Inquiry
My Account
Texas Instruments OPA686N/3K
- Part No.:
- OPA686N/3K
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- SC-74A, SOT-753
- Datasheet:
-
OPA686N/3K.pdf
- Description:
- IC OPAMP VFB 1.6GHZ SGL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:53,683
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
OPA686N/3K from Texas Instruments (formerly Burr-Brown) is a wideband, low-noise voltage-feedback operational amplifier optimized for high-dynamic-range signal conditioning. It delivers 250MHz bandwidth at G = +10, 1.3nV/√Hz input voltage noise, 600V/µs slew rate, and –90dBc 2nd-harmonic distortion at 5MHz - enabling use in VDSL line receivers, ultrasound channel amplifiers, and ADC preamplifiers.
For engineers reviewing the OPA686N/3K datasheet, OPA686N/3K pinout, OPA686N/3K application, or OPA686N/3K equivalent, this page provides verified specifications, SOT-23-5 package details, transimpedance design guidance, stability conditions for gains ≥7, and two validated alternative op amps with documented performance trade-offs.
Technical Context
The OPA686N/3K uses a classical differential-input stage followed by two forward-gain stages and a high-power output stage, delivering exceptional linearity and DC accuracy. Its voltage-feedback architecture supports standard op amp configurations while maintaining stability down to noise gain +7.
It achieves flat frequency response via external compensation techniques - including low-gain inverting compensation (e.g., G = –2 with CS/CF network) - enabling maximally flat Butterworth response and >5dB harmonic distortion improvement at 5MHz versus uncompensated operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Bandwidth (G = +10) | 250MHz min - ensures full-swing signal fidelity up to 250MHz in non-inverting gain-of-10 configurations. |
| Input Voltage Noise | 1.3nV/√Hz max - enables high-sensitivity transimpedance amplification where diode capacitance dominates noise. |
| Slew Rate | 600V/µs min - supports fast settling of large-signal steps (e.g., 2V step in ≤18ns to 0.01%). |
| Harmonic Distortion (2nd, 5MHz) | –90dBc max at RL = 500Ω - critical for high-SFDR ADC driver applications requiring clean spectral purity. |
| Gain Bandwidth Product | 1600MHz min - allows stable high-gain (>40×) amplification or ultra-low-distortion operation at moderate gains. |
| Supply Current | 12.4mA typ at +25°C - balances wideband performance with power efficiency in portable or multi-channel systems. |
| Stable Gain Minimum | G ≥ +7 - defines minimum closed-loop noise gain required for unconditional stability without external compensation. |
Pinout & Package
The OPA686N/3K is housed in a 5-pin SOT-23-5 surface-mount package (θJA = 150°C/W), with pin 1 marked by a dot or beveled edge. Pin 4 is +VS, pin 2 is –VS, pin 3 is non-inverting input, pin 5 is inverting input, and pin 1 is output. Pins are not internally connected to substrate or thermal pad.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Output) | Amplified signal output node | Capable of ±3.3V swing into 100Ω load; drives ADC inputs or transmission lines directly. |
| 2 (–VS) | Negative supply rail connection | Requires stable ±5V supply; absolute max rating ±6.5V; decoupling with 0.1µF ceramic essential. |
| 3 (Non-Inverting Input) | Positive differential input terminal | High-impedance node (2.9MΩ || 1pF); used in non-inverting configurations or grounded for IF amplifier topologies. |
| 4 (+VS) | Positive supply rail connection | Must be bypassed independently from –VS; shared decoupling degrades PSRR and distortion. |
| 5 (Inverting Input) | Negative differential input terminal | Low-impedance node (6kΩ || 2pF); accepts matched 50Ω source termination in inverting gain stages. |
Key Features
| Feature | Design Value |
|---|---|
| Wideband transimpedance support | 1.6GHz GBP + 1.3nV/√Hz noise enables optimal SNR in photodiode amplifiers with CD < 100pF. |
| External low-gain compensation | CS/CF network enables stable G = –2 operation with 170MHz flat bandwidth and >5dB SFDR improvement. |
| High-output drive capability | ±80mA output current into 400Ω load supports direct driving of 50Ω/75Ω transmission lines or ADC reference buffers. |
| DC precision at speed | ±0.35mV offset voltage and 80dB open-loop gain enable accurate DC-coupled gain stages up to 200MHz. |
| Thermal-stable quiescent current | 12.4mA trimmed at +25°C with <10% variation over –40°C to +85°C - simplifies thermal design in multi-op-amp layouts. |
Applications
| High-Dynamic-Range ADC Preamplifier | Low-Noise Transimpedance Amplifier |
|---|---|
Use Scenario: Driving 12- to 14-bit analog-to-digital converters in medical ultrasound or communications receivers with full-scale 2Vp-p signals. IC Role / Device Role / Timing Role: Final-stage gain block and buffer, providing flat frequency response, low distortion, and precise DC offset control before sampling. Use Value: Enables >72dBc SFDR at 20MHz using external compensation - exceeding CLC425 performance by >10dB in harmonic suppression. | Use Scenario: Converting photocurrent from high-capacitance photodiodes (e.g., 50pF) in fiber-optic or spectroscopy front-ends. IC Role / Device Role / Timing Role: Transimpedance gain element with CF-compensated pole placement to control bandwidth and minimize noise peaking. Use Value: Achieves 6.4pA/√Hz equivalent input noise at 15.5MHz - 3.5× lower than comparable FET-input op amps when CD dominates noise. |
| VDSL Line Receiver | Low-Noise Differential Receiver |
Use Scenario: Receiving asymmetric digital subscriber line signals with wide dynamic range and stringent crosstalk requirements. IC Role / Device Role / Timing Role: Single-ended to differential conversion and programmable gain stage in line card receiver path. Use Value: Delivers –95dBc 3rd-harmonic distortion at 10MHz and 43dBm two-tone intercept - meeting ITU-T G.992.1 linearity specs. | Use Scenario: Amplifying low-level differential sensor outputs (e.g., bridge transducers) in industrial instrumentation with EMI immunity. IC Role / Device Role / Timing Role: High-CMR, low-noise instrumentation amplifier core with matched feedback networks. Use Value: Provides 0.02% differential gain and 0.02° differential phase error at NTSC frequencies - preserving video signal integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar wideband, low-noise operational amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA2686 | Dual-channel version; identical 1.3nV/√Hz noise and 1600MHz GBP; 12.4mA per channel. | Used where space-constrained dual-path signal chains (e.g., I/Q demodulation) require matched performance. | Select OPA2686 when board area permits dual amplification with guaranteed channel-to-channel tracking. |
| OPA687 | Lower 0.95nV/√Hz noise and higher 3600MHz GBP; 14.5mA supply current; stable only at G ≥ +5. | Better suited for ultra-low-noise transimpedance designs with <20pF diode capacitance or >100MHz bandwidth needs. | Choose OPA687 only if noise reduction below 1.0nV/√Hz is required and layout supports tighter decoupling for higher supply current. |
Compared with OPA686N/3K, OPA2686 offers channel matching at no noise or bandwidth penalty but doubles footprint and supply current, while OPA687 improves noise and GBP at the cost of higher power and reduced stability margin - making OPA686N/3K the optimal balance for 250MHz-class ADC drivers and VDSL receivers.
Availability
OPA686N/3K is available at Aetrix Electronics and suitable for high-frequency data acquisition, broadband communications infrastructure, and medical imaging systems requiring stable component supply across extended temperature ranges (–40°C to +85°C).
Supply support for OPA686N/3K 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 acquired Burr-Brown in 2000 and maintains its precision analog portfolio, emphasizing high-speed, low-noise, and high-accuracy signal chain components.
The OPA686N/3K belongs to TI's OPAx686 family of voltage-feedback op amps, designed specifically for wideband, high-dynamic-range applications including ADC driving, optical receiver front-ends, and RF/IF signal conditioning.
FAQ
What is the minimum stable gain for OPA686N/3K?
The OPA686N/3K is guaranteed stable for closed-loop noise gains ≥ +7. Operation below this gain requires external compensation (e.g., CS/CF network) to maintain phase margin and prevent peaking or oscillation. The datasheet confirms stability down to G = +7 with no added components, and provides design equations for compensated G = –2 operation.
Does OPA686N/3K support single-supply operation?
No - the OPA686N/3K is specified only for dual-supply operation (±5V typical, ±6V absolute max). Its input common-mode range is ±3.2V and output swing is asymmetric under single-rail biasing. For single-supply applications, TI recommends alternatives like OPA837 or OPA847 with rail-to-rail input/output and appropriate quiescent current.
What is the thermal resistance (θJA) of the OPA686N/3K package?
The OPA686N/3K in its SOT-23-5 package has a junction-to-ambient thermal resistance (θJA) of 150°C/W, as confirmed in the Absolute Maximum Ratings table. This value assumes standard JEDEC 2-layer board conditions; actual θJA improves with PCB copper area and thermal vias.
Can OPA686N/3K drive a 50Ω load directly?
Yes - the OPA686N/3K delivers ±80mA output current and supports ±3.3V swing into 100Ω and ±3.0V into 50Ω loads. Driving 50Ω directly is valid for short traces (<2cm) with proper 0.1µF local decoupling; for longer traces, add series 22Ω damping resistor to suppress reflections.
Is there a SPICE model available for OPA686N/3K?
Yes - a validated SPICE macro model for OPA686N/3K is available from Texas Instruments' official website and through their Applications Support team (1-800-548-6132). The model accurately predicts small-signal AC response and transient behavior but does not replicate harmonic distortion - which must be verified via bench measurement or system-level simulation.
OPA686N/3K Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SpeedPlus™
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Amplifier Type:
- Voltage Feedback
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 600V/µs
- Gain Bandwidth Product:
- 1.6 GHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 10 µA
- Voltage - Input Offset:
- 350 µV
- Current - Supply:
- 12.4mA
- Current - Output / Channel:
- 80 mA
- Voltage - Supply Span (Min):
- 9 V
- Voltage - Supply Span (Max):
- 12 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
OPA686N/3K FAQ
1.How can I place an order for OPA686N/3K through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA686N/3K 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 OPA686N/3K reliable?
The price and inventory of OPA686N/3K are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA686N/3K is usually 5 days.
3.What payment methods are accepted for OPA686N/3K?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA686N/3K transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA686N/3K?
OPA686N/3K orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA686N/3K 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 OPA686N/3K?
For technical support, including OPA686N/3K datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA686N/3K requirements.
6.How does Aetrix verify that OPA686N/3K is sourced from the original manufacturer or authorized distributors?
All OPA686N/3K 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 OPA686N/3K meets industry standards.
7.What is the process for return or replacement of OPA686N/3K?
All OPA686N/3K units undergo pre-shipment inspection (PSI). If there is an issue with OPA686N/3K, 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 OPA686N/3K part is unused and in its original packaging.
Return procedure for OPA686N/3K:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
OPA686N/3K Tags
-
LM358DT
STMicroelectronics
-
LM358DR
Texas Instruments
-
LM2904DR
Texas Instruments
-
LM358ADR
Texas Instruments
-
LM2904DGKR
Texas Instruments
-
LM324DR
Texas Instruments
-
MCP6006T-E/OT
Microchip Technology
-
MCP6006UT-E/OT
Microchip Technology
-
LM324PWR
Texas Instruments
-
LM2902PWR
Texas Instruments
-
LM2902DR
Texas Instruments
-
LM358P
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
