My Inquiry
My Account
Texas Instruments OPA637AM
- Part No.:
- OPA637AM
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- TO-99-8 Metal Can
- Datasheet:
-
OPA637AM.pdf
- Description:
- IC OPAMP GP 1 CIRCUIT TO99-8
- Quantity:
- Payment:
- Shipping:
Inventory:4,988
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
OPA637AM from Texas Instruments is a precision high-speed JFET-input operational amplifier optimized for gain ≥ 5 configurations, delivering 80 MHz gain-bandwidth product, 135 V/µs slew rate, and 450 ns settling time to 0.01% in fast data acquisition and DAC output amplification circuits.
For engineers reviewing the OPA637AM datasheet, OPA637AM pinout, OPA637AM application, or OPA637AM equivalent, this page provides verified specifications, SOIC-8 and TO-99 package details, thermal performance metrics, stability requirements for noise gain ≥ 5, and validated alternative options for precision analog signal chains.
Technical Context
The OPA637AM uses dielectrically isolated complementary NPN/PNP process technology with laser-trimmed input circuitry to achieve low offset voltage (±130 µV max), low drift (±1.2 µV/°C max), and ultra-low input bias current (±2 pA max at 25°C). Its internal cascode architecture maintains low IB across ±11.5 V common-mode range.
Stability is guaranteed only at closed-loop noise gain ≥ 5 - unlike the unity-gain-stable OPA627AM. The device operates from ±4.5 V to ±18 V supplies, supports rail-to-rail output swing into 1 kΩ loads (±11.5 V), and delivers 45 mA short-circuit current with 55 Ω open-loop output impedance at 1 MHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain-bandwidth product | 80 MHz at G = 10 - enables stable high-frequency amplification in noninverting ≥10× or inverting ≥9× configurations |
| Slew rate | 135 V/µs at G = –4 - supports clean 10 V step response with minimal distortion in fast settling applications |
| Settling time | 450 ns to 0.01% error band - meets timing requirements for 16-bit ADC drivers and pulse amplifiers |
| Input offset voltage | ±130 µV maximum at 25°C - reduces DC error in precision instrumentation front-ends without trimming |
| Input bias current | ±2 pA maximum at 25°C - preserves signal integrity in high-impedance sensor interfaces (e.g., photodiode, piezoelectric) |
| Input voltage noise density | 4.8 nV/√Hz at 10 kHz - balances low-noise performance with JFET input advantages over bipolar op amps |
| Supply voltage range | ±4.5 V to ±18 V - supports dual-rail operation in industrial and test equipment with wide dynamic range |
Pinout & Package
OPA637AM is available in two industry-standard packages: 8-pin SOIC (D package) and 8-pin metal TO-99 (LMC package). Both support industrial temperature range (–55°C to +125°C) and share identical pin functions except for offset trim terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 5, 8 (SOIC); 1, 5 (TO-99) | Offset Trim / NC | SOIC pins are no-connect; TO-99 pins allow external 100 kΩ potentiometer for ±10 mV trim - optional, not required for most designs |
| 2 | Inverting Input (–IN) | Differential input node; high-impedance JFET gate with 10 TΩ || 8 pF input impedance |
| 3 | Noninverting Input (+IN) | Differential input node; same impedance as –IN; common-mode range extends to ±11.5 V |
| 4 | Negative Supply (V–) | Lowest potential supply rail; must be connected to system ground or negative rail - floating causes malfunction |
| 6 | Output (OUT) | Class-A output stage capable of ±45 mA drive into resistive loads; 55 Ω open-loop impedance at 1 MHz |
| 7 | Positive Supply (V+) | Highest potential supply rail; supports up to ±18 V differential; decoupling recommended within 1 cm |
| 8 (TO-99) | No Connect (NC) | Internally unconnected; must be left floating - not tied to case or ground |
Key Features
| Feature | Design Value |
|---|---|
| Laser-trimmed input stage | Enables ±130 µV max VOS and ±1.2 µV/°C max drift - eliminates need for external nulling in most precision systems |
| Stable at noise gain ≥ 5 | Allows higher bandwidth than unity-gain-stable alternatives in fixed-gain ≥5 circuits - e.g., DAC buffer with G = 10 |
| Ultra-low input bias current | ±2 pA max at 25°C and ±50 pA at –55°C to +125°C - preserves accuracy in >1 GΩ source impedances |
| High slew rate & fast settling | 135 V/µs and 450 ns to 0.01% - meets timing budgets for 1 MSPS data acquisition with 16-bit resolution |
| Wide supply range & robust output | Operates from ±4.5 V to ±18 V; delivers ±45 mA short-circuit current - suitable for driving cables and reactive loads |
Applications
| Precision Instrumentation | Fast Data Acquisition |
|---|---|
|
Use Scenario: High-resolution digital multimeter front-end measuring microvolt-level signals from calibrated shunts and thermocouples. IC Role / Device Role / Timing Role: Low-drift, low-noise gain stage amplifying sensor outputs before 24-bit sigma-delta ADC conversion. Use Value: ±130 µV VOS and ±1.2 µV/°C drift minimize calibration frequency; 4.8 nV/√Hz noise preserves SNR in sub-100 µV measurements. |
Use Scenario: 16-bit simultaneous-sampling data logger capturing transient waveforms from vibration sensors in predictive maintenance systems. IC Role / Device Role / Timing Role: Driver for SAR ADC reference buffer and multiplexed channel amplifier with <500 ns settling requirement. Use Value: 450 ns to 0.01% ensures full-scale step fidelity at 1 MSPS; 135 V/µs slew rate prevents slewing-induced distortion on 10 V pulses. |
| DAC Output Amplifier | High-Impedance Sensor Amp |
|
Use Scenario: Precision current-source driver for optical transceiver bias control, requiring monotonic 0–10 V output with <0.01% linearity error. IC Role / Device Role / Timing Role: Noninverting gain-of-10 amplifier buffering 16-bit DAC output to drive 50 Ω transmission lines and laser diodes. Use Value: Gain-bandwidth of 80 MHz ensures flat frequency response to 1 MHz; stability at G ≥ 5 avoids compensation networks. |
Use Scenario: Charge amplifier for piezoelectric accelerometers in structural health monitoring, where source impedance exceeds 1 GΩ. IC Role / Device Role / Timing Role: JFET-input transimpedance amplifier converting high-impedance charge signals to low-impedance voltage outputs. Use Value: ±2 pA IB minimizes input error current; 10 TΩ differential input impedance prevents signal loading and drift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar precision high-speed op amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA637AU | Same electrical specs but rated for –40°C to +125°C; higher ESD rating (HBM ±2000 V vs ±2500 V for AM) | Preferred for commercial/industrial environments where extended temp range is unnecessary and cost sensitivity is higher | Select OPA637AU if operating temperature stays above –40°C and lower procurement cost is prioritized over military-grade reliability |
| OPA627AM | Unity-gain stable; lower GBW (16 MHz); slower settling (550 ns); same package, temp range, and VOS spec | Required for unity-gain buffers, integrators, or circuits with feedback capacitors that reduce noise gain below 5 | Choose OPA627AM only when circuit topology mandates unity-gain stability - otherwise OPA637AM delivers superior speed and bandwidth |
Compared with OPA637AU, the OPA637AM offers enhanced reliability for aerospace and defense applications via extended –55°C operation and higher HBM ESD tolerance; compared with OPA627AM, it trades unity-gain stability for 5× higher gain-bandwidth and 22% faster settling - critical for gain-fixed high-speed signal paths.
Availability
OPA637AM is available at Aetrix Electronics and suitable for precision instrumentation, fast data acquisition, and DAC output amplification requiring stable component supply across extended temperature and long-lifecycle programs.
Supply support for OPA637AM 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 innovation in precision op amps and high-speed signal conditioning.
The OPA637AM belongs to TI's OPA6x7 family of precision JFET-input op amps, designed specifically for applications demanding both low noise and high speed - bridging the performance gap between legacy FET and modern bipolar op amps.
FAQ
What is the minimum stable gain for OPA637AM?
The OPA637AM is stable only at closed-loop noise gain ≥ 5. This means noninverting configurations require gain ≥ 5, and inverting configurations require gain magnitude ≥ 4. Using OPA637AM at lower noise gains risks oscillation - always verify phase margin in simulation or bench testing before deployment. The OPA637AM datasheet explicitly prohibits unity-gain or G = 2 use without external compensation.
Does OPA637AM support single-supply operation?
Yes, OPA637AM supports single-supply operation with total supply voltage up to 36 V (e.g., 0 V to +36 V). However, its input common-mode range extends only to (V–) – 0.5 V and (V+) + 0.5 V, so for single-supply use, the inputs must remain within 0.5 V of the rails. For true rail-to-rail input capability, an alternative op amp is required - OPA637AM is not rail-to-rail input.
What is the thermal resistance of OPA637AM in SOIC-8 package?
The OPA637AM in SOIC-8 (D) package has a junction-to-ambient thermal resistance (RθJA) of 107.9 °C/W. This value assumes standard JEDEC 2-layer board conditions. For high-power applications, derating is required above ambient temperatures - maximum junction temperature is 175°C for the AM grade, limiting continuous power dissipation to ~9.3 mW per °C of ambient rise above 25°C.
Can OPA637AM replace OPA627AM directly on the same PCB?
No - OPA637AM and OPA627AM are not pin-compatible replacements due to differing stability requirements and internal compensation. While both share identical pinouts in SOIC-8 and TO-99 packages, substituting OPA637AM for OPA627AM in a unity-gain circuit will cause instability. Layout reuse is possible only if the circuit is redesigned for noise gain ≥ 5 and verified for phase margin.
What is the input voltage noise density of OPA637AM at 1 kHz?
The OPA637AM has an input voltage noise density of 5.6 nV/√Hz at 1 kHz, as specified in Section 5.8 of the SBOS165C datasheet. This value is measured at TA = 25°C, VS = ±15 V, and RL = 10 kΩ. It reflects the device's optimized balance between JFET input noise and bandwidth - lower than general-purpose op amps but higher than ultra-low-noise bipolar types, making it ideal for medium-bandwidth precision applications.
OPA637AM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- Difet®
- Package/Case:
- TO-99-8 Metal Can
- Packaging:
- Tube
- Product Status:
- Not For New Designs
- Amplifier Type:
- General Purpose
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 135V/µs
- Gain Bandwidth Product:
- 80 MHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 2 pA
- Voltage - Input Offset:
- 130 µV
- Current - Supply:
- 7mA
- Current - Output / Channel:
- 45 mA
- Voltage - Supply Span (Min):
- 9 V
- Voltage - Supply Span (Max):
- 36 V
- Operating Temperature:
- -25°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-99-8
OPA637AM FAQ
1.How can I place an order for OPA637AM through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA637AM 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 OPA637AM reliable?
The price and inventory of OPA637AM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA637AM is usually 5 days.
3.What payment methods are accepted for OPA637AM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA637AM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA637AM?
OPA637AM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA637AM 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 OPA637AM?
For technical support, including OPA637AM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA637AM requirements.
6.How does Aetrix verify that OPA637AM is sourced from the original manufacturer or authorized distributors?
All OPA637AM 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 OPA637AM meets industry standards.
7.What is the process for return or replacement of OPA637AM?
All OPA637AM units undergo pre-shipment inspection (PSI). If there is an issue with OPA637AM, 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 OPA637AM part is unused and in its original packaging.
Return procedure for OPA637AM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
OPA637AM 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…
