My Inquiry
My Account
Texas Instruments LMH6645MFX
- Part No.:
- LMH6645MFX
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LMH6645MFX.pdf
- Description:
- IC OPAMP VFB 1 CIRCUIT SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,120
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LMH6645MFX from Texas Instruments is a single-channel, rail-to-rail input and output voltage feedback operational amplifier optimized for low-voltage, low-power, high-speed applications. It delivers 55 MHz −3 dB bandwidth, 22 V/μs slew rate, and 650 μA supply current per channel at 2.7 V, with output swing within 20 mV of both rails-enabling full dynamic range in battery-powered sensor interfaces and portable instrumentation.
For engineers reviewing the LMH6645MFX datasheet, LMH6645MFX pinout, LMH6645MFX application, or LMH6645MFX equivalent, key selection criteria include its rail-to-rail I/O capability at micro-power operation, shutdown-ready architecture (shared with LMH6647), ±20 mA linear output drive, and stable performance across 2.5–12 V supply range-critical for precision analog front-ends in space-constrained, low-noise systems.
Technical Context
The LMH6645MFX employs a proprietary VIP10 dielectrically isolated bipolar process enabling high ft (~8 GHz) under low 2.7 V bias. Its rail-to-rail input stage extends common-mode range 0.3 V beyond either supply rail, while the class A-B "turn-around" input stage reduces noise and offset versus conventional high-speed op-amps.
The output stage uses a common-emitter push-pull configuration delivering ±20 mA into loads while maintaining rail-to-rail swing (20 mV from rails at 1 kΩ) and consistent 55 MHz bandwidth and 22 V/μs slew rate across 2.5–12 V supplies-minimizing design iteration when scaling supply voltage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| −3 dB Bandwidth | 55 MHz at AV = +1 - supports high-fidelity signal conditioning up to video and medium-speed data acquisition rates |
| Slew Rate | 22 V/μs - enables clean 10 VPP step response with <1% settling in <250 ns |
| Supply Current | 650 μA per channel at 2.7 V - allows continuous operation in coin-cell-powered devices for >1 year |
| Input Voltage Noise | 17 nV/√Hz at 100 kHz - preserves SNR in low-level transducer amplification |
| Output Swing | Within 20 mV of V+ and V− at RL = 1 kΩ - maximizes usable dynamic range in 3.3 V or lower systems |
| Input Common-Mode Range | Extends 0.3 V beyond rails - simplifies level-shifting in single-supply sensor interfaces |
| CMRR | 77 dB at 2.7 V - rejects supply and reference noise in precision DC-coupled paths |
Pinout & Package
SOT-23-5 package (2.90 mm × 1.60 mm body), surface-mount, thermally enhanced for compact PCB layouts in portable electronics.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | OUTPUT | Amplifier output node; drives loads up to ±20 mA with rail-to-rail swing |
| 2 | V− | Negative supply terminal; accepts ground or negative rail (down to −5 V) |
| 3 | +IN | Non-inverting input; supports common-mode voltage up to V− − 0.3 V and V+ + 0.3 V |
| 4 | −IN | Inverting input; matched to +IN for precision closed-loop gain accuracy |
| 5 | V+ | Positive supply terminal; operates from 2.5 V to 12 V (single or split) |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-rail input and output | Enables full-scale signal handling in 2.7 V systems without level-shifting circuitry |
| 55 MHz bandwidth at 650 μA | Delivers video-grade speed with micro-power efficiency-uncommon in bipolar op-amps |
| 17 nV/√Hz input voltage noise | Preserves resolution in low-amplitude sensor signals (e.g., strain gauges, thermopiles) |
| ±20 mA linear output drive | Directly drives ADC drivers, active filters, or 50 Ω cables without external buffers |
| Stable over 2.5–12 V supply | Eliminates re-characterization when migrating from 3.3 V to 5 V or 10 V industrial rails |
Applications
| Current Sense Buffer | High-Speed Portable Instrumentation |
|---|---|
Use Scenario: Amplifying mV-level shunt voltage in battery management ICs with 3.3 V supply. IC Role / Device Role / Timing Role: Precision, low-offset, rail-to-rail op-amp configured as unity-gain buffer driving 12-bit SAR ADC input. Use Value: 20 mV output swing margin ensures full 0–3.3 V ADC range utilization; 650 μA quiescent current minimizes battery drain. | Use Scenario: Signal conditioning front-end in handheld oscilloscope with 200 MSPS sampling. IC Role / Device Role / Timing Role: High-speed, low-noise amplifier for anti-aliasing filter interface and ADC driver. Use Value: 55 MHz bandwidth and 22 V/μs slew rate support clean 10 MHz sine wave acquisition; SOT-23-5 footprint saves board area. |
| Active Filter Stage | Transducer Interface for Industrial Sensors |
Use Scenario: Second-order Sallen-Key low-pass filter (fc = 2 MHz) in medical ultrasound receive path. IC Role / Device Role / Timing Role: Unity-gain stable voltage feedback amplifier implementing filter transfer function with minimal phase distortion. Use Value: 77 dB CMRR rejects power supply ripple; 17 nV/√Hz noise maintains SNR above 70 dB in 100 kHz–2 MHz band. | Use Scenario: Conditioning output of piezoresistive pressure sensor (10 mV/V) in 24 V field transmitter with 3.3 V digital section. IC Role / Device Role / Timing Role: Low-drift, rail-to-rail I/O amplifier providing gain-of-100 with 0.3 V beyond rails input range. Use Value: Input common-mode range down to −0.3 V accommodates sensor offset; 2.5–12 V supply flexibility eases integration with existing 24 V power architecture. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed, low-power op-amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMH6642MF/NOPB | Lower 30 MHz bandwidth, 10 V/μs slew rate, same SOT-23-5 package and rail-to-rail I/O | Better suited for sub-10 MHz active filters where power is more constrained than speed | Select when 55 MHz is unnecessary and 350 μA supply current provides meaningful battery life extension |
| OPA355DBVR | CMOS input (0.2 pA IB), 200 MHz bandwidth, but 2.3 mA supply current and no shutdown option | Preferred for ultra-low-input-bias applications like photodiode TIA, not rail-to-rail output-critical paths | Choose only if femtoampere input bias outweighs 3.5× higher quiescent current and loss of rail-to-rail output swing |
Compared with LMH6642MF/NOPB, LMH6645MFX trades 25 MHz bandwidth for 300 μA lower supply current and retains full rail-to-rail output; versus OPA355DBVR, it sacrifices CMOS input impedance for bipolar noise performance and true rail-to-rail swing-making LMH6645MFX optimal for precision, low-voltage, high-fidelity analog front-ends where output headroom and micro-power coexist.
Availability
LMH6645MFX is available at Aetrix Electronics and suitable for current sense buffering, portable instrumentation signal chains, and active filter stages requiring stable component supply, long-term manufacturability, and guaranteed SOT-23-5 packaging consistency.
Supply support for LMH6645MFX 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 for industrial, automotive, and personal electronics markets.
The LMH664x product line was engineered for high-speed, low-voltage, rail-to-rail signal conditioning in portable and battery-operated equipment-prioritizing bandwidth-efficiency trade-offs without sacrificing precision or output drive.
FAQ
What is the maximum supply voltage for LMH6645MFX?
The LMH6645MFX supports a supply voltage range of 2.5 V to 12 V between V+ and V− terminals. Absolute maximum rating is 12.6 V. Operation at 12 V is fully characterized per datasheet Electrical Characteristics tables, with bandwidth, slew rate, and output current remaining stable-enabling use in industrial 10 V or 12 V rails without derating.
Does LMH6645MFX include a shutdown feature?
No, LMH6645MFX does not include a shutdown pin. Shutdown functionality is exclusive to the LMH6647 variant (SOT-23-6 and SOIC-8 packages). The LMH6645MFX is a single-channel amplifier in SOT-23-5 with pins limited to V+, −IN, +IN, V−, and OUTPUT-no SD terminal is present or supported.
What is the typical input offset voltage of LMH6645MFX over temperature?
The LMH6645MFX has a typical input offset voltage of ±1 mV at 25°C, with a maximum of ±4 mV across the full −40°C to +85°C operating range. Its average drift is ±5 μV/°C, meaning total offset variation due to temperature is typically ≤0.5 mV over a 100°C span-suitable for DC-coupled precision gain stages where offset stability matters.
Can LMH6645MFX drive a 50 Ω load directly?
Yes, LMH6645MFX can drive a 50 Ω load directly, delivering ±20 mA linear output current. At 2.7 V supply, it sustains >1.5 VPP into 50 Ω before clipping; at 5 V, output swing exceeds 4 VPP. For sustained 50 Ω driving, thermal limits must be observed-RθJA = 265°C/W in SOT-23-5 means power dissipation should remain below ~150 mW to avoid exceeding 150°C junction temperature.
Is LMH6645MFX unity-gain stable?
Yes, LMH6645MFX is unity-gain stable. The datasheet specifies −3 dB bandwidth and slew rate test conditions explicitly at AV = +1, and Figure 1 (Closed Loop Frequency Response) confirms stable phase margin (>45°) at gain ≥1. No external compensation is required for unity-gain follower or inverting configurations with standard layout practices.
LMH6645MFX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- VIP10™
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Amplifier Type:
- Voltage Feedback
- Number of Circuits:
- 1
- Output Type:
- Push-Pull, Rail-to-Rail
- Slew Rate:
- 22V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 55 MHz
- Current - Input Bias:
- 650 nA
- Voltage - Input Offset:
- 1 mV
- Current - Supply:
- 725µA
- Current - Output / Channel:
- 20 mA
- Voltage - Supply Span (Min):
- 2.5 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
LMH6645MFX FAQ
1.How can I place an order for LMH6645MFX through Aetrix?
Please submit a Request for Quotation (RFQ) for LMH6645MFX 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 LMH6645MFX reliable?
The price and inventory of LMH6645MFX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMH6645MFX is usually 5 days.
3.What payment methods are accepted for LMH6645MFX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMH6645MFX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMH6645MFX?
LMH6645MFX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMH6645MFX 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 LMH6645MFX?
For technical support, including LMH6645MFX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMH6645MFX requirements.
6.How does Aetrix verify that LMH6645MFX is sourced from the original manufacturer or authorized distributors?
All LMH6645MFX 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 LMH6645MFX meets industry standards.
7.What is the process for return or replacement of LMH6645MFX?
All LMH6645MFX units undergo pre-shipment inspection (PSI). If there is an issue with LMH6645MFX, 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 LMH6645MFX part is unused and in its original packaging.
Return procedure for LMH6645MFX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMH6645MFX 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…
