Features and Benefits
- Operates with Inputs Above V+
- Rail-to-Rail Input and Output
- Low Power: 230μA per Amplifier Max
- Gain Bandwidth Product: 1.2MHz
- Slew Rate: 0.4V/μs
- High Output Current: 25mA Min
- Specified on 3V, 5V and ±15V Supplies
- Reverse Battery Protection to 18V
- No Supply Sequencing Problems
- High Voltage Gain: 1500V/mV
- Single Supply Input Range: –0.4V to 44V
- High CMRR: 98dB
- No Phase Reversal
- Available in 14-Lead SO, 8-Lead MSOP and DFN Packages
The LT1638 is a low power dual rail-to-rail input and output operational amplifier available in the standard 8-pin PDIP and SO packages as well as the 8-lead MSOP package. The LT1639 is a low power quad rail-to-rail input and output operational amplifier offered in the standard 14-pin PDIP and surface mount packages. For space limited applications the LT1638 is available in a 3mm × 3mm × 0.8mm dual fine pitch leadless package (DFN).
The LT1638/LT1639 op amps operate on all single and split supplies with a total voltage of 2.5V to 44V drawing only 170μA of quiescent current per amplifier. These amplifiers are reverse battery protected and draw no current for reverse supply up to 18V.
The input range of the LT1638/LT1639 includes both supplies, and a unique feature of this device is its capability to operate over the top with either or both of its inputs above V+. The inputs handle 44V, both differential and common mode, independent of supply voltage. The input stage incorporates phase reversal protection to prevent false outputs from occurring when the inputs are below the negative supply. Protective resistors are included in the input leads so that current does not become excessive when the inputs are forced below the negative supply. The LT1638/LT1639 can drive loads up to 25mA and still maintain rail-to-rail capability. The op amps are unity-gain stable and drive all capacitive loads up to 1000pF when optional output compensation is used.
- Battery- or Solar-Powered Systems
- Portable Instrumentation
- Sensor Conditioning
- Supply Current Sensing
- Battery Monitoring
- Micropower Active Filters
- 4mA to 20mA Transmitters
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Documentation & Resources
R334 Reliability Data3/22/2018
DC594A - Demo Manual9/24/2009
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
Use the Analog Filter Wizard to design low-pass, high-pass, or band-pass filters with actual op amps in minutes. As you progress through the design process, you can observe the characteristics of your filter design from ideal specifications to real world circuit behavior. Quickly evaluate the tradeoffs in op amp specifications - including gain-bandwidth, noise, and supply current – to determine the best filter design for your requirements.
Use Photodiode Wizard to design a transimpedance amplifier circuit to interface with a photodiode. Select a photodiode from the library included in the tool, or enter custom photodiode specifications. Quickly observe tradeoffs between Bandwidth, Peaking (Q), and ENOB/SNR. Modify circuit parameters, and immediately see results in plots for pulse response, frequency response, and noise gain.
LT1638 Companion Parts
Recommended Related Parts
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.