Overview
Features and Benefits
- Accurate Linear Gain Control: ±1% Typ, ±3% Max
- Constant Gain with Temperature
- Wide Bandwidth: 40MHz
- High Slew Rate: 300V/µs
- Fast Control Path: 10MHz
- Low Control Feedthrough: 2.5mV
- High Output Current: 40mA
- Low Output Noise
- 45nV/√Hz at AV = 1
- 270nV/√Hz at AV = 100
- Low Distortion: 0.01%
- Wide Supply Range: ±2.5V to ±15V
- Low Supply Current: 13mA
- Low Differential Gain and Phase: 0.02%, 0.02°
Product Details
The LT1251/LT1256 are 2-input, 1-output, 40MHz current feedback amplifiers with a linear control circuit that sets the amount each input contributes to the output. These parts make excellent electronically controlled variable gain amplifiers, filters, mixers and faders. The only external components required are the power supply bypass capacitors and the feedback resistors. Both parts operate on supplies from ±2.5V (or single 5V) to ±15V (or single 30V).
Absolute gain accuracy is trimmed at wafer sort to minimize part-to-part variations. The circuit is completely temperature compensated.
The LT1251 includes circuitry that eliminates the need for accurate control signals around zero and full scale. For control signals of less than 2% or greater than 98%, the LT1251 sets one input completely off and the other completely on. This is ideal for fader applications because it eliminates off-channel feedthrough due to offset or gain errors in the control signals.
The LT1256 does not have this on/off feature and operates linearly over the complete control range. The LT1256 is recommended for applications requiring more than 20dB of linear control range.
Applications
- Composite Video Gain Control
- RGB, YUV Video Gain Control
- Video Faders, Keyers
- Gamma Correction Amplifiers
- Audio Gain Control, Faders
- Multipliers, Modulators
- Electronically Tunable Filters
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.
Documentation & Resources
Tools & Simulations
LTspice
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:
LT1251
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.
| Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
|---|---|---|---|---|
| LT1251CN#PBF | Material Declaration | Reliability Data | 14-Lead PDIP (Narrow 0.3 Inch) | |
| LT1251CS#PBF | Material Declaration | Reliability Data | 14-Lead SOIC (Narrow 0.15 Inch) | |
| LT1251CS#TRPBF | Material Declaration | Reliability Data | 14-Lead SOIC (Narrow 0.15 Inch) | |
| Wafer Fabrication Data | R164 Reliability Data |
PCN-PDN Information
Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.
Support & Discussions
Sample & Buy
Ordering FAQs
See our Ordering FAQs for answers to questions about online orders, payment options and more.
Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
List Pricing
(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.