LT1228
PRODUCTION100MHz Current Feedback Amplifier with DC Gain Control
- Part Models
- 6
- 1ku List Price
- Starting From $5.02
Part Details
- Very Fast Transconductance Amplifier
- Bandwidth: 75MHz
- Outputs Swing Within 0.8V of Supplies
- gm = 10 × ISET
- Low THD: 0.2% at 30mVRMS Input
- Wide ISET Range: 1µA to 1mA
- Very Fast Current Feedback Amplifier
- Bandwidth: 100MHz
- Slew Rate: 1000V/µs
- Output Drive Current: 30mA
- Differential Gain: 0.04%
- Differential Phase: 0.1°
- High Input Impedance: 25MΩ, 6pF
- Wide Supply Range: ±2V to ±15V
- Inputs Common Mode to Within 1.5V of Supplies
- Supply Current: 7mA
- Available in 8-Lead PDIP and SOIC Packages
The LT1228 makes it easy to electronically control the gain of signals from DC to video frequencies. The LT1228 implements gain control with a transconductance amplifier (voltage to current) whose gain is proportional to an externally controlled current. A resistor is typically used to convert the output current to a voltage, which is then amplified with a current feedback amplifier. The LT1228 combines both amplifiers into an 8-pin package, and operates on any supply voltage from 4V (±2V) to 30V (±15V). A complete differential input, gain controlled amplifier can be implemented with the LT1228 and just a few resistors.
The LT1228 transconductance amplifier has a high impedance differential input and a current source output with wide output voltage compliance. The transconductance, gm, is set by the current that flows into Pin5, ISET. The small signal gm is equal to ten times the value of ISET and this relationship holds over several decades of set current. The voltage at Pin 5 is two diode drops above the negative supply, Pin 4.
The LT1228 current feedback amplifier has very high input impedance and therefore it is an excellent buffer for the output of the transconductance amplifier. The current feedback amplifier maintains its wide bandwidth over a wide range of voltage gains making it easy to interface the transconductance amplifier output to other circuitry. The current feedback amplifier is designed to drive low impedance loads, such as cables, with excellent linearity at high frequencies.
Applications
- Video DC Restore (Clamp) Circuits
- Video Differential Input Amplifiers
- Video Keyer/Fader Amplifiers
- AGC Amplifiers
- Tunable Filters
- Oscillators
Documentation
Data Sheet 1
Reliability Data 1
User Guide 1
Application Note 5
Design Note 3
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 Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LT1228CN8#PBF | 8-Lead PDIP (Narrow 0.3 Inch) | ||
| LT1228CS8#PBF | 8-Lead SOIC (Narrow 0.15 Inch) | ||
| LT1228CS8#TRPBF | 8-Lead SOIC (Narrow 0.15 Inch) | ||
| LT1228IN8#PBF | 8-Lead PDIP (Narrow 0.3 Inch) | ||
| LT1228IS8#PBF | 8-Lead SOIC (Narrow 0.15 Inch) | ||
| LT1228IS8#TRPBF | 8-Lead SOIC (Narrow 0.15 Inch) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Oct 8, 2024 - 24_0234 Migrating Bottom Trace Code Marking to Top Side Laser Marking for PDIP Package |
||
| LT1228CN8#PBF | PRODUCTION | |
| LT1228IN8#PBF | PRODUCTION | |
|
Oct 11, 2022 - 22_0241 Epoxy Change from Henkel 8290 to 8290A for PDIP Package |
||
| LT1228CN8#PBF | PRODUCTION | |
| LT1228IN8#PBF | PRODUCTION | |
|
Aug 6, 2022 - 22_0172 Laser Top Mark Conversion for PDIP Packages Assembled in ADPG [PNG] |
||
| LT1228CN8#PBF | PRODUCTION | |
| LT1228IN8#PBF | PRODUCTION | |
|
Dec 14, 2023 - 22_0255 Epoxy Change from Henkel 8290 to 8290A for 8-Lead SOIC Package (PCN part 2 of 2) |
||
| LT1228CS8#PBF | PRODUCTION | |
| LT1228CS8#TRPBF | PRODUCTION | |
| LT1228IS8#PBF | PRODUCTION | |
| LT1228IS8#TRPBF | PRODUCTION | |
|
Jun 11, 2021 - 21_0060 Laser Top Mark for 8SOICN Assembled in ADPG, UTL and CRM |
||
| LT1228CS8#PBF | PRODUCTION | |
| LT1228CS8#TRPBF | PRODUCTION | |
| LT1228IS8#PBF | PRODUCTION | |
| LT1228IS8#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LT1228
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.
Evaluation Kits
DIP8, MS8, S8, SOT23-6 | Multi-Footprint General Purpose Board for Single Op. Amp