LT1228 Datasheet | Linear Technology

100MHz Current Feedback Amplifier with DC Gain Control Features DESCRIPTION n Very Fast Transconductance Amplifier Bandwidth: 75MHz gm = 10 × ISET Low THD: 0.2% at 30m VRMS Input Wide ISET Range: 1µA to 1m A n Very Fast Current Feedback Amplifier Bandwidth: 100MHz Slew Rate: 1000V/µs Output Drive Current: 30m A Differential Gain: 0.04% Differential Phase: 0.1° High Input Impedance: 25MΩ, 6p F n Wide Supply Range: ±2V to ±15V n Inputs mon Mode to Within 1.5V of Supplies n Outputs Swing Within 0.8V of Supplies n Supply Current: 7m A n Available in 8-Lead PDIP and SO Packages APPLICATIONS n Video DC Restore (Clamp) Circuits n Video Differential Input Amplifiers n Video Keyer/Fader Amplifiers n AGC Amplifiers n Tunable Filters n Oscillators L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. The LT®1228 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 bines both amplifiers into an 8-pin package, and operates on any supply voltage from 4V (±2V) to 30V (±15V). A plete 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 pliance. The transconductance, gm, is set by the current that flows into Pin 5, 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,...