LT1228 Datasheet PDF

●The LT1228CN8#PBF is an Operational Amplifier 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. 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 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, Pin 4.

● Inputs common mode to within 1.5V of supplies

● Outputs swing within 0.8V of supplies

● 7mA Supply current