特点
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/rtHz at A
V
= 1
270nV/rtHz at A
V
= 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°
典型应用
典型应用
描述
描述 The LT?1251/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.