Datasheet LT1352, LT1353 (Analog Devices) - 9

LT1352/LT1353
W U TYPICAL PERFORMANCE CHARACTERISTICS Small-Signal Transient Small-Signal Transient Small-Signal Transient (AV = 1) (AV = – 1) (AV = – 1, CL = 1000pF)
1352/53 G31 1352/53 G32 1352/53 G33
Large-Signal Transient Large-Signal Transient Large-Signal Transient (AV = 1) (AV = – 1) (AV = 1, CL = 10,000pF)
1352/53 G34 1352/53 G35 1352/53 G36
U U W U APPLICATIONS INFORMATION Layout and Passive Components Capacitive Loading
The LT1352/LT1353 amplifiers are easy to use and toler- The LT1352/LT1353 are stable with any capacitive load. ant of less than ideal layouts. For maximum performance As the capacitive load increases, both the bandwidth and (for example, fast 0.01% settling) use a ground plane, phase margin decrease so there will be peaking in the short lead lengths and RF-quality bypass capacitors (0.01µF frequency domain and in the transient response. Graphs to 0.1µF). For high drive current applications use low ESR of Frequency Response vs Capacitive Load, Capacitive bypass capacitors (1µF to 10µF tantalum). Load Handling and the transient response photos clearly The parallel combination of the feedback resistor and show these effects. gain setting resistor on the inverting input can combine
Input Considerations
with the input capacitance to form a pole which can cause peaking or even oscillations. If feedback resistors greater Each of the LT1352/LT1353 inputs is the base of an NPN than 10k are used, a parallel capacitor of value, CF > and a PNP transistor whose base currents are of opposite (RG)(CIN/RF), should be used to cancel the input pole and polarity and provide first-order bias current cancellation. optimize dynamic performance. For applications where Because of variation in the matching of NPN and PNP beta, the DC noise gain is one and a large feedback resistor is the polarity of the input bias current can be positive or used, CF should be greater than or equal to CIN. An negative. The offset current does not depend on NPN/PNP example would be an I-to-V converter as shown in the beta matching and is well controlled. The use of balanced Typical Applications section. source resistance at each input is recommended for 13523fa 9