9

LT1361/LT1362

Small-Signal Transient

Small-Signal Transient

Small-Signal Transient

1361/1362 TA31

1361/1362 TA32

1361/1362 TA33

Large-Signal Transient

Large-Signal Transient

Large-Signal Transient

1361/1362 TA36

1361/1362 TA34

1361/1362 TA35

Layout and Passive Components

The LT1361/LT1362 amplifiers are easy to use and toler-

ant of less than ideal layouts. For maximum performance

(for example, fast 0.01% settling) use a ground plane,

short lead lengths, and RF-quality bypass capacitors

(0.01

µF to 0.1µF). For high drive current applications use

low ESR bypass capacitors (1

µF to 10µF tantalum). The

parallel combination of the feedback resistor and gain

setting resistor on the inverting input combine with the

input capacitance to form a pole which can cause peaking

or oscillations. If feedback resistors greater than 5k

Ω are

used, a parallel capacitor of value

should be used to cancel the input pole and optimize

dynamic performance. For unity-gain applications where

Input Considerations

Each of the LT1361/LT1362 inputs is the base of an NPN

and a PNP transistor whose base currents are of opposite

polarity and provide first-order bias current cancellation.

Because of variation in the matching of NPN and PNP beta,

the polarity of the input bias current can be positive or

negative. The offset current does not depend on NPN/PNP

beta matching and is well controlled. The use of balanced

source resistance at each input is recommended for

applications where DC accuracy must be maximized.

The inputs can withstand transient differential input volt-

ages up to 10V without damage and need no clamping or

source resistance for protection. Differential inputs, how-

ever, generate large supply currents (tens of mA) as

required for high slew rates. If the device is used with

sustained differential inputs, the average supply current

will increase, excessive power dissipation will result and

the part may be damaged. The part should not be used as

a comparator, peak detector or other open-loop applica-