LT1358/LT1359
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TYPICAL PERFORMANCE CHARACTERISTICS
Small-Signal Transient
(AV = 1)
Small-Signal Transient
(AV = –1)
Small-Signal Transient
(AV = –1, CL = 1000pF)
1358/1359 G32
1358/1359 G33
1358/1359 G31
Large-Signal Transient
(AV = 1)
Large-Signal Transient
(AV = –1)
Large-Signal Transient
(AV = 1, CL = 10,000pF)
1358/1359 G36
1358/1359 G35
1358/1359 G34
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APPLICATIONS INFORMATION
Layout and Passive Components
alargefeedbackresistorisused, CF shouldbegreaterthan
or equal to CIN.
The LT1358/LT1359 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
(0.01µF to 0.1µF). For high drive current applications use
low ESR bypass capacitors (1µF to 10µF tantalum).
Capacitive Loading
The LT1358/LT1359 are stable with any capacitive load.
As the capacitive load increases, both the bandwidth and
phase margin decrease so there will be peaking in the
frequency domain and in the transient response. Coaxial
cable can be driven directly, but for best pulse fidelity a
resistor of value equal to the characteristic impedance of
the cable (i.e., 75Ω) should be placed in series with the
output. The other end of the cable should be terminated
with the same value resistor to ground.
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 5kare
used, a parallel capacitor of value
CF > RG x CIN / RF
Input Considerations
Each of the LT1358/LT1359 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.
should be used to cancel the input pole and optimize
dynamic performance. For unity-gain applications where
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Linear [ Linear ]
