LT1116
7
1116fc
For more information www.linear.com/LT1116
Input Characteristics
Each input to the LT1116 is buffered with a fast PNP
follower—input bias current therefore does not vary
significantly throughout the common mode range. When
either input exceeds the positive common mode limit, the
bias current drops to zero. Inputs that fall more than one
diode and drop below V
–
will forward bias the substrate
or clamp diode, causing large input current to flow.
Single ended input resistance is about 5MΩ, and re
-
mains roughly constant over the input common mode
range. The common mode resistance is about 2.5MΩ
with zero differential input voltage, and does not change
signifi cantly with the absolute value of differential input.
Effective input capacitance, typically 5pF, is determined
by measuring the resulting change in propagation delay
for a 1kΩ change in source resistance.
applicaTions inForMaTion
Latch Pin Dynamics
The internal latch uses local regenerative feedback to
shorten set-up and hold times. Driving the latch pin high
retains the output state. The latch pin floats to a high
state when disconnected, so it must be driven low for
flow-through operation. The set-up time required to
guarantee detecting a given transition of the inputs is 2ns.
The inputs must also remain stable for a
2ns hold time
after latch is asserted. New data will appear at the output
approximately 10ns to 12ns after the latch goes low. The
latch pin has no built-in hysteresis, and is designed to be
driven from TTL or CMOS logic gates.
Additional Information
Linear Technology’s Application Note 13 provides an
extensive discussion of design techniques for high speed
comparators.
Figure 2. This Single Supply Crystal Oscillator Utilizes Crystals
From 10MHz To 15MHz Without Component Changes
Single Supply Crystal Oscillator 10MHz to 15MHz
LT1116 • AI02
Q
2kΩ
1kΩ
1kΩ
24pF
5V
AT CUT
Q
LT1116
+
–
