LT1215 Linear Technology, LT1215 Datasheet - Page 15

• Manufacturer Part Number: LT1215
• Description: 23MHz/ 50V/us/ Single Supply Dual and Quad Precision Op Amps
• Manufacturer: Linear Technology

Comparator Applications
Sometimes it is desirable to use an op amp as a compara-
tor. When operating the LT1215/LT1216 on a single 3.3V
or 5V supply, the output interfaces directly with most TTL
and CMOS logic.
The response time of the LT1215/LT1216 is a strong
function of the amount of input overdrive as shown in the
I S PLI I F ED S
A
PPLICATI
W
100
4
2
0
0
Q7
V
R
Q9
S
L
= 5V
=
20mV, 10mV, 5mV, 2mV Overdrives
LT1215 Comparator Response (+)
O
Q8
U
I
1
–IN
CHE
S
C
I FOR ATIO
I
U
Q1
W
5 s/DIV
I
2
A
Q3
Q5
TIC
Q4
I
W
3
Q6
Q2
I
4
+IN
1215/16 AI01
U
Q10
I
5
C
F
following photos. These amplifiers are unity-gain stable
op amps and not fast comparators, therefore, the logic
being driven may oscillate due to the long transition time.
The output can be speeded up by adding 20mV or more of
hysteresis (positive feedback), but the offset is then a
function of the input direction.
Q11
I
7
R
F
100
C
M
4
2
0
0
V
R
S
L
= 5V
=
20mV, 10mV, 5mV, 2mV Overdrives
Q12
LT1215 Comparator Response (–)
I
6
BIAS
C
O
Q13
5 s/DIV
I
8
LT1215/LT1216
Q14
1215/16 SS
Q16
Q15
OUT
V
V
–
+
1215/16 AI02
15