LT1711 Linear Technology, LT1711 Datasheet - Page 7

• Manufacturer Part Number: LT1711
• Description: 4ns/ 150MHz Dual Comparator with Independent Input/Output Supplies
• Manufacturer: Linear Technology

APPLICATIO S I FOR ATIO
Power Supply Configurations
The LT1715 has separate supply pins for the input and
output stages that allow flexible operation, accommodat-
ing separate voltage ranges for the analog input and the
output logic. Of course, a single 3V/5V supply may be used
by tying + V
The minimum voltage requirement can be simply stated as
both the output and the input stages need at least 2.7V and
the V
The following rules must be adhered to in any
configuration:
Although the ground pin need not be tied to system
ground, most applications will use it that way. Figure 1
shows three common configurations. The final one is
uncommon, but it will work and may be useful as a level
translator; the input stage is run from – 5.2V and ground
while the output stage is run from 3V and ground. In this
case the common mode input voltage range does not
include ground, so it may be helpful to tie V
Conversely, V
the above rules are not violated.
TEST CIRCUITS
2.7V (V
2.7V (+ V
(+ V
V
EE
EE
S
pin must be equal to or less than ground.
– V
Ground
–3V
0V
S
CC
EE
and V
CC
S
) 12V
– V
– GND) 6V
may also be tied below ground, as long as
CC
U
EE
) 12V
together as well as GND and V
PULSE
IN
U
50
W
1N5711
0.1 F
0V
–5V
130
400
U
Response Time Test Circuit
CC
to 3V.
2N3866
EE
750
.
–100mV
25
*V1 = –1000 • (OVERDRIVE + V
NOTE: RISING EDGE TEST SHOWN.
12V Input, 5V Output Supplies
Input Voltage Considerations
The LT1715 is specified for a common mode range of
–100mV to 3.8V when used with a single 5V supply. A
more general consideration is that the common mode
range is 100mV below V
for this common mode limit is that the output still
FOR FALLING EDGE, REVERSE LT1719 INPUTS
V1*
25
50k
Single Supply
Figure 1. Variety of Power Supply Configurations
50
+
–
12V
+
–
2.7V TO 6V
V
V
V
V
CC
EE
CC
EE
V
V
CC
EE
1/2 LT1715
+
–
– V
– V
5V
TRIP
+V
+ V
GND
GND
+ V
DUT
–V
CM
CM
s
+
S
S
)
CM
– V
CM
EE
0.01 F
0.01 F
to 1.2V below V
5V Input, 3V Output Supplies
Front End Entirely Negative
10 SCOPE PROBE
(C
1715 TC02
IN
– 5.2V
– 5V
+
–
+
–
5V
10pF)
V
V
V
V
CC
EE
CC
EE
CC
. The criterion
LT1715
3V
3V
+ V
GND
+ V
GND
1715 F01
S
S
7