lt6703hv-2 Linear Technology Corporation, lt6703hv-2 Datasheet - Page 10

• Manufacturer Part Number: lt6703hv-2
• Description: Micropower, Low Voltage Comparator With 400mv Reference
• Manufacturer: Linear Technology Corporation

LT6703-2/LT6703-3
LT6703HV-2/LT6703HV-3
TYPICAL PERFORMANCE CHARACTERISTICS
APPLICATIONS INFORMATION
The LT6703-2/LT6703-3/LT6703HV-2/LT6703HV-3 devices
are micropower comparators with a built-in 400mV refer-
ence. Features include wide supply voltage range (1.4V to
18V), Over-The-Top input and output range, 2% accurate
rising input threshold voltage and 6.5mV typical built-in
hysteresis.
Internal Reference
Each comparator has one input available externally. The two
versions of the part differ by the polarity of the available
input (i.e., inverting or noninverting). The other comparator
10
V
THRESHOLD EQUATIONS:
V
V
IN
IN
IN
(L TO H) = (400mV) • (R1) •
(H TO L) = (393mV) • (R1) •
60
50
40
20
10
30
0
0
Propagation Delay
vs Input Overdrive
T
A
R1
= 25°C
20
Figure 1. Additional Hysteresis Circuit
INPUT OVERDRIVE (mV)
R2
40
+IN
(
(
R1
R1
1
1
60
+
+
R2
R2
LT6703-3
1
1
LH NONINV
HL NONINV
LH INV
HL INV
GND
+
+
R3
V
80
S
R3
R3 + R4
1
)
670323 G25
1
100
)
670323 F01
–
OUT
(
R3 + R4
V
S
• R1
0.01
100
0.1
10
R4
)
1
0.1
Rise and Fall Times
vs Output Pull-Up Resistor
V
C
T
S
L
A
= 5V
= 20pF
= 25°C
OUTPUT PULL-UP RESISTOR (kΩ)
V
OUT
1
RISE
10
input is connected internally to the 400mV reference. The
rising input threshold voltage of the comparator is designed
to be equal to that of the reference (i.e., ≈400mV). The
reference voltage is established with respect to the device
GND connection.
Hysteresis
Each comparator has built-in 6.5mV (typical) of hysteresis
to simplify designs, to insure stable operation in the pres-
ence of noise at the inputs, and to reject supply rail noise
that might be induced by state change load transients. The
hysteresis is designed such that the falling input threshold
voltage is nominally 393.5mV. External positive feedback
circuitry can be employed to increase effective hysteresis
if desired, but such circuitry will provide an apparent effect
on both the rising and falling input thresholds (the actual
internal thresholds remain unaffected).
Comparator Input
The comparator input can range from ground to 18V (36V
for LT6703HV), regardless of the supply voltage used. The
typical input current for inputs well above the threshold
(i.e., >800mV) is a few pA leaking into the input. With
decreasing input voltage, a small bias current begins
to be drawn out of the input, reaching a few nA when at
ground potential. The input may be forced 100mV below
FALL
100
670323 G26
1000
10mV/DIV
V
V
O(NINV)
5V/DIV
5V/DIV
O(INV)
V
DC
DC
AC
IN
V
T
R
V
VOLTAGE THRESHOLDS
Noninverting and Inverting
Comparator Propagation Delay
S
A
IN(OVERDRIVE)
LOAD
= 25°C
= 5V
= 10k CONNECTED TO V
= 10mV OVER THE INPUT
20μs/DIV
S
670323 G27
670323fc