MAX977EEE Maxim Integrated Products, MAX977EEE Datasheet - Page 12

• Manufacturer Part Number: MAX977EEE
• Description: IC COMPARATOR DUAL 16-QSOP
• Manufacturer: Maxim Integrated Products
• Type: General Purposer

Specifications of MAX977EEE

• Number Of Elements: 2
• Output Type: CMOS, Rail-to-Rail, TTL
• Voltage - Supply: 2.7 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

powered up, the high-speed comparator is enabled,
the low-power comparator is disabled, and STAT goes
high, placing the MAX975 back into high-speed mode
(Figure 2).
Use an external capacitor, C
period required for the comparator to enter auto-
standby mode. Determine the capacitor required for a
particular timeout period by the relationship t
10 x Cµs, where C is in pF. For example, connecting a
0.1µF capacitor to STO_ results in a timeout period of
1sec. The propagation delay of OUT_ when exiting auto
standby mode is equivalent to the low-power-mode
propagation delay. When STAT_ goes low, the low-
power comparator is disabled and the high-speed com-
parator is ready for operation. To bring the comparator
out of auto-standby mode without a transition occurring
on OUT_, toggle LP low-high-low. The LP pin is sensitive
to noise. If fall times larger than 10µs are expected,
bypass LP with a 0.1µF capacitor to GND. To disable
auto-standby mode, drive STO_ low or connect it to
ground. Note that driving STO_ low while in auto-
standby mode will not bring the comparator out of auto-
standby mode. Also, if driving STO_ with an open drain,
leakage must be less than 1nA. On power-up, the
device is in high-speed mode unless LP is high. The
MAX977 operates in the same manner as the MAX975.
Single/Dual, +3V/+5V Dual-Speed
Comparators with Auto-Standby
Figure 2. Timing Diagram
12
DIFFERENTIAL
______________________________________________________________________________________
VOLTAGE
I
CC (TYP)
INPUT
STAT_
OUT_
LP
300 A
3 A
V
V
V
V
OH
CC
0V
OS
OL
V
A
CC
t
PD+
STO
, to program the timeout
t
PD-
ASB
t
ASB
=
t
ASBE
Driving LP high switches the MAX975/MAX977 to low-
power mode. In this mode, the supply current drops to
a maximum of 5 A, and propagation delay increases
typically to 480ns. The high-speed comparator is dis-
abled and the low-power comparator is enabled for
continuous operation. Return to high-speed mode by
driving LP low. The LP pin is sensitive to noise. If fall
times larger than 10µs are expected, bypass LP with a
0.1µF capacitor to GND. The logic state and sink/
source capabilities of OUT_ remain unchanged in low-
power mode.
The MAX975/MAX977 input common-mode range is
from -0.2V to (V
each comparator input extends to both V
rails. The output remains in the correct logic state while
one or both of the inputs are within the common-mode
range. If both input levels are out of the common-mode
range, input-stage current saturation occurs and the
output becomes unpredictable.
t
ASCD
t
PWD
t
ASD
CC
- 1.2V). But the voltage range for
t
LPE
Input-Stage Circuitry
t
LPSH
Low-Power Mode
t
LPCD
CC
t
HSE
and GND