max9077euat Maxim Integrated Products, Inc., max9077euat Datasheet - Page 6

• Manufacturer Part Number: max9077euat
• Description: Low-cost, Ultra-small, 3?a Single-supply Comparators
• Manufacturer: Maxim Integrated Products, Inc.

Low-Cost, Ultra-Small, 3µA
Single-Supply Comparators
The MAX9075/MAX9077 feature a 580ns propagation
delay from an ultra-low supply current of only 3µA per
comparator. These devices are capable of single-sup-
ply operation in the 2.1V to 5.5V range. Large internal
output drivers allow rail-to-rail output swing with up to
2mA loads. Both comparators offer a push-pull output
that sinks and sources current.
The MAX9075/MAX9077 are designed to maintain a
low-supply current during repeated transitions by limit-
ing the shoot-through current.
The input common-mode voltage range for these
devices extends from -0.2V to V
other comparators, the MAX9075/MAX9077 can oper-
ate at any differential input voltage within these limits.
Input bias current is typically -5nA if the input voltage is
between the supply rails.
Although the comparators have a very high gain, useful
gain is limited by noise. The comparator has a wide-
band peak-to-peak noise of approximately 70µV.
6
SOT23
Noise Considerations, Comparator Input
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—
—
—
—
—
1
2
3
4
5
MAX9075
SC70
—
—
—
—
—
—
1
2
3
4
5
PIN
µMAX/SO
Detailed Description
—
—
—
1
4
3
2
8
5
6
7
MAX9077
Comparator Output
CC
SOT23
- 1.2V. Unlike many
—
—
—
1
2
4
3
8
5
6
7
NAME
OUTA
OUTB
GND
INA+
INB+
OUT
INA-
INB-
V
IN+
IN-
CC
Hysteresis extends the comparator’s noise margin by
increasing the upper threshold and decreasing the
lower threshold. A voltage divider from the output of the
comparator sets the trip voltage. Therefore, the trip
voltage is related to the output voltage. Set the hystere-
sis with three resistors using positive feedback, as
shown in Figure 1.
The design procedure is as follows:
1) Choose R3. The leakage current of IN+ may cause a
2) Choose the hysteresis voltage (V
3) Calculate R1 as follows:
Comparator Output
Output of Comparator A
Ground
Noninverting Comparator Input
Noninverting Input of Comparator A
Inverting Comparator Input
Inverting Input of Comparator A
Positive Supply Voltage
Noninverting Input of Comparator B
Inverting Input of Comparator B
Output of Comparator B
small error; however, the current through R3 can be
approximately 500nA and still maintain accuracy.
The added supply current due to the circuit at the
trip point is V
for R3, as this keeps the current well below the sup-
ply current of the chip.
voltage between the upper and lower thresholds. In
this example, choose V
V
R1 = R3 x V
REF
= 1.2V and V
HYS
Applications Information
CC
/R3; 10MΩ is a good practical value
/ V
CC
CC
FUNCTION
= 5V.
= 10MΩ x 0.05 / 5 = 100kΩ
HYS
Pin Description
Adding Hysteresis
= 50mV and assume
HYS
), which is the