Datasheet

MAX4373/MAX4374/MAX4375
Low-Cost, Micropower, High-Side Current-Sense
Amplifier + Comparator + Reference ICs
_______________________________________________________________________________________ 9
FUNCTION
Detailed Description
The MAX4373 high-side current-sense supervisor fea-
tures a high-side current-sense amplifier, bandgap ref-
erence, and comparator with latching output to monitor
a supply for an overcurrent condition (Figure 1). The
latching output allows the comparator to shut down a
power supply without oscillations. The MAX4374/
MAX4375 offer an additional comparator to allow win-
dow detection of the current.
Current-Sense Amplifier
The internal current-sense amplifier features a 0V to
+28V input common-mode range that is independent of
the supply voltage. With this feature, the device can
monitor the output current of a battery in deep dis-
charge and also high-side current-sensing voltages
exceeding V
CC
.
The current-sense amplifier is also suitable for low-side
current sensing. However, the total output voltage error
will increase when V
RS+
falls below 2V, as shown in
the
Electrical Characteristics and Typical Operating
Characteristics
.
Pin Description
RS-RS+
OUT
CIN2
GND
CIN1
LOAD
V
IN
= 0 TO 28V
V
CC
RESET
0.6V
BANDGAP
REFERENCE
R
SENSE
+ V
SENSE
-
V
PULL-UP
(UP TO 5V)
R2
R1 R4
R5
V
PULL-UP
(UP TO 5V)
R6
MAX4374
(MAX4375)
R3
COUT1
COUT2
CURRENT-
SENSE
AMPLIFIER
+
-
+(-)
-(+)
Figure 1. Functional Diagram
FUNCTIONNAME
1
1 V
CC
2 2 OUT
PIN
3 3 CIN1
— 4 CIN2
— 7 COUT2
6 8 COUT1
5 6
RESET
4
5 GND
— — N.C.
8 10 RS+
7 9 RS-
Supply Voltage Input
1
2
4
5
10
11
8
7
3, 6, 9, 12
14
13
MAX4374/MAX4375
Voltage Output. V
OUT
is proportional to V
SENSE
(V
RS+
- V
RS-
).
MAX4373
Comparator Input 1. Positive input of an internal comparator. The nega-
tive terminal is connected to a 0.6V internal reference.
Comparator Input 2. Terminal of a second internal comparator. The pos-
itive terminal for the MAX4374 and the negative terminal for the
MAX4375. The other terminal is connected to a 0.6V internal reference.
Open-Drain Comparator Output. Output of the second unlatched inter-
nal comparator.
Open-Drain Comparator Output. Latching output of the comparator con-
trolled by CIN1. Connect RESET to GND to disable the latch.
Reset Input. Resets the output latch of the comparator at CIN1.
µMAX
Ground
µMAX/SO SO
No Connection. Not internally connected.
Power Connection to the External Sense Resistor
Load-Side Connection for the External Sense Resistor