MAX4373/MAX4374/MAX4375

Low-Cost, Micropower, High-Side

Current-Sense Amplifier +

Comparator + Reference ICs

Maxim Integrated | 9

www.maximintegrated.com

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 VCC.

The current-sense amplifier is also suitable for low-side

current sensing. However, the total output voltage error

will increase when VRS+ falls below 2V, as shown in

the

Electrical Characteristics and Typical Operating

Characteristics.

Pin Description

Figure 1. Functional Diagram

FUNCTION

NAME

1

1

VCC

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. VOUT is proportional to VSENSE (VRS+ - VRS-).

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

RS-

RS+

OUT

CIN2

GND

CIN1

LOAD

VIN = 0 TO 28V

VCC

RESET

0.6V

BANDGAP

REFERENCE

RSENSE

+ VSENSE -

VPULL-UP

(UP TO 5V)

R2

R1

R4

R5

VPULL-UP

(UP TO 5V)

R6

MAX4374

(MAX4375)

R3

COUT1

COUT2

CURRENT-

SENSE

AMPLIFIER

+

-

+(-)

-(+)