8 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

8.1 Application Information

With its low response time, high common-mode transient immunity (CMTI) and reinforced isolation barrier,

the AMC23C12 is designed to provide fast and reliable overcurrent and overvoltage detection for high-voltage

applications in harsh and noisy environments.

8.2 Typical Applications

8.2.1 Overcurrent Detection

Fast overcurrent detection is a common requirement in DC/DC converter and motor-control applications, and

can be implemented with an AMC23C12 isolated window comparator as shown in Figure 8-1.

RSHUNT

10 m

HS Gate Driver Supply (3..27 V)

DC-link

VDD1

GND1

INP

INN

AMC1300B

VDD2

OUTP

OUTN

GND2

Low-side supply (3..5.5 V)

ADC

LS Gate Driver Supply

Low-side supply (3..5.5 V)

VDD1

GND1

IN

REF

AMC23C12

VDD2

LATCH

OUT

GND2

C5

100 nF

C1

100 nF

C2

1 µF

R1

1.96 k

C3

100 nF

C4

1 µF

R2

4.7 k

R4

10

to MCU

from MCU

C6

1 nF

R5

10

M

3~

Figure 8-1. Using the AMC23C12 for Overcurrent Detection

The load current flowing through an external shunt resistor RSHUNT produces a voltage drop that is sensed

by the AMC1300B for control purposes. The same voltage is monitored by the AMC23C12 that is connected in

parallel to the current-sensing amplifier and provides a fast sensing path for positive and negative fault-current

detection. The overcurrent detection threshold is set by the external resistor R1 and the overcurrent event is

signaled on the open-drain output OUT.

As depicted in Figure 8-1, the integrated low-dropout (LDO) regulator on the high-side allows direct connection

of the VDD1 input to a commonly used floating gate-driver supply. Alternatively, the AMC23C12 can share a

regulated supply with the AMC1300B. In that case, the VDD1 pin of the AMC23C12 connects directly to the

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AMC23C12

SBASAB2 – FEBRUARY 2022

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