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

The low analog input voltage range, excellent accuracy, and low temperature drift make the AMC3302-Q1 a

high-performance solution for automotive applications where shunt-based current sensing in the presence of

high common-mode voltage levels is required.

8.2 Typical Application

The AMC3302-Q1 is ideally suited for shunt-based, current-sensing applications where accurate current

monitoring is required in the presence of high common-mode voltages. The AMC3302-Q1 integrates an isolated

power supply for the high-voltage side and therefore makes the device particularly easy to use in applications

that do not have a high-side supply readily available or where a high-side supply is referenced to a different

ground potential than the signal to be measured.

Figure 8-1 shows a simplified schematic using the AMC3302-Q1 to measure the output current of a PFC stage

of an onboard charger (OBC). At this location in the system, there is no supply readily available for powering

the high-side of the isolated amplifier. The integrated isolated power supply solves this problem and, together

with its bipolar input voltage range, makes the AMC3302-Q1 ideally suited for bidirectional current sensing.

In this example, the AC line-voltage is sensed by the AMC3330-Q1 on the grid-side where there is also no

suitable supply available for powering the high-side of the isolated amplifier. The integrated power supply, high

input impedance, and bipolar input voltage range of the AMC3330-Q1 makes the device ideally suited for AC

voltage-sensing applications.

to MCU

Analog

Filter

to MCU

Analog

Filter

N

L1

L2

L3

PFC

RSHUNT

To Battery Management System

DC-Link

+

DC/DC

±

RL11

RL1SNS

N

RL12

N

N

1 µF

100 nF

1 nF

1 nF

100 nF

10 Ÿ

10 Ÿ

10 nF

DCDC_OUT

DCDC_HGND

HLDO_IN

HLDO_OUT

HGND

INP

INN

NC

AMC3302-Q1

1 µF

1 nF

100 nF

47 NŸ

DCDC_IN

LDO_OUT

VDD

OUTP

OUTN

GND

DIAG

DCDC_GND

3.3 V / 5 V supply

to uC (optional)

GND

1 µF

100 nF

1 nF

1 nF

100 nF

DCDC_OUT

DCDC_HGND

HLDO_IN

HLDO_OUT

HGND

INP

INN

NC

AMC3330-Q1

1 µF

1 nF

100 nF

47 NŸ

DCDC_IN

LDO_OUT

VDD

OUTP

OUTN

GND

DIAG

DCDC_GND

3.3 V / 5 V supply

to uC (optional)

GND

N

Voltage sensing

(AMC3330-Q1)

Voltage sensing

(AMC3330-Q1)

Current sensing

(AMC3302-Q1)

Figure 8-1. The AMC3302-Q1 in an OBC Application

AMC3302-Q1

SBASA84A – FEBRUARY 2021 – REVISED JULY 2021

www.ti.com

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