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. Customers should validate and test their design

implementation to confirm system functionality.

8.1 Application Information

The low input bias current, AC and DC errors, and temperature drift make the AMC3330 a high-performance

solution for applications where voltage measurement with high common-mode levels is required.

8.2 Typical Application

Isolated amplifiers are widely used for voltage measurements in high-voltage applications that must be isolated

from a low-voltage domain. Typical applications are AC line voltage measurements at the input of a power factor

correction (PFC) stage or the output of a solar inverter. Other applications are DC measurements at the output of

a PFC stage or DC/DC converter, or phase voltage measurements in motor and servo drives. The AMC3330

integrates an isolated power supply for the high-voltage side and therefore is 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 of the AMC3330 in a solar inverter where the AC phase voltage on the

grid-side must be measured. At that location in the system, there is no supply readily available for powering the

isolated amplifier. The integrated isolated power supply, together with its bipolar input voltage range, makes the

AMC3330 ideally suited for AC line-voltage sensing. In this example, phase current is sensed by the AMC3301

across a shunt resistor on the grid-side of an LCL filter where there is also no suitable supply available for

powering the isolated amplifier. The integrated power supply of the AMC3301 eliminates that problem and

enables current sensing at optimal locations for the system.

to MCU

ADS8363

16-Bit ADC

1 µF

100 nF

1 nF

1 nF

100 nF

10 Ÿ

10 Ÿ

8.2 nF

DCDC_OUT

DCDC_HGND

HLDO_IN

HLDO_OUT

HGND

INP

INN

NC

AMC3301

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 MCU

to uC (optional)

GND

1 µF

100 nF

1 nF

1 nF

100 nF

10 nF

DCDC_OUT

DCDC_HGND

HLDO_IN

HLDO_OUT

HGND

INP

INN

NC

AMC3330

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

ADS8363

16-Bit ADC

to grid (L1)

DC+

DC-

HS Gate

Driver

Supply

LS Gate

Driver

Supply

PGND

PGND

SW

SW

PGND

N

N

Figure 8-1. The AMC3330 in a Solar Inverter Application

AMC3330

SBASA34A – JUNE 2020 – REVISED OCTOBER 2020

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