R

2

12W

R

3

12W

R

SHUNT

AMC1204

AMC1204B

Gated

Drive

Circuit

To Load

Floating

Power Supply

HV+

Isolation

Barrier

C

2

330pF

C

3

10pF

(optional)

AVDD

VINP

VINN

AGND

DVDD

DATA

CLKIN

DGND

C

4

10pF

(optional)

C

1

(1)

0.1 F

m

D

1

5.1V

R

1

Gated

Drive

Circuit

Power

Supply

HV-

AMC1204

AMC1204B

www.ti.com

SBAS512C – APRIL 2011 – REVISED AUGUST 2012

APPLICATION INFORMATION

A typical operation of the AMC1204 and AMC1204B in a motor control application is shown in Figure 50.

when choosing the quality of these capacitors—mismatch in values of these capacitors leads to a common-mode

error at the input of the modulator.

The high-side power supply (AVDD) for the AMC1204 and AMC1204B is derived from the power supply of the

upper gate driver. For lowest cost, a zener diode can be used to limit the voltage to 5V ±10%. A decoupling

placed as close as possible to the AVDD pin for best performance. If better filtering is required, an additional 1µF

to 10µF capacitor can be used. The floating ground reference AGND is derived from the end of the shunt

resistor, which is connected to the negative input (VINN) of the AMC1204 and AMC1204B. If a four-terminal

shunt is used, the inputs of AMC1204 and AMC1204B are connected to the inner leads, while AGND is

connected to one of the outer leads of the shunt. Both digital signals, CLKIN and DATA, can be directly

connected to a digital filter (for example, the AMC1210); see Figure 51.

Figure 50. Typical Application Diagram

Copyright © 2011–2012, Texas Instruments Incorporated

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Product Folder Links: AMC1204 AMC1204B