Datasheet

+
120 VAC
to 240 VAC
50/60 Hz
PS2505-1A Opto Isolator
or Equivalent
AVDD
3.3 V
ZC
IN
ZC
OUT
AV
DD
AGND
Zero
Crossing
Inside the AFE030
0.0
3.3
ZC
OUT
Time (5 ms/div)
0 50 100
350
0
-350
120 VAC to 240 VAC
50 Hz to 60 Hz
AFE030
www.ti.com SBOS588A –DECEMBER 2011– REVISED DECEMBER 2011
For maximum protection of the AFE030 against line transients, it is recommended to use Schottky diodes as
indicated in Figure 38. These diodes should limit the ZC_IN pins (pins 38 and 39) to within the maximum rating
of (AV
DD
+ 0.4 V) and (AGND – 0.4 V). Some applications may require an isolated zero crossing detection circuit.
With a minimal amount of components, the AFE030 can be configured for isolated zero crossing detection, as
Figure 40 shows.
Figure 40. Isolated Zero Crossing Detection Using the AFE030
Isolated zero crossing waveforms are shown in Figure 41.
Figure 41. Isolated Zero Crossing Waveforms
Copyright © 2011, Texas Instruments Incorporated 33
Product Folder Link(s): AFE030