SI8513-C-IS Datasheet, PDF (22/37 Pages) List of Unclassifed Manufacturers – Si85XX UNIDIRECTIONAL AC CURRENT SENSORS

Si85xx
3.5. Full-Bridge Converter Example
The full-bridge circuit of Figure 19 uses an Si851x configured in 4-Wire Ping-Pong output mode. The switching
frequency of this phase-shifted full-bridge is 150 kHz, and the maximum control phase overlap is 70%.
C1
0.1 µF
VDD
C2
1 µF
VDD
MODE
GND
VIN
IIN
Si851x
R1 R2 R3 R4
IOUT
OUT1
OUT2
OUT1
OUT2
VDD
TRST
PH1
PH2
PH3
PH4
Q1
PH1
Switches Turned ON
1–4
1–2
2–3
3–4
PH2
Q2
Si85xx State MEASURE RESET MEASURE RESET
PH3
TI
Q3
OUT1
PH4
Q4
OUT2
Figure 19. Full-Bridge Converter
Given the 150 kHz switching frequency (duty cycle fixed at 50%), the equivalent period is 1/150 x 10³ = 6.6 µs. At
70% maximum overlap, this equates to a worst-case t_R value of 0.3 x 6.6 x 10^–6 = 1.98 µs. The default value for t_R
can, therefore, be used and is selected by connecting TRST to VDD. As shown in the timing diagram of Figure 19,
integrator reset occurs when current circulates between Q1 and Q2 and between Q3 and Q4 (i.e. when current is
not being sourced from VIN). The external driver delay ensures reset is complete prior to the start of measurement.
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Preliminary Rev. 0.4