Si823x
7. Applications
The following examples illustrate typical circuit configurations using the Si823x.
7.1. High-Side / Low-Side Driver
Figure 43A shows the Si8230/3 controlled using the VIA and VIB input signals, and Figure 43B shows the Si8231/4
controlled by a single PWM signal.
VDD2
VDD2
D1
D1
VDDI
VDDI
C2
1 µF
C2
1 µF
VDDI
GNDI
VDDI
C1
1uF
C1
1uF
1500 V max
1500 V max
VDDA
VDDA
GNDI
PWM
CB
CB
Q1
Q1
OUT1
OUT2
VIA
VIB
PWMOUT
CONTROLLER
I/O
VOA
VOA
GNDA
GNDA
DT
DT
RDT
RDT
CONTROLLER
Si8230/3
Si8231/4
VDDB
VDDB
VDDB
VDDB
C3
10uF
C3
10uF
I/O
DISABLE
DISABLE
GNDB
VOB
GNDB
VOB
Q2
Q2
A
B
Figure 43. Si823x in Half-Bridge Application
For both cases, D1 and CB form a conventional bootstrap circuit that allows VOA to operate as a high-side driver
for Q1, which has a maximum drain voltage of 1500 V. VOB is connected as a conventional low-side driver. Note
that the input side of the Si823x requires VDD in the range of 4.5 to 5.5 V, while the VDDA and VDDB output side
supplies must be between 6.5 and 24 V with respect to their respective grounds. The boot-strap start up time will
depend on the CB cap chosen. VDD2 is usually the same as VDDB. Also note that the bypass capacitors on the
Si823x should be located as close to the chip as possible. Moreover, it is recommended that 0.1 and 10 µF bypass
capacitors be used to reduce high frequency noise and maximize performance.
Rev. 0.3
29
SILICON [ SILICON ]
