ha16163t Renesas Electronics Corporation., ha16163t Datasheet - Page 16

• Manufacturer Part Number: ha16163t
• Description: Synchronous Phase Shift Full-bridge Control Ic
• Manufacturer: Renesas Electronics Corporation.

HA16163T
• Subinterval:2
• Subinterval:3
Rev.5.0, Mar.15.2004, page 16 of 29
As SD is turned off at point t1, the primary-side current flows into resonant capacitance Cr2. At this time Cr2 is
charged, and therefore the potential of V12 rises. Considering that the exciting current and the L1 and L2 ripple
currents are considerable smaller than Io, the following is an approximate equation for the slope of V12.
Here, N is the ratio of the primary coil to the secondary coil (N = N1/N2), and Io is the output current.
As SE and SF are on, the transformer secondary side is in the shorted state, and the value of the current flowing up
to that time is retained.
SC is turned on at point t2. ZVS operation can be attained by setting the SD off (t2) → SC on (t3) delay to the
optimal value. This delay time can be expressed by equation (2).
After SC is turned on, the transformer primary side is in the shorted state, and therefore the current value
immediately after SC was turned on is retained.
TD2 =
dV12
dt
=
0.5 Io
0.5 Io
N
N
Cr2 VIN
Cr1
Cr1
Cr2
1
V11
V11
SA
SB
SA
SB
[V/s]
[s]
VIN
VIN
Lr
Lr
(1)
(2)
Subinterval: 2
Subinterval: 3
SC
V12
SD
SC
V12
SD
Cr2
Cr2
SE
SF
SE
SF
L1
L2
L1
L2
VOUT
VOUT