MULTIPHSPOL-RD Silicon Laboratories Inc, MULTIPHSPOL-RD Datasheet - Page 19

• Manufacturer Part Number: MULTIPHSPOL-RD
• Description: KIT REFERENCE DESIGN FOR SI825X
• Manufacturer: Silicon Laboratories Inc
• Type: Other Power Managementr

Specifications of MULTIPHSPOL-RD

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 3.3V
• Current - Output: 40A
• Voltage - Input: 10 ~ 15V
• Regulator Topology: Buck
• Frequency - Switching: 391kHz
• Board Type: Fully Populated
• Utilized Ic / Part: SI8250, SI8251, SI8252
• Input Voltage: 10 V to 15 V
• Output Voltage: 3.3 V
• Interface Type: USB
• Product: Power Management Modules
• Supply Current: 10 A
• For Use With/related Products: Si8250
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1323

5. Example Applications
The Si825x is the ideal choice for digitally-controlled
switched mode power supplies. This section provides a
quick overview of the Si825x in an isolated half-bridge
dc/dc converter and a single-phase point-of-load
converter. Reference designs are available for both of
these. For more details, visit our web site at
www.silabs.com.
5.1. Isolated DC/DC Converter
A 35 W, 400 kHz, Si8250-based half bridge converter is
shown in Figure 7. This circuit is the same as that of the
target (evaluation) board shipped in the Si8250DK
development kit.
The Si8250/1/2 is located on the secondary-side of the
power supply for optimum transient response. DPWM
outputs PH3 and PH4 control gates of the synchronous
rectifiers via a dual driver I.C. DPWM outputs PH1 and
PH2 control the gates of the primary-side switching
transistors with isolation provided by a Silicon
Laboratories isolator. A current transformer circuit
provides peak current sensing. Primary side analog
VIN-
VIN+
0.010
120uF
1.2nF
33K
1K
1uH
Figure 7. Isolated Half-Bridge DC/DC Converter
2.2uF
2.2uF
33K
1K
DC BAL
VIN
3V3P
IIN
GND
AIN
DRIVE R
VDD
AIN
AIN
Microcontroller
C8051F300
4.7
TX
DRIV ER
Rev. 1.0
FDS3572
4.7
P3
P4
parameters (input voltage and current and the filter
node voltage) are digitized by a Silicon Laboratories
C8051F300
Si8250/1/2 using the onboard UART through additional
channels of the isolator IC to the Si8250/1/2.
The Si8250/1/2 uses the application software included
with the Si8250DK development kit after being
configured for the half-bridge application using the tools
supplied in the kit.
When power is applied, the CPU executes an internal
reset followed by initialization of all parameters. The
Si8250/1/2 remains in a low-power state, monitoring
digitized V
within specified limits. At this time, the controller is fully
enabled and executes soft-start by monitoring V
while sequentially incrementing the loop voltage
reference (REFDAC) until the supply output voltage is
within the specified range, at which time steady-state
operation begins.
During steady-state operation, the MCU operates in
interrupt mode where hardware events divert program
execution to specific routines in priority order.
4.7
0.01uF
DRIV ER
DRIV ER
FDS3572
6:1
IN
data from the primary-side MCU until V
10K
microcontroller
~
~
200
200
IRLR8113
IRLR8113
+
-
7.5
P2
P1
3V3P
3.9K
VDDA
GNDA
0.01uF
Isolator
180nH
180nH
VDDB
GNDB
and
Si8250/1/2
6 x 100uF
Ceramic
P3
P4
3V3P
passed
IPK
VDD
GND
RX
PH4
PH3
PH2
PH1
Digital Controller
.
Si8250
0.001
IOUT
Vsense
to
VOUT
IN
OUT
the
19
is