EPR-21 Datasheet, PDF (14/32 Pages) Power Integrations, Inc. – Engineering Prototype Report (EP-21) - 30 W DC-DC Converter with DPA424

EPR-21 – 5 V, 30 W DC-DC Converter
19-Nov-02
9 PIXls Design Spreadsheet
DCDC_DPAFwd_rev1.02_061802
Copyright Power Integrations
Inc. 2002
INPUT
INFO
OUTPUT VOLTAGE AND CURRENT
VMAIN
5
IMAIN
6
VOUT2
IOUT2
POUT
VBIAS
12.0
OUTPUT
UNIT
Volts
Amps
Volts
Amps
30 Watts
Volts
DPA_061802_R102xls: DPA-Switch
Forward Transformer Design
Spreadsheet
EP21 DC-DC Converter
Main output voltage
Main output current
Output2 voltage
Output2 current
Total output power
DC bias voltage from output inductor
winding
INPUT VOLTAGE AND UV/OV
VMIN
VMAX
VUV OFF
VUV ON
VOV ON
VOV OFF
RL
36
72
min
30
30.0
32.2
74.8
-
DC volts
DC volts
max
33.1 DC volts
34.6 DC volts
- DC volts
94.6 DC Volts
618.0 kOhm
Minimum DC input voltage
Maximum DC input voltage
Minimum undervoltage On-Off
threshold
Maximum undervoltage Off-On
threshold (turn-on)
Minimum overvoltage Off-On threshold
Maximum overvoltage On-Off threshold
(turn-off)
Line Sense resistor value (L-pin) - goal
seek (VUV OFF) for std 1% resistor
series
ENTER DPA-Switch VARIABLES
DPA-Switch
dpa424
Chosen Device
ILIMIT
Frequency - (F)=400kHz,
(L)=300kHz
fS
DPA424
2.32
f
375000
2.68
425000
KI
1
ILIMITEXT
RX
DUVON GOAL
KDI
VDS
VDSOP
16VDC
Power 15.5 W
Amps
400000 Hertz
2.32 Amps
- kOhm
0.71
0.15
2 Volts
178.7 Volts
36VDC
35W
From DPA-Switch datasheet
Full (F) frequency option - 400 kHz
From DPA-Switch datasheet
External limit reduction factor (KI=1.0
for default ILIMIT, KI <1.0 for lower
ILIMIT)
External current limit
Current Limit resistor value (X-pin) -
assumes minimum datasheet curve (fig
32)
Maximum allowed duty cycle at VUV
ON MIN undervoltage threshold
Maximum current ripple factor
DPA-Switch average on-state Drain to
Source Voltage
Required drain voltage for guaranteed
transformer reset
DIODE Vf SELECTION
VDMAIN
VDOUT2
0.5 Volts
0.5 Volts
Main output diodes forward voltage
drop
Secondary output diodes forward
Power Integrations, Inc.
Tel: [phone] Fax: [phone]
www.powerint.com
Page 14 of 32