VIPER12AS-E STMicroelectronics, VIPER12AS-E Datasheet - Page 9
VIPER12AS-E
Manufacturer Part Number
VIPER12AS-E
Description
IC OFFLINE SWIT PWM SMPS 8SOIC
Manufacturer
STMicroelectronics
Series
VIPER™r
Type
SMPS Primary Switcherr
Datasheet
1.VIPER12ADIP-E.pdf
(21 pages)
Specifications of VIPER12AS-E
Output Isolation
Isolated
Frequency Range
54 ~ 66kHz
Voltage - Input
8 ~ 50 V
Voltage - Output
730V
Power (watts)
5W
Operating Temperature
25°C ~ 125°C
Package / Case
8-SOIC (0.154", 3.90mm Width)
Number Of Outputs
1
Switching Frequency
60 KHz
Operating Supply Voltage
9 V to 38 V
Mounting Style
SMD/SMT
Output Power
8 W
Supply Current
3 mA
For Use With
497-6413 - BOARD EVAL VIPER12A LP AC/DC497-5084 - EVAL BOARD TRAVEL ADAPTOR 3.6W497-5082 - EVAL BOARD FLYBACK PWR SUPPLY 6W497-4932 - BOARD POWER SUPPLY 1.8W VIPER12A497-4931 - BOARD 6W DUAL OUTPUT VIPER12A497-4930 - BOARD 6W SINGLE OUTPUT VIPER12A
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
497-6791-5
VIPER12AS-E
VIPER12AS-E
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
VIPER12AS-E
Manufacturer:
YAZAKI
Quantity:
6 236
VIPER12A-E
6
Feedback pin principle of operation
A feedback pin controls the operation of the device. Unlike conventional PWM control
circuits which use a voltage input (the inverted input of an operational amplifier), the FB pin
is sensitive to current.
Figure 5.
The power MOSFET delivers a sense current I
R2 receives this current and the current coming from the FB pin. The voltage across R2 is
then compared to a fixed reference voltage of about 0.23 V. The MOSFET is switched off
when the following equation is reached:
By extracting I
Using the current sense ratio of the MOSFET G
Internal current control structure
S
:
Figure 5.
I
Doc ID 11977 Rev 2
D
presents the internal current mode structure.
=
R
G
2
ID
⋅
(
I
I
⋅
S
S
I
S
+
=
I
=
FB
0.23V
--------------- - I
R
G
)
2
ID
s
=
ID
which is proportional to the main current Id.
⋅
0.23V
–
⎛
⎝
:
0.23V
--------------- - I
FB
R
Feedback pin principle of operation
2
–
FB
⎞
⎠
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