HVLED805 STMicroelectronics, HVLED805 Datasheet - Page 21
HVLED805
Manufacturer Part Number
HVLED805
Description
IC LED DRVR ACDC OFFLINE 16NSOIC
Manufacturer
STMicroelectronics
Datasheet
1.HVLED805TR.pdf
(29 pages)
Specifications of HVLED805
Constant Current
Yes
Constant Voltage
Yes
Internal Driver
Yes
Type - Primary
General Purpose
Mounting Type
Surface Mount
Topology
AC DC Offline Switcher, PWM
Number Of Outputs
1
Voltage - Supply
11.5 V ~ 23 V
Package / Case
16-SOIC (0.154", 3.90mm Width)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Frequency
-
Voltage - Output
-
Operating Temperature
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
HVLED805
Manufacturer:
ST
Quantity:
20 000
Company:
Part Number:
HVLED805TR
Manufacturer:
TSC
Quantity:
6 000
Part Number:
HVLED805TR
Manufacturer:
ST
Quantity:
20 000
HVLED805
Figure 17. Feedforward compensation: internal schematic
During MOSFET’s ON-time the current sourced from DMG pin is mirrored inside the
“ Feedforward Logic ” block in order to provide a feedforward current, I
Such “feedforward current” is proportional to the input voltage according to the formula:
Equation 9
Where m is the primary-to-auxiliary turns ratio.
According to the schematic, the voltage on the non-inverting comparator will be:
Equation 10
The offset introduced by feedforward compensation will be:
Equation 11
As R
Equation 12
FF
Aux
>>R
Rdmg
SENSE
DMG
Rfb
, the previous one can be simplified as:
V
F eedforward
V = R
OFFSET
Doc ID 18077 Rev 1
Logic
(-)
V
SENSE D
=
OFFSET
I
m
FF
.
⋅
V
⋅
R
=
I +I
IN
dmg
m
IF F
=
FF
⋅
V
m
V
R
⋅
⋅
IN
IN
(
(
dmg
⋅
R
R +R
R
Block
⋅
CC
FF
FF
R
dmg
FF
+
R
SENSE
SENSE
+
-
)
CC
)
Application information
FF
RFF
.
LOGIC
PWM
SO URCE
DRAIN
Rsense
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