STMicroelectronics HVLED815PF Demonstration Board STEVAL-ILL044V1 STEVAL-ILL044V1 Data Sheet
Product codes
STEVAL-ILL044V1
Device description
HVLED815PF
28/36
Doc ID 023409 Rev 4
Figure 22.
High power factor implementation connection - single range input
The components selection flow starts from Rdmg resistor: this resistor has to be selected in
order to minimize the internal feed-forward effect.
order to minimize the internal feed-forward effect.
The maximum selectable value is limited is by the minimum internal current circuitry I
DMG
needed to guarantee the correct functionality of the internal circuitry:
Equation 16
where N
AUX
and N
PRIM
are the auxiliary and primary turn's number respectively and
V
IN_MIN
is the minimum rms input voltage of the application (i.e. 88 V for 110 Vac or 175 V
for 230 Vac range).
The RFB resistor defines the V
OUT
output voltage value in the open circuit condition (no-
load condition, i.e. no led on the output of led driver) and it can be selected using the
following relationship:
following relationship:
Equation 17
where N
AUX
and N
SEC
are the auxiliary and secondary turn's number respectively and V
REF
is the internal reference voltage (V
REF
=2.51 V typ - see
The R
1
resistor is typically selected in the range of 500
Ω -1.5 kΩ in order to minimize the
internal feed-forward effect and to minimize the power dissipation on the R
A
/R
B
resistor
offset circuitry.
The R
A
, R
B
, R
OS
resistors are selected to add a positive offset on CS pin in order to keep a
good line regulation over the input voltage range and cab be selected using the following
relationship:
relationship:
AM13572v1
COS
.
DRAIN
SOURCE
IFF
Feedf orward
Logic1
Logic1
+
-
CC
Rf f
Rsense
PWM
LOGIC2
DMG
CC
Block1
ROS
R1
RPF
RB
RA
VIN (after bridge diode)
CS
Aux
Rf b
Rdmg