HVLED805 STMicroelectronics, HVLED805 Datasheet - Page 20
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
Application information
5.6
20/29
Figure 16. Constant current operation: Switching cycle waveforms
Voltage feedforward block
The current control structure uses the voltage V
(7). Actually, the CC comparator will be affected by an internal propagation delay Td, which
will switch off the MOSFET with a peak current than higher the foreseen value.
This current overshoot will be equal to:
Equation 8
Will introduce an error on the calculated CC setpoint, depending on the input voltage.
The HVLED805 implements a Line Feedforward function, which solves the issue by
introducing an input voltage dependent offset on the current sense signal, in order to adjust
the cycle-by-cycle current limitation.
The internal schematic is shown in
Q
I
I
I
C
P
s
Doc ID 18077 Rev 1
Figure 17
Δ I
I
CLED
P
=
T
.
V
=
IN
−
L
C
V
⋅
P
R
T
C
to define the output current, according to
d
I
CLED
t
t
t
t
HVLED805