Linear Technology DC1816B Demo Manual

Description
Demonstration circuit 1816B is an off-line isolated flyback
LED driver featuring LT 3799-1. The demo board provides
®
a single constant current output of 3A over an LED string
voltage from 22V to 38V. It is optimized to operate over
a wide AC input voltage range (90VAC to 305VAC, 47Hz
to 63Hz). LED current typically stays within ±5% over the
whole input voltage range. It provides a high power factor
(>0.9) enabling a single design to be used worldwide. It
is also designed to comply with the IEC 61000-3-2 Class
C harmonics standard and the EN55015B conducted EMI
standard.
The LT3799-1 controls an isolated flyback converter in
boundary mode. Its novel current sensing scheme deliv-
ers a well-regulated output current to the secondary side
performance summary
PARAMETER
Input Voltage Range
Output Current I
OUT
Output Voltage
Open LED Voltage
Note 1: For applications with low LED string voltage, FB pin divider resistor R4 and output clamp Z3 can be adjusted to reduce the open voltage limit.
See "Protection from Open LED and Shorted LED Faults" section in the data sheet for detail.
Offline Isolated Flyback LED
(T = 25°C)
A
CONDITIONS
Line Frequency, 47Hz to 63Hz
V = 120VAC, V = 36V
IN LED
(Note 1)
DEMO MANUAL DC1816B
Driver with PFC
without using an opto-coupler. Open- and shorted-LED
protection ensures long term reliability.
The LT3799-1 is available in a low profile, thermally-
enhanced 16-lead MSOP package.
The LT3799-1 data sheet gives a complete description
of the device, operation and application information. The
data sheet must be read in conjunction with this quick
start guide for demo circuit 1816B.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
MIN
90
22
45
LT3799-1
TYP MAX UNITS
277 305 VAC
3 A
36 38 V
V
dc1816bfc
1