AMG-LL7AXX Datasheet, PDF (11/14 Pages) alpha microelectronics gmbh – Family of HV LED Driver Modules

AMG-LL7AXX
Family of HV LED Driver Modules
10.3. Application Notes
a) Considerations on heat dissipation...
tbd
b) Considerations on LED-string forward voltage and efficiency...
tbd
c) Considerations on LED-string forward voltage and current ripple...
tbd
d) Modification of max. string current
the maximum string current is set by two shunt resistors on the slave modules. The two
shunts are in parallel and combined provide the highest current setting for the board.
Removing either one will lower the maximum string voltage of that particular slave
module.
Slave module
Shunts 1+2 present
Shunt 1 present
Shunt 2 present
LL7A1-3
350mA
200mA
150mA
LL7A4-6
700mA
500mA
200mA
LL7A7-9
1500mA
1000mA
500mA
One shunt on the slave boards can be removed with a soldering iron to further reduce
the maximum string current if desired.
e) Dimming...
A 0-10V dimmer can be attached to the master module. Both linear and logarithmic
dimming curves will work. Logarithmic dimming curves usually are more appealing to the
eye. Care needs to be taken, that the dimmer is connected with it's positive and negative
connectors correctly to the master module. It is also possible to connect a 3k
potentiometer or a galvanically isolated 0-10v source instead of a dimmer. All slave
modules which are connected to that particular master module will all simultaneously be
dimmed from that one connected dimmer. If the dimming input is left open, the slave
modules will work with their highest current setting. No open ended wires should be
connected to the dimmer input of the master module. Wiring from the master module to
the dimmer should not run parallel to mains lines. This can cause flicker, particularly at
the lower dimming end.
High voltage (>15V) provided to the dimmer connector will potentially destroy the master
and all connected slave modules.
11. Module Dimensions
11.1. Master
Length = 147mm (may change)
Width = 30mm
Height < 16mm
AMG-
LL7AXX
Revision: A
11. Apr. 2012 © All rights reserved Page 11 of 14