LM3463_12 Datasheet, PDF (30/40 Pages) Texas Instruments – LM3463 Dynamic Headroom Controller with Thermal Control Interface and Individual Channel Dimming Control

LM3463
SNVS807 – MAY 2012
www.ti.com
In the Direct PWM Dimming mode, the master and slave units share the PWM dimming control signals at the
DIM01, DIM23, DIM4 and DIM5 pin to facilitate dimming control. In this mode, the SYNC and CLKOUT of all
slave units should be connected to the SYNC and CLKOUT pin of the master unit accordingly to perform startup
synchronization. Since the dimming control signal inputs of all the LM3464 are connected in parallel to share the
control signals, it is essential to ensure the signal source is strong enough to drive all the LM3463 in parallel.
Figure 19. Serial Data Interface
V_RAIL (Vout from AC/DC converter)
LM3463 Master
Vcc
LM3463 Slave 1
Vcc
LM3463 Slave 2
VLedFB
NC
MODE
VLedFB
NC
MODE
VLedFB
NC
MODE
GND
SDAT
SCLK
LOAD
Interface to MCU/
external logic control
circuit
GND
DIM01
DIM23
DIM4
DIM5
SYNC
CLKOUT
DIM01
DIM23
DIM4
DIM5
SYNC
CLKOUT
DIM01
DIM23
DIM4
DIM5
SYNC
CLKOUT
Figure 20. DC Voltage Dimming Control Interface
V_RAIL (Vout from AC/DC converter)
LM3463 Master
Vcc
LM3463 Slave 1
Vcc
LM3463 Slave 2
VLedFB
Vcc
MODE
VLedFB
MODE
VLedFB
MODE
GND
VDIM01
VDIM23
VDIM4
VDIM5
DC voltages
controlling average
LED currents (PWM)
DIM01
DIM23
DIM4
DIM5
SYNC
CLKOUT
DIM01
DIM23
DIM4
DIM5
SYNC
CLKOUT
DIM01
DIM23
DIM4
DIM5
SYNC
CLKOUT
Figure 21. Direct PWM Diming Control Interface
V_RAIL (Vout from AC/DC converter)
30175714
LM3463 Master
Vcc
LM3463 Slave 1
Vcc
LM3463 Slave 2
GND
GND
DIM01
DIM23
DIM4
DIM5
Interface to PWM
dimming signal sources
VLedFB
MODE
GND
SYNC
CLKOUT
VLedFB
MODE
DIM01
DIM23
DIM4
DIM5
SYNC
CLKOUT
GND
VLedFB
MODE
DIM01
DIM23
DIM4
DIM5
SYNC
CLKOUT
Figure 22. Connect diagram for cascade operations in different modes of dimming control
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