Datasheet

8 Atmel LED Driver-MSL3162
Pin Descriptions
PIN NAME
PIN
NUMBER
PIN DESCRIPTION
FBI1, FBI2,
FBI3
37, 39, 1
Efciency Optimizer feedback inputs
When using a common LED voltage over multiple MSL3162s, connect FBIs and FBOs in a chain,
with the rst FBI grounded and the last FBO controlling the external power source. For standalone
operation, connect FBI to GND.
FBO1, FBO2,
FBO3
38, 40, 2
Efciency Optimizer feedback outputs
FBO controls the external regulator to dynamically adjust the LED voltage for optimal efciency.
When using a common LED voltage over multiple MSL3162s, connect FBIs and FBOs in a chain,
with the rst FBI grounded and the last FBO driving the feedback node of an external power source.
CGND 3, 16
Signal ground
Connect all CGND and GND pins to system GND and to the exposed pad, EP, using short, wide
traces as close to the MSL3162 as possible
GND 15, 31
Power ground
Connect all GND and CGND pins to system GND and to the exposed pad, EP, using short, wide
traces as close to the MSL3162 as possible
PHI 4
Phase synchronization input
Drive PHI with an external signal from 40Hz to 10kHz to synchronize the MSL3162 PWM dimming to
the signal at PHI. Connect PHI to GND if unused.
GSC 5
Gate shift clock input
GSC sets the PWM dimming resolution. Drive GSC with the video signal gate shift clock up to 5MHz.
Connect GSC to GND if unused.
PWM 6
PWM dimming input
Drive PWM with a pulse-width modulated signal with a duty ratio ranging from 0% to 100% and
frequency from 20Hz to 50kHz to control the brightness of all LED strings.
STR0
to
STR15
7 - 14,
17 - 24
STR0 to STR15 LED string current sink outputs
Connect the cathode end of each series LED string to one of STR0 to STR15. Connect unused
outputs to GND, and disable unused strings using the master control registers.
FLTB 25
Fault indication output (open drain, active low)
FLTB sinks current to GND whenever the MSL3162 detects a fault. Once a fault is detected, FLTB
remains low until the fault registers have been read.
AD1, AD0 26, 29
I²C slave ID selection inputs
AD0 and AD1 select the I²C slave address used. Connect AD0 and AD1 to either GND, VDD, SCL, or
SDA to select the slave ID.
SCL 27
I²C serial clock input
SCL is the I²C serial interface clock input.
SDA 28
I²C serial data I/O
SDA is the I²C serial interface data I/O
N/C 30, 32 Factory connection. Leave unconnected.
ILED 33
Maximum LED current control input
Connect a resistor from ILED to GND to set the full-scale LED string current. A 34.8kΩ resistor to
GND sets a 60mA sink current through each LED string.
EN 34
Enable input (active high)
Drive EN high to turn on the MSL3162, and drive it low to turn it off. For automatic start-up, connect
EN to VIN.
Table 3. Pin Descriptions