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Atmel LED Driver-MSLB9061

On/Off (EN) Control Input

The on/off control Input, pin 9 of input connector J2, turns on/off the LED driver. Drive it high (between 2.3 and 5V)

to turn on the LED driver, and drive it low (0 to 0.8V) to turn it off. The on/off control input is internally pulled up by a

100k

Ω resistor. For automatic start-up, leave it unconnected.

PWM Control Input

The input connector, J2, pin 10, is the PWM control input. Drive PWM with a digital signal to pulse-width modulate

(PWM) the LED brightness. When using the internal PWM generator, the PWM input signal is ignored. The PWM

input is pulled high through a 100k

Ω resistor. If not used, leave PWM unconnected or drive it high.

Fault Indicator Output

The MSL1061 includes fault detection circuitry that detects an open-circuited LED string or an LED string with one or

more short-circuited LEDs. If any fault is detected, the fault indicator output is driven low. Use this output as an alert

signal to a system controller. Once the controller gets the alert signal, it determines which LED is faulty by reading the

Connecting the LEDs to the Atmel LED Driver-MSLB9061 LED Driver

The MSLB9061 driver board drives LED arrays with up to six parallel strings of up to 12 series LEDs each through the

output connector, J3. Six connections for LED cathode connections allow the use of separate LED strings, or common-

anode-connected LED strings. Connect unused LED cathode string connections (J3 pins 9-14) to GND to disable that

LED string. J3 pins 1-8 are provided for this purpose so that unused string cathode connections are connected to GND

through the wiring harness.

Setting the Full-Scale LED Current

The MSL1061 regulates the LED string current. The LED string current is set by a current sense resistor. Four different

values are programmed to the MSLB9061 LED driver module, and the switch S2 selects one of those resistors to set the

full-scale per-string LED current to 10mA, 15mA, 25mA or 30mA. Table 6 shows the switch settings and the full-scale

per-string LED current for each setting.

Atmel LED Driver-MSLB9061

LED Driver Module