MAX16826_15 Datasheet, PDF (9/26 Pages) Maxim Integrated Products – Programmable, Four-String HB LED Driver with Output-Voltage Optimization and Fault Detection

MAX16826
Programmable, Four-String HB
LED Driver with Output-Voltage
Optimization and Fault Detection
Pin Description (continued)
PIN NAME
FUNCTION
LED String 1 Linear Current Source Output. DL1 drives the gate of the external FET on LED String 1 and has
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DL1 approximately 15mA source/sink capability. Connect a minimum capacitor of 4700pF from DL1 to GND to
compensate the internal transconductance amplifier as well as program the rise and fall times of the LED currents.
LED String 1 External FET Drain Voltage Sense. The internal ADC uses this input to measure the drain to GND
19
DR1 voltage of the current sink FET. Drain voltage measurement information can be read back from the I²C
interface. Connect a voltage-divider to scale drain voltage as necessary.
20
CS2 ^{LED String 2 Current-Sense Input. CS2 is regulated to a value set by an internal register. The regulation voltage}
can be set between 97mV and 316mV.
LED String 2 Linear Current Source Output. DL2 drives the gate of the external FET on LED String 2 and has
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DL2
approximately 15mA source/sink capability. Connect a minimum capacitor of 4700pF from DL2 to GND to
compensate the internal transconductance amplifier, as well as program the rise and fall times of the LED
currents.
LED String 2 External FET Drain Voltage Sense. The internal ADC uses this input to measure the drain to GND
22
DR2 voltage of the current sink FET. Drain voltage measurement information can be read back from the I²C
interface. Connect a voltage-divider to scale drain voltage as necessary.
23
CS3 ^{LED String 3 Current-Sense Input. CS3 is regulated to a value set by an internal register. The regulation voltage}
can be set between 97mV and 316mV.
LED String 3 Linear Current Source Output. DL3 drives the gate of the external FET on LED String 3 and has
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DL3 approximately 15mA source/sink capability. Connect a minimum capacitor of 4700pF from DL3 to GND to
compensate the internal transconductance amplifier, as well as program the rise and fall times of the LED currents.
LED String 3 External FET Drain Voltage Sense. The internal ADC uses this input to measure the drain to GND
25
DR3 voltage of the current sink FET. Drain voltage measurement information can be read back from the I²C
interface. Connect a voltage-divider to scale drain voltage as necessary.
26
CS4
LED String 4 Current-Sense Input. CS4 is regulated to a value set by an internal register. The regulation voltage
can be set between 97mV and 316mV.
LED String 4 Linear Current Source Output. DL3 drives the gate of the external FET on LED String 4 and has
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DL4 approximately 15mA source/sink capability. Connect a minimum capacitor of 4700pF from DL4 to GND to
compensate the internal transconductance amplifier, as well as program the rise and fall times of the LED currents.
LED String 4 External FET Drain Voltage Sense. The internal ADC uses this input to measure the drain to GND
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DR4 voltage of the current sink FET. Drain voltage measurement information can be read back from the I²C
interface. Connect a voltage-divider to scale drain voltage as necessary.
Power Supply. IN is internally connected to a 26V shunt regulator that sinks current. In conjunction with an
29
IN
external resistor it allows time-limited load dump events as high as 40V to be safely handled by the IC. Bypass
IN to GND with a minimum 10μF capacitor.
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CS Current-Sense Input
Gate Driver Regulator Output. Bypass V_CC to GND with a minimum 4.7μF ceramic capacitor. Gate drive current
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V_CC pulses come from the capacitor connected to V_CC. Place the capacitor as close as possible to V_CC. If IN is
powered by a voltage less than 5.5V, connect V_CC directly to IN.
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DL Switching Regulator Gate Driver Output
—
EP
Exposed Pad. Connect the exposed pad to the ground plane for heatsinking. Do not use this pad as the only
ground connection to the IC.
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