lp5522tmx National Semiconductor Corporation, lp5522tmx Datasheet - Page 6

• Manufacturer Part Number: lp5522tmx
• Description: Programmable Led Driver
• Manufacturer: National Semiconductor Corporation

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LED Driver Operational Description
The LP5522 LED driver is constant current source. Current can be set with external resistor (R
resistor and LED is 1:400. R
adjusted using equation I
Use of external resistor is optional. If external resistor is not connected, default output current is 5 mA. When external resistor is
not used ISET pin should be connected to VDD.
LED Driver Typical Performance Characteristics
T
R
J
ISET
= 25°C. Unless otherwise noted, typical performance characteristics apply to the LP5522 Block Diagram with: V
= 24 kΩ, C
Output Current vs R
Output Current vs Input Voltage
IN
(ISET Connected To VDD)
= 100 nF.
OUT
ISET
= 480/R
ISET
current correlates to ISET reference voltage (V
(Expanded Range)
ISET
.
202172301
20217299
6
Output Current vs Headroom Voltage
ISET
). Consequently, current through LED can be
Output Current vs R
ISET
) so that the current ratio between
ISET
202172300
202172302
IN
= 3.6V,