L99LD01 datasheet(16/69 Pages) STMICROELECTRONICS

Teilenummer	L99LD01

Bauteilbeschribung	High efficiency constant current LED driver for automotive applications

PDF	69 Pages

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Hersteller	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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16 / 69 page

Functional description

L99LD01

16/69

DocID025319 Rev 3

Figure 7. Slow vs ramp down

2.2

Protections and functions

2.2.1

LED current adjust and temperature control

The LED current can be adjusted within a range of ± 66.7 %, with respect to the default

value set by the LED current sense resistor, via the SPI input, so allowing the end of line

calibration. The LED chain temperature measurement is achieved by means of an external

NTC resistor connected between the NTC pin and GND. The NTC resistor is supplied

through a resistor connected to the 5 V internal regulator output. As soon as the voltage on

the NTC resistor becomes lower than the internal threshold, VNTC_TH, (due to an

overtemperature in the LED chain) an internal circuitry is activated and the internal LED

current reference voltage decreases proportionally, so that the LED current is progressively

L99LD01 Datenblatt(PDF) 16 Page - STMicroelectronics