LP5526TLSLASHNOPB datasheet(20/41 Pages) TI1

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EN_RGB

RGB_PWM

RGB max

current reg

XSW

RGB total current

Max current

Pre-flash

Flash

Pre-flash current value

GPIO[0]/PWM

EN_PWM_PIN

LP5526

SNVS431D – FEBRUARY 2006 – REVISED MARCH 2013

www.ti.com

Figure 20. Using Flash Mode

FLASH SAFETY TIMER FUNCTION

Flash safety function can be used to prevent damages due to possible overheating when flash or RGB LEDs

have been stuck on because of software or user error. Safety function has two operation modes:

1. Disabling selected RGB drivers when no writing has been done to the RGB max current register (address

02H) for 1 second

2. Disabling selected RGB drivers if the external flash trigger pulse is longer than 1 second

Flash safety function can be individually enabled for all RGB LED drivers (EN_SAFETY_R, EN_SAFETY_G,

EN_SAFETY_B). The safety function operation mode depends on the state of EN_FLASH bit.

1. EN_FLASH = 0: Safety counter starts counting when at least one of the EN_SAFETY_X bits is enabled.

Safety counter can be cleared by executing an I2C read or write sequence to address 02H. If safety counter

reaches one second, the LEDs which have the safety function enabled, are switched off. Also the read-only

bit SAFETY_SET is set high.

2. EN_FLASH = 1: Safety counter starts counting when the external flash trigger pulse starts (GPIO[0]/PWM

goes high) and stops counting when flash pulse stops (GPIO[0]/PWM goes low). If flash pulse is longer than

one second, the LEDs which have the safety function enabled, are switched off. Also the read-only bit

SAFETY_SET is set high.

In both cases (EN_FLASH = 0/1) after one second is reached and the LEDs which safety bit has been enabled

are switched off, the LED state can be restored by disabling the safety function of the corresponding LED.

Counter can be cleared only by disabling all safety bits (EN_SAFETY_R = 0, EN_SAFETY_G = 0,

EN_SAFETY_B = 0), I2C read or write sequence to address 02H does not clear the counter when safety function

has been activated.

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