LP5526TL NSC [National Semiconductor], LP5526TL Datasheet - Page 18

• Manufacturer Part Number: LP5526TL
• Description: Lighting Management Unit with High Voltage Boost Converter with up to 150mA Serial FLASH LED Driver
• Manufacturer: NSC [National Semiconductor]

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Symbol
I
I
R
ƒ
V
LEAKAGE
MAX(RGB)
RGB
SW
SAT
Functionality of Color LED
Outputs (RLED, GLED, BLED)
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
2. Disabling selected RGB drivers if the external flash trig-
Flash safety function can be individually enabled for all RGB
LED drivers (EN_SAFETY_R, EN_SAFETY_G, EN_SAFE-
TY_B). The safety function operation mode depends on the
state of EN_FLASH bit.
RGB LEDs Driver Performance Characteristics
Note: RGB current should be limited as follows:
constant current mode – limited by external R
switch mode – limited by external ballast resistors
(Continued)
been done to the RGB max current register (address
02H) for 1 second
ger pulse is longer than 1 second
Output Current vs Pin Voltage (CC Mode)
Parameter
RLED, GLED, BLED pin leakage current
Maximum recommended sink current
Accuracy
Current mirror ratio
RGB current matching error
Switch resistance
RGB internal PMW switching frequency
Saturation voltage (current drop 10%)
@
50mA
RGB
resistor
20179705
Condition
CC mode
SW mode
CC mode
CC mode
I
SW mode
Accuracy same as internal clock
frequency accuracy
+25
-30
+85
RGB
o
o
o
C
C, I
C
set to 50mA, CC mode
18
RGB
1. EN_FLASH = 0: Safety counter starts counting when at
2. EN_FLASH = 1: Safety counter starts counting when the
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), I
sequence to address 02H does not clear the counter when
safety function has been activated.
set to 50mA
least one of the EN_SAFETY_X bits is enabled. Safety
counter can be cleared by executing an I
sequence to address 02H. If safety counter reaches one
second, the LEDs which have the safety function en-
abled, are switched off. Also the read-only bit SAFETY-
_SET is set high.
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 SAFE-
TY_SET is set high.
Output Current vs R
RGB
Min
(CC Mode)
Typ
1:100
230
3.2
20
5
2
2
2
C read or write
C read or write
20179706
Max Units
12.5
350
300
430
50
60
1
kHz
mA
mA
mV
µA
%
%
Ω