AS3665_04 Datasheet, PDF (17/78 Pages) ams AG – 9 Channel Advanced Command Driven RGB/White LED Driver

AS3665
Datasheet, Confidential - Detailed Description Current Sources
7. LED7, LED8 and LED9 have the option to be powered by VBAT directly (configured by
LED7_on_cp...LED9_on_cp)
Interface to sequencers
pwm_LED1 (see page 22), pwm_LED2...pwm_LED9 is the input PWM value of the current sources (8 bit value). This
value can be either controlled by the I²C interface or by any of the sequencers (see section Sequencers on page 48).
Logarithmic/Linear Ramping
All current sources support logarithmic or linear ramping (selected by register bits loglin1 (see page 25),
lid ^{loglin2...loglin9). As light is perceived logarithmically, it is recommended to keep the current sources in logarithmic}
mode (default setting).
RGB Color Correction
a The RGB Color correction changes the output PWM value depending on the temperature (either the junction tempera-
ture if temp_int_ext (see page 24)=0, or a I²C value stored in led_temp (see page 24) if temp_int_ext=1). This compen-
v _{sates different temperature drifts of LEDs and keep the white point over temperature. The slope of this temperature}
compensation is adjustable with the register color_slope1 (see page 25), color_slope2...color_slope9 (set to 0 if the
ill ^{color correction is not used).}
Faders
t _{There are three global faders: fader1 (see page 23), fader2 and fader3. Each current source can be configured to be}
multiplied by any of the three faders (controlled by fader_src1 (see page 25), fader_src2...fader_src9). Therefore a
G _{s fader can operate on any number of current sources in parallel (e.g. to generate smooth fade-out effects on several}
LEDs). The faders can operate linear or logarithmic (defined by fader_loglin1 (see page 23), fader_loglin2 and
A ^t _{fader_loglin3).}
s ^{n Analog Current Setting}
All current sources can be completely enabled/disable by the register LED1_on, LED2_on...LED9_on. The actual
e _{analog current is set by LED_current1 (see page 17), LED_current2...LED_current9. The maximum current}
m ^{t driving capability of the current sources is set by registers LED1_max (see page 20), LED2_max...LED9_max6.}
a ^{n Current Source Registers}
o _{Analog Current setting registers}
c Table 9. LED_Control1 Register
Addr: 02h
l _Bit
Bit Name
Default Access
a₀
0
LED1_on
0b
R/W
ic ¹
0
1
LED2_on
0b
R/W
1
n₀
h ²
LED3_on
0b
R/W
1
c0
3
LED4_on
0b
R/W
1
e₀
T⁴
LED5_on
0b
R/W
LED_Control1 Register
Description
LED1 is off
LED1 is enabled
LED2 is off
LED2 is enabled
LED3 is off
LED3 is enabled
LED4 is off
LED4 is enabled
LED5 is off
1
LED5 is enabled
6. Always use the minimum setting for LED1_max, LED2_max...LED9_max suitable for the application to
reduce quiescent current of the internal current source
www.austriamicrosystems.com
Revision 1.0.2
16 - 77