IS31FL3193
Integrated Silicon Solution, Inc. – www.issi.com 11
Rev. C, 11/27/2014
TYPICAL APPLICATION
GENERAL DESCRIPTION
IS31FL3193 is a 3-channel LED driver with
two-dimensional auto breathing and PWM Control
mode. It can drive three individual LEDs or one group
of RGB.
PWM CONTROL
By setting the RGB bit of the LED Mode Register (02h)
to “0”, the IS31FL3193 will operate in PWM Control
mode. The PWM Registers (04h~06h) can modulate
LED brightness of 3 channels with 256 steps. For
example, if the data in PWM Register is “0000 0100”,
then the PWM is the fourth step, with a duty cycle of
4/256.
In PWM control mode, a new value must be written to
the PWM registers to change the output PWM duty
cycle. Writing new data continuously to the registers
can modulate the brightness of the LEDs to achieve a
breathing effect, blinking, or any other effects that the
user defines.
RGB BREATHING CONTROL WITH AUTO COLOR
CHANGING
By setting the RGB bit of the LED Mode Register (02h)
to “1”, the IS31FL3193 will operate in One Shot
Programming mode. In this mode, the RGB intensity is
automatically modulated in a breathing cycle,
independently controlled by T0~T4. T0 is an offset time
period which runs only once at the start of the cycle.
The full cycle is T1 to T4 (Figure 6). Setting different
T0~T4 can achieve RGB breathing with auto color
changing. The maximum intensity of each RGB is
adjusted independently by the PWM Registers
(04h~06h).
Figure 6 Breathing Timing
RGB AUTO BREATHING CONTROL WITH COLOR
SETTING
IS31FL3193 can pre-establish pattern achieving mixing
color breathing. There is one group RGB. The RGB
consists of three channels. Every channel has an 8-bit
PWM data register. The color can be set by the PWM
data register. By adjusting the individual intensity of the
red, green and blue LED, different colors are perceived.
For example, the three PWM data: 20h, 80h, C8h, will
determine one particular color.
After setting the color, T0~T4 time register will be set to
control the LED breathing panel. And T0~T4 time
should be same for each of the RGB LEDs, otherwise
the pre-established color will change.
SEMIAUTOMATIC BREATHING
By setting the RGB bit of the LED Mode Register (02h)
to “1” and the RM bit of the Breathing Control Register
(01h) to “1”, the ramping function is enabled. HT is the
time select bit. When HT bit is set to “0”, T2 will be
held forever, and the LED will remain at the
programmed maximum intensity. When HT bit is set to
“1”, T3 will continue and T4 will be held, causing the
LED to complete one breathing cycle and then remain
off.
BREATHING MARK FUNCTION
By setting the BME bit of the Breathing Control
Register (01h) to “1”, the breathing mark function is
enabled. V_BM is an output pin. The breathing mark
function is useful as a signal to notify the MCU when to
update the color data. At the end of time period T1,
V_BM will induce a falling edge and hold logic low, so
the new data can be sent by MCU at this time. At the
end of T3, V_BM will induce a rising edge and the
MCU can send an update command to update all data
simultaneously (Figure 7). The marking channel
(OUT1~OUT3) is selected by the CSS bits of the
Breathing Control Register (01h).
Figure 7 V_BM Signal
SHUTDOWN MODE
Shutdown mode can either be used as a means of
reducing power consumption or generating a flashing
display (repeatedly entering and leaving shutdown
mode). During shutdown mode all registers retain their
data.
SOFTWARE SHUTDOWN
By setting SSD bit of the Shutdown Register (00h) to
“1”, the IS31FL3193 will operate in software shutdown
mode, wherein they consume only 2μA (typ.) current.
When the IS31FL3193 is in software shutdown mode,
all current sources are switched off.
HARDWARE SHUTDOWN
The chip enters hardware shutdown mode when the
SDB pin is pulled low.
