IS31FL3196A
Integrated Silicon Solution, Inc. — www.issi.com
Rev. D, 04/27/2018
12
APPLICATION INFORMATION
GENERAL DESCRIPTION
IS31FL3196A is a 6-channel LED driver with
two-dimensional auto breathing and PWM Control
mode. It can drive six LEDs or two groups RGB.
POWER ON SEQUENCE
IS31FL3196A provides a power-on reset feature that is
controlled by V
BAT
(voltage at pin1) supply voltage.
When the V
BAT
exceeds 2.0V (POR_H, Typ.), the
internal circuit starts to work. The reset signal will be
generated to perform a power-on reset (POR_H)
operation, which will reset all control circuits and
configuration registers until the internal power voltage
become stable.
Before SDB pull high, the I2C operation is allowed. The
SDB rising edge will reset the I2C bus.
Figure 7 SDB Pin Sequence
Note 1: I2C operation is allowed when SDB is low.
Note 2: There should be no I2C operation 10µs before and after SDB
rinsing edge.
In some case, like a mouse, when plug-out and quickly
plug-in back the USB power, the LED will flash for a
very short time. The reason is the power is not lower
than the POR_L voltage point 1.92V (Typ.), and the
device still stores the previous setting data, if user
pull-up the SDB high when power up, following with the
initial operation, the LED will be ON between SDB rising
edge and PWM initial effective, to avoid this, as above
figure, a writing to 00h is recommended to shutdown
the chip before pull-high the SDB pin.
PWM CONTROL
By setting the RGBx bits of the Configuration Register
1 (03h) to “0”, the IS31FL3196A will operate in PWM
Control mode. The PWM Registers (07h~0Ch) can
modulate LED brightness of 6 channels with 256 steps.
For example, if the data in PWM Register is “0000
0100”, then the PWM is the fourth step.
Writing new data continuously to the registers can
modulate the brightness of the LEDs to achieve a
breathing effect.
RGB BREATHING CONTROL WITH AUTO COLOR
CHANGING
By setting the RGBx bits of the Configuration Register
1 (03h) to “1”, the IS31FL3196A will operate in One
Shot Programming mode. In this mode each group
RGB can be modulated breathing cycle independently
by T0~T4. The full cycle is T1 to T4 (Figure 8). Setting
different T0~T4 can achieve RGB breathing with auto
color changing. The maximum intensity of each RGB
can be adjusted independently by the PWM Registers
(07h~0Ch).
Note, if IS31FL3196A operates in the One Shot
Programming mode and then enters into the shutdown
mode, an 8-bit data write operation to the Time Update
Register is required to restart the LED breathing effect
after the IC is re-enabled.
Figure 8 Breathing Timing
RGB AUTO BREATHING CONTROL WITH COLOR
SETTING
IS31FL3196A can pre-establish pattern achieving
mixing color breathing. There are two groups RGB.
Each RGB consists of three channels. Every channel
has an 8-bit PWM data register. The color can be set
by the PWM data register. For example, there are three
PWM data: 20h, 80h, C8h, so the three data will
determine a kind of 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 one RGB or the pre-established
color will change.
SEMIAUTOMATIC BREATHING
By setting the RGBx bits of the Configuration Register
1 (03h) to “1” and the RM bit of the Ramping Mode
Register (05h) 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.
AUDIO MODULATE DISPLAY MODE WITH AGC
FUNCTION
In audio modulate display mode the output current can
be modulated by the audio input signal. An AGC
automatically adjusts the audio input gain to improve
the dynamic range of the LED current modulation, thus
improving the visual effect. When the input signal is
