IS31FL3731-QFLS2-TR Datasheet, PDF (18/22 Pages) Integrated Silicon Solution, Inc – AUDIO MODULATED MATRIX LED DRIVER

IS31FL3731
MORE FRAMES DISPLAY
The IS31FL3731 can store 8 frames data at best.
Each 4 frames writing in Frame Registers is
recommended if there are more frames to play (Figure
14). First, store 8 frames data and play 4 frames in
front. Then play last 4 frames and writing new data in
the Frame Registers (1~4) at the same time. Play the
new 4 frames (1~4) and write new data in the Frame
Registers (5~8).
SHUTDOWN MODE
Shutdown mode can be used as a means of reducing
power consumption. During shutdown mode all
registers retain their data.
SOFTWARE SHUTDOWN
By setting SSD bit of the Shutdown Register (0Ah) to
“0”, the IS31FL3731 will operate in software shutdown
mode. When the IS31FL3731 is in software shutdown
mode, all current sources and digital drivers are
switched off, so that the matrix is blanked. All registers
can be writing or read when the SDB pin is pulled high
in software shutdown mode.
HARDWARE SHUTDOWN
The chip enters hardware shutdown mode when the
SDB pin is pulled low. All registers are forbidden
writing and reading.
Figure 14 More frame data writing in
R_EXT
The average output current of each LED can be
adjusted by the external resistor, R_EXT, as described in
Formula (2).
I _LED  64.7 / R_EXT
(2)
For example, in Figure 1, R_EXT = 20kΩ,
So I _LED  64.7 / 20  3.2mA
The recommended minimum value of R_EXT is 18kΩ, or
it may cause a large current.
Figure 15 Shutdown Control
Integrated Silicon Solution, Inc. – www.issi.com
18
Rev.D, 04/22/2013