DM164 SITI [Silicon Touch Technology Inc.], DM164 Datasheet - Page 17

• Manufacturer Part Number: DM164
• Description: 8x3-CHANNEL CONSTANT CURRENT LED DRIVER
• Manufacturer: SITI [Silicon Touch Technology Inc.]

One-Shot Option
The DM164 provides an option that users can make the output turn on for just a PWM
cycle time, i.e. in the GD mode, after a LTH signal, the output only turn on for 65536 T
time. After 65536 T
function. Figure 9 shows the difference between One-Shot or not. When ONEST = H,
one-shot function is enabled. The output will just turn on at 1
L, one-shot function is disabled. The output will repeat at every PWM cycle.
Grayscale PWM Operation
When DCKPH=L, the grayscale PWM cycle starts with the falling edge of LTH (see Figure
10). A LTH = H signal will set the 16-bit PWM counter value to FFFFh. The first GCK pulse
after LTH increases the PWM counter by one and switches on all IOUT with grayscales
value not zero. Each following rising edge of GCK increases the PWM counter by one. The
DM164 compare the grayscale PWM value of each output IOUT with grayscale counter
value. If the grayscale PWM value is larger than grayscale counter value, the IOUT will
switch on.
(ONEST=H)
(ONEST=L)
DCKPH
Internal
counter
IOUT0
IOUT0
MSEL
DCK
GCK
LTH
DIN
8x3-CHANNEL CONSTANT CURRENT LED DRIVERS
GND
GND
GD[383]
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
1
GCK
, the output will automatically turn off. This is called One-Shot
384
65535
Figure 9. One-Shot Operation
GD[0]
0
1st PWM cycle
GD mode
1
65535
0
2nd PWM cycle
1
Version:A.002
st
PWM cycle. When ONEST =
65535
0
3rd PWM cycle
1
DM164
Page 16
65535
GCK