AS1121 Datasheet, PDF (18/22 Pages) ams AG – 16-Channel LED Driver with Dot Correction and Greyscale PWM

AS1121
Datasheet - Detailed Description
Serial Data Transfer Rate
Figure 25 shows a cascaded arrangement AS1121 devices connected to a controller, building a basic module of an LED display system.
Figure 25. Cascaded Configuration
VCC
VLED
VLED
VLED
VLED
100kΩ
lid ^SIN
XERR
CLK
a ^LD
GSCLK
v _MODE
ill ^OEN
SOUT
G _st ^Controller
OUT0
SDI
XERR
CLK
LD
GSCLK
MODE
OEN
...
OUT15
AS1121
...
SDO
VCC
VCC
VCC
100nF
GND
IREF
OUT0
SDI
XERR
CLK
LD
GSCLK
MODE
OEN
...
OUT15
AS1121
SDO
VCC
VCC
VCC
100nF
GND
IREF
6
s ^{A nt The maximum number of cascading AS1121 devices depends on the application system and is in the range of 40 devices. The minimum fre-}
quency needed can be calculated by the following equations:
m ^{te fGSCLK = 4096 x fUPDATE}
(EQ 5)
a ⁿ _Where:
o _{fGSCLK is the minimum frequency needed for GSCLK;}
c fUPDATE is the update rate of whole cascaded system.
l_{fCLK = 193 x fUPDATE x n}
(EQ 6)
a _Where:
ic ^{fCLK is the minimum frequency needed for CLK and SIN;}
fUPDATE is the update rate of whole cascaded system;
Techn ^{n is the number of cascaded of AS1121 devices.}
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Revision 1.01
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