TLC5923 Datasheet, PDF (9/15 Pages) Texas Instruments – LED DRIVER

TLC5923
www.ti.com
SLVS550 – DECEMBER 2004
Serial Interface Data Transfer Rate
The TLC5923 includes a flexible serial interface, which can be connected to microcontroller or digital signal
processor. Only 3 pins are in required to input data into the device. The rising edge of SCLK signal shifts the
data from SIN pin to internal shift register. After all data is clocked in, a rising edge of XLAT latches the serial
data to the internal registers. All data is clocked in with MSB first. Multiple TLC5923 devices can be cascaded by
connecting SOUT pin of one device with SIN pin of following device. The SOUT pin can also be connected to
controller to receive LOD information from TLC5923.
V_CC
V_(LED)
V_(LED)
V_(LED)
V_(LED)
Controller
SIN
XERR
SCLK
XLAT
MODE
BLANK
SOUT
100 k
SIN
XERR
SCLK
XLAT
MODE
BLANK
OUT0
TLC5923
IC 0
5
OUT15
SOUT
V_CC
100 nF
IREF
SIN
XERR
SCLK
XLAT
MODE
BLANK
OUT0
TLC5923
OUT15
SOUT
V_CC
100 nF
IREF
IC n
Figure 11. Cascading Devices
Figure 11 shows a example application with n cascaded TLC5923 devices connected to a controller. The
maximum number of cascaded TLC5923 devices depends on application system and data transfer rate.
Equation 3 calculates the minimum data input frequency needed.
f_(SCLK) + 112 f_(update) n
(3)
where:
f_(SCLK): The minimum data input frequency for SCLK and SIN.
f_(update): The update rate of the whole cascaded system.
n: The number of cascaded TLC5923 devices.
Operating Modes
The TLC5923 has different operating modes depending on MODE signal. Table 2 shows the available operating
modes.
Table 2. TLC5923 Operating Modes Truth Table
MODE SIGNAL
LOW
HIGH
INPUT SHIFT REGISTER
16 bit
112 bit
MODE
On/Off Mode
Dot Correction Data Input Mode
9