TLC59108F_15 Datasheet, PDF (10/37 Pages) Texas Instruments – 8-Bit FM+ I2C Bus LED Driver

TLC59108F
SLDS162B – MARCH 2009 – REVISED DECEMBER 2015
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8.3 Feature Description
8.3.1 Power-On Reset
When power is applied to V_CC, an internal power-on reset holds the TLC59108F in a reset condition until V_CC has
reached V_POR. At this point, the reset condition is released and the TLC59108F registers and I²C bus state
machine are initialized to their default states causing all the channels to be deselected. Thereafter, V_CC must be
lowered below 0.2 V to reset the device.
8.3.2 External Reset
A reset can be accomplished by holding the RESET pin low for a minimum of t_W. The TLC59108F registers and
I²C state machine will be held in their default state until the RESET input is once again high.
This input requires a pullup resistor to V_CC if no active connection is used.
8.3.3 Software Reset
The Software Reset Call (SWRST Call) allows all the devices in the I²C bus to be reset to the power-up state
value through a specific I²C bus command. To be performed correctly, the I²C bus must be functional and there
must be no device hanging the bus.
The SWRST Call function is defined as the following:
1. A Start command is sent by the I²C bus master.
2. The reserved SWRST I²C bus address 1001 011 with the R/W bit set to 0 (write) is sent by the I²C bus
master.
3. The TLC59108F device(s) acknowledge(s) after seeing the SWRST Call address 1001 0110 (96h) only. If
the R/W bit is set to 1 (read), no acknowledge is returned to the I²C bus master.
4. Once the SWRST Call address has been sent and acknowledged, the master sends two bytes with two
specific values (SWRST data byte 1 and byte 2):
(a) Byte1 = A5h: the TLC59108F acknowledges this value only. If byte 1 is not equal to A5h, the TLC59108F
does not acknowledge it.
(b) Byte 2 = 5Ah: the TLC59108F acknowledges this value only. If byte 2 is not equal to 5Ah, the
TLC59108F does not acknowledge it.
If more than two bytes of data are sent, the TLC59108F does not acknowledge any more.
5. Once the correct two bytes (SWRST data byte 1 and byte 2 only) have been sent and correctly
acknowledged, the master sends a Stop command to end the SWRST Call. The TLC59108F then resets to
the default value (power-up value) and is ready to be addressed again within the specified bus free time
(t_BUF).
The I²C bus master may interpret a non-acknowledge from the TLC59108F (at any time) as a SWRST Call
Abort. The TLC59108F does not initiate a reset of its registers. This happens only when the format of the Start
Call sequence is not correct.
8.3.4 Individual Brightness Control With Group Dimming or Blinking
A 97-kHz fixed frequency signal with programmable duty cycle (8 bits, 256 steps) is used to control individually
the brightness for each LED.
On top of this signal, one of the following signals can be superimposed (this signal can be applied to the 4 LED
outputs):
• A lower 190-Hz fixed frequency signal with programmable duty cycle (8 bits, 256 steps) is used to provide a
global brightness control.
• A programmable frequency signal from 24 Hz to 1/10.73 s (8 bits, 256 steps) is used to provide a global
blinking control.
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