TLC5926_15 Datasheet, PDF (14/39 Pages) Texas Instruments – 16-Channel Constant-Current LED Sink Drivers

TLC5926, TLC5927
SLVS677C – JULY 2008 – REVISED OCTOBER 2015
www.ti.com
Feature Description (continued)
Table 1. Open-Circuit Detection
STATE OF OUTPUT PORT
Off
On
(1) I_OUT,Th = 0.5 × I_OUT,target (typical)
CONDITION OF
OUTPUT CURRENT
I_OUT = 0 mA
I_OUT < I_OUT,Th ⁽¹⁾
I_OUT ≥ I_OUT,Th ⁽¹⁾
ERROR STATUS CODE
0
0
1
MEANING
Detection not possible
Open circuit
Normal
9.3.2 Short-Circuit Detection Principle (TLC5927 Only)
The LED short-circuit detection compares the effective voltage level V_OUT with the shorted-load detection
threshold voltages V_OUT,TTh and V_OUT,RTh. If V_OUT is above the V_OUT,TTh threshold, the TLC5927 detects a shorted-
load condition. If the V_OUT is below V_OUT,RTh threshold, no error is detected and the error bit is reset. This error
status can be read as an error status code in the Special mode. For short-circuit error detection, a channel must
be on.
STATE OF OUTPUT PORT
Off
On
Table 2. Short-Circuit Detection
CONDITION OF
OUTPUT VOLTAGE
I_OUT = 0 mA
V_OUT ≥ V_OUT,TTh
V_OUT < V_OUT,RTh
ERROR STATUS CODE
0
0
1
MEANING
Detection not possible
Short circuit
Normal
9.3.3 Overtemperature Detection and Shutdown
The TLC592x is equipped with a global overtemperature sensor and 16 individual, channel-specific
overtemperature sensors.
• When the global sensor reaches the trip temperature, all output channels are shutdown, and the error status
is stored in the internal Error Status register of every channel. After shutdown, the channels automatically
restart after cooling down, if the control signal (output latch) remains on. The stored error status is not reset
after cooling down and can be read out as the error status code in the Special mode.
• When one of the channel-specific sensors reaches trip temperature, only the affected output channel is shut
down, and the error status is stored only in the internal Error Status register of the affected channel. After
shutdown, the channel automatically restarts after cooling down, if the control signal (output latch) remains
on. The stored error status is not reset after cooling down and can be read out as error status code in the
Special mode.
For channel-specific overtemperature error detection, a channel must be on.
The error status code is reset when the TLC592x returns to Normal mode.
Table 3. Overtemperature Detection ⁽¹⁾
STATE OF OUTPUT PORT
Off
On
On → all channels
Off
On
On → Off
CONDITION
I_OUT = 0 mA
T_j < T_j,trip global
T_j > T_j,trip global
T_j < T_j,trip channel n
T_j > T_j,trip channel n
ERROR STATUS CODE
0
1
All error status bits = 0
1
Channel n error status bit = 0
(1) The global shutdown threshold temperature is approximately 170°C.
MEANING
Normal
Global overtemperature
Normal
Channel n overtemperature
14
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