TLC5916_10 Datasheet, PDF (20/30 Pages) Texas Instruments – 8-BIT CONSTANT-CURRENT LED SINK DRIVERS

TLC5916, TLC5917
8-BIT CONSTANT-CURRENT LED SINK DRIVERS
SLVS695A – JUNE 2007 – REVISED MARCH 2008
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Open-Circuit Detection Principle
The LED Open-Circuit Detection compares the effective current level I_out with the open load detection threshold
current I_OUT,Th. If I_OUT is below the I_OUT,Th threshold, the TLC5916/TLC5917 detects an open-load condition. This
error status can be read as an error status code in the Special Mode. For open-circuit error detection, a channel
must be on.
Table 1. Open-Circuit Detection
STATE OF OUTPUT PORT
Off
On
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
Channel n error status bit 1
(1) I_OUT,Th = 0.5 × I_OUT,target (typical)
MEANING
Detection not possible
Open circuit
Normal
Short-Circuit Detection Principle (TLC5917 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 TLC5917 detects an
shorted-load condition. If V_OUT is below the V_OUT,RTh threshold, no error is detected/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. Shorted-Load 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
No Fault
Minimum
Return
Threshold
Minimum
Trigger
Threshold
Maximum
Trigger
Threshold
Short Fault
2.2 V
V_OUT,RTh
2.5 V
3.1 V
V_OUT,TTh
V_OUT
Figure 18. Short-Circuit Detection Principle
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