Datasheet

OVER CURRENT PROTECTION AND SHORT CIRCUIT PROTECTION
R3 VR3
M5
VIN
1 : k
1 : n
IR3
Ip
vbias
Vmax
M9
M10
M7
M3
M11
OUTPUT REVERSE CURRENT PROTECTION
CP-
VIN
VOUT
GND
CP+
ENA
Ireverse
ENABLE
/DISABLE
C2
1 Fm
C1
2.2 Fm
C3
2.2 Fm
Vpre_bias
VIN
TPS60151
SLVSA02 – SEPTEMBER 2009 ......................................................................................................................................................................................... www.ti.com
The TPS60151 has internal short circuit protection to protect the IC when the output is over loaded or shorted to
ground. Figure 25 illustrates the protection circuit. I
P
is directly related to I
O
and the maximum I
P
is clamped by
IR3*k*n. The TPS60151 ensures a current limit of 500mA or less which is mandated by the HDMI electrical
specification. To further avoid damage when output is shorted to ground, the short circuit protection circuitry
senses the output voltage and adjusts V
bias
down to clamp the maximum output current to a lower value – 80mA
(typ).
Figure 25. Current Limit
Applications like HDMI or USB OTG generally do not tolerate output reverse current that can drain power from
connected devices. Special considerations were put in place to prevent that from happening. Figure 26 is a
testing circuit; and, Figure 27 shows reverse current protection test results under various conditions.
Figure 26. Output Reverse Current Test Setup
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