TPS1H100-Q1
ZHCSDD8D –OCTOBER 2014–REVISED DECEMBER 2019
www.ti.com.cn
Feature Description (continued)
Current Sense
Voltage
Vcs,H
ADC Full Scale
Range
Max Normal
Operating Current
Open Load Current
Operating
Range
On-state:
open load/short to battery
On-state: Current limit, thermal fault
Off-state: Open load/ short to battery
Over
current
Normal
Figure 30. Voltage Indication on the Current-Sense Pin
VBAT
VS
Iout/K
Iout/Kcl
CURRENT
CLAMP
t
Iout
Vcs,H
FAULT
+
CS
OUT
CL
Vcl,th
Rcs
RCL
Figure 31. Current-Sense and Current-Limit Block Diagram
7.3.2 Programmable Current Limit
A high-accuracy current limit allows higher reliability, which protects the power supply during short circuit or
power up. Also, it can save system costs by reducing PCB traces, connector size, and the capacity of the
preceding power stage.
Current limit offers protection from overstressing to the load and integrated power FET. Current limit holds the
current at the set value, and pulls up the CS pin to VCS,h as a diagnostic report. The two current-limit thresholds
are:
•
External programmable current limit -- An external resistor is used to convert a proportional load current into a
voltage, which is compared with an internal reference voltage, Vth,cl. When the voltage on the CL pin exceeds
Vth.cl, a closed loop steps in immediately. VGS voltage regulates accordingly, leading to the Vds voltage
regulation. When the closed loop is set up, the current is clamped at the set value. The external
programmable current limit provides the capability to set the current-limit value by application.
18
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