Specifications

cl,th CL
CL
OUT
V K
1.233 2000
R 493.2
I 5
u
u
:
CS CS
CS
CS OUT
V V K
3 500
R 750
I I 2
u
u
:
TPS1H100-Q1
www.ti.com SLVSCM2A –OCTOBER 2014–REVISED JANUARY 2014
Typical Application (continued)
9.2.1 Design Requirements
• V
S
range from 9 to 16 V
• Nominal current of 2 A
• Current sense for fault monitoring
• Expected current limit value of 5 A
• Full diagnostic with 5-V MCU
• Reverse protection with GND network
9.2.2 Detailed Design Procedure
The R
CS
, V
CS
linear region is from 0 to 4 V. To keep the 2-A nominal current in the 0- to 3-V range, calculate the
R
CS
as in Equation 11. To achieve better current sense accuracy, 1% accuracy or an even higher resistor is
preferred.
(11)
R
CL
, V
CL,th
is the current limit internal threshold 1.233 V. To set the programmable current limit value at 5 A,
calculate the R
CL
as in Equation 12.
(12)
TI recommends R
SER
= 10 kΩ for 5-V MCU.
TI recommends R
GND
= 1 kΩ, 200 V / 0.2 A D
GND
for the GND network.
9.2.2.1 Distinguishing of Different Fault Modes
Some applications require that open load, short to battery, and short to GND can be distinguished from each
other. This requires two steps:
1. In the on state, for current sense version device (version B), on-state open load/ short to battery are
recognized as an extremely-low voltage level in current sense pin, while short to GND is reported as a
pulled-up voltage V
CS,h
. Therefore, the user can find a short to GND (see Figure 46).
2. If reported as an on-state open load or short to battery fault in the first step, turn off the input signal. In the off
state, with an external pulldown resistor, open load and short to battery can be easily distinguished. When
the output pulls down, the short to battery is still reported as an off-state fault condition, while the open load
is ignored.
Copyright © 2014, Texas Instruments Incorporated Submit Documentation Feedback 33
Product Folder Links: TPS1H100-Q1