TPS1H100-Q1 Datasheet, PDF (33/46 Pages) Texas Instruments – TPS1H100-Q1 40-V, 100-m Single-Channel Smart High-Side Power Switch

www.ti.com
TPS1H100-Q1
SLVSCM2B – OCTOBER 2014 – REVISED JUNE 2015
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.
R_CS
V_CS
I_CS
V_CS u K
I_OUT
3 u 500 _{750 :}
2
(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.
R_CL
V_cl,th u K_CL
I_OUT
1.233 u 2000 _{493.2 :}
5
(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 © 2014–2015, Texas Instruments Incorporated
Product Folder Links: TPS1H100-Q1
Submit Documentation Feedback
33