SFFS034A July 2021 – July 2021 TPS1H000-Q1

4 Pin Failure Mode Analysis (Pin FMA)

This section provides a Failure Mode Analysis (FMA) for the pins of the TPS1H000-Q1. The failure modes covered in this document include the typical pin-by-pin failure scenarios:

Pin short-circuited to Ground (see Table 4-2)
Pin open-circuited (see Table 4-3)
Pin short-circuited to an adjacent pin (see Table 4-4)
Pin short-circuited to supply (see Table 4-5)

Table 4-2 through Table 4-5 also indicate how these pin conditions can affect the device as per the failure effects classification in Table 4-1.

Table 4-1 TI Classification of Failure Effects

Class	Failure Effects
A	Potential device damage that affects functionality
B	No device damage, but loss of functionality
C	No device damage, but performance degradation
D	No device damage, no impact to functionality or performance

Figure 4-1 shows the TPS1H000-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS1H000-Q1 data sheet.

Figure 4-1 Pin Diagram

Following are the assumptions of use and the device configuration assumed for the pin FMA in this section:

Follow data sheet recommendation for operating conditions, external component selection and PCB layout.

Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground

Pin Name	Pin No.	Description of Potential Failure Effect(s)	Failure Effect Class
IN	1	Normal operation with output off (FET turned off).	B
DIAG_EN	2	Normal operation with diagnostics function disabled.	B
FAULT	3	Open drain fault diagnostics cannot be reported.	B
CL	4	Current limit defaults to internal limit.	C
DELAY	5	Normal operation with device in holding mode as defined in the data sheet.	B
GND	6	Resistor/diode network will be bypassed if present.	B
OUT	7	Short to GND protection kicks in to protect the device.	B
VS	8	Device will have no input supply and will not function.	B

Table 4-3 Pin FMA for Device Pins Open-Circuited

Pin Name	Pin No.	Description of Potential Failure Effect(s)	Failure Effect Class
IN	1	Output will be shut off because the pin is pulled down internally.	B
DIAG_EN	2	Diagnostics will be disabled as the pin is pulled down internally.	B
FAULT	3	Open drain fault diagnostics cannot be reported.	B
CL	4	Device will not be able to provide output current.	B
DELAY	5	Normal operation with device in auto-retry mode because the pin is pulled up internally.	B
GND	6	Resistor/diode network will be bypassed if present.	B
OUT	7	Loss of ground detection engages and device shuts off.	B
VS	8	Device will have no input supply and will not function.	B

Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin

Pin Name	Pin No.	Shorted to	Description of Potential Failure Effect(s)	Failure Effect Class
IN	1	2 (DIAG_EN)	IN will affect DIAG_EN and vice versa. Diagnostics and the channel will be enabled if pin voltage > VIH; diagnostics and channel will be disabled if pin voltage < VIL.	B
DIAG_EN	2	3 (FAULT)	Undefined device behavior depends on pin voltage. Diagnostics will be enabled if pin voltage > VIH; diagnostics will be disabled if pin voltage < VIL. Open drain fault reporting could not be correct.	B
FAULT	3	4 (CL)	Open drain fault reporting could not be correct. Current limit would not be anticipated value.	B
DELAY	5	6 (GND)	Device would be in the holding mode as defined in the data sheet.	B
GND	6	7 (OUT)	Short to ground protection would kick in. Device would be protected.	B
OUT	7	8 (VS)	Short to battery detection would be triggered if configured. Device cannot turn off output.	B

Table 4-5 Pin FMA for Device Pins Short-Circuited to supply

Pin Name	Pin No.	Description of Potential Failure Effect(s)	Failure Effect Class
IN	1	Normal operation with output turned on.	B
DIAG_EN	2	Normal operation with diagnostics turned on.	B
FAULT	3	Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell.	A
CL	4	Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell.	A
DELAY	5	Potential violation of absolute maximum rating of pin and possible breakdown of ESD cell.	A
GND	6	Supply power will be bypassed and device will not turn on.	B
OUT	7	Output will be pulled to supply voltage. Short-to-battery detection will be triggered if configured.	B
VS	8	Device functions as intended.	D