SFFS897 May 2024 SN4599-Q1

4 Pin Failure Mode Analysis (Pin FMA)

This section provides a Failure Mode Analysis (FMA) for the pins of the SN4599-Q1 (SOT-23 package). 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 VDD (see Table 4-5)

Table 4-2 through 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 pin diagram. For a detailed description of the device pins, please refer to the Pin Configuration and Functions section in the SN4599-Q1 data sheet.

Figure 4-1 Pin Diagram (SOT-23 Package)

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
SEL	1	SEL stuck low. Cannot control switch states	B
VDD	2	Device not functional. Observe that the absolute maximum ratings for all pins of the device are met, otherwise device damage may be plausible.	A
GND	3	No effect, normal operation	D
S1	4	Corruption of signal passed onto the D pin. If there is no limiting resistor in the switch path device damage possible Device unpowered.	A
D	5	Corruption of signal passed onto the S1/S2 pins. If there is no limiting resistor in the switch path device damage possible	A
S2	6	Corruption of signal passed onto the D pin. If there is no limiting resistor in the switch path device damage possible	A

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

Pin Name	Pin No.	Description of Potential Failure Effect(s)	Failure Effect Class
SEL	1	Loss of control of SEL pin. Cannot control switch.	B
VDD	2	Device unpowered. Device not functional.	B
GND	3	Device unpowered. Device not functional.	B
S1	4	Corruption of signal passed onto the D pin.	B
D	5	Corruption of signal passed onto the S1/S2 pins.	B
S2	6	Corruption of signal passed onto the D pin.	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
SEL	1	VDD	SEL stuck high. Can no longer switch signal path of the device	B
VDD	2	GND	Device is unpowered. Device is not functional. Observe that the absolute maximum ratings for all pins of the device are met, otherwise device damage may be plausible.	A
GND	3	S2	Not considered. This is a corner pin.	D
S2	4	D	Corruption of signal passed onto the D pin.	B
D	5	S1	Corruption of signal passed onto the S1/S2 and D pins.	A
S1	6	VDD	Not considered. This is a corner pin.	D

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

Pin Name	Pin No.	Description of Potential Failure Effect(s)	Failure Effect Class
SEL	1	SEL stuck high. Cannot control switch states	B
VDD	2	No effect; normal operation	D
GND	3	Device unpowered. Device not functional. Observe that the absolute maximum ratings for all pins of the device are met. Otherwise, device damage may be plausible.	A
S2	4	Corruption of signal passed onto the D pin. If there is no limiting resistor in the switch path device damage is possible.	A
D	5	Corruption of signal passed onto the S1/S2 pins. If there is no limiting resistor in the switch path device damage is possible.	A
S1	6	Corruption of signal passed onto the D pin. If there is no limiting resistor in the switch path device damage is possible.	A