SBAA445 September 2021 AMC1301-Q1

4 Pin Failure Mode Analysis (Pin FMA)

This section provides a failure mode analysis (FMA) for the pins of the AMC1301-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 AMC1301-Q1 pin diagram. For a detailed description of the device pins see the Pin Configuration and Functions section in the AMC1301-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:

Differential RC filter between VINP and VINN.
Series resistors are sized to limit the input currents into VINP and VINN to <10 mA in all circumstances (for example, if the device is unpowered and the input signal is applied).
VINN is connected to GND1 through the filter resistor.
For pins on high side:
Short-circuited to ground means short to GND1.
Short-circuited to supply means short to VDD1.
For pins on low side:
Short-circuited to ground means short to GND2.
Short-circuited to supply means short to VDD2.

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
VDD1	1	Device high side unpowered. Fail-safe output (see data sheet for more details).	B
VINP	2	VINP stuck low (GND1). Differential output (VOUTP – VOUTN) = –VINN x 8.2 with common-mode voltage approximately 1.44 V.	B
VINN	3	VINN stuck low (GND1). Differential output (VOUTP – VOUTN) = VINP x 8.2 with common-mode voltage approximately 1.44 V.	D
GND1	4	No effect. Normal operation.	D
GND2	5	No effect. Normal operation.	D
VOUTN	6	VOUTN stuck low (GND2). Excess current consumption from VDD2 source. Device damage plausible if condition is present for extended period of time.	A
VOUTP	7	VOUTP stuck low (GND2). Excess current consumption from VDD2. Device damage plausible if condition is present for extended period of time.	A
VDD2	8	Device low side unpowered. VOUTP and VOUTN pins are driven to GND2.	B

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

Pin Name	Pin No.	Description of Potential Failure Effect(s)	Failure Effect Class
VDD1	1	Device high side unpowered. Fail-safe output (see data sheet for more details).	B
VINP	2	Differential output (VOUTP – VOUTN) undetermined, but with tendency to output +FS.	B
VINN	3	Differential output (VOUTP – VOUTN) undetermined.	B
GND1	4	Device high side unpowered. Fail-safe output (see data sheet for more details).	B
GND2	5	Device behavior undetermined. VOUTN and VOUTP undetermined.	B
VOUTN	6	Differential output (VOUTP – VOUTN) undetermined.	B
VOUTP	7	Differential output (VOUTP – VOUTN) undetermined.	B
VDD2	8	Device low side unpowered. VOUTN and VOUTP undetermined.	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
VDD1	1	VINP	VINP stuck high (VDD1). In case V_CM < V_CMov, differential output (VOUTP – VOUTN) = +FS. In case V_CM ≥ V_CMov, fail-safe output (see data sheet for more details).	B
VINP	2	VINN	Differential input shorted. Differential output (VOUTP – VOUTN) = 0 V	B
VINN	3	GND1	VINN stuck low (GND1). Differential output (VOUTP – VOUTN) = VINP x 8.2 with common-mode voltage approximately 1.44 V.	D
GND1	4	GND2	Not considered. Corner pin.	D
GND2	5	VOUTN	VOUTN stuck low (GND2). Excess current consumption from VDD2 source. Device damage plausible if condition is present for extended period of time.	A
VOUTN	6	VOUTP	Differential output (VOUTP – VOUTN) = 0 V with common-mode voltage approximately 1.44 V. Excess current consumption from VDD2 source. Device damage plausible if condition is present for extended period of time.	A
VOUTP	7	VDD2	VOUTP stuck high (VDD2). Excess current consumption from VDD2 source. Device damage plausible if condition is present for extended period of time.	A
VDD2	8	VDD1	Not considered. Corner pin.	D

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
VDD1	1	No effect. Normal operation.	D
VINP	2	VINP stuck high (VDD1). In case V_CM < V_CMov, differential output (VOUTP – VOUTN) = +FS. In case V_CM ≥ V_CMov, fail-safe output (see data sheet for more details).	B
VINN	3	VINN stuck high (VDD1). In case V_CM < V_CMov, differential output (VOUTP – VOUTN) incorrect. In case V_CM ≥ V_CMov, fail-safe output (see data sheet for more details).	B
GND1	4	Device high side unpowered. Fail-safe output (see data sheet for more details).	B
GND2	5	Device low side unpowered. VOUTP and VOUTN pins are driven to GND2.	B
VOUTN	6	VOUTN stuck high (VDD2). Excess current consumption from VDD2 source. Device damage plausible if condition is present for extended period of time.	A
VOUTP	7	VOUTP stuck high (VDD2). Excess current consumption from VDD2 source. Device damage plausible if condition is present for extended period of time.	A
VDD2	8	No effect. Normal operation.	D