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This document contains information for the AMC1350-Q1 (SOIC package) to aid in a functional safety system design. Information provided are:
Figure 1-1 shows the device functional block diagram for reference.
The AMC1350-Q1 was developed using a quality-managed development process, but was not developed in accordance with the IEC 61508 or ISO 26262 standards.
This section provides functional safety failure in time (FIT) rates for the AMC1350-Q1 based on two different industry-wide used reliability standards:
FIT IEC TR 62380 / ISO 26262 | FIT (Failures Per 109 Hours) |
---|---|
Total component FIT rate | 17 |
Die FIT rate | 3 |
Package FIT rate | 14 |
The failure rate and mission profile information in Table 2-1 comes from the reliability data handbook IEC TR 62380 / ISO 26262 part 11:
Table | Category | Reference FIT Rate | Reference Virtual TJ |
---|---|---|---|
5 | CMOS, BICMOS Digital, analog, or mixed | 25 FIT | 55°C |
The reference FIT rate and reference virtual TJ (junction temperature) in Table 2-2 come from the Siemens Norm SN 29500-2 tables 1 through 5. Failure rates under operating conditions are calculated from the reference failure rate and virtual junction temperature using conversion information in SN 29500-2 section 4.
The failure mode distribution estimation for the AMC1350-Q1 in Table 3-1 comes from the combination of common failure modes listed in standards such as IEC 61508 and ISO 26262, the ratio of sub-circuit function size and complexity, and from best engineering judgment.
The failure modes listed in this section reflect random failure events and do not include failures resulting from misuse or overstress.
Die Failure Modes | Failure Mode Distribution (%) |
---|---|
Output out of specification (gain error) | 20% |
Output out of specification (offset error) | 20% |
Output out of specification (differential output at positive or negative full scale) | 20% |
OUTN stuck high or low | 10% |
OUTP stuck high or low | 10% |
Reduced CMTI performance | 9% |
Output out of specification (spikes, increased noise) | 5% |
Device behavior undetermined | 5% |
Output fail-safe function fails to indicate an error(1) | 1% |
The FMD in Table 3-1 excludes short-circuit faults across the isolation barrier. Faults for short circuits across the isolation barrier can be excluded according to ISO 61800-5-2:2016 if the following requirements are fulfilled:
Apply creepage and clearance requirements according to the specific equipment isolation standards of an application. Care must be taken to maintain the creepage and clearance distance of a board design to ensure that the mounting pads of the isolator on the printed-circuit board do not reduce this distance.
This section provides a failure mode analysis (FMA) for the pins of the AMC1350-Q1. The failure modes covered in this document include the typical pin-by-pin failure scenarios:
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.
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 AMC1350-Q1 pin diagram. For a detailed description of the device pins, see the Pin Configuration and Functions section in the AMC1350-Q1 data sheet.
Following are the assumptions of use and the device configuration assumed for the pin FMA in this section:
Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
---|---|---|---|
VDD1 | 1 | Device primary side unpowered. Fail-safe output (see data sheet for more details). Observe that the absolute maximum ratings for the INP and INN pins of the device are met, otherwise device damage may be plausible. | A |
INP | 2 | INP stuck low (GND1). Differential output (VOUTP – VOUTN) = 0 V with common-mode voltage approximately 1.44 V. | B |
INN | 3 | INN stuck low (GND1). Differential output (VOUTP – VOUTN) = VINP × 0.4 with common-mode voltage approximately 1.44 V. Normal operation for the assumed use case. | D |
GND1 | 4 | No effect. Normal operation. | D |
GND2 | 5 | No effect. Normal operation. | D |
OUTN | 6 | OUTN stuck low (GND2). Excess current consumption from VDD2 source because of short-circuit condition. Device damage plausible if condition is present for extended period of time. | A |
OUTP | 7 | OUTP stuck low (GND2). Excess current consumption from VDD2 source because of short-circuit condition. Device damage plausible if condition is present for extended period of time. | A |
VDD2 | 8 | Device secondary side unpowered. OUTP and OUTN pins are driven to GND2. | B |
Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
---|---|---|---|
VDD1 | 1 | Device primary side unpowered. Fail-safe output (see data sheet for more details). | B |
INP | 2 | Differential output (VOUTP – VOUTN) undetermined. | B |
INN | 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 |
OUTN | 6 | Differential output (VOUTP – VOUTN) undetermined. | B |
OUTP | 7 | Differential output (VOUTP – VOUTN) undetermined. | B |
VDD2 | 8 | Device secondary side unpowered. OUTP and OUTN pins are driven to GND2. | B |
Pin Name | Pin No. | Shorted to | Description of Potential Failure Effect(s) | Failure Effect Class |
---|---|---|---|---|
VDD1 | 1 | INP | INP stuck high (VDD1). Differential output (VOUTP – VOUTN) = VCLIPout. See data sheet for details. | B |
INP | 2 | INN | Differential input shorted. Differential output (VOUTP – VOUTN) = 0 V. | B |
INN | 3 | GND1 | INN stuck low (GND1). Differential output (VOUTP – VOUTN) = VINP × 0.4 with common-mode voltage approximately 1.44 V. Normal operation for the assumed use case. | D |
GND1 | 4 | GND2 | Not considered. Corner pin. | D |
GND2 | 5 | OUTN | OUTN stuck low (GND2). Excess current consumption from VDD2 source because of short-circuit condition. Device damage plausible if condition is present for extended period of time. | A |
OUTN | 6 | OUTP | 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 |
OUTP | 7 | VDD2 | OUTP 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 |
Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
---|---|---|---|
VDD1 | 1 | No effect. Normal operation. | D |
INP | 2 | INP stuck high (VDD1). Differential output (VOUTP – VOUTN) = VCLIPout. See data sheet for details. | B |
INN | 3 | INN stuck high (VDD1). Differential output (VOUTP – VOUTN) incorrect. | B |
GND1 | 4 | Device primary side unpowered. Fail-safe output (see data sheet for details). Observe that the absolute maximum ratings for INP and INN of the device are met, otherwise device damage may be plausible. | A |
GND2 | 5 | Device secondary side unpowered. OUTP and OUTN pins are driven to GND2. | B |
OUTN | 6 | OUTN stuck high (VDD2). Excess current consumption from VDD2 source. Device damage plausible if condition is present for extended period of time. | A |
OUTP | 7 | OUTP 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 |