SFFS766 November 2023 OPA2377-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a failure mode analysis (FMA) for the pins of the OPA2377-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.
| 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 OPA2377-Q1 pin diagram. For a detailed description of the device pins, see the Pin Configuration and Functions section in the OPA2377-Q1 data sheet.
Figure 4-1 Pin DiagramFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- 'Short circuit to Power' means to V+ supply.
- 'Short circuit to GND or Ground' means to V‒ supply.
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
|
OUT A |
1 |
Depending on circuit configuration, device will likely be forced into short circuit condition with OUT A voltage ultimately forced to V‒ voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. |
A |
|
‒IN A |
2 |
Negative feedback not present to device. Depending on circuit configuration, output will most likely move to negative supply. |
B |
|
+IN A |
3 |
Device common‒mode tied to negative rail. Depending on circuit configuration, output will likely not respond due to the device being put in an invalid common‒mode condition. |
C |
|
+IN B |
5 |
Device common‒mode tied to negative rail. Depending on circuit configuration, output will likely not respond due to the device being put in an invalid common‒mode condition. |
C |
|
‒IN B |
6 |
Negative feedback not present to device. Depending on circuit configuration, output will most likely move to negative supply. |
B |
|
OUT B |
7 |
Depending on circuit configuration, device will likely be forced into short circuit condition with OUT B voltage ultimately forced to V‒ voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. |
A |
|
V+ |
8 |
Op‒Amp supplies will be shorted together leaving V+ pin at some voltage between V+ and V‒ sources (depending on source impedance). |
A |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
|
OUT A |
1 |
No negative feedback or ability for OUT A to drive application. |
B |
| ‒IN A |
2 |
Inverting pin of Op‒Amp left floating. Negative feedback will not be provided to device, likely resulting in device output moving between positive and negative rail. ‒IN A pin voltage will likely end up at positive or negative rail due to leakage on ESD diodes. |
B |
| +IN A |
3 |
Input common‒mode left floating. Op‒Amp will not be provided with common‒mode bias, device output will likely end up at positive or negative rail. +IN A pin voltage will likely end up at positive or negative rail due to leakage on ESD diodes. |
B |
|
V‒ |
4 |
Negative supply left floating. Op‒Amp will cease to function as no current can source/sink to the device. |
A |
|
+IN B |
5 |
Input common‒mode left floating. Op‒Amp will not be provided with common‒mode bias, device output will likely end up at positive or negative rail. +IN B pin voltage will likely end up at positive or negative rail due to leakage on ESD diodes. |
B |
| ‒IN B |
6 |
Inverting pin of Op‒Amp left floating. Negative feedback will not be provided to device, likely resulting in device output moving between positive and negative rail. ‒IN B pin voltage will likely end up at positive or negative rail due to leakage on ESD diodes. |
B |
|
OUT B |
7 |
No negative feedback or ability for OUT B to drive application. |
B |
|
+V |
8 |
Positive supply left floating. Op‒Amp will cease to function as no current can source/sink to the device. |
A |
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|---|
|
OUT A |
1 |
‒IN A |
Depending on circuit configuration, gain of circuit will be reduced to unity gain and application may not function as intended |
B |
| ‒IN A |
2 |
+IN A |
Both inputs will be tied together. Depending on the offset of the device, this will likely move the output voltage near mid supply. |
D |
|
+IN A |
3 |
V‒ |
Device common‒mode tied to negative rail. Depending on circuit configuration, output will likely not respond due to the device being put in an invalid common‒mode condition. |
C |
| V‒ |
4 |
+IN B |
Device common‒mode tied to negative rail. Depending on circuit configuration, output will likely not respond due to the device being put in an invalid common‒mode condition. |
C |
|
+IN B |
5 |
‒IN B |
Both inputs will be tied together. Depending on the offset of the device, this will likely move the output voltage near mid supply. |
D |
| ‒IN B |
6 |
OUT B |
Depending on circuit configuration, gain of circuit will be reduced to unity gain and application may not function as intended |
B |
|
OUT B |
7 |
V+ |
Depending on circuit configuration, device will likely be forced into short circuit condition with OUT B voltage ultimately forced to V+ voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. |
A |
|
V+ |
8 |
OUT A |
Depending on circuit configuration, device will likely be forced into short circuit condition with V+ voltage ultimately forced to OUT A voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. |
A |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
|
OUT A |
1 |
Depending on circuit configuration, device will likely be forced into short circuit condition with OUT A voltage ultimately forced to V+ voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. |
AB |
|
‒IN A |
2 |
Negative feedback not present to device. Depending on non‒inverting input voltage and circuit configuration, output will most likely move to negative supply. |
B |
|
+IN A |
3 |
Depending on circuit configuration, application will likely not function due to the device common‒mode being connected to +IN A. |
B |
|
V‒ |
4 |
Op‒Amp supplies will be shorted together leaving V‒ pin at some voltage between V‒ and V+ sources (depending on source impedance). |
A |
|
+IN B |
5 |
Depending on circuit configuration, application will likely not function due to the device common‒mode being connected to +IN B. |
B |
|
‒IN |
6 |
Negative feedback not present to device. Depending on non‒inverting input voltage and circuit configuration, output will most likely move to negative supply. |
B |
|
OUT B |
7 |
Depending on circuit configuration, device will likely be forced into short circuit condition with OUT B voltage ultimately forced to V+ voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. |
A |