SBOA407 November 2020 ALM2403-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a Failure Mode Analysis (FMA) for the pins of the ALM2403-Q1 (HTSSOP). 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 ALM2403-Q1 pin diagram. For a detailed description of the device pins please refer to the 'Pin Configuration and Functions' section in the ALM2403-Q1 datasheet.
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 Supply or Power' means short to VS+
- 'Short to GND' means short to VS‒
- VS+ is equivalent to VCC and VS‒ equivalent to VEE
- OTF/SH_DN pin is configured in such a state as to enable the amplifier
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
IN1‒ | 1 | Negative feedback not present to device. Depending on circuit configuration, output will most likely move to negative supply. | B |
IN+ | 2 | 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 |
OTF | 3 | GND pin will be likely be driven to OTF voltage. the device will turn off. No damage to device. | B |
INA2+ | 4 | 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 |
IN2‒ | 5 | Negative feedback not present to device. Depending on circuit configuration, output will most likely move to negative supply. | B |
NC | 7 | NC pin internally disconnected, no effect. | D |
NC | 8 | NC pin internally disconnected, no effect. | D |
OUT2 | 9 | Depending on circuit configuration, device will likely be forced into short circuit condition with OUT2 voltage ultimately forced to GND voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. | A |
VCC | 10 | Op‒Amp supplies will be shorted together leaving VCC pin at some voltage between VCC and GND sources (depending on source impedance). | A |
VCC | 11 | Op‒Amp supplies will be shorted together leaving VCC pin at some voltage between VCC and GND sources (depending on source impedance). | A |
VCC | 12 | Op‒Amp supplies will be shorted together leaving VCC pin at some voltage between VCC and GND sources (depending on source impedance). | A |
OUT1 | 13 | Depending on circuit configuration, device will likely be forced into short circuit condition with OUT1 voltage ultimately forced to GND 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 |
|---|---|---|---|
IN1‒ | 1 | 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. IN1‒ pin voltage will likely end up at positive or negative rail due to leakage on ESD diodes. | B |
IN+ | 2 | 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. IN1+ pin voltage will likely end up at positive or negative rail due to leakage on ESD diodes. | B |
OTF | 3 | No damage to device, but OTF pin will be vulnerable to capacitive coupling and potential switching between shutdown and non-shutdown states. | B |
IN2+ | 4 | 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. IN2+ pin voltage will likely end up at positive or negative rail due to leakage on ESD diodes. | B |
IN2‒ | 5 | 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. IN2‒ pin voltage will likely end up at positive or negative rail due to leakage on ESD diodes. | B |
GND | 6 | Negative supply left floating. Op‒Amp will cease to function as no current can source/sink to the device. | B |
NC | 7 | NC pin internally disconnected, no effect. | D |
NC | 8 | NC pin internally disconnected, no effect. | D |
OUT2 | 9 | No negative feedback or ability for OUT2 to drive application. | B |
VCC | 10 | Positive supply left floating. Op‒Amp will cease to function as no current can source/sink to the device. | A |
VCC | 11 | Positive supply left floating. Op‒Amp will cease to function as no current can source/sink to the device. | A |
VCC | 12 | Positive supply left floating. Op‒Amp will cease to function as no current can source/sink to the device. | A |
OUT1 | 13 | No negative feedback or ability for OUT1 to drive application. | B |
GND | 14 | Negative 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 |
|---|---|---|---|---|
IN1‒ | 1 | 2 | Both inputs will be tied together. Depending on the offset of the device, this will likely move the output voltage near mid supply. | D |
IN1+ | 2 | 3 | Device will toggle between shutdown or non-shutdown depending on OTF voltage. This is a 3.3V logic gate, so exceeding the ABS max ratings for current or voltage could damage the device. | A |
OTF | 3 | 4 | Device will toggle between shutdown or non-shutdown depending on OTF voltage. This is a 3.3V logic gate, so exceeding the ABS max ratings for current or voltage could damage the device. | A |
IN2+ | 4 | 5 | Both inputs will be tied together. Depending on the offset of the device, this will likely move the output voltage near mid supply. | D |
IN2‒ | 5 | 6 | Negative feedback not present to device. Depending on circuit configuration, output will most likely move to negative supply. | B |
GND | 6 | 7 | NC pin internally disconnected, no effect. | D |
NC | 8 | 9 | NC pin internally disconnected, no effect. | D |
OUT2 | 9 | 10 | Depending on circuit configuration, device will likely be forced into short circuit condition with OUT2 voltage ultimately forced to VCC voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. | A |
VCC | 12 | 13 | Depending on circuit configuration, device will likely be forced into short circuit condition with VCC voltage ultimately forced to OUT1 voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. | A |
OUT1 | 13 | 14 | Depending on circuit configuration, device will likely be forced into short circuit condition with OUT1 voltage ultimately forced to GND voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. | A |
GND | 14 | 1 | Negative feedback not present to device. Depending on circuit configuration, output will most likely move to negative supply. | B |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
IN1‒ | 1 | Negative feedback not present to device. Depending on non‒inverting input voltage and circuit configuration, output will most likely move to negative supply. | B |
IN1+ | 2 | Depending on circuit configuration, application will likely not function due to the device common‒mode being connected to IN1+. | B |
OTF | 3 | Device will be likely be enabled. This is a 3.3V logic gate, so exceeding the ABS max ratings for current or voltage could damage the device. | A |
IN2+ | 4 | Depending on circuit configuration, application will likely not function due to the device common‒mode being connected to IN2+. | B |
IN2‒ | 5 | Negative feedback not present to device. Depending on non‒inverting input voltage and circuit configuration, output will most likely move to negative supply. | B |
GND | 6 | Op‒Amp supplies will be shorted together leaving GND pin at some voltage between GND and VCC sources (depending on source impedance). | A |
NC | 7 | NC pin internally disconnected, no effect. | D |
NC | 8 | NC pin internally disconnected, no effect. | D |
OUT2 | 9 | Depending on circuit configuration, device will likely be forced into short circuit condition with OUT2 voltage ultimately forced to VCC voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. | A |
OUT1 | 13 | Depending on circuit configuration, device will likely be forced into short circuit condition with OUT1 voltage ultimately forced to VCC voltage. Prolonged exposure to short circuit conditions could result in long term reliability issues. | A |
GND | 14 | Op‒Amp supplies will be shorted together leaving GND pin at some voltage between GND and VCC sources (depending on source impedance). | A |