SNVA950C April 2020 – March 2024 LM63635-Q1
4.1 HTSSOP Package
Figure 4-1 shows the LM63635-Q1 pin diagram for the HTSSOP package. For a detailed description of the device pins, please refer to the Pin Configuration and Functions section in the LM63635 data sheet.
Figure 4-1 Pin Diagram for
HTSSOPTable 4-2 Pin FMA for Device Pins Short-Circuited to Ground
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| SW | 1,2 | Damage to internal power FET(s) and other internal circuits | A |
| BOOT | 3 | Damage to internal circuits | A |
| VCC | 4 | Fault mode will shut device off | B |
| RT | 5 | Depends on exact application configuration. For application circuit as shown in the Example Application Circuit in the device data sheet, no effect will be produced. If an RT resistor is used the frequency will be set to 2.1MHz. If a 0Ω jumper is used to connect the RT input to VCC, then the VCC output will be pulled to ground; see short to ground on pin 4. | B |
| VSEL | 6 | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, VCC will be shorted to ground; see short to ground on pin 4. If a VSEL resistor is used, or if the VSEL input is pulled to ground with a 0Ω jumper, then the output voltage will be set to 3.3V, before power-up. No effect after power-up. | B |
| SYNC/MODE | 7 | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, no effect will be produced. If a 0Ω jumper is used to connect the SYNC/MODE input to VCC, then the VCC output will be pulled to ground; see short to ground on pin 4. | B |
| RESET | 8 | RESET functionality will be lost. | B |
| FB | 9 | The regulator will operate at maximum duty cycle. Output voltage will rise to nearly the input voltage (VIN) level. Possible damage to customer load and output stage components may occur. No effect on device. | B |
| AGND | 10 | No effect | D |
| EN | 11 | Loss of ENABLE functionality Device will remain in shut-down mode. | B |
| VIN | 12,13 | Device will not operate. No output voltage will be generated. Output capacitors will discharge through input short. Large reverse current may damage device. | A |
| N/C | 14 | No effect | D |
| PGND | 15,16 | No effect | D |
Table 4-3 Pin FMA for Device Pins Open-Circuited
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| SW | 1,2 | With both pins open, there can be a loss of output voltage. With one pin open, there can be some loss of device performance. | B |
| BOOT | 3 | Loss of output voltage regulation; low or no output voltage. | B |
| VCC | 4 | VCC LDO will be unstable. Loss of output voltage regulation and possible damage to internal circuits. | A |
| RT | 5 | Device switching frequency will drop to zero or become erratic. Loss of output voltage. | B |
| VSEL | 6 | Device will enter ADJ mode when EN or VIN is cycled. Incorrect output voltage if fixed VOUT mode was intended. No effect after power-up. | C |
| SYNC/MODE | 7 | Internal pull-down will place device in AUTO mode. | B |
| RESET | 8 | RESET functionality will be lost. | B |
| FB | 9 | Loss of output voltage regulation. Output voltage may rise or fall outside of intended regulation window. | B |
| AGND | 10 | Loss of output voltage regulation. Possible damage to internal circuits. | A |
| EN | 11 | Loss of ENABLE functionality. Erratic operation; probable loss of regulation. | B |
| VIN | 12,13 | With both pins open: loss of output voltage. With one pin open: possible device damage. | A |
| N/C | 14 | No effect | D |
| PGND | 15,16 | With either one or both pins open, possible device damage. | A |
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 |
|---|---|---|---|---|
| SW | 1 | SW | No effect | D |
| SW | 2 | BOOT | Loss of output regulation, possible damage to internal circuits | A |
| BOOT | 3 | VCC | Loss of output regulation, possible damage to internal circuits | A |
| VCC | 4 | RT | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, VCC will be shorted to ground; see short to ground on pin 4. For all other configurations, the effect will either be no change or erratic switching frequency with possible damage to device internal circuits. | A |
| RT | 5 | VSEL | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, VCC will be shorted to ground; see short to ground on pin 4. For all other configurations, the effect will either be no change or erratic output voltage and switching frequency with possible damage to device internal circuits. | A |
| VSEL | 6 | SYNC/MODE | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, VCC will be shorted to ground; see short to ground on pin 4. For all other configurations, the effect will either be no change or erratic operation and switching frequency with possible damage to device internal circuits. | A |
| SYNC/MODE | 7 | RESET | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, RESET will be shorted to ground; see short to ground on pin 8. For all other configurations, the effect will either be no change or erratic operation and loss of RESET and/or SYNC/MODE functionality with possible damage to device internal circuits. | A |
| FB | 9 | AGND | See see short to ground on pin 9 | B |
| AGND | 10 | EN | See see short to ground on pin 11 | B |
| EN | 11 | VIN | See see short to VIN on pin 11 | B |
| VIN | 12,13 | N/C | No effect | D |
| N/C | 14 | PGND | No effect | D |
Table 4-5 Pin FMA for Device Pins Short-Circuited to
VIN
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| SW | 1,2 | Damage to internal power FET(s) and other internal circuits | A |
| BOOT | 3 | Damage to internal circuits | A |
| VCC | 4 | Damage to internal circuits for VIN >5.5V | A |
| RT | 5 | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, no damage will occur. For all other configurations, damage to internal circuits will occur for VIN >5.5V. | A |
| VSEL | 6 | Damage to internal circuits for VIN >5.5V | A |
| SYNC/MODE | 7 | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, no damage will occur. For all other configurations, damage to internal circuits will occur for VIN >5.5V. | A |
| RESET | 8 | Damage to internal circuits. | A |
| FB | 9 | Depends on exact application configuration. For an application circuit as shown in the Example Application Circuit in the device data sheet, damage to internal circuits will occur for VIN >16V. For operation in the ADJ mode, damage to internal circuits will occur for VIN >5.5V. | A |
| AGND | 10 | Possible damage to internal circuits or package | A |
| EN | 11 | No damage to device. Loss of ENABLE functionality. | B |
| VIN | 12,13 | No effect. | D |
| N/C | 14 | No effect. | D |
| PGND | 15,16 | Possible damage to internal circuits or package | A |