SFFS760 December 2023 TLVM365R1 , TLVM365R15
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a Failure Mode Analysis (FMA) for the pins of the TLVM365R15 and TLVM365R1. 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 TLVM365R15 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TLVM365R15 data sheet.
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| PGOOD | 1 | When not in use, this pin can be left open or grounded. However, PGOOD is no longer reliably relays Power-Good information to devices connected to this pin. | B |
| EN | 2 | VOUT = 0 V, device is disabled. | B |
| VIN | 3 | VOUT = 0 V. | B |
| VOUT | 4 | Goes into hiccup, short-circuit operation. | B |
| SW | 5, 6 | Damage occurs. | A |
| BOOT | 7 | VOUT = 0 V, HS FET does not turn on. | B |
| VCC | 8 | VOUT = 0 V. | B |
| FB/BIAS | 9 | VOUT = 0 V. | B |
| GND | 10 | Normal operation. | D |
| RT | 11 | For RT, the switching frequency is set to 2.2 MHz. | B |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| PGOOD | 1 | When not in use, this pin can be left open or grounded. However, PGOOD is no longer reliably relays Power-Good information to devices connected to this pin. | B |
| EN | 2 | VOUT behavior is not defined. VOUT may be 0 V, but it also may be up. Do not float this pin. Device can no longer reliably be enabled or disabled by other devices connected to this pin. | B |
| VIN | 3 | VOUT = 0 V. | B |
| VOUT | 4 | VOUT = 0 V. | B |
| SW | 5, 6 | Normal operation. | D |
| BOOT | 7 | Normal operation. | D |
| VCC | 8 | VCC output is unstable, can increase above 5.5 V | A |
| FB/BIAS | 9 | VOUT = 0 V. Do not float this pin. | B |
| GND | 10 | VOUT can be abnormal, as reference voltage is not fixed. | B |
RT | 11 | If it is RT device, then frequency is not defined. VOUT is up, but only partially functional. | C |
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|---|
| PGOOD | 1 | EN | If EN > 20 V, it damages devices connected to the PGOOD pin. | A |
| EN | 2 | VIN | VOUT normal (enable is on, all other blocks work). However, the device can no longer be disabled. | B |
| VIN | 3 | VOUT | If VIN >16 V, damage occurs. | A |
| VOUT | 4 | SW | Damage occurs. | A |
| SW | 6 | BOOT | VOUT = 0 V, HS does not turn on, no Cboot. | B |
| BOOT | 7 | VCC | Damage occurs to VCC LDO. The VCC LDO could no longer supply voltage to internal control circuits. | A |
| VCC | 8 | FB | Can be partially nonfunctional, no damage occurs. | B |
| FB/BIAS | 9 | GND | VOUT = 0 V (for fixed option) switches at maximum duty cycle for ADJ option. | B |
| GND | 10 | RT or MODE | For RT, Switching Frequency is set to 2.2 MHz. For MODE/SYNC the device goes into PFM mode. | B |
RT | 11 | PGOOD | If PGOOD is high and < 5.5 V, then Fsw = 1 MHz. If PGOOD is low, then Fsw = 2.2 MHz for RT. PGOOD absmax being 20 V, RT ESD damages if PG goes to 20 V. | A |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| PGOOD | 1 | If VIN > 20 V, it damages PGOOD. PGOOD is no longer reliably relays Power-Good information to devices connected to this pin. | A |
| EN | 2 | VOUT normal (enable is on, all other blocks work). However, the device can no longer be disabled. | B |
| VIN | 3 | Normal operation. | D |
| VOUT | 4 | Damage occurs, if VIN > 16 V. | A |
| SW | 5, 6 | Damage occurs. | A |
| BOOT | 7 | Damage occurs, the BOOT ESD clamp is damaged. | A |
| VCC | 8 | If Vin > 5.5 V, damage occurs. | A |
| FB/BIAS | 9 | If VIN > 20 V, damage occurs. | A |
| GND | 10 | VOUT = 0 V. | A |
RT | 11 | If Vin > 5.5 V, damage occurs. If Vin < 5.5 V, switching frequency is 1 MHz. | A |