SFFS525A September 2022 – November 2022 UCC28C50 , UCC28C51 , UCC28C52 , UCC28C53 , UCC28C54 , UCC28C55 , UCC28C56L , UCC28C57H , UCC28C57L , UCC28C58 , UCC28C59
Figure 4-1 shows the UCCx8C5x pin diagram for the SOIC (8) and VSSOP (8) packages. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the UCCx8C5xdata sheet.
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| COMP | 1 | OUT zero duty cycle, output loss of regulation. Possible IC damage | B |
| FB | 2 | COMP pin go high, OUT excessive duty-cycle, output loss of regulation. | B |
| CS | 3 | Maximum OUT duty-cycle, loss of regulation, likely damage to power switch | B |
| RT/CT | 4 | Oscillator stops, OUT zero duty cycle, output loss of regulation | B |
| GND | 5 | N/A | D |
| OUT | 6 | OUT remains low, zero duty cycle. Likely IC damage | A |
| VDD | 7 | IC not biased, OUT zero duty cycle, output loss of regulation | B |
| VREF | 8 | OUT zero duty cycle, output loss of regulation, possible IC damage | A |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| COMP | 1 | Regulation loop becomes unstable, oscillation may result | C |
| FB | 2 | COMP stays high, OUT excessive duty-cycle, output loss of regulation | B |
| CS | 3 | CS pin stays high, OUT zero duty cycle, output loss of regulation | B |
| RT/CT | 4 | Oscillator stops, OUT zero duty cycle, output loss of regulation | B |
| GND | 5 | Internal GND pulled up to 0.65 V, IC behavior unpredictable | B |
| OUT | 6 | OUT at maximum duty cycle, output loss of regulation | B |
| VDD | 7 | IC not biased, OUT at zero duty cycle, output loss of regulation | B |
| VREF | 8 | VREF reglator unstable and oscillates, output oscillates | C |
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|---|
| COMP | 1 | FB | COMP at VREF level, OUT excessive duty cycle, output loss of regulation | B |
| FB | 2 | CS | COMP stays at high, OUT excessive duty cycle, output loss of regulation | B |
| CS | 3 | RT/CT | Oscillator stops, OUT zero duty cycle, output loss of regulation | B |
| RT/CT | 4 | N/A | D | |
| GND | 5 | OUT | OUT stays low, OUT zero duty cycle, output loss of regulation, likely IC damage | A |
| OUT | 6 | VDD | OUT stays high, 100% duty cycle, likely IC and power supply damage | A |
| VDD | 7 | VREF | VREF excess Abs max rating, IC damage, output loss of regulation | A |
| VREF | 8 | N/A | D |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
| COMP | 1 | Possible IC damange. OUT excessive duty cycle, output loss of regulation | A |
| FB | 2 | Excess Abs. Max rating, IC damage. OUT excessive duty cycle, output loss of regulation | A |
| CS | 3 | Excess Abs. Max rating, IC damage, OUT zero duty cycle, output loss of regulation | A |
| RT/CT | 4 | Excess Abs. Max rating, IC damage, OUT zero duty cycle, output loss of regulation | A |
| GND | 5 | IC is not biased. OUT zero duty cycle, output loss of regulation | B |
| OUT | 6 | OUT stays high, 100% duty cycle, likely IC and power supply damage | A |
| VDD | 7 | N/A | D |
| VREF | 8 | VREF excess Abs max rating, IC damage, output loss of regulation | A |