TIDT256A March 2022 – March 2022
This section provides the testing guide used in the detailed testing of the SEPIC and in verification of the overall operation of the board.
Table 1-1 and Table 1-2 detail the PMP22817 headers and test points.
| Header | Description |
|---|---|
| J1 | VIN to LM5156-Q1 SEPIC: 6 V to 42 V: Main power input |
| J2 | Vbias: 3.3 V to 5 V |
| J5 | Remove to power up the LM5156-Q1 SEPIC alone. Install to power all devices. |
| J3 | Digital I/O on UCC5870-Q1. The UCC5870-Q1 EVM programmer can be connected to this header to use the UCC5870-Q1 EVM GUI to test the UCC5870-Q1 with a plug-in PMP22817-adapterA board. For more information, see Section 1.3. |
| J4 | Optional analog inputs to UCC5870-Q1 referenced to target SiC source or IGBT emitter |
| Test Point | Description |
|---|---|
| TP1 | VIN |
| TP2 | +15-V output from UCC14240-Q1 |
| TP3 | 24-V output from LM5156-Q1 TP3 used as VOUT for bode plot or loop stability of LM5156-Q1 SEPIC |
| TP4, TP10 | Ground, primary TP10 used as ground for bode plot or loop stability of LM5156-Q1 SEPIC |
| TP5, TP11 | Ground, secondary |
| TP6 | Power good pin on UCC14240-Q1 |
| TP7 | ENA pin on UCC14240-Q1 |
| TP8 | Power good pin on LM5156-Q1, modified to be used as injection point for bode plot to evaluate loop stability |
| TP9 | –5-V output from UCC14240-Q1 |
| TP12 | LM5156-Q1 switch node |
Two supplies are needed to power PMP22817, VIN and Vbias. VIN must be in the range of 9 V to 18 V. Vbias must be in the range of 3.3 V to 5 V. The order in which VIN and Vbias are supplied and removed is not important.
Once VIN and Vbias are supplied, then VIN is present on TP1, the switch node on TP12 is switching at 445 kHz, TP3 measures 24 V, and 20 V is present between TP2 and TP9. TP6 reads high.