Datasheet LTC3703 (Analog Devices) - 29
| Hersteller | Analog Devices |
| Beschreibung | 100V Synchronous Switching Regulator Controller |
| Seiten / Seite | 34 / 29 — applicaTions inForMaTion. Figure 20. LTC3703 Buck Converter Suggested … |
| Dateiformat / Größe | PDF / 459 Kb |
| Dokumentensprache | Englisch |
applicaTions inForMaTion. Figure 20. LTC3703 Buck Converter Suggested Layout
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LTC3703
applicaTions inForMaTion
5. Place the small-signal components away from high 7. For optimum load regulation and true remote sensing, frequency switching nodes (BOOST, SW, TG, and BG). the top of the output resistor divider should connect In the layout shown in Figure 20, all the small-signal independently to the top of the output capacitor (Kelvin components have been placed on one side of the IC connection), staying away from any high dV/dt traces. and all of the power components have been placed on Place the divider resistors near the LTC3703 in order the other. This also helps keep the signal ground and to keep the high impedance FB node short. power ground isolated. 8. For applications with multiple switching power con- 6. A separate decoupling capacitor for the supply, VCC, verters connected to the same input supply, make is useful with an RC filter between the DRVCC supply sure that the input filter capacitor for the LTC3703 and VCC pin to filter any noise injected by the drivers. is not shared with other converters. AC input current Connect this capacitor close to the IC, between the from another converter could cause substantial input VCC and GND pins and keep the ground side of the VCC voltage ripple, and this could interfere with the opera- capacitor (signal ground) isolated from the ground side tion of the LTC3703. A few inches of PC trace or wire of the DRVCC capacitor (power ground). (L ≅ 100nH) between CIN of the LTC3703 and the actual source VIN should be sufficient to prevent input noise interference problems. VCC VIN DB 1 16 MODE/SYNC VIN RSET 2 15 M1 fSET BOOST + R LTC3703 C1 3 14 CIN COMP TG C CB C2 CC1 4 13 FB SW RMAX L1 5 12 IMAX VCC + R2 6 11 RF M2 INV DRV + CC C C SS OUT 7 10 D1 VOUT RUN/SS BG CDRVCC X5R RC2 R1 8 9 GND BGRTN – CVCC CC3 X5R 3703 F18
Figure 20. LTC3703 Buck Converter Suggested Layout
3703fc 29 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
applicaTions inForMaTion
5. Place the small-signal components away from high 7. For optimum load regulation and true remote sensing, frequency switching nodes (BOOST, SW, TG, and BG). the top of the output resistor divider should connect In the layout shown in Figure 20, all the small-signal independently to the top of the output capacitor (Kelvin components have been placed on one side of the IC connection), staying away from any high dV/dt traces. and all of the power components have been placed on Place the divider resistors near the LTC3703 in order the other. This also helps keep the signal ground and to keep the high impedance FB node short. power ground isolated. 8. For applications with multiple switching power con- 6. A separate decoupling capacitor for the supply, VCC, verters connected to the same input supply, make is useful with an RC filter between the DRVCC supply sure that the input filter capacitor for the LTC3703 and VCC pin to filter any noise injected by the drivers. is not shared with other converters. AC input current Connect this capacitor close to the IC, between the from another converter could cause substantial input VCC and GND pins and keep the ground side of the VCC voltage ripple, and this could interfere with the opera- capacitor (signal ground) isolated from the ground side tion of the LTC3703. A few inches of PC trace or wire of the DRVCC capacitor (power ground). (L ≅ 100nH) between CIN of the LTC3703 and the actual source VIN should be sufficient to prevent input noise interference problems. VCC VIN DB 1 16 MODE/SYNC VIN RSET 2 15 M1 fSET BOOST + R LTC3703 C1 3 14 CIN COMP TG C CB C2 CC1 4 13 FB SW RMAX L1 5 12 IMAX VCC + R2 6 11 RF M2 INV DRV + CC C C SS OUT 7 10 D1 VOUT RUN/SS BG CDRVCC X5R RC2 R1 8 9 GND BGRTN – CVCC CC3 X5R 3703 F18
Figure 20. LTC3703 Buck Converter Suggested Layout
3703fc 29 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts