AN2815 datasheet(4/42 Pages) STMICROELECTRONICS

4 / 42 page

List of figures

AN2815

4/42

List of figures

Figure 1.

PM6675AS demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2.

PM6675AS demonstration board schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3.

Top side component placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 4.

Top view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 5.

Layer 2 view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 6.

Layer 3 view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 7.

Bottom view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 8.

Bottom side component placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 9.

JP3 (VSEL) setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 10.

JP1 (NOSKIP) setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 11.

JP2 (LILIM) setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 12.

JP5 (COMP) setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 13.

PM6675AS demonstration board test setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 14.

VOUT soft-start at 150 mW load, pulse-skip mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 15.

LOUT turn-on, VOUT in pulse-skip mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 16.

VOUT = 1.5 V, VIN = 24 V, IVOUT = 0 A, forced-PWM mode . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 17.

VOUT = 1.5 V, VIN = 24 V, IVOUT = 0 A, pulse-skip mode . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 18.

VOUT = 1.5 V, VIN = 24 V, no load, non-audible pulse-skip mode (33 kHz) . . . . . . . . . . . . 23

Figure 19.

VOUT load regulation - VIN = 24 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 20.

LOUT load regulation - LDOIN = VOUT , VOUT in forced PWM mode . . . . . . . . . . . . . . . . . 25

Figure 21.

VOUT load transient (VIN=24 V, LOAD=0 A to 7 A at 2.5 A/µs), pulse-skip mode. . . . . . . . 26

Figure 22.

VOUT load transient (VIN = 24 V, LOAD=0 A to 7 A at 2.5 A/µs), pulse-skip mode. . . . . . . 27

Figure 23.

Forced PWM (blue), non-audible pulse-skip (green), pulse-skip (red), efficiency vs.

output current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 24.

External MOSFET gate signals (VIN = 24 V, LOAD = 0), pulse-skip mode . . . . . . . . . . . . 29

Figure 25.

External MOSFET gate signals (VIN = 24 V, LOAD = 7 A), pulse-skip mode . . . . . . . . . . 29

Figure 26.

VOUT and LOUT output voltages, VOUT soft-end, LOUT powered by an auxiliary rail. . . . . . 30

Figure 27.

VOUT and LOUT output voltages, LOUT soft-end . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 28.

UV protection, pulse-skip mode, LOUT powered by an auxiliary rail . . . . . . . . . . . . . . . . . . 32

Figure 29.

OV protection, pulse-skip mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 30.

VOUT and LOUT rails, thermal shutdown, pulse-skip mode, LOUT powered by VOUT . . . . . 34

Figure 31.

VOUT current limit protection during a load transient (0 A to 9 A at 2.5 A/µs . . . . . . . . . . . 35

Figure 32.

LOUT current limit during an output short . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figure 33.

Switching frequency vs. input voltage, VOUT = 1.5 V, IVOUT = 2 A, forced PWM mode . . . 37

Figure 34.

Forced PWM (blue), non-audible pulse-skip (green) and pulse-skip (red), Switching

frequency vs. output current, VOUT = 1.5 V, VIN = 24 V . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 35.

ILOUT = 0 A, average IC temperature = 31.0 °C, max internal IC temperature = 33.1 °C. . 39

Figure 36.

ILOUT = 0.2 A, average IC temperature = 38.2°C, max internal IC temperature = 40.7 °C . 39

Figure 37.

ILOUT = 0.5 A, average IC temperature = 38.2 °C, max internal IC temperature = 41.5 °C 40

Figure 38.

ILOUT = 1.0 A, average IC temperature = 48°C, max internal IC temperature = 55.2 °C . . 40

AN2815 Datasheet(PDF) 4 Page - STMicroelectronics

AN2815 Datasheet(HTML) 4 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Datasheet Download

Link URL