L6986H datasheet(22/68 Pages) STMICROELECTRONICS

22 / 68 page

Table 12. SYNCH/ISKIP pin voltage thresholds and driving current

Parameter

Value

VSKIP_TH_L_MAX

0.65 V

VSKIP_TH_H_MIN

1.6 V

ISYNCH/ISKIP_DRIVING_MIN

± 10 µA

Figure 17. L6986H skip current level transition at ILOAD = 150 mA with L = 10 µH shows a skip current threshold

transition at ILOAD = 150 mA measured on the L6986H - VOUT = 3.3 V with fsw = 500 kHz and L = 10 µH:

•

When V(SYNCH/ISKIP) < VSKIP_TH_L_MAX, the L6986H operates in the pulse skipping mode minimizing

current consumption

•

When V(SYNCH/ISKIP) > VSKIP_TH_H_MIN, the L6986H operates in the continuous conduction mode

minimizing the output voltage ripple

Figure 17. L6986H skip current level transition at ILOAD = 150 mA with L = 10 µH

Figure 18. Light-load efficiency comparison at different ISKIP - linear scale and Figure 19. Light-load efficiency

comparison at different ISKIP - log scale report the efficiency measurements to highlight the ISKIPH and ISKIPL

efficiency gap at the light-load also in comparison with the LNM operation. The same efficiency at the medium /

high load is confirmed at different ISKIP levels.

L6986H

Light-load operation

DS12905 - Rev 2

page 22/68

L6986H 数据表(PDF) 22 Page - STMicroelectronics