A6986H datasheet(30/71 Pages) STMICROELECTRONICS

30 / 71 page

Figure 27. Quiescent current at VOUT = 5 V and zero output load

100

120

VIN [V]

A6986H input current with VBIAS=VOUT=5V and ILOAD =0

LCM-500kHz

ISKIPH

ISKIPL

When VIN approaches VOUT (see Figure 27. Quiescent current at VOUT = 5 V and zero output load and zoomed

Figure 28. Quiescent current at VIN while regulating VOUT = 5 V at zero output load) the device increases the

switching activity towards the continuous conduction mode operation for the internal slope contribution effect on

the programmed skip current threshold. As a consequence the quiescent current increases.

When VIN is lower than VOUT (see Figure 28. Quiescent current at VIN while regulating VOUT = 5 V at zero

output load), the device enters in the low-dropout operation with the high-side always switched on. In this

operating condition, all the internal circuit blocks are active and the quiescent current corresponds to what

measured in the low noise mode operation (see IQ OP VIN and IQ OP VBIAS in Table 5. Electrical characteristics TJ =

- 40 to 135 °C, VIN = 12 V unless otherwise specified. given VFB = GND).

Figure 28. Quiescent current at VIN while regulating VOUT = 5 V at zero output load

4.2

4.4

4.6

4.8

5.2

5.4

5.6

5.8

VIN [V]

A6986H Input Current VBIAS =VOUT =5V and ILOAD =0

LCM -500kHz

ISKIPH

ISKIPL

Pulse Skipping

SLEEP Mode

Continuous

Conduction Mode

Drop Out

No SLEEP Mode

A6986H

Light-load operation

DS12861 - Rev 3

page 30/71

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