L6986 datasheet(24/68 Pages) STMICROELECTRONICS

Part #	L6986

Description	38 V, 2 A synchronous step-down switching regulator with 30 A quiescent current

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

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Functional description

L6986

24/68

DocID025376 Rev 7

4.5

Light load operation

The MLF pinstrapping during the power-up phase determines the light load operation (refer

to Table 7: LNM / LCM selection).

4.5.1

Low noise mode (LNM)

The low noise mode implements a forced PWM operation over the different loading

conditions. The LNM features a constant switching frequency to minimize the noise in the

final application and a constant voltage ripple at fixed VIN. The regulator in steady loading

condition never skip pulses and it operates in continuous conduction mode (CCM) over the

different loading conditions.

Figure 13. Low noise mode operation

Typical applications for the LNM operation are car audio, sensors.

4.5.2

Low consumption mode (LCM)

The low consumption mode maximizes the efficiency at light load. The regulator prevents

the switching activity whenever the switch peak current request is lower than the ISKIP

threshold (700 mA typical). As a consequence the L6986 device works in bursts and it

minimizes the quiescent current request in the meantime between the switching operation.

L6986 Datasheet(PDF) 24 Page - STMicroelectronics