L6983 datasheet(12/63 Pages) STMICROELECTRONICS

部件名	L6983

功能描述	38 V, 3 A synchronous step-down converter with 17 μA quiescent current

PDF	63 Pages

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制造商	STMICROELECTRONICS [STMicroelectronics]

网页	http://www.st.com

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12 / 63 page

Figure 4. Power-up/down behavior

When the voltage applied on the EN pin rises over VWAKEUP, RISING, the device powers up the internal circuit thus

increasing the current consumption.

As soon as the voltage rises over the VEN, RISING, the device starts the switching activities as described on

Section 6.2 Soft-start.

Once the voltage becomes lower than VEN, FALLING, the device interrupts the switching activities.

As soon as the voltage becomes lower than VWAKEUP.FALLING, the device powers down the internal circuit

reducing the current consumption.

The pin is VIN compatible.

Please refer to Table 6. Electrical characteristics for the reported thresholds.

6.2

Soft-start

The soft-start (SS) limits the inrush current surge and makes the output voltage increase monotonically.

The device implements the soft-start phase ramping the internal reference with very small steps. Once the SS

ends the error amplifier reference is switched to the internal value of 0.85 V coming directly from the band gap

cell.

L6983

Soft-start

DS13116 - Rev 1

page 12/63

L6983 数据表(PDF) 12 Page - STMicroelectronics