L7986 datasheet(11/43 Pages) STMICROELECTRONICS

номер детали	L7986

подробное описание детали	3 A step-down switching regulator

Download	43 Pages

Scroll/Zoom	100%

производитель	STMICROELECTRONICS [STMicroelectronics]

домашняя страница	http://www.st.com

Logo

11 / 43 page

DocID022450 Rev 6

11/43

L7986

Functional description

43

5.2

Soft-start

The soft-start is essential to assure correct and safe startup of the step-down converter. It

avoids inrush current surge and makes the output voltage increase monothonically.

The soft-start is performed by a staircase ramp on the non inverting input (VREF) of the error

amplifier. So the output voltage slew rate is:

Equation 1

where SRVREF is the slew rate of the non inverting input, while R1and R2 is the resistor

divider to regulate the output voltage (see Figure 7). The soft-start staircase consists of 64

steps of 9.5 mV each, from 0 V to 0.6 V. The time base of one step is of 32 clock cycles. So

the soft-start time and then the output voltage slew rate depend on the switching frequency.

Figure 7. Soft-start scheme

Soft-start time results:

Equation 2

For example, with a switching frequency of 250 kHz, the SSTIME is 8 ms.

SROUT

SRVREF 1

R1

R2

--------

+







=

SSTIME

32 64



Fsw

-----------------

=

Аналогичный номер детали - L7986

производитель	номер детали	датащи	подробное описание детали
STMicroelectronics	L7986TA	784Kb / 43P	3 A step-down switching regulator

More results

Аналогичное описание - L7986

производитель	номер детали	датащи	подробное описание детали
STMicroelectronics	L7981ATR	1Mb / 44P	3 A step-down switching regulator
	L5987	1Mb / 42P	3 A step-down switching regulator
	L7986TA	784Kb / 43P	3 A step-down switching regulator
	L7981ATR	1Mb / 44P	3 A step-down switching regulator
	ST1S40	849Kb / 30P	3 A DC step-down switching regulator August 2019
	ST1S40	1Mb / 29P	3 A DC step-down switching regulator
	ST1S40IPUR	1Mb / 30P	3 A DC step-down switching regulator
	PM8903A	2Mb / 33P	3 A step-down monolithic switching regulator January 2013 Rev 1
	PM8903	2Mb / 34P	3 A step-down monolithic switching regulator
	ST1S31	1Mb / 35P	3 A DC step-down switching regulator March 2016 Rev 4

More results

L7986 датащи(PDF) 11 Page - STMicroelectronics

L7986 датащи(HTML) 11 Page - STMicroelectronics

Аналогичный номер детали - L7986

Аналогичное описание - L7986

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 43

датащи скачать

ссылки URL