VIPER22A-E datasheet(10/21 Pages) STMICROELECTRONICS

Il numero della parte	VIPER22A-E

Spiegazioni elettronici	Low power OFF-line SMPS primary switcher

PDF	21 Pages

Scroll/Zoom	100%

Produttore elettronici	STMICROELECTRONICS [STMicroelectronics]

Homepage	http://www.st.com

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10 / 21 page

Operations

VIPer22A-E, VIPer22ADIP-E, VIPer22AS-E

10/21

Doc ID 12050 Rev 2

Figure 6.

IFB transfer function

It is then possible to build the total DC transfer function between ID and IFB as shown on

Figure 6 on page 10

. This figure also takes into account the internal blanking time and its

associated minimum turn on time. This imposes a minimum drain current under which the

device is no more able to control it in a linear way. This drain current depends on the primary

inductance value of the transformer and the input voltage. Two cases may occur, depending

on the value of this current versus the fixed 85 mA value, as described above.

IFBsd

IDlim

IFB

ONmin

⋅

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

ONmin

⋅

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

85mA

IDpeak

Part masked by the IFBsd

threshold

VIPER22A-E Scheda tecnica(PDF) 10 Page - STMicroelectronics