AN1882 datasheet(11/30 Pages) STMICROELECTRONICS

Part #	AN1882

Description	This application note details the main features

PDF	30 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

Logo

11 / 30 page

AN1882

Functional description

Doc ID 10209 Rev 4

11/30

In order to have zero DC error in the voltage regulation, the feedback voltage loop is

implemented with an integrator stage; the transfer function of the signal stage is shown in

the

Equation 2.

Equation 2

Where gm is the integrator transconductance (250 µS). The total gain loop is:

Equation 3

where AV is the current loop factor (1Ω typ.) and α is the feedback resistor divider ratio

(R2/(R2+R3).

Once the gain loop is known the system will be stabilized with the compensation network as

shown in the

Section 5.1.4.

()

mα

-----------

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

⋅

LOOP s

()

Ogmα 1sESRCO

() sC

CRC

()

VsCC 1sCO ESR

()

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

AN1882 Datasheet(PDF) 11 Page - STMicroelectronics