UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. __1__ )*
VOLTERRA SEMICONDUCTOR CORP
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(Name of Issuer)
Common Stock
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(Title of Class of Securities)
928708106
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(CUSIP Number)
November 30, 2005
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(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:
[ X ] Rule 13d-1(b)
[ ] Rule 13d-1(c)
[ ] Rule 13d-1(d)
*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
SCHEDULE 13G
CUSIP No. 928708106
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1. Names of Reporting Persons. I.R.S. Identification Nos. of above
persons (entities only).
AMVESCAP PLC
INVESCO Private Capital, Inc.
INVESCO Institutional (N.A.), Inc.
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2. Check the Appropriate Box if a Member of a Group (see
Instructions)
(a)
(b)
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3. SEC Use Only _______________________________________________
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4. Citizenship or Place of Organization
AMVESCAP PLC: England
INVESCO Private Capital, Inc.: Delaware
INVESCO Institutional (N.A.), Inc.: Delaware
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5. Sole Voting Power 924,738: Such
shares are held by the following
entities in the respective amounts
listed: INVESCO Private Capital, Inc.
923,814; INVESCO Institutional (N.A.),
Inc. 924
Number of Shares --------------------------------------------------------------------------------------------------
Beneficially Owned
by Each Reporting 6. Shared Voting Power ______-0-______
Person With
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7. Sole Dispositive Power 924,738:
Such shares are held by the
following entities in the respective
amounts listed: INVESCO Private Capital, Inc.
923,814; INVESCO Institutional (N.A.),
Inc. 924
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8. Shared Dispositive Power ______-0-______
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9. Aggregate Amount Beneficially Owned by Each Reporting Person
924,738
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10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares
(See Instructions) N/A
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11. Percent of Class Represented by Amount in Row (9) 3.9%
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12. Type of Reporting Person (See Instructions)
IA, HC. See Items 2 and 3 of this statement.
SCHEDULE 13G
Item 1(a) Name of Issuer:
VOLTERRA SEMICONDUCTOR CORP
Item 1(b) Address of Issuer's Principal Executive Offices:
3839 Spinnaker Court
Fremont, CA 94538
Item 2(a) Name of Person Filing:
AMVESCAP PLC
In accordance with Securities and Exchange Commission Release
No. 34-39538 (January 12, 1998), this statement on Schedule
13G or amendment thereto is being filed by AMVESCAP PLC
("AMVESCAP"), a U.K. entity, on behalf of itself and its
subsidiaries listed in Item 4 of the cover of this statement.
AMVESCAP through such subsidiaries provides investment
management services to institutional and individual investors
worldwide.
Executive officers and directors of AMVESCAP or its
subsidiaries may beneficially own shares of the securities of
the issuer to which this statement relates (the "Shares"), and
such Shares are not reported in this statement. AMVESCAP and
its subsidiaries disclaim beneficial ownership of Shares
beneficially owned by any of their executive officers and
directors. Each of AMVESCAP's direct and indirect subsidiaries
also disclaim beneficial ownership of Shares beneficially
owned by AMVESCAP and any other subsidiary.
Item 2(b) Address of Principal Business Office:
30 Finsbury Square
London EC2A 1AG
England
Item 2(c) Citizenship:
See the response to Item 2(a) of this statement.
Item 2(d) Title of Class of Securities:
Common Stock, $.01 par value per share
Item 2(e) CUSIP Number:
928708106
Item 3 If this statement is filed pursuant to ss240.13d-1(b) or
240.13d-2(b) or (c), check whether the person filing is a:
(e) [x] An investment adviser in accordance with section 240.13d-1(b)(1)(ii)(E)
(g) [x] A parent holding company or control person in accordance with section 240.13d-1(b)(1)(ii)(G)
As noted in Item 2 above, AMVESCAP is making this filing on
behalf of its subsidiaries listed herein. Each of these
entities is either an investment adviser registered with the
United States Securities and Exchange Commission under Section 203
of the Investment Advisers Act of 1940, as amended, or under
similar laws of other jurisdictions. AMVESCAP is a holding
company.
Item 4 Ownership:
Please see responses to Items 5-8 on the cover of this
statement, which are incorporated herein by reference.
Item 5 Ownership of Five Percent or Less of a Class:
If this statement is being filed to report the fact that as of the date hereof the reporting
person has ceased to be the beneficial owner of more than five percent of the class of securities,
check the following [ X ]
Item 6 Ownership of More than Five Percent on Behalf of Another Person:
N/A
Item 7 Identification and Classification of the Subsidiary Which Acquired the Security Being Reported
on By the Parent Holding Company:
Please see Item 3 of this statement, which is incorporated herein by reference.
Item 8 Identification and Classification of Members of the Group:
N/A
Item 9 Notice of Dissolution of a Group:
N/A
Item 10 Certification:
By signing below I certify that, to the best of my knowledge
and belief, the securities referred to above were acquired and
are held in the ordinary course of business and were not
acquired and are not held for the purpose of or with the
effect of changing or influencing the control of the issuer of
the securities and were not acquired and are not held in
connection with or as a participant in any transaction having
that purpose or effect.
Signature:
After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this
statement is true, complete and correct.
December 29, 2005
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Date
AMVESCAP PLC
By: /s/ Kevin M. Carome
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Kevin M. Carome
General Counsel