April 19, 2005



Mail Stop 0306

Richard K. Williams
President, Chief Executive Officer
and Chief Technical Officer
Advanced Analogic Technologies Incorporated
830 East Arques Avenue
Sunnyvale, CA 94085

Re:	Advanced Analogic Technologies Incorporated
	Registration Statement on Form S-1
	Filed April 4, 2005
	         File No. 333-123798
Dear Mr. Williams:
      We have the following comments to your filing.  Where
indicated, we think you should revise your document in response to
these comments.  If you disagree, we will consider your
explanation
as to why our comment is inapplicable or a revision is
unnecessary.
Please be as detailed as necessary in your explanation.  In some
of
our comments, we may ask you to provide us with supplemental
information so we may better understand your disclosure.  After
reviewing this information, we may or may not raise additional
comments.
      Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or on any other
aspect
of our review.  Feel free to call us at the telephone numbers
listed
at the end of this letter.
General
1. Please confirm that any preliminary prospectus you circulate
will
include all non-Rule 430A information. This includes the price
range
and related information based on a bona fide estimate of the
public
offering within that range. Also note that we may have additional
comments after you include this information.
Summary - Page 1
2. In the forepart of the prospectus, including the summary and
the
risk factors, please limit the use of technical jargon and terms
that
may not be familiar to investors, including terms and
abbreviations
such as ASSPs, analog ICs, DRAM fabs, and analog CMOS process
technology.  Where you believe it is essential to use technical
terms
and abbreviations, please define them when you use them.
3. Please supplementally support your statements about being a
"leading supplier."
Risk Factors - Page 6
Our customers may cancel their orders - Page 6
4. Please expand this risk factor to include a discussion of the
impact of your sales and development cycle as you discuss on page
23.
For example, please describe the impact of technology obsolesence
on
your inventory.
We receive a substantial proportion of our revenues from one
customer
- Page 6
5. Please explain whether you believe LG Electronics will continue
to
be a significant customer in the future.
6. You state that your sales may be impacted by customers managing
their quarterly inventories for "seasonal variations and other
reasons."  Please expand to explain the seasonal variations and
what
some other reasons may be for such quarterly variations.
The nature of the design process requires us - Page 8
7. Please include in this risk factor a brief description of an
average product sales and development cycle timeline.
Because we receive a substantial portion of our revenues - Page 9
8. Disclose the percentage of your revenues that EPCO Technology
represented in 2004.
We outsource our wafer fabrication - Page 11
9. You explain that transitioning to a backup supplier would
required
you to meet consumer demand from your then existing inventory for
a
period of six to twelve months.  In light of the fact that you
have
had inventory write-downs, please explain how much inventory you
keep
for such a potential transition.
Assertions by third parties of infringement - Page 12
10. Please explain the impact on your product line and future
revenues if Siliconix is successful in asserting its patent claim.
Are these patents critical to your TrenchDMOS product?

Our failure to protect our intellectual property rights - Page 12
11. In light of the fact that most of your business is done in
South
Korea, Taiwan and China, please expand your discussion about
foreign
patent protection not being as comprehensive as in the U.S. to
discuss your experiences in these particular countries.
The price of our stock could decrease - Page 16
12. Please explain what percentage of your total outstanding stock
will be available for resale after this offering and when your
lockup
agreements expire on such shares.
Capitalization - Page 20
13. "Cash and cash equivalents" is not a component of
capitalization
for purposes of this disclosure.  Please revise to delete the
line.
Dilution - Page 21
14. Expand the disclosure on page 21 to quantify how many other
options and warrants are currently outstanding.  Expand to state
how
the table at the bottom of the page would change if you assume
exercise of all warrants and outstanding options with exercise
prices
less than the IPO price.
Management`s Discussion and Analysis - Page 23
Results of Operations - Page 28
General
15. We see that substantially all of your revenues are from
foreign
customers. Please revise to quantify the impact of changes in
exchange rates on reported revenues and expenses, if material.
Revenues - Page 28
16. As a related matter, please disclose more details of the
"tightening credit supply" in China discussed on page 18 and the
impact that this is expected to have on future operations.

Gross profit - Page 29
17. Please revise to quantify each of the significant factors
cited,
such as increases in higher-margin products, economy of scale and
cost reduction initiatives, in explaining the changes in your
gross
profit margin. In addition, each significant factor that
contributed
to the significant variances in revenue and expense amounts each
period should also be quantified and discussed. Please apply
throughout MD&A to the extent practicable.
18. We note your inventory write-downs of $1.5 million, $550,000
and
$939,000 in 2004, 2003 and 2002, respectively. Revise to disclose
more details of these write-downs and the specific circumstances
that
resulted in the significant impairments each period. In addition,
disclose whether this inventory was sold, discarded or otherwise
disposed. The impact of any sales of this inventory on margins
should
also be clarified each period.
Liquidity and Capital Resources - Page 34
19. Please revise to discuss details of the significant variances
in
the balance sheet accounts each period. For example, the
significant
increases in inventory and deferred income tax assets at December
31,
2004 should be addressed.
Intellectual Property - Page 48
20. On page 49 you describe two letters from Linear Technologies
and
International Rectifier alleging patent infringement.  Please
explain
the status of those two allegations in this section.
Board Committees - Page 53
21. You state you intend to add one more director to your audit
committee.  Clarify whether this additional director will be a
current board member or a new director.
Director Compensation - Page 55
22. Please identify those directors eligible to receive any
director
compensation under your compensation policy.  Disclose whether the
chairperson can receive compensation, even if he were not
otherwise
eligible to receive it.
Summary Compensation Table - Page 55
23. We note footnote 4.  Briefly describe the position of "AATI
Fellow."
Preferred Stock, Convertible Note and Warrant Issuances - Page 62
24. Please disclose the conversion ratio of the preferred stock,
and
state the number of shares of common stock that will be issued
upon
conversion.
Common Stock Warrant Issuance - Page 62
25. Please disclose the amounts each of these officers loaned to
the
company that were subsequently cancelled in exchange for issuing
these warrants.
Voting Agreement - Page 63
26. Disclose whether Vision 2000 has designated Mr. Seto`s
replacement yet.
Principal and Selling Shareholders - Page 64
27. Please identify the selling shareholders, and provide the
information required by Item 507 of Regulation S-K.
28. Identify the individuals why have voting and/or investment
control over the shares held by the entities identified in the
table.
Registration Rights - Page 67
29. Please expand this discussion to explain which "certain"
holders
are entitled to demand registration rights and how many shares
they
own.
Shares eligible for future sale - Page 70
30. Please identify what amount "substantially all" of the holders
of
your stock are subject to lockup agreements.
31. Please identify the amount of shares eligible to be sold under
the provisions of Rule 144.
Report of Independent Registered Public Accounting Firm
32. The report of Independent Registered Public Accounting Firm on
page F-2 references Advanced Analogic Technologies Incorporated
and
Subsidiaries. This is not consistent with the reference to the
registrant in the financial statements. Please revise.
Financial Statements
33. Please include an updated and signed consent from your
independent auditors with any amendment.
34. The financial statements should be updated, as necessary, to
comply with Rule 3-12 of Regulation S-X at the effective date.


Balance Sheet - Page F-3
35. Total amounts included in the column Unaudited Pro Forma
December
31, 2004 on page F-3 do not add to total assets. Please revise.
Note 1- Business and Significant Accounting Policies - Page F-8
Revenue Recognition - Page F-8
36. With respect to product sales, revise to describe your return
policy, post shipment obligations and any customer acceptance
provisions. Clarify how these impact your revenue recognition.
Clarify that you policy is in accordance with SAB 104.
37. Revise to disclose more details of sales incentives and
discounts
and the specific accounting treatment under EITF 01-09. Provide
details disclosure of how you estimate discounts and incentives,
including how amounts are reported in the financial statements.
Clarify how you are able to estimate price protection. In
addition,
tell us why you refer to SFAS 48 for the accounting for price
protection.
38. We reference the discussion on page 9 of the numerous support
functions provided by the distributors. Please disclose details of
the accounting for these services.
Note 6 - Stockholders` Equity - Page F-14
39. In each transaction involving the issuance of shares, options
or
warrants for services or financing arrangements, expand your
disclosures to state the fair value of the issuance and how the
value
was determined. Address both the method and the significant
assumptions used to determine the values.

Stock Options - Page F-15
40. Supplementally provide us with details of each significant
issuance of stock options and warrants from January 2004 through
the
date of your response.  This should include the options and
warrants
issued pursuant to employment agreements discussed on page 57.
Include the following information for each grant:
		      a.	Number of shares issuable in the grant and the
date issued;
b.	Exercise price per share;
c.	Any restriction or vesting terms;
d.	Management`s fair value per share estimate;
e.	How management determined the fair value estimate;
f.	Identity of the recipient and relationship to the company;
g.	Nature and terms of any concurrent transactions with the
recipient;
h.	Amount of any recorded compensation element and accounting
literature relied upon.

In the analysis requested above, highlight any transactions with
unrelated parties believed by management to be particularly
evident
of an objective fair value per share. In addition, indicate the
considering given to the estimated IPO price when determining
management`s estimate of fair value.  Also, indicate when
discussions
were initiated with your underwriter(s) and provide a history of
pricing discussions therewith. We may delay our assessment of your
response pending inclusion of the estimated IPO price in the
filing.

Note 7 - Income Taxes - Page F-17
41. Given that you have had only two years of operating profits
(2004
and 2003), supplementally describe all available evidence, both
positive and negative, to support your $11.2 million reversal of
prior valuation allowance in 2004. Revise footnote and MD&A as
necessary.
42. We see that your have operations in many foreign countries.
Revise to make disclosure about any tax holidays in those
jurisdictions, if material. Refer to SAB 11-C.
Note 12 - Litigation - Page F-21
43. Please revise to also disclose details of the other litigation
discussed on page 49, including International Rectifier, Linear
Technology, etc. The discussion should include details of whether
you
believe that these matters will have a significant impact on
results
of operations, financial condition or liquidity.

Exhibits
44. Please file all your exhibits so we can complete our review,
also
please confirm that you will be filing the voting agreement you
describe on page 63.  We note you intend to seek confidential
treatment on some exhibits.  Confidential treatment requests must
be
resolved prior to your filing becoming effective.
Closing Comments
      As appropriate, please amend your registration statement in
response to these comments.  You may wish to provide us with
marked
copies of the amendment to expedite our review.  Please furnish a
cover letter with your amendment that keys your responses to our
comments and provides any requested supplemental information.
Detailed cover letters greatly facilitate our review.  Please
understand that we may have additional comments after reviewing
your
amendment and responses to our comments.
      We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filings reviewed by the staff to
be
certain that they have provided all information investors require
for
an informed decision.  Since the company and its management are in
possession of all facts relating to a company`s disclosure, they
are
responsible for the accuracy and adequacy of the disclosures they
have made.
	Notwithstanding our comments, in the event the company
requests
acceleration of the effective date of the pending registration
statement, it should furnish a letter, at the time of such
request,
acknowledging that:
* should the Commission or the staff, acting pursuant to delegated
authority, declare the filing effective, it does not foreclose the
Commission from taking any action with respect to the filing;
* the action of the Commission or the staff, acting pursuant to
delegated authority, in declaring the filing effective, does not
relieve the company from its full responsibility for the adequacy
and
accuracy of the disclosure in the filing; and
* the company may not assert this action as defense in any
proceeding
initiated by the Commission or any person under the federal
securities laws of the United States.
	In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division of Corporation Finance in connection with our review of
your
filing or in response to our comments on your filing.

We will consider a written request for acceleration of the
effective
date of the registration statement as a confirmation of the fact
that
those requesting acceleration are aware of their respective
responsibilities under the Securities Act of 1933 and the
Securities
Exchange Act of 1934 as they relate to the proposed public
offering
of the securities specified in the above registration statement.
We
will act on the request and, pursuant to delegated authority,
grant
acceleration of the effective date.
	We direct your attention to Rules 460 and 461 regarding
requesting acceleration of a registration statement.  Please allow
adequate time after the filing of any amendment for further review
before submitting a request for acceleration.  Please provide this
request at least two business days in advance of the requested
effective date.
      You may contact Patrick Enunwaonye at (202) 824-5529 or in
his
absence, Brian Cascio at (202) 942-1791, if you have questions
regarding comments on the financial statements and related
matters.
Please contact Jay Mumford at (202) 824-5348 or me at (202) 942-
1880
with any other questions.

      Sincerely,




							Peggy Fisher
							Assistant Director

cc:	Mario M. Rosati, Esq.
	Mark L. Reinstra, Esq.
	Alexander D. Phillips, Esq.





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Richard K. Williams
Advanced Analogic Technologies Incorporated
April 19, 2005
Page 9