UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment no. 1)
Power Integrations, Inc.
- --------------------------------------------------------------------------------
(Name of Issuer)
Common Stock
- --------------------------------------------------------------------------------
(Title of Class of Securities)
739276 10 3
- --------------------------------------------------------------------------------
(CUSIP Number)
*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).
Page 1 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 2 of 14 Pages
-----------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
InterWest Partners V, LP
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
California
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 0
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
0
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
PN
- ---------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 2 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 3 of 14 Pages
------------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
InterWest Management Partners V, L.P.
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
California
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 0
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
0
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
PN
- --------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 3 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 4 of 14 Pages
-----------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
Alan W. Crites
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 937
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
937
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
937
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
IN
- ---------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 4 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 5 of 14 Pages
-----------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
Philip T. Gianos
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 5,877
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
5,877
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
5,877
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
IN
- ---------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 5 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 6 of 14 Pages
------------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
Wallace R. Hawley
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 0
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
0
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
IN
- ---------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 6 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 7 of 14 Pages
-----------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
W. Scott Hedrick
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 1,752
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
1,752
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,752
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
IN
- ---------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 7 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 8 of 14 Pages
-----------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
W. Stephen Holmes
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 0
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
0
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
IN
- ---------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 8 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 9 of 14 Pages
-----------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
Robert R. Momsen
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 1,546
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
1,546
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,546
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
IN
- ---------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 9 of 14 pages
<PAGE>
<TABLE>
<CAPTION>
- ----------------------------------------------- -----------------------------------
13G
CUSIP NO. 739276 10 3 Page 10 of 14 Pages
-----------
- ----------------------------------------------- -----------------------------------
<S> <C> <C>
- ---------- -------------------------------------------------------------------------------------------------------------
1 NAME OF REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
Arnold L. Oronsky
- ---------- -------------------------------------------------------------------------------------------------------------
2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ]
(b) [ ]
- ---------- -------------------------------------------------------------------------------------------------------------
3 SEC USE ONLY
- ---------- -------------------------------------------------------------------------------------------------------------
4 CITIZENSHIP OR PLACE OF ORGANIZATION
United States
- ------------------------------ -------- --------------------------------------------------------------------------------
5 SOLE VOTING POWER
NUMBER OF 0
-------- --------------------------------------------------------------------------------
SHARES 6 SHARED VOTING POWER
BENEFICIALLY OWNED BY
0
-------- --------------------------------------------------------------------------------
EACH REPORTING PERSON WITH 7 SOLE DISPOSITIVE POWER
0
-------- --------------------------------------------------------------------------------
8 SHARED DISPOSITIVE POWER
0
- ---------- -------------------------------------------------------------------------------------------------------------
9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0
- ---------- -------------------------------------------------------------------------------------------------------------
10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
- ---------- -------------------------------------------------------------------------------------------------------------
11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0.0%
- ---------- -------------------------------------------------------------------------------------------------------------
12 TYPE OF REPORTING PERSON*
IN
- ---------- -------------------------------------------------------------------------------------------------------------
<FN>
*SEE INSTRUCTION BEFORE FILLING OUT!
</FN>
</TABLE>
Page 10 of 14 pages
<PAGE>
Item 1.
(a) Name of Issuer: Power Integrations, Inc. ("Issuer")
(b) Address of Issuer's Principal Executive Offices:
477 North Mathilda Avenue
Sunnyvale, CA 94086
Item 2.
(a) Name of Person(s) Filing:
InterWest Partners V, L.P. ("IWP V")
InterWest Management Partners V, L.P. ("IMP V")
Alan W. Crites ("Crites")
Philip T. Gianos ("Gianos")
Wallace R. Hawley ("Hawley")
W. Scott Hedrick ("Hedrick")
W. Stephen Holmes ("Holmes")
Robert R. Momsen ("Momsen")
Arnold L. Oronsky ("Oronsky")
(b) Address of Principal Business Office or, if none, Residence:
3000 Sand Hill Road
Building 3, Suite 255
Menlo Park, CA 94025
(c) Citizenship/Place of Organization:
IWP V: California
IMP V: California
Crites: United States
Gianos: United States
Hawley: United States
Hedrick: United States
Holmes: United States
Momsen: United States
Oronsky: United States
(d) Title of Class of Securities: Common Stock
(e) CUSIP Number: 739276 10 3
Item 3. Not applicable.
Page 11 of 14 Pages
<PAGE>
Item 4 Ownership.
<TABLE>
<CAPTION>
- ------- ------------- ---------- ---------- ------------- ------------ ----------- ------------ ----------------
Other
Individuals
IWP V IMP V Crites Gianos Hedrick Momsen *
- ------- ------------- ---------- ---------- ------------- ------------ ----------- ------------ ----------------
<S> <C> <C> <C> <C> <C> <C> <C> <C>
(a) Beneficial
Ownership 0 0 937 5,877 1,752 1,546 0**
- ------- ------------- ---------- ---------- ------------- ------------ ----------- ------------ ----------------
(b) Percentage
of Class 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
- ------- ------------- ---------- ---------- ------------- ------------ ----------- ------------ ----------------
(c) Sole Voting
Power 0 0 937 5,877 1,752 1,546 0
- ------- ------------- ---------- ---------- ------------- ------------ ----------- ------------ ----------------
Shared
Voting Power
0 0 0 0 0 0 0
- ------- ------------- ---------- ---------- ------------- ------------ ----------- ------------ ----------------
Sole
Dispositive
Power 0 0 937 5,877 1,752 1,546 0
- ------- ------------- ---------- ---------- ------------- ------------ ----------- ------------ ----------------
Shared
Dispositive
Power 0 0 0 0 0 0 0
- ------- ------------- ---------- ---------- ------------- ------------ ----------- ------------ ----------------
<FN>
*Individuals included in this column are Hawley, Holmes and Oronsky
</FN>
</TABLE>
Item 5. Ownership of Five Percent or Less of a Class
This statement is being filed to report the fact that as of the date hereof the
Reporting Persons have ceased to be the beneficial owners of more than five
percent of the class of securities.
Item 6. Ownership of More than Five Percent on Behalf of Another Person
Under certain circumstances set forth in the partnership agreement of IMP V, the
general partners and/or limited partners of such partnership have the right to
receive dividends from, or the proceeds from the sale of, the Common Stock of
Issuer beneficially owned by such Partnership.
Item 7. Identification and Classification of the Subsidiary Which
Acquired the Security Being Reported on By the Parent Holding
Company.
Not applicable.
Item 8. Identification and Classification of Members of the Group
No reporting person is a member of a group as defined in section
240.13d-1(b)(1)(iii)(H) of the Act.
Item 9. Notice of Dissolution of Group
Not applicable.
Item 10. Certification
Not applicable
EXHIBITS
A. Joint Filing Statement
Page 12 of 14 Pages
<PAGE>
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.
Date: February ____, 1999
INTERWEST PARTNERS V, L.P.
By: InterWest Management Partners V, L.P. ---------------------------
Alan W. Crites
By:
----------------------------------
General Partner ---------------------------
Philip T. Gianos
INTERWEST MANAGEMENT PARTNERS V, L.P.
---------------------------
By: Wallace R. Hawley
------------------------------------------
General Partner
---------------------------
W. Scott Hedrick
---------------------------
W. Stephen Holmes
---------------------------
Robert R. Momsen
---------------------------
Arnold L. Oronsky
Page 13 of 14 Pages
<PAGE>
EXHIBIT A
We, the undersigned, hereby express our agreement that the attached Schedule 13G
is filed on behalf of each of us.
Date: February ____, 1999
INTERWEST PARTNERS V, L.P.
By: InterWest Management Partners V, L.P. ---------------------------
Alan W. Crites
By:
---------------------------------
General Partner ---------------------------
Philip T. Gianos
INTERWEST MANAGEMENT PARTNERS V, L.P.
---------------------------
By: Wallace R. Hawley
----------------------------------------
General Partner
---------------------------
W. Scott Hedrick
---------------------------
W. Stephen Holmes
---------------------------
Robert R. Momsen
---------------------------
Arnold L. Oronsky
Page 14 of 14 Pages
