Exhibit 5.1

	140 Scott Drive
	Menlo Park, California 94025
	Tel: +1.650.328.4600 Fax: +1.650.463.2600
	www.lw.com
	FIRM / AFFILIATE OFFICES

	Abu Dhabi	Moscow
	Barcelona	Munich
	Beijing	New Jersey
	Boston	New York
	Brussels	Orange County
	Chicago	Paris
	Doha	Riyadh
May 24, 2012	Dubai	Rome
	Frankfurt	San Diego
	Hamburg	San Francisco
	Hong Kong	Shanghai
	Houston	Silicon Valley
Micrel, Incorporated	London	Singapore
2180 Fortune Drive	Los Angeles	Tokyo
San Jose, California 95131	Madrid	Washington, D.C.
	Milan

Re:	Registration Statement on Form S-8;
	6,000,000 shares of Common Stock

Ladies and Gentlemen:

We have acted as special counsel to Micrel, Incorporated, a California corporation (the “Company”), in connection with the registration of 6,000,000 shares of common stock, no par value (the “Shares”), issuable under the Company’s 2012 Equity Incentive Award Plan (the “Plan”), under the Securities Act of 1933, as amended (the “Act”), pursuant to a Registration Statement on Form S-8 filed with the Securities and Exchange Commission (the “Commission”) on the date hereof (the “Registration Statement”).  This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or related prospectus, other than as expressly stated herein with respect to the issue of the Shares.

As such counsel, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter.  With your consent, we have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters.

We are opining herein only as to the General Corporation Law of the State of California, and we express no opinion with respect to any other laws.

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, when the Shares shall have been duly registered on the books of the transfer agent and registrar therefor in the name or on behalf of the holders and have been issued by the Company against payment therefor in the circumstances contemplated by the Plan, assuming in each case that the individual issuances, grants or awards under the Plan are duly authorized by all necessary corporate action and duly issued, granted or awarded and exercised in accordance with the requirements of law and the Plan (and the agreements and awards duly adopted thereunder and in accordance therewith), the issue and sale of the Shares will have been duly authorized by all necessary corporate action of the Company, and the Shares will be validly issued, fully paid and nonassessable.  In rendering the foregoing opinion, we have assumed that the Company will comply with all applicable notice requirements regarding uncertificated shares in the General Corporation Law of the State of California.

May 24, 2012

Page 2

This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Act.  We consent to your filing this opinion as an exhibit to the Registration Statement.  In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.

 Very truly yours,

 /s/ Latham & Watkins LLP