High frequency signal processing chip having signal pins distributed to minimize signal interference

• US 5,955,783 A
• Filed: 06/18/1997
• Issued: 09/21/1999
• Est. Priority Date: 06/18/1997
• Status: Expired due to Term

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Keate, Christopher, Ben-Efraim, Nadav
• Primary Examiner(s): Martin-Wallace, Valencia
• Assistant Examiner(s): CLARK, JASMINE JHIHAN B
• Application Number:
  US08/878,333
• Time in Patent Office: 825 Days
• Field of Search: 257/678, 257/692, 257/693, 257/694, 257/695, 257/696, 257/697, 257/728
• US Class Current: 257/728
• CPC Class Codes: H03D 3/007 by converting the oscillations into two quadrature related signals H03D3/245 takes precedence
• CPC Class Codes: H03D 7/166 using two or more quadrature frequency translation stages
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22
• CPC Class Codes: H04H 40/90 specially adapted for satellite broadcast receiving

Abstract

A DBS receiver front end which includes a tuner chip and a demodulator/decoder chip. The tuner chip converts a receive signal to a baseband signal using a tuning frequency signal generated from a tank circuit. The design of a package for the tuner chip maximally spaces the pins associated with high frequency signals by placing them on opposite sides of the chip (in the case of two high frequency signal sources) or (in the case of three high frequency signal sources) in a triangle formation with widely spaced vertices wherein at least two of the pins are adjacent to corners of the package. For two or more high frequency signal sources, a good determination of pin locations can be determined according to the formula P_i =C+i·.left brkt-bot.N/M.right brkt-bot., i=1, . . . , M, where P_i are the pin numbers, N is a total number of pins around the perimeter of the package, M is a total number of the high frequency signal sources, and C is an offset number. Where a high frequency signal source has more than one associated pin, one pin number is found from the above formula, and the associated pins are placed on adjacent pins.

Claims

1. A package for holding a tuner chip for converting a receive signal into a baseband signal using a tuning frequency signal generated from a tank circuit, wherein said package comprises:

a first side having a first set of pins arrayed along said first side from a first corner to a second corner, wherein said first set of pins includes a receive signal input pin for receiving the receive signal;

a second side having a second set of pins arrayed along said second side from a third corner to a fourth corner, wherein said fourth corner is diagonally opposite said second corner, and wherein said second set of pins includes a pair of tank circuit pins positioned to minimize tank oscillation signal interference with the receive signal.

2. The package of claim 1, wherein said receive signal input pin is adjacent to the second corner.

3. The package of claim 1, wherein said third corner is diagonally opposite said first corner.

4. The package of claim 1, wherein said third corner is identically said first corner, wherein said receive signal input pin is adjacent to the second corner, wherein said package further comprises a third side having a third set of pins arrayed along said third side from the fourth corner to a fifth corner, wherein said fifth corner is diagonally opposite said first corner, wherein said third set of pins includes a second receive signal input pin adjacent to said fifth corner, and wherein said pair of tank circuit pins is positioned substantially at a midpoint between said third and fourth corners.

5. The package of claim 2, wherein said pair of tank circuit pins is adjacent to the fourth corner.

6. The package of claim 2, wherein said first set of pins includes a second receive signal input pin adjacent to the first corner.

7. The package of claim 5, wherein said second set of pins includes a second receive signal input pin adjacent to the third corner.

8. The package of claim 5, wherein said first set of pins includes a second receive signal input pin adjacent to the first corner.

9. The package of claim 6, wherein said pair of tank circuit pins is positioned substantially at a midpoint between said third and fourth corners.

10. A package for holding an integrated circuit chip, wherein the package comprises a four-side perimeter having a set of pins attached, wherein each of the sides has a respective subset of pins along the respective side, wherein the pins are identified by a set of pin numbers beginning in a corner and proceeding sequentially in a counter-clockwise fashion along the four sides of the package, wherein the set of pins includes one or more high frequency signal pins and a pair of high frequency oscillator pins, and wherein the high frequency signal pins and the pair of oscillator pins are evenly distributed around the perimeter of the package.

11. The package of claim 10, wherein the pin numbers P_i of the high frequency signal pins and a first pin of the pair of oscillator pins are determined according to:

P_i =C+i·

.left brkt-bot.N/(M+1).right brkt-bot., i=1, . . . , (M+1), wherein N is a total number of pins in the set of pins, M is a total number of the high frequency signal pins, and C is an offset number, and wherein a second pin of the pair of oscillator pins is adjacent to the first pin.

12. The package of claim 11, wherein a smallest pin number is 1, and wherein C is nonpositive.

13. A method for reducing signal interference between a plurality of high frequency signal pins on a package, wherein the method comprises:

numbering a set of pins sequentially in a counter-clockwise fashion along a perimeter of the package;

designating a group of pins in the set of pins as the plurality of high frequency signal pins, so that the plurality of high frequency signal pins has a corresponding plurality of pin numbers P_i =round(i·

N/M)+C mod N, i=1, . . . , M, wherein N is a total number of pins in the set of pins, M is a total number in the plurality of high frequency signal pins, and C is an offset number.

14. The method of claim 13, wherein the method further comprises adjusting C until the signal interference is below a desired threshold.

15. The method of claim 13, wherein the plurality of high frequency signal pins includes one pin from each pair of high frequency oscillator pins, and wherein the high frequency oscillator pins in each pair are designated to have adjacent pin numbers.