Browse Prior Art Database

HIGH PRECISION REFERENCE OSCILLATOR WITH ANALOG EEPROM MEMORY

IP.com Disclosure Number: IPCOM000006558D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2002-Jan-15
Document File: 2 page(s) / 84K

Publishing Venue

Motorola

Related People

John Wetters: AUTHOR

Abstract

Current digital oscillator compensation is accom- of oscillator compensation (estimated chip area is plished by storing compensation voltages in a digital conservatively one-quarter to one-half of the present memory and retrieving those values to warp the crystal technology using digital EEprom). This invention oscillator from a D/A as a function of the oscillator accomplishes high precision temperature compensation temperature. The advent of Analog EE prom, as opposed of crystal oscillators (approximately lppm) with drasti- to digital EE prom, simplifies the overhead of this type tally less chip area (no D/A's or A/D's required).

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MOTOROLA INC. Technical Developments Volume 16 August 1992

HIGH PRECISION REFERENCE OSCILLATOR WITH ANALOG EEPROM MEMORY

by John Wetters

  Current digital oscillator compensation is accom- of oscillator compensation (estimated chip area is plished by storing compensation voltages in a digital conservatively one-quarter to one-half of the present memory and retrieving those values to warp the crystal technology using digital EEprom). This invention oscillator from a D/A as a function of the oscillator accomplishes high precision temperature compensation temperature. The advent of Analog EE prom, as opposed of crystal oscillators (approximately lppm) with drasti- to digital EE prom, simplifies the overhead of this type tally less chip area (no D/A's or A/D's required).

Figure1 Block diagram of reference oscillator test equipment compensation using analog EE prom for compensation run

address for unmmpensated osc. center freq

1

port out for

Latch

                                    analog v0nage compensation uncompensated. Latch in vs. temp.
ox. freq. trim

21

analog read

address loo-212

p--j-jpfjqL--

                                       analog EE prom analog write program mode latch enable (ISD patented
technology)

k

high stabilny osc. out -1ppm

test cO""t*l test equipment for compensation run

temperature run -30 to 80 degrees C

116 0 Moforola. 1°C. 1992

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MOTOROLA INC. Technical Developments Volume 16 August 1992

@

  Figure 1 shows a block diagram of the oscillator compensation system using analog EEprom. The com- pensation is accomplished comparing a known oscilla- tor signal and an uncompensated oscillator on the sam...