74aup1z125 NXP Semiconductors, 74aup1z125 Datasheet - Page 21

• Manufacturer Part Number: 74aup1z125
• Description: Low-power X-tal Driver With Enable And Internal Resistor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
74AUP1Z125_1
Product data sheet
13.1.2 Testing
After the calculations are performed for a particular crystal, the oscillator circuit should be
tested. The following simple checks will verify the prototype design of a crystal controlled
oscillator circuit. Perform them after laying out the board:
As the 74AUP1Z125 isolates the system loading, once the design is optimized, the single
layout may work in multiple applications for any given crystal.
Fig 12. Crystal oscillator configuration
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Test the oscillator over worst-case conditions (lowest supply voltage, worst-case
crystal and highest operating temperature). Adding series and parallel resistors can
simulate a worse case crystal.
Insure that the circuit does not oscillate without the crystal.
Check the frequency stability over a supply range greater than that which is likely to
occur during normal operation.
Check that the start-up time is within system requirements.
Rev. 01 — 3 August 2006
X1
74AUP1GU04
C2
portion
Low-power X-tal driver with enable and internal resistor
1 M
Xtal
X2
C1
74AUP1G125
portion
Y
system
001aaf147
load
C sys
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
R sys
74AUP1Z125
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