PCA2003 datasheet(13/21 Pages) NXP

13 / 21 page

PCA2003_2

Product data sheet

Rev. 02 — 21 July 2009

13 of 21

NXP Semiconductors

PCA2003

32 kHz watch circuit with programmable adaptive motor pulse

7.9 Frequency tuning of assembled watch

Figure 9 shows the test set-up for frequency tuning the assembled watch.

7.10 Measurement of oscillator frequency and inhibition time

The output of the two measuring states can either be monitored directly at pad RESET or

as a modulation of the supply voltage (a modulating resistor of 30 k

Ω is connected

between VDD and VSS when the signal at pad RESET is at HIGH-level).

The supply voltage modulation must be followed as shown in Figure 10 in order to

guarantee the correct start-up of the circuit during production and testing.

Measuring states:

Fig 9.

Frequency tuning the assembled watch

mgw568

FREQUENCY

COUNTER

PROGRAMMABLE

DC POWER SUPPLY

PC INTERFACE

motor

32 kHz

PCA200x

battery

VDD(nom): nominal supply voltage.

Fig 10. Supply voltage at start-up during production and testing

VDD

VP(prog)(stop)

td(start) > 500 ms

VSS

VDD(nom)

001aac503

tp(stop)

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