5075 series

SEIKO NPC CORPORATION —9

FUNCTIONAL DESCRIPTION

Oscillation Start-up Detector Function

The devices also feature an oscillation start-up detector circuit. This circuit functions to disable the outputs

until the oscillation starts. This prevents unstable oscillator output at oscillator start-up when power is applied.

TYPICAL PERFORMANCE (5075B1)

The following characteristics measured using the crystal below. Note that the characteristics will vary with the

crystal used.

I

Crystal used for measurement

I

Crystal parameters

Frequency Pulling Range

Pulling Sensitivity

Measurement circuit

Parameter

C0 [pF]

1.5

γ (= C0/C1)

300

L1

C0

R1

C1

0

50

−50

−100

−150

−200

−250

100

150

200

250

0.00 0.25 0.50

0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50

0

50

−50

−100

−150

−200

−250

100

150

200

250

0.00 0.30 0.60

0.90 1.20 1.50

1.80

1.65

2.10 2.40 2.70

3.30

3.00

0.0 0.3 0.6 0.9 1.2

1.5 1.8 2.1 2.4 2.7 3.0 3.3

0

50

100

150

200

250

VDD

VSS

XT

Q

Crystal

XTN

VC

0.1

µF

(Including probe

capacitance)