CF5008A1 参数 Datasheet PDF下载

CF5008A1

VARICAP (Variable Capacitance Diodes) SELECTION

The CF5008A1 forms a VCXO with addition of an external varicap (variable capacitance diode) device. This

section examines the results using various varicap devices. When the equivalent circuit in figure 1 is used, the

load capacitance C

L

must be changed by a factor of 4 to 5 (10 to 40pF) to affect a ±100ppm frequency change.

Varicap devices that can change the capacitance by a factor of 5 require a maximum capacitance in the range

approximately 20 to 50pF. Devices matching this criteria are listed in the following table.

L

4.08673mH

Ca

7.56439fF

R

17.7068Ω

Cb

2.05389pF

Frequency:28.633MHz

C

L

:20pF

Figure 1. Crystal oscillator element equivalent circuit

Company

HITA C H I

HITA C H I

HITA C H I

HITA C H I

HITA C H I

P anasonic

P anasonic

P anasonic

TO K O

TO K O

Product

HVU17

HVU359

HVU362

HVC374B

HVC375B

MA304

MA2S304

MA2ZV05

KV1811E

KV1812

Capacitance 1

50.0 to 85.0pF (VR

=

1V)

24.8 to 29.8pF (VR

=

1V)

41.6 to 49.9pF (VR

=

1V)

21.5 to 24.0pF (VR

=

1V)

15.5 to 17.0pF (VR

=

1V)

24.8 to 29.8pF (VR

=

1V)

24.8 to 29.8pF (VR

=

1V)

18.5 to 20.5pF (VR

=

1V)

21.5pF typ (VR

=

1V)

16.0pF typ (VR

=

1V)

Capacitance 2

5.23 to 8.84pF (VR

=

4.5V)

6.00 to 8.30pF (VR

=

4V)

10.1 to 14.8pF (VR

=

4V)

12.5 to 14.5pF (VR

=

2V)

4.0pF typ (VR

=

4V)

6.00 to 8.30pF (VR

=

4V)

6.00 to 8.30pF (VR

=

4V)

3.60 to 4.10pF (VR

=

4V)

4.00pF typ (VR

=

4V)

3.00pF typ (VR

=

4V)

NIPPON PRECISION CIRCUITS—7