CF5037 series

SEIKO NPC CORPORATION —3

BLOCK DIAGRAM

OSCILLATOR CIRCUIT CONSTANT

The CF5037 series oscillator setting varies with device version to optimize characteristics over the recom-

mended operating frequency range.

Oscillator Equivalent Circuit

Version

Oscillation mode

*1. The oscillator internal capacitance values includes parasitic capacitance.

*2. Values in parentheses ( ) are provisional only.

Recommended operating

*3. The recommended operating frequency is a yardstick value derived from the crystal used for NPC characteristics authentication. How-

ever, the oscillator frequency band is not guaranteed. Specifically, the characteristics can vary greatly due to crystal characteristics

and mounting conditions, so the oscillation characteristics of components must be carefully evaluated.

CF5037A1

Fundamental

or

3rd overtone

12

12

80 to 120

CF5037B

×

8

8

100 to 180

CF5037C

×

6

6

150 to 250

CF5037D

×

Fundamental

5

5

250 to 400

CF5037E

×

(5)

(5)

(400 to 600)

CF5037F

×

(4)

(4)

(600 to 700)

The CF5037 series oscillator circuit has a C0 cancel circuit built-in to improve the oscillator margin. If power is applied when there is an

open circuit between XIN and XOUT, self oscillation may occur, which is not abnormal. Users should confirm that the oscillator operates

normally when a crystal unit is connected.

XIN

VCC

OE

XOUT

1/2

OUT

VCC2

GND

OUTN

LVDS

Colpitts

OSC

XIN

XOUT

C0 cancel

Oscillator block equivalent circuit