µPD75P308

17

32

32.768

35

kHz

1.0

2

s

32

100

kHz

515

µs

Crystal

Oscillation

Oscillation stabilization

External Clock

XT1 input frequency

XT1 input high-, low-level

SUBSYSTEM CLOCK OSCILLATOR CIRCUIT CHARACTERISTICS

Oscillator

Item

Conditions

MIN.

TYP.

MAX.

Unit

Recommended

Constants

XT1

XT2

R

C3

C4

XT1

XT2

Open

range.

Caution: When using the oscillation circuit of the subsystem clock, wire the portion enclosed in dotted line

in the figures as follows to avoid adverse influences on the wiring capacity:

• Keep the wiring length as short as possible.

• Do not cross the wiring over the other signal lines. Do not route the wiring in the vicinity of

lines through which a high alternating current flows.

• Always keep the ground point of the capacitor of the oscillator circuit at the same potential

• Do not extract signals from the oscillation circuit.

The amplification factor of the subsystem clock oscillation circuit is designed to be low to reduce the

current dissipation and therefore, the subsystem clock oscillation circuit is influenced by noise more

easily than the main system clock oscillation circuit. When using the subsystem clock, therefore,

exercise utmost care in wiring the circuit.

Parameter

Symbol

Conditions

MIN.

TYP.

MAX.

Unit

Input Capacitance

f = 1 MHz

15

pF

Output Capacitance

Pins other than thosemeasured are at 0 V

15

pF

Input/Output

15

pF

Capacitance

5