LC86F3448B Datasheet, PDF (17/21 Pages) Sanyo Semicon Device – 8-bit 1-chip Microcontroller

LC86F3448B
Recommended Oscillation Circuit and Sample Characteristics
The sample oscillation circuit characteristics in the table below is based on the following conditions:
Recommended circuit parameters are verified by an oscillator manufacturer using a Sanyo provided oscillation
evaluation board.
Sample characteristics are the result of the evaluation with the recommended circuit parameters connected externally.
Recommended oscillation circuit and sample characteristics (Ta = -10°C to +70°C)
Frequency
Manufacturer
Oscillator
Recommended circuit parameters
C1
C2
Rf
Rd
Operating
supply
voltage
range
Oscillation
stabilizing time
typ
max
Notes
32.768kHz
SEIKO
EPSON
C-002RX
18pF
18pF
OPEN
510kΩ
4.5 to 5.5V
1.0s
1.5s
Notes: The oscillation stabilizing time period is the time until the VCO oscillation for the internal system becomes
stable after the following conditions. (Refer to Figure 2.)
1. The VDD becomes higher than the minimum operating voltage after the power is supplied.
2. The HOLD mode is released.
The sample oscillation circuit characteristics may differ applications. For further assistance, please contact with
oscillator manufacturer with the following notes in your mind.
• Since the oscillation frequency precision is affected by wiring capacity of the application board, etc., adjust the
oscillation frequency on the production board.
• The above oscillation frequency and the operating supply voltage range are based on the operating temperature of
-10°C to +70°C. For the use with the temperature outside of the range herein, or in the applications requiring high
reliability such as car products, please consult with oscillator manufacturer.
• When using the oscillator which is not shown in the sample oscillation circuit characteristics, please consult with
Sanyo sales personnel.
Since the oscillation circuit characteristics are affected by the noise or wiring capacity because the circuit is designed
with low gain in order to reduce the power dissipation, refer to the following notices.
• The distance between the clock I/O terminal (XT1 terminal XT2 terminal) and external parts should be as short as
possible.
• The capacitors’ VSS should be allocated close to the microcontroller’s GND terminal and be away from other GND.
• The signal lines with rapid state changes or with large current should be allocated away from the oscillation circuit.
XT1
C1
Rf
X’tal
XT2
Rd
C2
Figure 1 Recommended Oscillation Circuit
No.A0120-17/21