FEDL7055-02

OKI Semiconductor

ML7055

21/30

REFERENCE FOR OSCILLATOR CIUCUIT

Note 1: The values of C0 and C1, and R0 and R1 should be determined according to the specifications for the

external crystal X’tal 1 (32 or 32.768 kHz).

The values of C2 and C3, and R2 and R3 should be determined according to the specifications for the

external crystal X’tal 2 (13 or 12 MHz).

Note 2: The crystal oscillator circuit should be connected to pins SCLKP and SCLKN only when the OKI RF-LSI

(ML7050) is connected. In other cases, the system clock should be input from the RF-LSI to pin SCLKP.

Note 3: In the case of 13 MHz or 12 MHz system clock (SCLKP) input, make sure the crystal frequency tolerance

is ±20 ppm for temperature, supply voltage, and aging.

In the case of 32 kHz or 32.768 kHz sub-clock (XC32KP) input, make sure the crystal frequency tolerance

is ±250 ppm for temperature, supply voltage, and aging.

Note 4: Precautions to build a crystal oscillator circuit

- Keep length of wire traces as short as possible.

- Do not cross the crystal oscillator circuit wires over other signal line wires.

- Do not keep signal line wires through which high current flows close to the crystal oscillator circuit.

- Keep the grounding point of the capacitors in the oscillator circuit at the potential equal to GND. And do

not connect the capacitors to the GND or GND lines through which high current flows.

- Do not output signals from the oscillator circuit.

The circuit is subject to change according to the specific LSI board design. Please contact Oki Electric Industry Co.,

Ltd. for detailed information. It is recommended to determine the final circuit values including the capacitance of

the circuit board designed by the user.

ML7055

C1

C0

R0

X’tal 1

R1

C3

C2

R2

X’tal 2

R3

Example of oscillator circuit

Connect this oscillator circuit only when

connecting the OKI RF-LSI ML7050.