HD404374 Datasheet, PDF (57/161 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip A/D Converter

HD404374/HD404384/HD404389/HD404082/HD404084 Series
Table 21 Oscillator Circuit Examples
External clock
operation
Circuit Structure
External
oscillator
OSC1
Circuit Constants
Open OSC2
Ceramic oscillator
(OSC₁, OSC₂)
Crystal oscillator
(OSC₁, OSC₂)
CR oscillator*⁴
(OSC , OSC )
1
2
C1
OSC1
Ceramic
oscillator
Rf _OSC2
C2
GND
C1
OSC1
Crystal
oscillator
Rf _OSC2
C2
GND
OSC1
Rf
OSC2
Ceramic oscillator: CSA4.00MG (Murata)
R_f=1MΩ±20%
C =C =24pF±20%
12
R_f=1MΩ±20%
C₁=C₂=10–20pF±20%
R_f=20kΩ±1%
Crystal oscillator
C1
(X1, X2)
X1
HD404374 Series
Crystal
oscillator
X2
C2
GND
Crystal: 32.768 kHz: MX38T (Nihon Denpa
Kogyo)
C₁=C₂=20pF±20%
Notes: 1. With a crystal or ceramic oscillator, circuit constants will differ depending on the resonator, stray
capacitance in the interconnecting circuit, and other factors. Suitable constants should be
determined in consultation with the resonator manufacturer.
2. Make the connections between the OSC₁ and OSC₂ pins (X1 and X2 pins) and external
components as short as possible, and ensure that no other lines cross these lines (see layout
example in figure 23).
3. When 32.768 kHz crystal oscillation is not used, fix the X1 pin at V and leave the X2 pin open.
CC
4. Applies to HD40C4372, HD40C4374, HD40C4382, HD40C4384, HD40C4388, HD40C4389,
HD40C4081, HD40C4082, HCD40C4082, HD40C4084, HCD40C4084, HD407C4374 and
HD407C4384.
Rev.5.00, Sep.11.2003, page 57 of 161