tmp88ps38bng TOSHIBA Semiconductor CORPORATION, tmp88ps38bng Datasheet - Page 15

• Manufacturer Part Number: tmp88ps38bng
• Description: Cmos 8-bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Recommended Oscillating Conditions
Oscillation for OSD
Item
Note 1: Toshiba’s OSD circuit determines a horizontal display start position by counting clock
Note 2: When using the LSI package in a strong electric field, such as near a CRT, electrically shield
The frequency generated in LC oscillation can be obtained using the following equations.
C
f
1
=
2
is not fixed at a constant value. It can be changed to tune into the desired frequency.
π
pulses generated in LC oscillation. For this reason, the OSD circuit may fail to detect clock
pulses normally, resulting in the horizontal start position becoming unstable, at the
beginning of oscillation, if the oscillation amplitude is low.
Changing L and C
stable OSD display.
If the LC oscillation frequency is the same as a high-frequency clock value, the oscillation of
the high-frequency oscillator may cause the LC oscillation frequency to fluctuate, thus
making OSD displays flicker.
When determining these parameters, please check the oscillation frequency and the
stability of oscillation on your TV sets.
Also check the determined parameters on your final products, because the optimum
parameter values may vary from one product to another.
the package so that its normal operation can be maintained.
1
LC
,
C
=
C
C
1
1
･
+
Resonator
LC resonator
C
C
2
2
2
from the values recommended for a specific frequency may hamper a
C
88PS38B-15
OSC1
1
(V
Oscillation for OSD
SS
Frequency
Oscillation
12 MHz
16 MHz
20 MHz
24 MHz
= 0 V, V
8 MHz
L
DD
OSC2
= 4.5 V to 5.5 V, Topr = −30 to 70°C)
C
2
L (μH)
Recommended Parameter Value
6.8
4.7
33
15
10
C
5 to 30
5 to 30
5 to 30
5 to 25
5 to 25
1
(pF)
TMP88PS38B
2005-05-18
C
2
10
10
10
10
10
(pF)