SAA5X9X Datasheet, PDF (48/68 Pages) NXP Semiconductors – Economy teletext and TV microcontrollers

Philips Semiconductors
Economy teletext and TV microcontrollers
Preliminary specification
SAA5x9x family
9.23 Clock generator
The oscillator circuit is a single-stage inverting amplifier in a Pierce oscillator configuration. The circuitry between OSCIN
and OSCOUT is basically an inverter biased to the transfer point. A crystal must be used as the feedback element to
complete the oscillator circuitry. It is operated in parallel resonance. OSCIN is the high gain amplifier input and OSCOUT
is the output. To drive the device externally OSCIN is driven from an external source and OSCOUT is left open-circuit.
handbook, halfpage
OSCGND
C1 ⁽¹⁾
OSCIN
C2 ⁽¹⁾
OSCOUT
VSS
MLC110
(1) The values of C1 and C2 depend on the crystal specification:
C1 = C2 = 2C_L.
Fig.17 Oscillator circuit.
handbook, halfpage
external clock
OSCGND
VSS
OSCIN
not connected
OSCOUT
MLC111
Fig.18 Oscillator circuit driven from external source.
1997 Jul 07
48