Z86D73 Datasheet, PDF (62/92 Pages) Zilog, Inc. – 40/44/48-Pin Low-Voltage IR OTP

Z86D73
40/44/48-Pin Low-Voltage IR OTP
56
Clock
The Z86D73 on-chip oscillator has a high-gain, parallel-resonant amplifier, for
connection to a crystal, LC, ceramic resonator, or any suitable external clock
source (XTAL1 = Input, XTAL2 = Output). The crystal must be AT cut, 1 MHz to 8
MHz maximum, with a series resistance (RS) less than or equal to 100 Ω. The
Z86D73 on-chip oscillator can be driven with a low-cost RC network or other suit-
able external clock source.
For 32-kHz crystal operation, an external feedback (Rf) and a serial resistor (Rd)
are required. See Figure 32.
The crystal must be connected across XTAL1 and XTAL2 using the recommended
capacitors (capacitance greater than or equal to 22 pF) from each pin to ground.
The RC oscillator configuration is an external resistor connected from XTAL1 to
XTAL2, with a frequency-setting capacitor from XTAL1 to ground (Figure 32).
C1
XTAL1
C1
XTAL1
L
XTAL2
C2
C2
XTAL2
Ceramic Resonator or Crystal
C1, C2 = 47 pF TYP *
f = 8 MHz
LC
C1, C2 = 22 pF
L = 130 µH *
f = 3 MHz *
C1
XTAL1
R
XTAL2
RC
@ 3V VCC (TYP)
C1 = 33 pF *
R = 1K *
C1
Rf
XTAL1
XTAL1
C2
Rd
XTAL2
32 kHz XTAL
C1 = 20 pF, C = 33 pF
Rd = 56 - 470K
Rf = 10 M
XTAL2
External Clock
* Preliminary value including pin parasitics
Figure 32. Oscillator Configuration
PS019402-1103
PRELIMINARY