GDPXA255A0E400 Datasheet, PDF (29/40 Pages) Intel Corporation – Electrical, Mechanical, and Thermal Specification

Electrical Specifications
To drive the 32.768-kHz crystal pins from an external source
• Drive the TEXTAL pin with a digital signal that has a low level near 0 volts and a high level
near VCC. Do not exceed VCC or go below VSS by more than 100 mV. The minimum slew
rate is 1 volt per 1 µs. The maximum current sourced by the external clock source when the
clock is at its maximum positive voltage should be approximately 1 mA.
• Float the TXTAL pin or drive it complementary to the TEXTAL pin, with the same voltage
level, slew rate, and input current restrictions.
4.6.2
3.6864 MHz Oscillator Specifications
The 3.6864-MHz oscillator is connected between the PXTAL (amplifier input) and PEXTAL
(amplified output). Table 14 shows the 3.6864-MHz specifications.
Table 14. 3.6864-MHz Oscillator Specifications
Symbol
Description
Crystal Specifications - Typical is FOX HC49S
F_XP
ESR
Crystal Frequency, PXTAL/PEXTAL
Equivalent series resistance, PXTAL/PEXTAL
P
Drive Level
Amplifier Specifications
VIH_X Input High Voltage, PXTAL
VIL_X Input Low Voltage, PXTAL
IIN_XP Input Leakage, PXTAL
CIN_XP Input Capacitance, PXTAL/PEXTAL
tS_XP Stabilization Time
Board Specifications
RP_XP Parasitic Resistance, PXTAL/PEXTAL to any node
CP_XP Parasitic Capacitance, PXTAL/PEXTAL, total
COP_XP Parasitic Shunt Capacitance, PXTAL to PEXTAL
Min Typical Max Units
—
3.6864
—
MHz
50
-
300
Ω
—
—
100
uW
0.8*VCC
VCC
V
VSS
0.2*VCC V
10
µA
40
50
pF
17.8
67.8
ms
20
MΩ
5
pF
0.4
pF
To drive the 3.6864-MHz crystal pins from an external source
• Drive the PEXTAL pin with a digital signal with a low level near 0 volts and a high level near
VCC. Do not exceed VCC or go below VSS by more than 100 mV. The minimum slew rate is
1 volt / 100 ns. The maximum current sourced by the external clock source when the clock is
at its maximum positive voltage should be approximately 1 mA.
• Float the PXTAL pin or drive it complementary to the PXTAL pin, with the same voltage
level, slew rate, and input current restrictions. If floated, some degree of noise susceptibility
will be introduced in the system; therefore, it is not recommended.
Intel® PXA255 Processor Electrical, Mechanical, and Thermal Specification
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