AM6548, AM6528, AM6526
ZHCSLA7B –DECEMBER 2019 –REVISED JUNE 2021
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MAX UNIT
表7-14. WKUP_OSC0 Crystal Electrical Characteristics
NAME
DESCRIPTION
MIN
TYP
fp
Parallel resonance crystal frequency
19.2, 20, 24, 25, 26, 27
MHz
pF
Cf1
Cf1 load capacitance for crystal parallel resonance with Cf1 = Cf2
Cf2 load capacitance for crystal parallel resonance with Cf1 = Cf2
Crystal ESR
12
12
24
Cf2
24
100
7
pF
ESR(Cf1,Cf2)
CO
Ω
Crystal shunt capacitance
19.2 MHz, 20 MHz, 24
MHz, 25 MHz, 26 MHz, 27
MHz
pF
ESR = 30 Ω
ESR = 40 Ω
19.2 MHz, 20 MHz
7
5
pF
pF
ESR = 50 Ω
ESR = 60 Ω
ESR = 80 Ω
ESR = 100 Ω
24 MHz, 25 MHz, 26 MHz,
27 MHz
19.2 MHz, 20 MHz
7
5
3
pF
-
24 MHz, 25 MHz, 26 MHz,
27 MHz
Not Supported
19.2 MHz, 20 MHz
pF
-
24 MHz, 25 MHz, 26 MHz,
27 MHz
Not Supported
Not Supported
19.2 MHz, 20 MHz
pF
-
24 MHz, 25 MHz, 26 MHz,
27 MHz
LM
Crystal motional inductance for fp = 20 MHz
Crystal motional capacitance
10.16
3.42
mH
fF
CM
fj(WKUP_OSC0_XI)
Frequency accuracy, WKUP_OSC0_XI
Ethernet RGMII and RMII
not used
±100 ppm
Ethernet RGMII and RMII
using derived clock
±50
When selecting a crystal, the system design must consider the temperature and aging characteristics of a based
on the worst case environment and expected life expectancy of the system.
表7-15 details the switching characteristics of the oscillator and the requirements of the input clock.
表7-15. WKUP_OSC0 Switching Characteristics –Crystal Mode
NAME
fp
tsX
DESCRIPTION
Oscillation frequency
Start-up time
MIN
TYP
MAX
UNIT
MHz
ms
19.2, 20, 24, 25, 26, 27
2(1)
(1) In order to meet the start-up time defined in this table, the crystal needs to be selected according to the following equation:
Tsu = K×Lm/ (Ro-ESR) + Δt
where Lm is crystal motional inductance, RO is the negative resistance of amplifier, ESR is the crystal Effective series resistance and K
is a constant which represents the initial conditions. Δt is the time amplifier takes to reach its bias point after power down is released.
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