AM6548, AM6528, AM6526
ZHCSLA7B –DECEMBER 2019 –REVISED JUNE 2021
www.ti.com.cn
7.9.4.1.1 WKUP_OSC0 Internal Oscillator Clock Source
图 7-15 shows the recommended crystal circuit. It is recommended that preproduction printed-circuit board
(PCB) designs include the two optional resistors Rbias and Rd in case they are required for proper oscillator
operation when combined with production crystal circuit components. In most cases, Rbias is not required and Rd
is a 0-Ω resistor. These resistors may be removed from production PCB designs after evaluating oscillator
performance with production crystal circuit components installed on preproduction PCBs.
Device
WKUP_OSC0_XO
WKUP_OSC0_XI
Rd
(Optional)
Crystal
(Optional)
Rbias
Cf2
Cf1
PCB Ground
SPRSP08_PCB_CLK_OSC_2
图7-15. WKUP_OSC0 Crystal Implementation
Note
The load capacitors, Cf1 and Cf2 in the load capacitance equation (1) below, should be chosen such
that the below equation is satisfied. CL in the equation is the load specified by the crystal
manufacturer. All discrete components used to implement the oscillator circuit should be placed as
close as possible to the associated oscillator WKUP_OSC0_XI, WKUP_OSC0_XO, and VSS pins.
Cf1Cf2
C
= (Cf1+Cf2)
L
SPRS932_CLOCK_03
(1)
The crystal must be in the fundamental mode of operation and parallel resonant. 表 7-14 summarizes the
required electrical constraints.
Copyright © 2021 Texas Instruments Incorporated
Submit Document Feedback 153
Product Folder Links: AM6548 AM6528 AM6526
TI [ TEXAS INSTRUMENTS ]
