TMS470MF04207_16 Datasheet, PDF (39/68 Pages) Texas Instruments – TMS470MF04207/TMS470MF03107 16/32-Bit RISC Flash Microcontroller

www.ti.com
TMS470MF04207
TMS470MF03107
SPNS159C – JANUARY 2012
5.2 PLL and Clock Specifications
f_(OSC)
t_c(OSC)
t_w(OSCIL)
t_w(OSCIH)
Table 5-5. Timing Requirements for PLL Circuits Enabled or Disabled
PARAMETER
Input clock frequency
Cycle time, OSCIN
Pulse duration, OSCIN low
Pulse duration, OSCIN high
MIN
MAX
5
20
50
15
15
UNIT
MHz
ns
ns
ns
5.2.1 External Reference Resonator/Crystal Oscillator Clock Option
The oscillator is enabled by connecting the appropriate fundamental 5-20 MHz resonator/crystal and load
capacitors across the external OSCIN and OSCOUT pins as shown in Figure 5-3(a). The oscillator is a
single stage inverter held in bias by an integrated bias resistor.
TI strongly encourages each customer to submit samples of the device to the resonator/crystal
vendors for validation. Vendors are equipped to determine which load capacitors will best tune their
resonator/crystal to the microcontroller device for optimum start-up and operation over
temperature/voltage extremes.
5.2.2 External Clock Source
An external oscillator source can be used by connecting a 1.55-V clock signal to the OSCIN pin and
leaving the OSCOUT pin unconnected (open) as shown in Figure 5-3(b).
OSCIN
OSCOUT
OSCIN
OSCOUT
C1^(A)
Crystal
C2^(A)
External
Clock Signal
(toggling 0-1.55 V)
(a)
(b)
A. The values of C1 and C2 should be provided by the resonator/crystal vendor.
Figure 5-3. Recommended Crystal/Clock Connection
Copyright © 2012, Texas Instruments Incorporated
Peripheral Information and Electrical Specifications
39
Submit Documentation Feedback
Product Folder Link(s): TMS470MF04207 TMS470MF03107