MC68HC705MC4MP datasheet(24/180 Pages) FREESCALE

24 / 180 page

General Description

MC68HC705MC4 — Rev. 2.0

General Description

startup. The load capacitance values used in the oscillator circuit design

should include all stray capacitances. Mount the crystal and components

as close as possible to the pins for startup stabilization and to minimize

output distortion. The ground return path for C1 and C2 should be as

direct to VSS (pin 6) as possible to minimize the oscillator loop area.

Figure 1-4. Oscillator Connections

1.5.2.2 Ceramic Resonator

In cost-sensitive applications, use a ceramic resonator in place of a

crystal. Use the circuit in Figure 1-4(a) for a ceramic resonator and

follow the resonator manufacturer’s recommendations, as the resonator

parameters determine the external component values required for

maximum stability and reliable starting. The load capacitance values

used in the oscillator circuit design should include all stray capacitances.

Mount the resonator and components as close as possible to the pins for

startup stabilization and to minimize output distortion.

1.5.2.3 External Clock

An external clock from another CMOS-compatible device can be

connected to the OSC1 input, with the OSC2 input not connected, as

shown in Figure 1-4(b).

TO VDD (OR STOP CONTROL)

(a)

Crystal or Ceramic Resonator

Connections

(b)

External Clock Source

Connections

OSC1

OSC2

MCU

OSC1

OSC2

UNCONNECTED

EXTERNAL CLOCK

*Typical values shown. Follow the ceramic resonator manufacturer’s

recommendations for values of R, C1, and C2.

Rexternal

15–18 pF*

2 M

Ω∗

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

MC68HC705MC4MP 数据表(PDF) 24 Page - Freescale Semiconductor, Inc

MC68HC705MC4MP 数据表(HTML) 24 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载