mc9s12q128 Freescale Semiconductor, Inc, mc9s12q128 Datasheet - Page 65

• Manufacturer Part Number: mc9s12q128
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

1.8
The PCB must be carefully laid out to ensure proper operation of the voltage regulator as well as of the
MCU itself. The following rules must be observed:
Freescale Semiconductor
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Every supply pair must be decoupled by a ceramic capacitor connected as near as possible to the
corresponding pins.
Central point of the ground star should be the V
Use low ohmic low inductance connections between V
V
Keep traces of V
C7, C11, and Q1 as small as possible.
Do not place other signals or supplies underneath area occupied by C6, C7, C5, and Q1 and the
connection area to the MCU.
Central power input should be fed in at the V
SSPLL
1. In 48LQFP and 52LQFP package versions, V
Recommended Printed Circuit Board Layout
V
Component
DD1
R3 / R
R4 / R
C10
C11
Q1
C1
C2
C3
C4
C5
C6
C7
C8
C9
R1
R2
.
must be directly connected to V
B
S
SSPLL
V
DD2
Pierce Mode Select Pullup
Table 1-12. Recommended Component Values
, EXTAL, and XTAL as short as possible and occupied board area for C6,
PLL loop filter capacitor
PLL loop filter capacitor
filter capacitor (80 QFP only)
V
PLL loop filter resistor
PLL loop filter resistor
PLL loop filter resistor
V
V
V
V
OSC load capacitor
OSC load capacitor
DDPLL
DC cutoff capacitor
DDR
DDA
DDX
DD1
Purpose
filter capacitor
filter capacitor
filter capacitor
filter capacitor
Quartz
filter capacitor
MC9S12Q128
SSR
DD2
Rev 1.09
.
is not available. Thus 470nF must be connected to
DDA
SSR
/V
Chapter 1 MC9S12Q Device Overview (MC9S12Q128-Family)
pin.
SSA
Colpitts mode only, if recommended by
X7R/tantalum
X7R/tantalum
Ceramic X7R
Ceramic X7R
Ceramic X7R
Ceramic X7R
SS1
See PLL Specification chapter
See PLL specification chapter
See PLL specification chapter
pins.
Type
—
, V
quartz manufacturer
Pierce Mode Only
SS2
Pierce mode only
, and V
SSR
220nF, 470nF
>=100nF
>=100nF
.
100nF
220nF
100nF
Value
—
(1)
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