MC68HC912D60A MOTOROLA [Motorola, Inc], MC68HC912D60A Datasheet - Page 182
MC68HC912D60A
Manufacturer Part Number
MC68HC912D60A
Description
Microcontrollers
Manufacturer
MOTOROLA [Motorola, Inc]
Datasheet
1.MC68HC912D60A.pdf
(460 pages)
- Current page: 182 of 460
- Download datasheet (4Mb)
Oscillator
12.4.1.2 Internal Parasitic Reduction
12.4.1.3 Bias Current Process Optimization
Technical Data
182
Any oscillator circuit’s gain margin is reduced when a low AC-impedance
(low resistance or high capacitance) is placed in parallel with the
resonator. In the Colpitts oscillator configuration, this impedance is
dominated by the parasitic capacitance from the EXTAL pin to VSS.
Since this capacitance is large compared to the shunt capacitance of the
resonator, the gain margin in a Colpitts configuration is less than in other
configurations.
To remedy this issue, the internal circuits were optimized for lower
capacitance. This should increase the gain margin and allow more
robust operation over process, temperature and voltage variation. To
maximize the benefit of this change, different external component values
are required. However, the oscillator will function at least as well as the
MC68HC912D60A version with the same components.
For proper oscillation, the gain margin of the oscillator must exceed one
or the circuit will not oscillate. Due to the sensitive gain margin of the
Colpitts configuration, process variance in the bias current (which
controls the gain of the amplifier) can cause the gain margin to be much
lower than typical. This can be as a result of either too much or too little
current.
To reduce the process sensitivity of the gain, the material of the device
that sets the bias current was changed to a material with tighter process
and temperature control. As a result, the transconductance and Ibias
variances are more limited than in the previous design.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
Oscillator
MC68HC912D60A — Rev 3.0
MOTOROLA
Related parts for MC68HC912D60A
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Motorola, Inc [VOLTAGE REGULATOR]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
6367254 MOTOROLA SC (XSTRS/R F)
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
MC1494LMotorola, Inc [MONOLITHIC FOUR-QUADRANT MULTIPLIER]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
MC1466LMotorola, Inc [PRECISION WIDE RANGE VOLTAGE AND CURRENT REGULATOR]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
MC145532DWMotorola, Inc [ADPCM Transcoder]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
Silicon Controlled Rectifiers
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF Power Field Effect Transistors N-Channel Enhancement-Mode Lateral MOSFETs
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF POWER FIELD EFFECT TRANSISTORS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
LATERAL N-CHANNEL BROADBAND RF POWER MOSFETs
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF POWER FIELD EFFECT TRANSISTOR
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF LOW POWER TRANSISTOR NPN SILICON
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
PLASTIC SURFACE MOUNT ZENER DIODES 1.5 WATTS 3.3-68 VOLTS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
OVERVOLTAGE TRANSIENT SUPPRESSOR
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
TMOS POWER FET 15 AMPERES 60 VOLTS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
TMOS POWER FET LOGIC LEVEL 19 AMPERES 30 VOLTS RDS(on) = 0.099 OHM
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet: