- 您现在的位置：买卖IC网 > PDF目录378665 > MC74HC4060N (MOTOROLA INC) 14-Stage Binary Ripple Counter with Oscillator PDF资料下载
参数资料
| 型号： | MC74HC4060N |
| 厂商： | MOTOROLA INC |
| 元件分类： | 通用总线功能 |
| 英文描述： | 14-Stage Binary Ripple Counter with Oscillator |
| 中文描述： | HC/UH SERIES, ASYN NEGATIVE EDGE TRIGGERED 14-BIT UP BINARY COUNTER, PDIP16 |
| 封装： | PLASTIC, DIP-16 |
| 文件页数： | 8/11页 |
| 文件大小： | 256K |
| 代理商： | MC74HC4060N |
MC54/74HC4060A
MOTOROLA
High–Speed CMOS Logic Data
DL129 — Rev 6
3–8
DESIGN PROCEDURES
The following procedure applies for oscillators operating below 2MHz where Z is a resistor R1. Above 2MHz, additional
impedance elements should be considered: Cout and Ca of the amp, feedback resistor Rf, and amplifier phase shift error from
180
°
C.
Step 1: Calculate the equivalent series circuit of the crystal at the frequency of oscillation.
Ze
jXCo(Rs
jXCo
jXLs
jXLs
jXCs)
jXCs
Rs
Re
jXe
Reactance jXe should be positive, indicating that the crystal is operating as an inductive reactance at the oscillation frequency.
The maximum Rs for the crystal should be used in the equation.
Step 2: Determine
β
, the attenuation, of the feedback network. For a closed-loop gain of 2,A
νβ
= 2,
β
= 2/A
ν
where A
ν
is the gain
of the HC4060A amplifier.
Step 3: Determine the manufacturer’s loading capacitance. For example: A manufacturer may specify an external load capaci-
tance of 32pF at the required frequency.
Step 4: Determine the required Q of the system, and calculate Rload, For example, a manufacturer specifies a crystal Q of
100,000. In-circuit Q is arbitrarily set at 20% below crystal Q or 80,000. Then Rload = (2
π
foLS/Q) – Rs where Ls and Rs are crystal
parameters.
Step 5: Simultaneously solve, using a computer,
XC
XC2
R
Re
XC2(Xe
XC)
( Eq 1 )
(with feedback phase shift = 180
°
)
Xe
XC2
XC
ReXC2
R
XCload
( Eq 2 )
(where the loading capacitor is an external load, not including Co)
Rload
RXCoXC2[(XC
XC2)(XC
XCo)
R2(XC
XC(XC
XCo
XC2)2
XC2)]
X2C2(XC
XCo)2
XCo
( Eq 3 )
Here R = Rout + R1. Rout is amp output resistance, R1 is Z. The C corresponding to XC is given by C = C1 + Cin.
Alternately, pick a value for R1 (i.e, let R1 = RS). Solve Equations 1 and 2 for C1 and C2. Use Equation 3 and the fact that Q =
2
π
foLs/(Rs + Rload) to find in-circuit Q. If Q is not satisfactory pick another value for R1 and repeat the procedure.
CHOOSING R1
Power is dissipated in the effective series resistance of the
crystal. The drive level specified by the crystal manufacturer
is the maximum stress that a crystal can withstand without
damage or excessive shift in frequency. R1 limits the drive
level.
To verify that the maximum dc supply voltage does not
overdrive the crystal, monitor the output frequency as a func-
tion of voltage at Osc Out 2 (Pin 9). The frequency should
increase very slightly as the dc supply voltage is increased.
An overdriven crystal will decrease in frequency or become
unstable with an increase in supply voltage. The operating
supply voltage must be reduced or R1 must be increased in
value if the overdriven condition exists. The user should note
that the oscillator start-up time is proportional to the value of
R1.
SELECTING Rf
The feedback resistor, Rf, typically ranges up to 20M
. Rf
determines the gain and bandwidth of the amplifier. Proper
bandwidth insures oscillation at the correct frequency plus
roll-off to minimize gain at undesirable frequencies, such as
the first overtone. Rf must be large enough so as to not affect
the phase of the feedback network in an appreciable manner.
ACKNOWLEDGEMENTS AND RECOMMENDED
REFERENCES
The following publications were used in preparing this data
sheet and are hereby acknowledged and recommended for
reading:
Technical Note TN-24, Statek Corp.
Technical Note TN-7, Statek Corp.
D. Babin, “Designing Crystal Oscillators”, Machine Design,
March 7, 1985.
D. Babin, “Guidelines for Crystal Oscillator Design”,
Machine Design, April 25, 1985.
ALSO RECOMMENDED FOR READING:
E. Hafner, “The Piezoelectric Crystal Unit-Definitions and
Method of Measurement”, Proc. IEEE, Vol. 57, No. 2, Feb.,
1969.
D. Kemper, L. Rosine, “Quartz Crystals for Frequency
Control”, Electro-Technology, June, 1969.
P. J. Ottowitz, “A Guide to Crystal Selection”, Electronic
Design, May, 1966.
相关PDF资料 |
PDF描述 |
|---|---|
| MC74HC4511 | BCD-to-Seven-Segment Latch/Decoder/Display Driver |
| MC74HC4511D | BCD-to-Seven-Segment Latch/Decoder/Display Driver |
| MC74HC4511N | BCD-to-Seven-Segment Latch/Decoder/Display Driver |
| MC74HC4514 | 1-of-16 Decoder/Demultiplexer with Address Latch |
| MC74HC4514DW | 1-of-16 Decoder/Demultiplexer with Address Latch |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MC74HC4066AD | 功能描述:多路器开关 IC 2-12V Quad Mux/Demux RoHS:否 制造商:Texas Instruments 通道数量:1 开关数量:4 开启电阻（最大值）:7 Ohms 开启时间（最大值）: 关闭时间（最大值）: 传播延迟时间:0.25 ns 工作电源电压:2.3 V to 3.6 V 工作电源电流: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UQFN-16 |
| MC74HC4066ADG | 功能描述:多路器开关 IC 2-12V Quad Mux/Demux -55 to 85deg C RoHS:否 制造商:Texas Instruments 通道数量:1 开关数量:4 开启电阻（最大值）:7 Ohms 开启时间（最大值）: 关闭时间（最大值）: 传播延迟时间:0.25 ns 工作电源电压:2.3 V to 3.6 V 工作电源电流: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UQFN-16 |
| MC74HC4066ADR2 | 功能描述:多路器开关 IC 2-12V Quad Mux/Demux RoHS:否 制造商:Texas Instruments 通道数量:1 开关数量:4 开启电阻（最大值）:7 Ohms 开启时间（最大值）: 关闭时间（最大值）: 传播延迟时间:0.25 ns 工作电源电压:2.3 V to 3.6 V 工作电源电流: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UQFN-16 |
| MC74HC4066ADR2G | 功能描述:多路器开关 IC 2-12V Quad Mux/Demux -55 to 85deg C RoHS:否 制造商:Texas Instruments 通道数量:1 开关数量:4 开启电阻（最大值）:7 Ohms 开启时间（最大值）: 关闭时间（最大值）: 传播延迟时间:0.25 ns 工作电源电压:2.3 V to 3.6 V 工作电源电流: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UQFN-16 |
| MC74HC4066ADR2G-CUT TAPE | 制造商:ON 功能描述:MC74HC4066A Series Quad Analog Switch/Multiplexer/Demultiplexer - SOIC-14 |
发布紧急采购，3分钟左右您将得到回复。