There have been many advances in communication circuits since the publication of the first edition of this book.Yet most of communication circuit fundamentals remain intact.amplifier,oscillator , tuned circuits,transformers,mixers and power amplifiers still among fundamental building blocks of communication circuits.
The single-carrier frequency division multiple access (SC-FDMA)
system is a well-known system that has recently become a preferred
choice for mobile uplink channels. This is attributed to its advantages
such as the low peak-to-average power ratio (PAPR) and the use of
frequency domain equalizers. Low PAPR allows the system to relax
the specifications of linearity in the power amplifier of the mobile
terminal, which reduces cost and power consumption.
This design uses Common-Emitter amplifier (Class A) with 2N3904 Bipolar Junction Transistor.
Use “Voltage Divider Biasing” to reduce the effects of varying β (= ic / ib) (by holding the Base voltage constant)
Base Voltage (Vb) = Vcc * [R2 / (R1 + R2)]
Use Coupling Capacitors to separate the AC signals from the DC biasing voltage (which only pass AC signals and block any DC component).
Use Bypass Capacitor to maintain the Q-point stability.
To determine the value of each component, first set Q-point close to the center position of the load line. (RL is the resistance of the speaker.)
Wherever possible the overall technique used for this series will be "definition by example" withgeneric formulae included for use in other applications. To make stability analysis easy we will usemore than one tool from our toolbox with data sheet information, tricks, rules-of-thumb, SPICESimulation, and real-world testing all accelerating our design of stable operational amplifier (op amp)circuits. These tools are specifically targeted at voltage feedback op amps with unity-gain bandwidths<20 MHz, although many of the techniques are applicable to any voltage feedback op amp. 20 MHz ischosen because as we increase to higher bandwidth circuits there are other major factors in closing theloop: such as parasitic capacitances on PCBs, parasitic inductances in capacitors, parasitic inductancesand capacitances in resistors, etc. Most of the rules-of-thumb and techniques were developed not justfrom theory but from the actual building of real-world circuits with op amps <20 MHz.
2.7V to 5.5V input voltage Range? Efficiency up to 96%
? 24V Boost converter with 12A switch
current Limit? 600KHz fixed Switching Frequency? Integrated soft-start? Thermal Shutdown? Under voltage Lockout? Support external LDO auxiliary power
supply? 8-Pin SOP-PP PackageAPPLICATIONSPortable Audio amplifier Power SupplyPower BankQC 2.0/Type CWireless ChargerPOS Printer Power SupplySmall Motor Power Supply
74HC595 A4950 MAX3232 ULN2003AD STM32F207VCT6 AD集成封裝庫，原理圖庫器件型號列表：Library Component Count : 53Name Description----------------------------------------------------------------------------------------------------1N4148 High Conductance Fast Diode1N4448 High Conductance Fast Diode1N914 High Conductance Fast Diode1N914A High Conductance Fast Diode1N914B High Conductance Fast Diode1N916 High Conductance Fast Diode1N916A High Conductance Fast Diode1N916B High Conductance Fast Diode2N3904 NPN General Purpose amplifier74ALS86 74HC595 8M貼片晶振 A4950 直流電機驅動AO4805CAP CapacitorCAP SMD CapacitorCON2 ConnectorCON2*10 ConnectorCON2*12P ConnectorCON2*7 ConnectorCON2*9 ConnectorCON3 ConnectorCON4 ConnectorCON5 ConnectorCON7 ConnectorCap Pol 極性電解電容DIODE DiodeFUSE1 FuseFUSE2 FuseINDUCTOR2 IRF7351PbF N-MOSJS1-12V-FLED MAX487 MAX809RD R0.125 Less than 1/4 Watt Power Resistor.RES2 RGRPI*4 Res1 ResistorSGM8955XN5G/TR 測量放大器SM712 SN74LV4052AD SP3232ESST25VF016B-50-4I-S2AFI2C Real-Time Clock.STM32F107VTC6 STM32F107VTC6SW DIP-4 編碼開關SW-PB SwitchTPS54302 45UA靜態(tài)電流 3ATVS SMBJ30CAULN2003 XC6214XTAL Crystal OscillatorPCB封裝庫列表：Component Count : 40Component Name-----------------------------------------------4G模塊-外置7D181K0603-LED0603C0603R0805C12061210181232255569-2*1P直針5569-2*2P直針AT-26CAP-D8DO-214AANHSOP-8J-SPDT-5JTAGL
ABSTRACTThe flyback power stage is a popular choice for single and multiple output dc-to-dc converters at powerlevels of 150 Watts or less. Without the output inductor required in buck derived topologies, such as theforward or push-pull converter, the component count and cost are reduced. This application note will reviewthe design procedure for the power stage and control electronics of a flyback converter. In these isolatedconverters, the error signal from the secondary still needs to cross the isolation boundary to achieveregulation. By using the UC3965 Precision Reference with Low Offset Error amplifier on the secondaryside to drive an optocoupler and the UCC3809 Economy Primary Side Controller on the primary side, asimple and low cost 50 Watt isolated power supply is realized.
