Electronic Components Datasheet Search |
|
AD9851 Datasheet(PDF) 11 Page - Analog Devices |
|
AD9851 Datasheet(HTML) 11 Page - Analog Devices |
11 / 24 page AD9851 –11– REF CLOCK 90 PHASE DIFFERENCE 8-BIT DATA BUS FQ UD RESET W CLK AD9851 #2 IOUT AD9851 #1 W CLK FQ UD RESET IOUT RESET FQ UD RESET FQ UD W CLK #2 W CLK #1 MICROPROCESSOR OR MICROCONTROLLER W CLK #2 W CLK #1 Figure 7. Application Showing Synchronization of Two AD9851 DDSs to Form a Quadrature Oscillator After a common RESET command is issued, separate W_CLKs allow independent programming of each AD9851 40-bit input reg- ister via the 8-bit data bus or serial input pin. A common FQ_UD pulse is issued after programming is completed to simultaneously engage both oscillators at their specified frequency and phase. AD9851 IOUT 30MHz CLOCK BANDPASS FILTER 50 50 FUNDAMENTAL FCLK IMAGE FC – FO IMAGE FC + FO 60 120 180 240 FREQUENCY – MHz 240 FREQUENCY – MHz IMAGE FC + FO BANDPASS FILTER 6 AMPLIFIER 240MHz AD9851 SPECTRUM FINAL OUTPUT SPECTRUM Figure 8. Deriving a High Frequency Output Signal from the AD9851 by Using an Alias or Image Signal The differential DAC output connection in Figure 9 enables reduction of common-mode signals and allows highly reactive filters to be driven without a filter input termination resistor (see above single-ended example, Figure 8). A 6 dB power advantage is obtained at the filter output as compared with the single-ended example, since the filter need not be doubly terminated. REFERENCE CLOCK FILTER DIFFERENTIAL TRANSFORMER COUPLED OUTPUT 50 1:1 TRANSFORMER i.e., MINI-CIRCUITS T1–1T 50 AD9851 DDS 21 20 Figure 9. Differential DAC Output Connection for Reduction of Common-Mode Signals The AD9851 RSET input is driven by an external DAC (Figure 10) SET SET to provide amplitude modulation or fixed, digital amplitude control of the DAC output current. Full description of this application is found as a Technical Note in the AD9851 data sheet under Related Information. An Analog Devices' application note for the AD9850, AN-423, describes another method of amplitude control using an enhancement mode MOSFET that is equally applicable to the AD9851. NOTE: If the 6 REFCLK multiplier of the AD9851 is engaged, the 125 MHz clocking source shown in Figure 10 can be reduced by a factor of six. AD9851 DDS DIFFERENTIAL TRANSFORMER COUPLED OUTPUT 50 1:1 TRANSFORMER 50 IOUT IOUT RSET +5V 21 20 12 9 4k 200 330 +5V 20mA MAX 10-BIT DAC AD9731 +5V –5V 125MHz 10 BITS DATA GENERATOR e.g., DG-2020 COMPUTER CONTROL DATA Figure 10.The AD9851 RSET Input Being Driven by an External DAC REV. D |
Similar Part No. - AD9851 |
|
Similar Description - AD9851 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |