数据搜索系统,热门电子元器件搜索 |
|
AD9280ARSRL 数据表(PDF) 11 Page - Analog Devices |
|
AD9280ARSRL 数据表(HTML) 11 Page - Analog Devices |
11 / 24 page AD9280 –11– REV. D The actual reference voltages used by the internal circuitry of the AD9280 appear on REFTF and REFBF. For proper opera- tion, it is necessary to add a capacitor network to decouple these pins. The REFTF and REFBF should be decoupled for all internal and external configurations as shown in Figure 17. AD9280 REFTF REFBF 0.1 F 0.1 F 10 F 0.1 F Figure 17. Reference Decoupling Network Note: REFTF = reference top, force REFBF = reference bottom, force REFTS = reference top, sense REFBS = reference bottom, sense INTERNAL REFERENCE OPERATION Figures 18, 19 and 20 show sample connections of the AD9280 internal reference in its most common configurations. (Figures 18 and 19 illustrate top/bottom mode while Figure 20 illustrates center span mode). Figure 29 shows how to connect the AD9280 for 1 V p-p differential operation. Shorting the VREF pin directly to the REFSENSE pin places the internal reference amplifier, A1, in unity-gain mode and the resultant reference output is 1 V. In Figure 18 REFBS is grounded to give an input range from 0 V to 1 V. These modes can be chosen when the supply is either +3 V or +5 V. The VREF pin must be bypassed to AVSS (analog ground) with a 1.0 µF tantalum capacitor in parallel with a low inductance, low ESR, 0.1 µF ceramic capacitor. 1V 0V MODE AVDD 10k 10k 10k A/D CORE 4.2k TOTAL REFTS REFBS 10 F 0.1 F REFTF REFBF 0.1 F AIN 0.1 F AD9280 10k REF SENSE VREF 1V A2 SHA A1 0.1 F 1.0 F Figure 18. Internal Reference—1 V p-p Input Span (Top/Bottom Mode) Figure 19 shows the single-ended configuration for 2 V p-p operation. REFSENSE is connected to GND, resulting in a 2 V reference output. 2V 0V MODE AVDD 10k 10k 10k A/D CORE 4.2k TOTAL REFTS REFBS 10 F 0.1 F REFTF REFBF 0.1 F AIN 0.1 F AD9280 10k REF SENSE VREF A1 1V SHA A2 0.1 F 1.0 F Figure 19. Internal Reference, 2 V p-p Input Span (Top/Bottom Mode) Figure 20 shows the single-ended configuration that gives the good high frequency dynamic performance (SINAD, SFDR). To optimize dynamic performance, center the common-mode voltage of the analog input at approximately 1.5 V. Connect the shorted REFTS and REFBS inputs to a low impedance 1.5 V source. In this configuration, the MODE pin is driven to a volt- age at midsupply (AVDD/2). Maximum reference drive is 1 mA. An external buffer is re- quired for heavier loads. AVDD/2 +1.5V 2V 1V MODE 10k 10k 10k A/D CORE 4.2k TOTAL REFTS REFBS 10 F 0.1 F REFTF REFBF 0.1 F AIN 0.1 F AD9280 10k REF SENSE VREF 1V SHA A2 A1 0.1 F 1.0 F Figure 20. Internal Reference 1 V p-p Input Span (Center Span Mode) |
类似零件编号 - AD9280ARSRL |
|
类似说明 - AD9280ARSRL |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 链接交换 | 制造商名单 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 |