数据搜索系统,热门电子元器件搜索 |
|
SM840021KATR 数据表(PDF) 8 Page - Micrel Semiconductor |
|
SM840021KATR 数据表(HTML) 8 Page - Micrel Semiconductor |
8 / 10 page Micrel, Inc. SM840021 March 2010 8 M9999-031810-B hbwhelp@micrel.com or (408) 955-1690 Power Supply Filtering The SM840021 provides separate power supply pins to isolate any high switching noise from outputs to internal core blocks. VDD and VDDA should be individually connected to the power plane through vias. Bypass capacitors should be used for each pin. Figure 2 illustrates how the power supply filter for 3.3 V and 2.5 V is configured. Figure 2. Crystal Loading Crystal Recommendations This device requires a parallel resonance crystal. Substituting a series resonance crystal will cause this device to operate at the wrong frequency and violate the ppm specifications. To achieve low ppm error, the total capacitance of the crystal must be considered in order to calculate appropriate capacitive loading (CL). Load Capacitance at each side: Trim Capacitance = Ct = (2*CL-(Cb + Cd)) CL: Crystal load capacitance. Defined by manufacturer Ct: External trim capacitors. (Trimmed CL Load capacitance to get the right ppm) Cb: Board capacitance (vias, traces, etc.) Cd: Internal capacitance of the device (lead frame, bond wires, pin, etc.) Equivalent Series Resistance (ESR) Max. Cut Load Cap. Shunt Cap. Max. Drive Max. 70Ω AT 7pF 0.1mW Crystal Input Interface |
类似零件编号 - SM840021KATR |
|
类似说明 - SM840021KATR |
|
|
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 |