전자부품 데이터시트 검색엔진 |
|
CDC960DL 데이터시트(PDF) 7 Page - Texas Instruments |
|
CDC960DL 데이터시트(HTML) 7 Page - Texas Instruments |
7 / 10 page CDC960 200MHz CLOCK SYNTHESIZER/DRIVER WITH SPREAD SPECTRUM CAPABILITY AND DEVICE CONTROL INTERFACE SCAS675 – APRIL 2002 7 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 connecting SCLK and SDATA to 5-V SMBus signals (continued) There are many manufacturers making Zener diodes that can be used for this application. Panasonic MA8033 and Vishay BZX84C3V3 that have 3.1 V < VZ < 3.5 V can be used for this application. In this case R1 is recommended as 150 Ω. The worst IOH in equation (1) is 16 mA when VOH = 5.5 V, RS = 0 Ω and VIO = 3.1 V. The current in equation (2), between 4 mA and 4.6 mA, satisfies the requirement. Equation (3) is also satisfied with the selected R1 and diode. 2. Clamping Diode to VDD VO 150 k Ω SCLK OR SDATA Driver R1 D1 VIO SCLK or SDATA CDC960 3.3 V 3.3 V Figure 2. SCLK SDATA Connection to 5-V SMBus Using Clamping Diode to VDD Diode D1 in Figure 2 should have a small forward voltage (VF). Ideally, we want VF to be less than 300 mV to meet the input voltage requirement of the CDC960. International IOR Rectifier has a device (part number 10BQ015) with maximum VF of 350 mV at 1.0 A. Using the 10BQ015 with R1 = 150 Ω, the worst-case IOH is calculated using equation (4). I OH + 5.5 V * (3.0 * 0.35) V 150 W + 14 mA The calculation for equations (2) and (3) is the same as in part 1. When using the configuration in Figure 2, the power supply is required to have a capability of sinking current. The total amount of sinking current is dependent on the overall load connected to that power supply. Using the above interface circuitry with a high-impedance source, the available high-level voltage on the SMBus is limited to about (Vzk) for the configuration in Figure 1 and (VDD(CDC960) + VF(D1)) for the configuration in Figure 2. One has to choose which option best fits a given SMBus configuration. Actually, the typical SMBus configuration is an open-drain configuration with pullup resistors to the corresponding power supply. It does not require a 5-V SMBus driver that has a low impedance to drive the CDC960 SMBus ports with its additional components as shown in Figure 1 and Figure 2. The external components are not needed if the pullup resistors of the SMBus are directly connected to a voltage equal to the supply voltage of the CDC960 (typically 3.3 V). This pullup resistor connection is strongly recommended. (4) |
유사한 부품 번호 - CDC960DL |
|
유사한 설명 - CDC960DL |
|
|
링크 URL |
개인정보취급방침 |
ALLDATASHEET.CO.KR |
ALLDATASHEET 가 귀하에 도움이 되셨나요? [ DONATE ] |
Alldatasheet는? | 광고문의 | 운영자에게 연락하기 | 개인정보취급방침 | 링크교환 | 제조사별 검색 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 |