參數(shù)資料
型號(hào)： XPC755BRX400LE
英文描述： Microprocessor
中文描述： 微處理器
文件頁(yè)數(shù)： 36/52頁(yè)
文件大?。?/td> 1274K
代理商： XPC755BRX400LE
36
MPC755 RISC Microprocessor Hardware Specifications
MOTOROLA
System Design Information
Power and ground connections must be made to all external V
DD
, OV
DD
, L2OV
DD
, and GND pins of the
MPC755. Note that power must be supplied to L2OV
DD
even if the L2 interface of the MPC755 will not be
used; it is recommended to connect L2OV
DD
to OV
DD
and L2VSEL to BVSEL if the L2 interface is unused.
(This requirement does not apply to the MPC745 since it has neither an L2 interface nor L2OV
DD
pins.)
1.8.5
Output Buffer DC Impedance
The MPC755 60x and L2 I/O drivers are characterized over process, voltage, and temperature. To measure
Z
0
, an external resistor is connected from the chip pad to (L2)OV
DD
or GND. Then, the value of each
resistor is varied until the pad voltage is (L2)OV
DD
/2 (see Figure 22).
The output impedance is the average of two components, the resistances of the pull-up and pull-down
devices. When data is held low, SW2 is closed (SW1 is open), and R
N
is trimmed until the voltage at the
pad equals (L2)OV
DD
/2. R
N
then becomes the resistance of the pull-down devices. When data is held high,
SW1 is closed (SW2 is open), and R
P
is trimmed until the voltage at the pad equals (L2)OV
DD
/2. R
P
then
becomes the resistance of the pull-up devices.
Figure 22 describes the driver impedance measurement circuit described above.
Figure 22. Driver Impedance Measurement Circuit
Alternately, the following is another method to determine the output impedance of the MPC755. A voltage
source, V
force
, is connected to the output of the MPC755 as shown in Figure 23. Data is held low, the voltage
source is set to a value that is equal to (L2)OV
DD
/2 and the current sourced by V
force
is measured. The
voltage drop across the pull-down device, which is equal to (L2)OV
DD
/2, is divided by the measured current
to determine the output impedance of the pull-down device, R
N
. Similarly, the impedance of the pull-up
device is determined by dividing the voltage drop of the pull-up, (L2)OV
DD
/2, by the current sank by the
pull-up when the data is high and V
force
is equal to (L2)OV
DD
/2. This method can be employed with either
empirical data from a test setup or with data from simulation models, such as IBIS.
R
P
and R
N
are designed to be close to each other in value. Then Z
0
= (R
P
+ R
N
)/2.
Figure 24 describes the alternate driver impedance measurement circuit.
(L2)OV
DD
OGND
R
P
R
N
Pad
Data
SW1
SW2
(L2)OV
DD
相關(guān)PDF資料
PDF描述
XPC750EC XPC750P/D XPC750P RISC Microprocessor Hardware Specifications
XPC801ZP25 Microprocessor
XPC801ZP40 Microprocessor
XPC821ZP40 Microprocessor
XPC823ZP25 Microprocessor
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
XPC801ZP25 制造商:未知廠(chǎng)家 制造商全稱(chēng):未知廠(chǎng)家 功能描述:Microprocessor
XPC801ZP40 制造商:未知廠(chǎng)家 制造商全稱(chēng):未知廠(chǎng)家 功能描述:Microprocessor
XPC821ZP40 制造商:未知廠(chǎng)家 制造商全稱(chēng):未知廠(chǎng)家 功能描述:Microprocessor
XPC823CVR66B2T 功能描述:IC MPU POWERQUICC 66MHZ 256-PBGA RoHS:是 類(lèi)別:集成電路 (IC) >> 嵌入式 - 微處理器 系列:MPC8xx 標(biāo)準(zhǔn)包裝:2 系列:MPC8xx 處理器類(lèi)型:32-位 MPC8xx PowerQUICC 特點(diǎn):- 速度:133MHz 電壓:3.3V 安裝類(lèi)型:表面貼裝 封裝/外殼:357-BBGA 供應(yīng)商設(shè)備封裝:357-PBGA（25x25） 包裝:托盤(pán)
XPC823CZC66A 制造商:Freescale Semiconductor 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠(chǎng)商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*