參數(shù)資料
型號： PC755M8
英文描述： PC755M8 [Updated 6/03. 35 Pages] 32-bit RISC PowerPC-based Multichip Module
中文描述： PC755M8 [更新6月3日。 35頁] 32位RISC PowerPC的多芯片模塊
文件頁數(shù)： 47/50頁
文件大小： 1064K
代理商： PC755M8
47
PC755/745
2138D–HIREL–06/03
Alternately, the following is another method to determine the output impedance of the
PC755. A voltage source, V
force
, is connected to the output of the PC755 as in Figure 33.
Data is held low, the voltage source is set to a value that is equal to (L2)O
V
DD
/2 and the
current sourced by V
force
is measured. The voltage drop across the pull-down device,
which is equal to (L2)O
V
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)O
V
DD
/2, by the current sank
by the pull-up when the data is high and V
force
is equal to (L2)O
V
DD
/2. This method can
be employed with either empirical data from a test set up 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 33 describes the alternate driver impedance measurement circuit.
Figure 33.
Alternate Driver Impedance Measurement Circuit
Table 20 summarizes the signal impedance results. The driver impedance values were
characterized at 0
°
C, 65
°
C, and 105
°
C. The impedance increases with junction temper-
ature and is relatively unaffected by bus voltage.
Pull
–
up Resistor
Requirements
The PC755 requires pull-up resistors (1 k
– 5 k
) on several control pins of the bus
interface to maintain the control signals in the negated state after they have been
actively negated and released by the processor or other bus masters. These pins are
TS, ABB, AACK, ARTRY, DBB, DBWO, TA, TEA, and DBDIS. DRTRY should also be
connected to a pull-up resistor (1 k
– 5 k
) if it will be used by the system; otherwise,
this signal should be connected to HRESET to select NO-DRTRY mode.
Three test pins also require pull-up resistors (100
– 1 k
). These pins are
L1_TSTCLK, L2_TSTCLK, and LSSD_MODE. These signals are for factory use only
and must be pulled up to OV
DD
for normal machine operation.
Table 20.
Impedance Characteristics
V
DD
= 2.0V, OV
DD
= 3.3V, T
c
= 0 - 105
°
C
Impedance
Processor bus
L2 bus
Symbol
Unit
RN
25-36
25-36
Z
0
W
RP
26-39
26-39
Z
0
W
(L2)OVDD
BGA
Pin
Data
OGND
Vforce
相關(guān)PDF資料
PDF描述
PC755CMGHU300LE PowerPC 755/745 RISC Microprocessor
PC755CMGHU350LE PowerPC 755/745 RISC Microprocessor
PC755CMGHU366LE PowerPC 755/745 RISC Microprocessor
PC755CMGHU400LE PowerPC 755/745 RISC Microprocessor
PC755CMGSU300LE PowerPC 755/745 RISC Microprocessor
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PC75B 制造商:Datak Corporation 功能描述:
PC75-C 功能描述:PCB COPPER CLAD 4.5X7" 2 SIDE RoHS:是 類別:原型開發(fā)產(chǎn)品 >> 原型開發(fā)板 - 未穿孔 系列:- 標(biāo)準(zhǔn)包裝:5 系列:500 原型板類型:包銅，無涂層 尺寸/尺寸:36.00" x 24.00"（914.4mm x 609.6mm） 板厚度:0.063"（1.60mm）1/16" 材質(zhì):雙面包銅 FR4，1 盎斯
PC75P 功能描述:PCB COPPER CLAD POS 4 X 6"2 SIDE RoHS:是 類別:原型開發(fā)產(chǎn)品 >> 原型開發(fā)板 - 未穿孔 系列:- 標(biāo)準(zhǔn)包裝:5 系列:500 原型板類型:包銅，無涂層 尺寸/尺寸:36.00" x 24.00"（914.4mm x 609.6mm） 板厚度:0.063"（1.60mm）1/16" 材質(zhì):雙面包銅 FR4，1 盎斯
PC75P-C 功能描述:PCB COPPER CLAD POS 4.5X7"2 SIDE RoHS:是 類別:原型開發(fā)產(chǎn)品 >> 原型開發(fā)板 - 未穿孔 系列:- 標(biāo)準(zhǔn)包裝:5 系列:500 原型板類型:包銅，無涂層 尺寸/尺寸:36.00" x 24.00"（914.4mm x 609.6mm） 板厚度:0.063"（1.60mm）1/16" 材質(zhì):雙面包銅 FR4，1 盎斯
PC75P-S 功能描述:PCB COPPER CLAD POS 6 X 6"2 SIDE RoHS:是 類別:原型開發(fā)產(chǎn)品 >> 原型開發(fā)板 - 未穿孔 系列:- 標(biāo)準(zhǔn)包裝:5 系列:500 原型板類型:包銅，無涂層 尺寸/尺寸:36.00" x 24.00"（914.4mm x 609.6mm） 板厚度:0.063"（1.60mm）1/16" 材質(zhì):雙面包銅 FR4，1 盎斯
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*