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IBM25EMPPC750LCBE4000 参数 Datasheet PDF下载

IBM25EMPPC750LCBE4000图片预览
型号: IBM25EMPPC750LCBE4000
PDF下载: 下载PDF文件 查看货源
内容描述: [RISC Microprocessor, 32-Bit, 400MHz, CMOS, CBGA360, 25 X 25 MM, 1.27 MM PITCH, CERAMIC, BGA-360]
分类和应用: 时钟外围集成电路
文件页数/大小: 50 页 / 600 K
品牌: IBM [ IBM ]
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PowerPC 740 and PowerPC 750 Embedded Microprocessor  
IBM CMOS 0.20 um Copper Technology EMPPC740L and EMPPC750L  
External clock routing should ensure that the rising-edge of the L2 clock is coincident at the CLK input of all  
SRAMs and at the L2SYNC_IN input of the 750. The L2CLKOUTA network could be used only, or the  
L2CLKOUTB network could also be used depending on the loading, frequency, and number of SRAMs.  
Output Buffer DC Impedance  
The 750 60x and L2 I/O drivers were characterized over process, voltage, and temperature. To measure Z ,  
0
an external resistor is connected to the chip pad, either to OVDD or GND. Then the value of such resistor is  
varied until the pad voltage is OVDD/2; see Figure 19, “Driver Impedance Measurement,” below.  
The output impedance is actually the average of two components, the resistances of the pull-up and pull-  
down devices. When Data is held low, SW1 is closed (SW2 is open), and RN is trimmed until Pad = OVDD/2. RN  
then becomes the resistance of the pull-down devices. When Data is held high, SW2 is closed (SW1 is open),  
and RP is trimmed until Pad = OVDD/2. RP then becomes the resistance of the pull-up devices. With a properly  
designed driver RP and RN are close to each other in value, then Z0 = (RP + RN)/2.  
Figure 19. Driver Impedance Measurement  
OVDD  
RN  
SW2  
Pad  
Data  
SW1  
RP  
GND  
The following table summarizes the impedance a board designer would design to for a typical process. These  
values were derived by simulation at 65°C. As the process improves, the output impedance will be lower by  
several ohms than this typical value.  
Impedance Characteristics  
VDD = 1.9VDC, L2OVDD=OVDD = 3.3VDC, T = 65°C  
J
Process  
Typical  
60x  
43  
L2  
38  
Symbol  
Z0  
Unit  
5/20/99  
Version 1.51  
PowerPC 740 and PowerPC 750 Datasheet  
Page 37  
 
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