DC Characteristics

9.2 DC Characteristics

This section contains the dc characteristics for the 21264/EV68A. The 21264/EV68A pins can be divided into 10 distinct electrical signal types. The mapping between these signal types and the package pins is shown in Chapter 3. Table 9–2shows the signal types.

Table 9–2 Signal Types

Signal Type

Description

 

 

I_DC_POWER

Supply voltage pins (VDD/PLL_VDD)

I_DC_REF

Input dc reference pin

I_DA

Input differential amplifier receiver

I_DA_CLK

Input differential amplifier clock receiver

O_OD

Open-drain output driver

O_OD_TP

Open-drain driver for test pins

O_PP

Push-pull output driver

O_PP_CLK

Push-pull output clock driver

B_DA_OD

Bidirectional differential amplifier receiver — open-drain

B_DA_PP

Bidirectional differential amplifier receiver — push-pull

 

 

Tables 9–3through 9–12show the dc switching characteristics of each signal type. Also, the following notes apply to Tables 9–3through 9–12.

1.The differential voltage, Vdiff, is the absolute difference between the differential input pins.

2.Delta VBIAS is defined as the open-circuit differential voltage on the appropriate

differential pairs. Test condition for these inputs are to let the input network self bias and measure the open circuit voltage. The test load must be 1M ohm. In nor- mal operation, these inputs are coupled with a 680-pF capacitor.

3.Functional operation of the 21264/EV68A with less than all VDD and VSS pins connected is not implied.

4.The test load is a 50-ohm resistor to VDD/2. The resistor can be connected to the 21264/EV68A pin by a 50-ohm transmission line of any length.

5.DC test conditions set the minimum swing required. These dc limits set the trip point precision.

6.Input pin capacitance values include 2.0 pF added for package capacitance.

9–2

Electrical Data

21264/EV68A Hardware Reference Manual

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Compaq EV68A specifications DC Characteristics, Signal Types, Idcpower