TP3071 datasheet(22/26 Pages) NSC

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Definitions and Timing Conventions

DEFINITIONS

IH is the D.C. input level above which

an input level is guaranteed to appear as

a logical one. This parameter is to be

measured by performing a functional

test at reduced clock speeds and nomi-

nal timing, (i.e., not minimum setup and

hold times or output strobes), with the

high level of all driving signals set to V

and maximum supply voltages applied

to the device.

IL is the D.C. input level below which

an input level is guaranteed to appear as

a logical zero to the device. This param-

eter is measured in the same manner as

IH but with all driving signal low levels

set to V

IL and minimum supply voltages

applied to the device.

OH is the minimum D.C. output level to

which an output placed in a logical one

state will converge when loaded at the

maximum specified load current.

OL is the maximum D.C. output level to

which an output placed in a logical zero

state will converge when loaded at the

maximum specified load current.

Threshold Region The threshold region is the range of in-

put voltages between V

IL and VIH.

Valid Signal

A signal is Valid if it is in one of the valid

logic states. (i.e., above V

IH or below

IL). In timing specifications, a signal is

deemed valid at the instant it enters a

valid state.

Invalid signal

A signal is invalid if it is not in a valid

logic state, i.e., when it is in the thresh-

old region between V

IL and VIH. In timing

specifications, a signal is deemed In-

valid at the instant it enters the threshold

region.

TIMING CONVENTIONS

For the purposes of this timing specification the following

conventions apply.

Input Signals

All input signals may be characterized

as: V

L = 0.4V, VH = 2.4V, tR < 10 ns, tF<

10 ns.

Period

The period of the clock signal is desig-

nated as t

Pxx where xx represents the

mnemonic of the clock signal being

specified.

Rise Time

Rise times are designated as t

Ryy, where

yy represents a mnemonic of the signal

whose rise time is being specified. t

Ryy is

measured from V

IL to VIH.

Fall Time

Fall times are designated as t

Fyy, where

yy represents a mnemonic of the signal

whose fall time is being specified. t

Fyy is

measured from V

IH to VIL.

Pulse Width High The high pulse width width is designated

as t

WzzH, where zz represents the mne-

monic of the input or output signal whose

pulse width is being specified. High

pulse widths are measured from V

IH to

IH.

Pulse Width Low

The low pulse width is designated as

WzzL,

where zz represents the mne-

monic of the input or output signal whose

pulse width is being specified. Low pulse

widths are measured from V

IL to VIL.

Setup Time

Setup times are designated as t

Swwxx,

where ww represents the mnemonic of

the input signal whose setup time is be-

ing specified relative to a clock or strobe

input represented by mnemonic xx.

Setup times are measured from the ww

Valid to xx Invalid.

Hold Time

Hold times are designated as T

Hwwxx,

where ww represents the mnemonic of

the input signal whose hold time is being

specified relative to a clock or strobe in-

put represented by the mnemonic xx.

Hold times are measured from xx Valid

to ww Invalid.

Delay Time

Delay

times

are

designated

Dxxyy[ IHIL], where xx represents the

mnemonic of the input reference signal

and yy represents the mnemonic of the

output signal whose timing is being

specified relative to xx. The mnemonic

may optionally be terminated by an H or

L to specify the high going or low going

transition of the output signal. Maximum

delay times are measured from xx Valid

to yy Valid. Minimum delay times are

measured from xx Valid to yy Invalid.

This parameter is tested under the load

conditions specified in the Conditions

column of the Timing Specifications sec-

tion of this datasheet.

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