TMS279X (WD279X) FLOPPY DISK FORMATTER / CONTROLLER FAMILY

33

absolute maximum ratings over operating free-air temperature range (unless otherwise noted) †

Voltage on any input (see Note 1) ..................................................................................... - 0.5 V to 7 V

Power dissipation (all outputs open) .......................................................................................... 0.75 W

Operating free-air temperature range ................................................................................... 0°C to 70°C

Storage temperature range .......................................................................................... - 55 °C to 125°C

† Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only

and functional operation of the device at these or any other conditions beyond those indicated in the "Recommended Operating Conditions"

section of this specification is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect devic e reliability.

NOTE 1: All voltage values in this data sheet are with respect to VSS

.

recommended operating conditions

PARAMETER

MIN

NOM

MAX

UNIT

Supply voltage, VCC

4.75

5

5.25

V

Supply voltage, VSS

0

High-level input voltage, VIH

2

V

Low-level input voltage, VIL

0.8

V

Operating free-air temperature, TA

0

70

°C

electrical characteristics over full ranges of recommended operating conditions (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP† MAX

UNIT

VOH High-level voltage output

PUMP

IOH = -1 mA

2.2

All others

IOH = -100 µA

2.4

V

VOL Low-level output voltage

PUMP

IOL = 1 mA

0.2

All others

IOL = 1.6 mA

0.45

V

II

Input current (leakage)

VI = VCC

10

µA

IO

Output current (leakage)

VO = VCC

10

µA

IPU

Internal pull-up current ‡

VI = 0 V

100

1700

µA

ICC

Supply current

All outputs open

70

150

mA

† All typical values are at TA = 25°C and nominal supply voltages.

‡ Internal pull-up resistors are on pins 1, 1 7, 19, 22, 36, 37, and 40. Also, pin 25 on 2791 and 2793 devices.

timing characteristics over recommended supply voltage range and operating free-air temperature range

READ ENABLE TIMING

PARAMETER

TEST

CONDITIONS

ALT.

SYMBOL†

MIN

TYP

MAX

UNIT

tsu(A-RE)

A0, A1 to RE# setup time

TSET

50

ns

tsu(CS-RE)

CS# to RE# setup time

TSET

50

ns

th(A-RE)

A0, A1 from RE# hold time

THLD

10

ns

th(CS-RE)

CS# from RE# hold time

THLD

10

ns

tw(RE)

RE pulse duration

CL = 50 pF

THE

200

ns

trs(RE-DRQ)

Reset time, DRQ from RE#

TDRR

100

200

ns

trs(RE-INT)

Reset time, INTRQ from RE#

TIRR

500

3000

ns

ta(RE)

Data access time from RE#

CL = 50 pF

TDACC

100

200

ns

tdis(RE)

Data disable time from RE #

CL = 50 pF

TDOH

20

150

ns

† Symbol used in Western Digital Corporation WD279X-02 Data Sheet