ls7055 LSI Computer Systems, Inc., ls7055 Datasheet

ls7055

Manufacturer Part Number

ls7055

Description

6 Decade Predetermining Up/down Counter

Manufacturer

LSI Computer Systems, Inc.

Datasheet

1.LS7055.pdf (6 pages)

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Part Number

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Company:

Meier Automation Equipment Co., Limited

Part Number:

LS7055

Manufacturer:

LST

Quantity:

20 000

Current page: 1 of 6
Download datasheet (85Kb)

7055-012703-1

FEATURES:

• +4.75V to +15V (Vss - V

• Preset, Presignal and Mainsignal Store

• DC to 250kHz Count Frequency

• Fully Synchronous Operation

• Thumbwheel Interface for Storage Selects

• Prescale on Count Input Selectable

• Count Inhibit

• Up/Down Control

• Scan Rate up to 150kHz

• Scan Oscillator has Override Capability

• Blanking Override for Decimal Point Operaton

• Multiplexed 7 Segment and BCD Data Output

• Output latches

• Reset

• Hysteresis on Count Input

• CMOS Type Noise Immunity on all other inputs

• LS7055, LS7056 (DIP) - See Figure 1

DESCRIPTION:

The LS7055/LS7056 is a MOS synchronous 6 decade Up/Down

counter. The circuit includes storages and comparators, zero de-

tect, automatic presetting and resetting, output latches, multi-

plexed output BCD and seven segment data. Thumbwheel

switches can be used to provide BCD data to the storage net-

works in the circuit.

COUNT (Pin 40)

Counter operates at speeds up to 250kHz and advances on the

positive edge of the input count pulse.

UP/DOWN (Pin 39)

Counter operates in up or down mode. A high input causes the

counter to operate in the up mode while a low input causes it to

operate in the down mode.

COUNT INHIBIT (Pin 1)

A high input inhibits counting and the counter remains at its last

count. A low input enables counting.

DATA TRANSFER INPUT (Pin 37)

A high input allows the seven segment display and BCD data to

follow the count (the internal latches become transparent). A low

input prevents updating of the latches as the count advances and

the seven segment display and BCD data outputs remain fixed.

RESET (Pin 4)

A high input resets and holds all counter stages at zero. A low

input allows counter operation.

Three Comparators with Output Flags

Automatic or Manual Preset/Reset Control

U L

A3800

LSI/CSI

LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747

6 DECADE PREDETERMINING UP/DOWN COUNTER

)

INHIBIT INTERNAL PRESET INPUT

INHIBIT INTERNAL RESET INPUT

INHIBIT INTERNAL RESET (Pin 5)

A high input prevents the automatic reset of the counter to zero when

in the up mode and when the counter reaches the number in the

main signal store.

PRESET (Pin 7)

A high level presets the BCD counter to the number set in the preset

store. A low input allows counter operation.

INHIBIT INTERNAL PRESET (Pin 6)

A high input prevents the automatic preset of the counter to the

number set in preset store when in the down mode and the counter

reaches zero.

SELECT STORAGE OF DATA INPUTS (Pins 15, 16)

Two inputs which allow BCD data to be stored in either the preset,

presignal or main signal store. The proper method for loading the

stores is depicted in Figure 4.

SELECT STORAGE INPUT 1

SELECT STORAGE INPUT 2

DIVIDE CONTROL INPUT 2

DIVIDE CONTROL INPUT 1

OPTIONAL CHOICE-LAMP TEST (SPECIFY LS7056)

PIN 15

DIGIT

S E L E C T

O U T P U T S

MAIN SIGNAL OUTPUT

COUNT INHIBIT INPUT

BCD

DATA

INPUTS

PRESET INPUT

RESET INPUT

PIN16

L S D + 1

L S D + 2

L S D + 3

(-V)

(+V)

LSD

(631) 271-0400 FAX (631) 271-0405

PIN ASSIGNMENT - TOP VIEW

LS7055

LS7056

L S 7 0 5 5

FIGURE 1

STORAGE

No Selection

Presignal

Main Signal

Preset

COUNT INPUT

UP/DOWN INPUT

ZERO DETECT OUTPUT

DATA TRANSFER INPUT

PRESIGNAL OUTPUT

BLANKING OVERRIDE

SCAN OSCILLATOR INPUT

MSD

L S D + 4

January 2003

SEGMENT

O U T P U T S

DIGIT

S E L E C T

O U T P U T S

BCD

DATA

O U T P U T S

Related parts for ls7055

ls7055 Summary of contents

Page 1

... CMOS Type Noise Immunity on all other inputs • LS7055, LS7056 (DIP) - See Figure 1 DESCRIPTION: The LS7055/LS7056 is a MOS synchronous 6 decade Up/Down counter. The circuit includes storages and comparators, zero de- tect, automatic presetting and resetting, output latches, multi- plexed output BCD and seven segment data. Thumbwheel switches can be used to provide BCD data to the storage net- works in the circuit ...

Page 2

... Table 2 indicates the external drive requriements. When displaying, leading zero blanking and unblanking on LSD is provided. BLANKING OVERRIDE (LS7055 only) (Pin 31) On circuits with this option, unblanking can be made to occur on any digit by connecting that digit select output to the unblanking in- put ...

Page 3

MAXIMUM RATINGS PARAMETER SYMBOL Storage Temperature Tstg Operating Temperature T A Voltage (any pin to Vss) Vmax DC ELECTRICAL CHARACTERISTICS ( 0V, Vss = +4.75 to +15V, -25° otherwise specified.) PARAMETER SYM MIN Quescent Supply ...

Page 4

COUNTER AT MAINSIGNAL VALUE AUTOMATIC MANUAL COUNTER PRESIGNAL VALUE COUNTER FIGURE 2. AUTOMATIC OR MANUAL OPERATION IN UP MODE COUNT INPUT UP/DOWN T UDH ...

Page 5

... Vss LOAD COMMAND 10k DIVIDE CONTROL INPUTS COUNT INPUT COUNT INHIBIT BCD DATA INPUTS 7055-012703-5 LED DISPLAY 6 DIGIT 7 SEGMENT OUTPUTS SELECT OUTPUT LS7055/LS7056 SELECT STORAGE INPUTS 51K V DD Vss V DD THUMBWHEEL SWITCHES FIGURE 5. SYSTEM INTERCONNECTION DIAGRAM LATCH ENABLE BUFFER MAINSIGNAL OUTPUT ...

Page 6

... LATCH MAINSIGNAL STORE MAINSIGNAL COMPARATOR PRESIGNAL STORE PRESIGNAL COMPARATOR ZERO DETECTOR COUNT 6 DECADE UP/DOWN COUNTER PRESET STORE FIGURE 7. LS7055/LS7056 BLOCK DIAGRAM FIGURE 6. Driving a small LED Display (Typically 1/8") at 12V power supply. The 2.7k resistors provide approximately 3 mA segment drive. 7 SEGMENT OUTPUTS ...

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