 2000 Infineon Technologies Corp. • Optoelectronics Division • San Jose, CA

SLR/SLO/SLG/SLY2016

www.infineon.com/opto • 1-888-Infineon (1-888-463-4636)

OSRAM Opto Semiconductors GmbH & Co. OHG • Regensburg, Germany

www.osram-os.com • +49-941-202-7178

3

March 23, 2000-01

AC Characteristics (guaranteed minimum timing

Note:

Loading Data

The desired data code (D0–D6) and digit address (A0, A1) must

be held stable during the write cycle for storing new data.

Data entry may be asynchronous. Digit 0 is defined as right

hand digit with A1=A2=0.`

Clearing the entire internal four-digit memory can be accom-

plished by holding the clear (CLR) low for 1.0 msec minimum.

The clear function will clear the ASCII RAM. Loading an illegal

data code will display a blank.

Typical Loading State Table

Display Blanking

Blank the display by loading a blank or space into each digit of

the display or by using the (BL) display blank input. Setting the

(BL) input low does not affect the contents of data memory.

A flashing circuit can easily be constructed using a 555 as table

multivibrator. Figure 3 illustrates a circuit in which varying R1

(100K~10K) will have a flash rate of 1.0 Hz~10 Hz.

The display can be dimmed by pulse width modulating the (BL)

at a frequency sufficiently fast to not interfere with the internal

clock. The dimming signal frequency should be 2.5 kHz or

higher. Dimming the display also reduces power consumption.

Parameter

Symbol

–40

°C

+25

°C +85°C Unit

Address Set

Up Time

10

10

10

ns

Write Time

60

70

90

ns

Data Set Up

Time

20

30

50

ns

Address Hold

Time

20

30

40

ns

Data Hold Time

20

30

40

ns

Access Time

90

110

140

ns

Clear Disable

Time

1.0

1.0

1.0

µs

Clear Time

1.0

1.0

1.0

ms

WR

A1 A0 D6 D5 D4 D3 D2 D1 D0 Digit

3210

H

previously loaded display

G

R

E

Y

L

LLH

LLLH

LH

G

R

E

E

L

L

HHL

HL

HL

HG

R

U

E

L

H

LH

LLH

H

LLG

L

U

E

L

HHHL

LLLH

LB

L

U

E

L

L

H

H

L

LLH

LH

B

L

E

E

L

L

L

H

L

H

L

HHHB

L

E

W

L

X

X

see character code

see char. set

An example of a simple dimming circuit using a 556 is illus-

trated in Figure 4. Adjusting potentiometer R3 will dim the dis-

play by changing the blanking pulse duty cycle.

Figure 3. Flashing Circuit Using a 555 and Flashing

(Blanking) Timing

Figure 4. Dimming Circuit Using a 556 and Dimming

(Blanking) Timing

Blanking Pulse Width

≈50% Duty Factor

500 ms

2 Hz Blanking Frequency

1

0

~

~

~

~

555

Timer

R1

4.7 K

Ω

R2

100 K

Ω

C4

0.01

µF

C3

10

µF

VCC=5.0 V

To BL

Pin on

Display

1

2

3

4

8

7

6

5

C3

1000 pF

1

2

3

4

5

6

7

14

13

12

11

10

9

8

556

Dual Timer

R2

47 K

Ω

R1

200

Ω

C1

4700 pF

C4

0.01

µF

R3

500 K

Ω

VCC=5.0 V

Dimming (Blanking)

Control

C2

0.01

µF

To BL Pin

on Display

1

0

200

µs

Blanking Pulse Width

4

µs min., 196 µs max.

5 KHz Blanking Frequency

~

~

~

~