5–4

DLR/DLO/DLG2416

Loading Data

Setting the chip enable (CE1, CE2) to their true state will enable

data loading. 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 and random. Digit 0 is

defined as right hand digit with A1=A2=0.`

To clear the entire internal four-digit memory hold the clear

(CLR) low for 1

µs. All illuminated dots will be turned off within

one complete display multiplex cycle, 1 msec minimum. The

clear function will clear both the ASCII RAM and the cursor

RAM.

Setting the chip enables (CE1, CE2) and cursor select (CU) to

their true state will enable cursor loading. A write (WR) pulse

will now store or remove a cursor into the digit location

addressed by A0, A1, as defined in data entry. A cursor will be

stored if D0=1 and will removed if D0=0. The cursor (CU) pulse

width should not be less than the write (WR) pulse or erroneous

data may appear in the display.

If the cursor is not required, the cursor enable signal (CUE)

may be tied low to disable the cursor function. For a flashing

cursor, simply pulse CUE. If the cursor has been loaded to any

or all positions in the display, then CUE will control whether the

cursor(s) or the characters will appear. CUE does not affect the

contents of cursor memory.

Loading Cursor

Setting the chip enables (CE1, CE2) and cursor select (CU) to

their true state will enable cursor loading. A write (WR) pulse

will now store or remove a cursor into the digit location

addressed by A0, A1, as defined in data entry. A cursor will be

stored if D0=1 and will removed if D0=0. The cursor (CU) pulse

width should not be less than the write (WR) pulse or erroneous

data may appear in the display.

If the cursor is not required, the cursor enable signal (CUE)

may be tied low to disable the cursor function. For a flashing

cursor, simply pulse CUE. If the cursor has been loaded to any

or all positions in the display, then CUE will control whether the

cursor(s) or the characters will appear. CUE does not affect the

contents of cursor memory.

Display Blanking

Blanking the display may be accomplished by loading a blank

or space into each digit of the display or by using the (BL) dis-

play blank input.

Setting the (BL) input low does not affect the contents of either

data or cursor memory.

A flashing circuit can easily be constructed using a 555 astable

multivibrator. Figure 3 illustrates a circuit in which varying R2

(100K~10K) will have a flash rate of 1 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 con-

sumption.

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. DLX2416—Flashing circuit using a 555

and Flashing (Blanking) timing

Figure 4. DLX2416Dimming circuit using a 556

and Dimming (Blanking) timing

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

Blanking Pulse Width

≈50% Duty Factor

500 ms

2 Hz Blanking Frequency

1

0

~

~

~

~

1

0

200

µs

Blanking Pulse Width

4

µs min., 196 µs max.

5 KHz Blanking Frequency

~

~

~

~

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