Digital Displays

Prepared by Charles S. Tritt, Ph.D.

Pins are numbered from left to right as you look at the front of the displays.

Hexadecimal Display Boards (Blue)

Pin	Name	Function
1	Vcc	+ 5 V
2	A1	Address (really data) input (2's).
3	A2	Address (really data) input (4's).
4	EL	Latch enable (active low). Generally tie low. This input must be low for the displayed value to change.
5	RBO	Ripple blanking output. Leave open.
6	RBI	Ripple blanking input. Generaly tie high. A low on this input will prevent the display of zero values (all other values will be displayed normally).
7	A3	Address (really data) input (Most significant bit, 8's).
8	A0	Address (really data) input (Least significant bit, 1's).
9	Gnd	Ground
10	DP	Decimal point (active low). Generally tie high (or leave open).

BCD Display Boards (Tan)

Pin	Name	Function
1	Vcc	+ 5 V
2	A1	Address (really data) input (2's).
3	A2	Address (really data) input (4's).
4	LTI	Lamp test input. Generally tie high. A momentary low on this line will light all the segments of the display until the power is cycled.
5	RBO	Ripple blanking output. Leave open.
6	RBI	Ripple blanking input. Generally tie high. A low on this input will prevent the display of zero values (all other values will be displayed normally).
7	A3	Address (really data) input (Most significant bit, 8's).
8	A0	Address (really data) input (Least significant bit, 1's).
9	Gnd	Ground
10	DP	Decimal point (active low). Generally tie high (or leave open).