6

Electrical Description

Pin Function

Description

RESET (RST)

Sets Control Register bits to logic low. The Dot Register contents are

unaffected by the Reset pin. (logic low = reset; logic high = normal

operation).

DATA IN (D

Serial Data input for Dot or Control Register data. Data is entered on the

rising edge of the Clock input.

DATA OUT (D

Serial Data output for Dot or Control Register data. This pin is used for

cascading multiple displays.

CLOCK (CLK)

Clock input for writing Dot or Control Register data. When Chip Enable is

logic low, data is entered on the rising Clock edge.

REGISTER SELECT (RS)

Selects Dot Register (RS = logic low) or Control Register (RS = logic high)

as the destination for serial data entry. The logic level of RS is latched on

the falling edge of the Chip Enable input.

CHIP ENABLE (CE)

This input must be a logic low to write data to the display. When CE

returns to logic high and CLK is logic low, data is latched to either the LED

output drivers or a Control Register.

OSCILLATOR SELECT

Selects either an internal or external display oscillator source.

(SEL)

(logic low = External Display Oscillator; logic high = Internal Display

Oscillator).

OSCILLATOR (OSC)

Output for the Internal Display Oscillator (SEL = logic high) or input for an

External Display Oscillator (SEL = logic low).

BLANK (BL)

Blanks the display when logic high. May be modulated for brightness control.

GND

LED

Ground for LED drivers.

GND

LOGIC

Ground for logic.

V

LED

Positive supply for LED drivers.

V

LOGIC

Positive supply for logic.

Optical Characteristics at 25

Peak

Dominant

Wavelength

Wavelength

Character Average (

µcd)

Display Color

Part Number

Min.

Typ.

Typ.

Typ.

AlGaAs Red

HCMS-29X5

95

230

645

637

High Efficiency Red

HCMS-29X2

29

64

635

626

Orange

HCMS-29X4

29

64

600

602

Yellow

HCMS-29X1

29

64

583

585

Green

HCMS-29X3

57

114

568

574

Notes:

1. Refers to the initial case temperature of the device immediately prior to measurement.

2. Measured with all LEDs illuminated.