HCMS-3903 Avago Technologies US Inc., HCMS-3903 Datasheet - Page 12

• Manufacturer Part Number: HCMS-3903
• Description: LED DISPLAY 5X7 4CHAR 3.8MM GRN
• Manufacturer: Avago Technologies US Inc.
• Series: HCMS-39xxr

Specifications of HCMS-3903

• Display Type: Alphanumeric
• Millicandela Rating: *
• Internal Connection: *
• Size / Dimension: *
• Color: Green
• Configuration: *
• Voltage - Forward (vf) Typ: *
• Package / Case: 12-DIP
• Number Of Digits/alpha: 4
• Digit/alpha Size: 0.15" (3.8mm)
• Number Of Digits: 4
• Character Size: 2.11 mm x 3.71 mm
• Illumination Color: Green
• Wavelength: 574 nm
• Operating Voltage: 3.3 V
• Operating Current: 5 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Luminous Intensity: 252 ucd
• Power Consumption: 0.766 W
• Viewing Area (w X H): 15.46 mm x 3.71 mm
• Common Pin: None
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

Control Register
The Control Register allows software modification of
the IC’s operation and consists of two independent
7-bit control words. Bit D
in the shift register selects
7
one of the two 7-bit control words. Control Word 0
performs pulse width modulation brightness control,
peak pixel current brightness control, and sleep mode.
Control Word 1 sets serial/simultaneous data out
mode, and external oscillator prescaler. Each function is
independent of the others.
Control Register Data Loading
Data is loaded into the Control Register, MSB first,
according to the procedure shown in Table 1 and Figure
5. First, RS is brought to logic high and then CE is brought
to logic low. Next, each successive rising CLK edge will
shift in the data on the D
pin. Finally, when 8 bits
IN
have been loaded, the CE line is brought to logic high.
When CLK goes to logic low, new data is copied into the
selected control word. Loading data into the Control
Register takes place while the previous control word
configures the display.
Control Word 0
Loading the Control Register with D
= Logic low selects
7
Control Word 0 (see Table 2). Bits D
-D
adjust the
0
3
display brightness by pulse width modulating the LED
on time, while Bits D
-D
adjusts the display brightness
4
5
by changing the peak pixel current. Bit D
selects normal
6
operation or sleep mode.
Sleep mode (Control Word 0, bit D
= Low) turns off the
6
Internal Display Oscillator and the LED pixel drivers. This
mode is used when the IC needs to be powered up, but
does not need to be active. Current draw in sleep mode
is nearly zero. Data in the Dot Register and Control Words
are retained during sleep mode.
Control Word 1
Loading the Control Register with D
= logic high
7
selects Control Word 1. This Control Word performs
two functions: serial/simultaneous data out mode and
external oscillator prescale select (see Table 2).
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