EDE1144 Datasheet, PDF (1/7 Pages) List of Unclassifed Manufacturers – Keypad Encoder IC

EDE1144 Keypad Encoder IC
4 x 4 Matrix Keypad Encoder IC
EDE1144
RS-232 Output 1
0=2400, 1=9600 Baud 2
Connect to +5V 3
Connect to +5V 4
Digital Ground 5
Row 0 Output 6
Row 1 Output 7
Row 2 Output 8
Row 3 Output 9
XMIT
Baud
+5V
+5V
GND
R0
R1
R2
R3
Beep
Valid
OSC1
OSC2
+5V
C3
C2
C1
C0
18 Beeper Output
17 Data Valid Output
16 Oscillator Conection
15 Oscillator Connection
14 Connect to +5V
13 Column 3 Input
12 Column 2 Input
11 Column 1 Input
10 Column 0 Input
Functionality & Feature Set:
• Automatic key repeat after delay
• Contact debouncing
• Keybeep provides tactile feedback to operator
• Electrically quiet (reduced EMI) keypad scanning
• Serial / Parallel outputs available
• Data Valid output signal for interrupt activation
• 2400/ 9600 serial Baud rates
• Available in 18 pin DIP or SOIC packages
• Interfaces to any microcontroller or microprocessor
• Cost effective for OEM applications
The EDE1144 Keypad Encoder IC is designed to interface a matrix-type 4 row x 4 column (16 key
or less) keypad to a microcontroller or other host processor. A one-wire serial or four-wire
parallel interface returns the keypress data and can be used in conjunction with a 'data valid'
signal for polled or interrupt-driven applications. The EDE1144 provides enhanced keypad
features such as contact debouncing and key auto-repeat in an easy-to-use package that will lower
software overhead in the host microcontroller and reduce the I/O pin requirements from eight to
one, frequently resulting in the use of a less costly host microcontroller in your design.
In addition, the EDE1144 is electrically quiet. Many keypad encoders continually scan the
keypad, radiating EMI noise from the wires leading to the keypad (resulting in trouble during
emissions testing & final product certification & approval). The EDE1144 reduces this problem by
monitoring the keypad with unchanging signals, and then scanning only once each time a
keypress is detected.
Copyright © 1999 E-Lab Digital Engineering, Inc. All Rights Reserved.
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