SerialCoder鈩?700 UR5HC703-700
Extremely Low-Power Keyboard
Encoder Interfaces RS-232
HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODER鈩?FAMILY
DESCRIPTION
The SerialCoder鈩?700
UR5HC703-700 is an extremely low-
power, 鈥渙ff-the-shelf鈥?serial keyboard
encoder. Robust, tiny and flexible,
the IC is a good match for any
application where the use of
complicated keyboard protocols are
not required and where
asynchronous serial interface
hardware is available.
The SerialCoder鈩?700 provides
Self-Power Management鈩?and
draws its power entirely from the
host device. It is ideal for use in
add-on keyboards for handheld and
cellular / web phones and other
portable applications.
Self-Power Management鈩?is
transparent to the host. Power
consumption is reduced to just the
circuit鈥檚 leakage when all keys are
released. The average current
consumption is less than 1 碌A at
room temperature and 10 碌A at
85擄C.
If a key or group of keys stays in the
depressed position for ten minutes
(with no other keyboard activity), the
IC shuts down to save power.
The SerialCoder鈩?700 is simple to
implement. It requires few external
components and utilizes a tiny, low-
profile 32-pin LQFP package that
measures 7mm x 7mm.
FEATURES
鈥?8 x 14 keyboard matrix encoding
鈥?IC is independent of the keyboard
layout
鈥?Extremely low-power operation,
transparent to the host
鈥?Typical current consumption of less
than 1 碌A at room temperature; 10
碌A at 85擄C
APPLICATIONS
鈥?Built-in keyboards for personal
digital assistant (PDA) and hand-
held PC (H/PC) devices
鈥?Add-on accessory keyboards for
PDA and H/PC devices
PIN ASSIGNMENTS
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Portable personal computers
Instrumentation
Remote control
Cellular phones
鈥?9600 Baud 8N1 serial data format
鈥?Direct connection to RS-232
signals from the host UART
鈥?Simple, proprietary serial protocol
鈥?Robust algorithm for ghost-key
elimination
鈥?Self-Power Management鈩? sleeps
between keystrokes
PRELIMINARY
ROW7
COL12
TxD
COL13
HS
COL0
COL1
COL2
32
1
25
24
COL3
COL4
COL5
COL6
VDD2
RESET
VSS2
VDD
8
9
UR5HC703-700-FG
LQFP
ROW6
ROW5
ROW4
ROW3
ROW2
ROW1
ROW0
RxD
17
16
SerialCoder, KeyCoder, and Self-Power
Management are trademarks of Semtech
Corporation. All other trademarks belong to their
respective companies.
Copyright 漏1999-2001 Semtech Corporation
DOC5-703-700-DS-105
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OCSIN
OSCOUT
VSS
COL7
COL8
COL9
COL10
COL11
www.semtech.com
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