Datasheet UR5HC703-600-FG Datasheet (Semtech)

1

9

16

8

25

32

24 17

UR5HC703-600-FG

LQFP

C2

C1

C0

C14

C13

TxD

C12

R7

OSCIN

_OSCOUT

VSS

C7

C8

C9

C10

C11

C3

C4C5C6

VDD2

_RESET

VSS2

VDD

C15

R0

R1

R2

R3

R4

R5

R6

USAR SerialCoderTMUR5HC703-600-FG

USAR SerialCoder

TM

Low-Power Keyboard Encoder
interfaces RS-232

Preliminary

USAR KeyCoderTMfamily
product specifications

Description Features

• 8 x 16 Matrix Encoding

• 9600 Baud 8N1Serial Data Format

• IC is independent of the
keyboard layout

• Zero-PowerTMoperation,
transparent to the Host

• Average current consumption of
less than 1µA at room
temperature; 10µA at 85°C

• Customized versions available

• TTL/CMOS Output-only
Asynchronous Serial Interface
to the Host (direct connection to
the UART)

• Very simple serial protocol —
Two-Byte Identification String on
power-up; single-Byte Matrix­position for each key-press or
key-release

• Robust algorithm for Ghost-key
elimination

Applications

• Built-in keyboards for HH
PDAs/Organizers

• Add-on accessory keyboards for
Palm and H/PC Devices

• Portable Personal Computers

• Instrumentation

• Remote Control

• Cellular Phones

DOC5-703-600-DS-102

1

Pin Assignments

The USAR SerialCoder

TM

UR5HC703 is an extremely
low-power, “off-the-shelf” 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 USAR SerialCoderTMprovides
unprecedented power
consumption minimization, making
it ideal for use in add-on keyboards
for handheld and cellular / web
phones and single-board systems
designed for portable applications.

The IC provides Zero-Power

TM

operation, transparent to the host.
Power consumption is reduced to
just the circuit’s leakage when all
keys are released. The average
current consumption is less than
1µA at room temperature and 10µA
at 85°C. If a single key or groups
of keys are stuck in the depressed
position, the IC will enter a total
shutdown after a 10-minute wait —
to protect against unintended and
unnecessary discharge of the
batteries in the Host.

Custom versions of the USAR
SerialCoderTMare available with
Hardware Handshaking for the
Communication channel, support
for extra-low-power operations of
the Host, various baud rates and
Full-Duplex I/O, etc. The USAR
SerialCoderTMis simple to
implement. It requires few external
components and utilizes a tiny, low­profile 32-pin LQFP package that
measures 7mm x 7mm.

Copyright 2000 USAR Systems, Inc. All rights
reserved.

USAR – A Semtech Company
Datasheet

A Semtech Company

USAR – A Semtech Company
Datasheet

USAR SerialCoderTMUR5HC703-600-FQ

Preliminary

USAR KeyCoderTMfamily
product specifications

Descri

DOC5-703-600-DS-102

2

USAR — A Semtech Company

Ordering Code

Functional Diagram

TxD

4

Data

Buffer

Key

Matrix

Interface

Communication

Interface

Matrix

Scan Logic

Reset Logic

Oscillator

Power Supply

_RESET

OSCIN

_OSCOUT

8

16

R0-R7

C0-C15

®

USAR SerialCoder

TM

Package Options Pitch in mm’s Ta=-20° C to +85° C

32-pin, Plastic LQFP 0.8 UR5HC703-600-FG

Other Materials Type Order number

USAR SerialCoderTMEval Kit Evaluation Kit EVK5-703-600-XXX

USAR – A Semtech Company
Datasheet

USAR SerialCoderTMUR5HC703-600-FQ

Preliminary

USAR KeyCoderTMfamily
product specifications

DOC5-703-600-DS-102

3

USAR — A Semtech Company

Pin Definitions

Pin Numbers
Mnemonic LQFP Type Name and Function
Power Supply

Vdd, Vdd2 8,5 PWR Positive Supply Voltage
Vss, Vss2 11,7 PWR Negative Power Supply:

Signal Ground

Reset

_RESET 6 I Hardware reset pin: Reset Input

for orderly start-up. Low logic level is
required until power supply reaches
minimum operating voltage

Oscillator pins

OSCI 9 I Oscillator input: Connect ceramic

resonator with built-in load capacitors
or CMOS clock from external oscillator

2 MHz operating frequency
_OSCO 10 O Oscillator Output: Connect
ceramic resonator with built-in load capacitors

or keep open if external oscillator

is used

Host Interface

TxD 27 0 Serial Data Output: Idle at high

voltage (logical 1), non-inverted Data

(direct connection to the UART)

Scanned
matrix pins

ROW0-ROW7 18-25 I, pup Row matrix inputs: With pulsed

pull-up current sources

COL0-COL15 1-4, O, nD Column matrix output

12-17
26,28-32

Descri

USAR SerialCoderTMUR5HC703-600-FQ

Preliminary

USAR KeyCoderTMfamily
product specifications

Descri

Protocol

Serial transmissions are at the rate of 9600 Baud, 8 data bits, no parity,
least significant bit is transmitted first, Idle/Stop level is High (logical 1),
Start bit level is Low (logical 0), non-inverted Data.

Within 5ms after the power-up the IC sends a two-Byte Identifications String
of 0xF9, 0xFB. These two Bytes are transmitted only once after each reset
of the IC.

These two ID values also represent key release action in the locations
[Row=1, Column=15] and [Row=3, Column=15] on the key Matrix. Since
the values of these Bytes represent release action of the keys, extraneous
characters will never be generated, even if synchronization between the
Driver and IC is lost, or power fluctuations/erroneous resets are applied to
the chip. If logistics of the Driver do not permit "shared" use of the
Identification Values 0xF9 and 0xFB, then the user is advised not to
incorporate keys in the locations [Row=1, Column=15] and
[Row=3, Column=15] for the key Matrix design.

Subsequent single-Byte transmissions indicate the Row (0-7), Column
(0-15), and Press/Release action for each change of the state of every key.
If after the current key release all of the keys on the key Matrix are in the
released state, the last transmission is repeated. Host's Driver looking for
two Bytes with exactly the same value and key release indication (b7=1)
can recognize that the keyboard is completely idle.

Byte Transmission
Bit Number Comment

b7 0 for key press, 1 for key release
b6 Column location in the key Matrix (0-15)
b5
b4
b3
b2 Row location in the key Matrix (0-7)
b1
b0

DOC5-703-600-DS-102

4

USAR — A Semtech Company

USAR – A Semtech Company
Datasheet

USAR – A Semtech Company
Datasheet

USAR SerialCoderTMUR5HC703-600-FQ

Preliminary

USAR KeyCoderTMfamily
product specifications

Sample Schematic for the USAR UR5HC703-600-FG

DOC5-703-600-DS-102

5

USAR — A Semtech Company

GROUND

POWER

CMOS_TTL_TxD

9600 Baud

IDLE=HIGH

TxD

0.7

REV

GND

App Circuit for UR5HC703-600-FG

(C)1999-2000, USAR Systems - A Semtech Company

Y1

2.00MHz

GND

C2

2.2uF

10V

GND

9

10

15

16

C10

1

1

1

2

2

2

2

2

C11

7

C15

8

R

0

9

R

1

0

R

2

1

R

2

R

3

R

4

R

U1

3

4

5

6

R7

C12

TXD

25

26

27

11C712C813C914

VSS

OSCOUT

32-pin LQFP

UR5HC703_600_FG

C13

C14

28

29C0 30C1 31C2 32

VDD

OSCIN

VSS

RESET

VDD

C1

.1uF

8

7

2

6

5

2

4

C

6

3

C

5

2

C

4

1

C

3

GND

GND

U2

1

OUT

2

VDD

3

GND

2.2V or Higher

Voltage Detector

GND

To Keyboard Matrix

USAR – A Semtech Company
Datasheet

USAR SerialCoderTMUR5HC703-600-FQ

Preliminary

USAR KeyCoderTMfamily
product specifications

USAR SerialCoder™ Electrical Characteristics

Absolute Maximum Ratings
Ratings Symbol Value Unit

(VSS = 0V, Ambient Temperature T

A is in the range TLOW

to THIGH)

Supply Voltage VDD

-0.3 to +7.0 V
Input voltage:
All input pins VIN -0.3 to V

DD +0.3 V

Output current:
Total peak for all pins ΣI

OH (Peak) -80

ΣIOL

(Peak) 80 mA

Total average for all pins ΣI

OH (Avg) -40

ΣIOL (Avg) 40 mA

Peak for each pin IOH (Peak) -10

IOL (Peak) 10 mA

Average for each pin I

OH

(Avg) -5

IOL (Avg) 5 mA

Temperature range

Operating Temperature T

LOW to THIGH -20 TO 85 °C

Storage Temperature TSTG -40 TO 125 °C

DC Electrical Characteristics, Temperature range=T low to T high unless otherwise noted)
Characteristic Symbol Min Typ Max Unit

Operating Voltage V

DD 2.2 5.5 V

Input Voltage

High VIH .8 VDD VDD V
L

OW VIL

0 .3 VDD

V

V

IL (_RESET) 0 .2 VDD V

VIL (OSCIN) 0 .16 VDD V

Input Current High

l

IH 5.0 µA

lIH (OSCIN) 4.0 µA

Input Current Low

I

IL -5.0 µA

IIL (OSCIN) -4.0 µA

Output Voltage

V

OH

IOH=-1.0mA VDD-1.0 VDD V
VOL
IOL

=1.0mA 1.0 V

Power Consumption

I

DD 600 µA

ONE OR MORE KEYS ARE

DEPRESSED
IDD
ALL KEYS ARE RELEASED
TA=25°C .1 1.0 µA
TA=85°C 10.0 µA

Control Timing (Vdd=2.2 to 5.5 V, Vss=0 Vdc, Temperature range=T low to T high unless otherwise noted)
Characteristic Symbol Value Unit
Frequency of Operations fosc

Ceramic Resonator with built-in load 2.0 MHz
capacitors
External Oscillator 2.0 MHz

Note: Communications Baud Rate and Active-state power consumption are scaled linearly with operating frequency. Higher operating
frequencies are possible within a reduced operating voltage range. Consult USAR for further information.

DOC5-703-600-DS-102

6

USAR — A Semtech Company

USAR – A Semtech Company
Datasheet

USAR SerialCoderTMUR5HC703-600-FQ

Preliminary

USAR KeyCoderTMfamily
product specifications

Mechanicals for the UR5HC703-600 LQFP Package

DOC5-703-600-DS-102

7

USAR — A Semtech Company

e

b

y

F

1

HD

D

32 25

24

E

E

H

16

0.1

0.8

1.0

0.5

7.4

–

1.4

–
–

7.4

17

1.7

0.2

0.450.350.3

0.1750.1250.105

7.17.06.9

7.17.06.9

–

9.29.08.8

9.29.08.8

0.70.50.3

0.1

10ϒ0ϒ

––
––
––
––

8

L1

c

A1 A2

L

9

Symbol

A

A1

2

A

Dimension in Millimeters

Min Nom Max

–

0

––

b

Detail F

A

M

D

e

ME

b2

I2

c
D
E
e

D

H

E

H

–

L

1

L

y

b

2

I

2

M

D

M

E

––
–

1.0

Recommended PCB Footprint

A Semtech Company

For sales information
and product literature,
contact:

USAR – A Semtech Company
568 Broadway
New York, NY 10012

[e-mail]
http://www.usar.com

212 226 2042 Telephone
212 226 3215 Telefax

In Japan:
Semtech Japan
Tel: [phone]
Fax: [phone]

In Taiwan:
Semtech Asia/Pacific Sales
Tel: [phone]
Fax: [phone]

Koryo Electronics Co., Ltd.
Telephone [phone]
E-mail [e-mail]

In Korea:
Semtech Korea
Tel: [phone]
Fax: [phone]

In Europe
Semtech Limited
Tel: [phone]
Fax: [phone]

Copyright 2000 USAR – A Semtech Company. All rights
reserved. KeyCoder, SerialCoder and Zero-Power are
trademarks of USAR Systems, Inc. USAR and the USAR
logo are registered trademarks of USAR – A Semtech
Company. All other trademarks belong to their respective
companies.

INTELLECTUAL PROPERTY DISCLAIMER
This specification is provided "as is" with no warranties
whatsoever including any warranty of merchantability,
fitness for any particular purpose, or any warranty
otherwise arising out of any proposal, specification or
sample.

A license is hereby granted to reproduce and distribute
this specification for internal use only. No other license,
expressed or implied to any other intellectual property
rights is granted or intended hereby. Authors of this
specification disclaim any liability, including liability for
infringement of proprietary rights, relating to the
implementation of information in this specification. Authors
of this specification also do not warrant or represent that
such implementation(s) will not infringe such rights.