Datasheet K25C81-P, K25C81-FN, K25C81-FB Datasheet (Semtech Corporation)

FlexiCoderTMK25C81

Versatile PC/XC/AT/PS/2 Compatible

Keyboard Encoder

FlexiCoderTMis a trademark of Semtech Corp. All
other trademarks belong to their respective
companies.

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

1

HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODERTMFAMILY

DESCRIPTION FEATURES

1

_RESET

40 Vcc

OSCI
OSCO
EKC1
R7
NC
R5
R4
R3
R2
R1
R0
C8
C9
C10
C11
C12
C13
C14
C15

_IRQ

VX

C17

R6

RP
KD
KC

EKC
EKD
C16

C0
C1
C2
C3
C4
C5
C6
C7

Vss

2

39

3

38

4

37

5

36

6

35

7

34

8

33

9

32
10 31
11 30
12 29
13 28
14 27
15 26
16 25
17 24
18 23
19 22
20 21

DIP

R6

C17VXNC

_IRQ

_RESET

VCC

OSCI

OSC0

EKC1

NC

RP
KD

KC
EKC
EKD

C16

C0

C1

C2

C3

C4

R7
NC
R5
R4
R3
R2
R1
R0
C8
C9
C10

NC

C5C6C7

VSS

NC

C15

C14

C13

C12

C11

40

1

6

7

12

17

18

23

28

29

34

39

R6

RP
KD
KC

EKC
EKD

C16

C0
C1
C2
C3

C17VX_IRQ

_RESETNCNC

VCC

OSCI

OSCO

EKC1

R7

NC
R5
R4
R3
R2
R1
R0
C8
C9
C10
C11

C4C5C6

C7

NC

VSS

C15

C14

C13

C12

NC

1

PLCC

QFP

• Custom keyboards/keypads

• Control panels

• Automatic teller machines

• Embedded control systems

• Public Information Kiosks

• Instrumentation

• Test and Measurement equipment

• Point of Sales terminals

• Industrial Controllers

• Medical Instruments

• Enables custom keypad scan
codes to remain unaffected by
the Shift States of an external
keyboard

• Includes jumper-selectable auto­repeat for designated keys

• Offers two-key inhibit scanning
mode

• Directly interfaces a PC
keyboard port

• Encodes up to 144 custom keys
on an 8 X 18 matrix

• Buffers up to 122 keycodes

• Interfaces to 83/101/102
standard keyboard or other
8042-compatible device

The FlexiCoderTMis a versatile, low­power keyboard encoder. It offers
two bi-directional channels for
communicating with a
PC/XT/AT/PS2 system, and/or any
optional keyboard-compatible
devices, such as an 83 or 101/102
standard desktop keyboard, OCR,
barcode reader, etc. The K25C81
directly interfaces a PC keyboard
port, making custom keyboard to
system communications fully
transparent.

On an 8 x 18 matrix, the
FlexiCoder

TM

will scan, debounce
and encode up to 144 keys. Scan
codes corresponding to single keys
of the IBM 101 keyboard, or a
combination of these keys when
depressed with Shift, Ctrl, and Alt
keys, are generated with each key
press. Custom keypad input is not
effected by the Shift States of an
external keyboard.

Users can conveniently define key
assignments on the matrix as single
or repeating actions. All keys must
be released between key strokes or
scanning is suspended. The
encoder can buffer up to 122
keycodes, and control inputs and
outputs are provided for interfacing
with contact keyboards.

The FlexiCoderTMis ideal for use
with either BIOS-compatible chip
sets or single-board computers for
PC systems requiring a custom
keyboard / keypad as an alternate
or additional input device. Boards
and evaluation kits are immediately
obtainable and ready to connect.

APPLICATIONS

PIN ASSIGNMENTS

FUNCTIONAL DIAGRAM

ORDERING CODE

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

2

Package options

40-pin, Plastic DIP
44-pin, Plastic PLCC
44-pin, Plastic QFP

Pitch In mm’s

2.54 mm

1.27 mm

0.8 mm

TA = -40°C to +85°C

K25C81-XX-P
K25C81-XX-FN
K25C81-XX-FB

Data Buffer

Interrupt Control

PC

Communication

Channel

8042 Emulation

(Standard Keyboard)

Communication Channel

EKC1

KC
KD

EKC
EKD

Keyboard Encoder

Mode Control

Row Data Inputs

Column Select Ouputs

R0-R7

RP

C0-C17

8

18

FUNCTIONAL DESCRIPTION PIN DEFINITIONS

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

3

Mnemonic DIP PLCC QFP TYPE Name and Function

Vcc 40 44 38 I Power Supply: +5V
Vss 20 22 17 I Ground
OSCI 39 43 37 I Oscilator Input
OSCO 38 42 36 O Oscilator Output
_RESET 1 1 41 I Reset: apply 0 V to provide orderly

start-up.
_IRQ 2 2 42 I Must be tied to Vcc
VX 3 4 43 I Tie to Vcc.
RP 672I Rollover Mode Selection: tie to

Vcc to select N-Key Rollover. Tie to

Ground to select Two-Key Inhibit

Mode.
KC 894I/OKeyboard Clock: connects to PC’s

keyboard port Clock Line.
KD 783I/OKeyboard Data: connects to PC’s

keyboard port Data Line.
EKD 10 11 6 I/O External Keyboard Data:

connects to external keyboard Data

Line.
EKC 9 10 5 I/O External Keyboard Clock:

connects to external keyboard Clock

Line.
EKC1 37 41 35 I External Keyboard Clock 2:

connects to external keyboard Clock

Line and is used to generate an

interrupt for every Clock Line transition.

This signal must be inverted for PC/XT

keyboards.
C0-C7 12-19 3-17 8-15 O Column Select Outputs: select

18 one of columns.

19-21
C8-C15 28-21 31-24 26-18
C16 11 12 7 O
C17 4 5 44 I/O Keyboard type selection: this pin

is used both as outputs for column
select and as input for standard

keyboard-type selection.
R0-R5 29-34 32-37 27-32 I Row data inputs
R6 561I
R7 36 39 34 I
NC 35 38, 3 16, 33 - No Connects: these pins are

18, 23 22, 39 - unused.
40 40

Note: An underscore before a pin mnemonic denotes an active low signal.

The FlexiCoderTMconsists of six
major sections (see functional
diagram, previous page). These
are the Keyboard Encoder, the
Mode Control Unit, the PC
Communication Channel, the 8042
Emulation Channel, the Interrupt
Control Unit and the Data Buffer.
These sections communicate with
each other and operate
concurrently.

The controller continuously scans a
keyboard organized as an 8 row by
18 column matrix, for a maximum of
144 keys. Smaller-size keyboards
can be connected provided that all
unused row pins are connected to
Vcc. The microcontroller selects
one of the 18 column lines (C0-C17)
every 512 µS and then reads the
row data lines (R0-R7).

A key closure is detected as a zero
in the corresponding position of the
matrix. A complete scan cycle for
the entire keyboard takes approxi­mately 9.2 mS. Each key press is
debounced for a period of 20 mS.
Once the key is verified, the
corresponding key code(s) are
loaded into the transmit buffer of
the PC Keyboard Communication
Channel.

REPEAT KEYS FUNCTIONAL DESCRIPTION, (CON’T)

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

4

In custom masks, each key can be
defined individually to be either
Typematic or Single-Touch Action.
In the standard mask, all keys are
defined to be Single-Touch Action,
except the Arrow Keys. Pin RP
controls the repeat action of keys
that are defined to be Typematic.

Table 1: Typematic Action Control

The Typematic rate can be
controlled by issuing the
appropriate commands from the
system.

Repeat Mode RP

No repeat action L
Repeat action H

Switch Matrix Encoding

Each matrix location is programmed to represent either a single key or a
combination of keys of the IBM-standard 101/102 keyboard.

Scan Code Table Sets

The FlexiCoderTMsupports two scan code table sets. Scan Code Sets 1 and
2 are the default sets for PC/XT and AT/PS/2 systems respectively. For
more information, refer to the IBM Technical Reference Manual. Custom
scan code tables, including macros, are also available. Operating modes
are defined by the logic level of the relevant mode pins in the Mode Control
Unit.

Scan Matrix Data Integrity

The FlexiCoderTMmaintains the integrity of the codes corresponding to the
scanned matrix locations, independently of the Shift Status of the external
keyboard or the system. For example, if a key has been defined on the
matrix to send code corresponding to lower case letter “a”, it will still send
the scan code for “a” even if the Shift Key has been pressed or the Caps
Lock has been set by the external keyboard. This is accomplished by
internally maintaining a set of flags to monitor the Shift Status of the external
keyboard and the system. If, for instance, the lower case key “a” is found to
be pressed and Caps Lock is set, the codes sent will be as follows:

1. Caps Lock Make Code

2. Caps Lock Break (this will reset the Caps Lock status of the system)

3. “a” Make Code

4. “a” Break Code

5. Lock Make Code

6. Caps Lock Break Code (this will restore the Caps Lock status of the
system)

SPECIAL HANDLING

SPECIAL HANDLING, (CON’T)

External Keyboard Connection

If an external keyboard was not
connected during power-on and
then connected at a later time, the
controller will proceed with the
normal reset routine in order to
initialize the external keyboard
properly. Thereafter, the
FlexiCoderTMchecks for the
presence of an external keyboard
every 2 seconds. After
communication has been
established, the controller continues
checking for the external
keyboard’s presence. Should the
external keyboard be removed at a
later time, the K25C81 detects the
disconnection and will reinitiate the
reset sequence upon reconnection.
This feature allows the user to
connect and disconnect an external
keyboard at any time without
resetting the system.

EXT. KBD COMMUNICATION MODE CONTROL

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

5

The external keyboard
communication port of the
FlexiCoderTMfully emulates a
standard 8042, available to an
83/101/102 external keyboard or
other compatible device.
Communication with an external
keyboard is accomplished via EKC
and EKD, Clock and Data lines
respectively. A third pin, EKC1
which connects to the Clock Line,
interrupts the controller whenever
an external keyboard initiates a
communication.

When power is first applied, the
controller proceeds with the
standard reset sequence with the
external keyboard. Data and
commands coming from the
external keyboard are buffered in
the controller’s FIFO, along with
data from the scanned matrix, and
then presented to the system as if
originating from a single source.
Commands and data from the
system, after being acknowledged,
are then transmitted to the external
keyboard.

The FlexiCoderTMimplements all the
standard functions of
communication with a BIOS­compatible PC/XT or AT/PS/2 host
system. Two lines, KC and KD,
provide bi-directional clock and
data signals according to the
protocol (PC or AT) selected. In
addition, the K25C81 supports
commands from and to the system,
as described in the IBM Technical
Reference Manuals. The following
table shows the commands that the
system may send and their value in
hex.

Command Hex Value
Set/Reset Status ED

Indicators
Echo EE
Invalid Command EF
Select Alternate F0

Scan Codes
Invalid Command F1
Read ID F2
Set Typematic F3

Rate/Delay
Enable F4
Default Disable F5
Set Default F6

Set All Keys

Typematic F7
Make/Break F8
Make F9
Typematic/Make/Break FA

Set Key Type

Typematic FB
Make/Break FC

Make FD
Resend FE
Reset FF

Table 2: Keyboard Commands from the

System (AT/PS/2 protocol)

These commands are supported in
the AT/PS/2 protocol and can be
sent to the keyboard at any time.
Mode 1 accepts only the ‘reset’
command. Commands shown in
italics do not affect the operation of
the K25C81. Nevertheless, they
are acknowledged and relayed to
the external keyboard, if an
external standard keyboard is
present.

The following table shows the
commands that the keyboard may
send to the system.

Command Hex Value
Key Detection 00*

Error/Overrun
Keyboard ID 83AB
BAT Completion Code AA
BAT Failure Code FC
Echo EE
Acknowledge (Ack) FA
Resend FE
Key Detection

Error/Overrun FF*

*Scan Code Set 2
Table 3: Keyboard Commands to the

System (AT/PS/2 protocol)

When an external keyboard is
connected, commands from the
system will also be directed to the
external keyboard. Presence or
absence of an external keyboard
will not affect the normal operation
of the FlexiCoderTM.

SUGGESTED INTERFACING FOR K25C81-FN (44-PIN PLCC PACKAGE)

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

6

Rows (R0-R7)

01234567
F29 F28 End F36 F34 F35 F33 F37
Pg Dn Home PgUp : F27 F30 F31 F32
]()*^F22F21F25
vwxyz; [F20
opqr st uF23
hijklmnF18
abcdef gi
. , (comma) - (dash) / % & # 0
STUVWXYZ
JKLMNOPQ
ABCDEF GH
12345678
f3 f4 f6 f5 f7 f8 f9 f2
f14 f13 f12 f15 f11 f16 9 f10
f1 Backspace Rt Arrow* Dn Arrow* F38 Space F19 +
Ins Esc Up Arrow* Lft Arrow* R Enter $ =
Back-quote ! @ -{}\|
’(Apostrophe) " < > ? ~ Tab Del

* Typematic Keys

n Upper case A–Z correspond to Shift a–Shift z n F11–F20 correspond to Shift F1–Shift F10
n

F21–F30 correspond to Ctrl F1–Ctrl F10 n F31–... correspond to Alt F1–Alt F10

Columns (C0–C17)

0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

STANDARD KEYMAP FOR K25C81

VC

C

C

VC

C1

B

.

1uF

+

C6

10u

F

1

44

RST

VCC

11

EKD

10

EKC

41

EKC1

9

KC

8

KD

K25C81-FN

3

NC

23

NC

2

IRQ

4

VX

7

RP

OSCI

43

R5
1M

Y1

Hz

AVX

PLCC

38

NC

5

C17

12

C16

24

C15

25

C14

26

C13

27

C12

28

C11

29

C10

30

C9

31

C8

21

C7

20

C6

19

C5

17

C4

16

U2

ODCO

42

C3

15

C2

14

C1

13

C0

18

C4A

40

R7A

39

R7

6

R6

37

R5

36

R4

35

R3

34

R2

33

R1

32

R0

VSS

22

RP1
NET_15

EXTERNAL_KBD_PS2DATA

EXTERNAL_KBD_PS2CLOC

HOST_PS2DAT

HOST_PS2CLOC

23

U1

1

TC54VC4502EC

TELCOM

VCC

R1

2x4.7K

K

A
K

C2

R4R3R2

2x2K

C3

C4

C5

4x47pF

VCC

4.00M

PBRC4.00BR

K

VCC

JP1

123

C

VC

R6

100K

JUPERS SETTINGS
JP1 1-2: PC/XT

C17
C16
C15
C14
C13
C12
C11
C10
C9
C8
C7
C6
C5
C4
C3
C2
C1
C0

R7
R6
R5
R4
R3
R2
R1
R0

(c)1994-2001 USAR SYSTEMS, Inc.

Applica tion Circuit f or K25C81-FB

K25C81FB.sch

Document Number

PC/AT2-3

.6

Rev

SUGGESTED INTERFACING FOR K25C81-FB (44-PIN QFP PACKAGE)

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

7

.6

Rev

K25C81FB.sch

Document Number

Application Circuit for K25C81-FB

(c)1994-2001 USAR SYSTEMS, In c.

Hz

1M

Y1

AVX

4.00M

PBRC4.00BR

C
VC

C
VC

U1

23

PC/AT2-3

R6R3R0

U2

K25C81-FB

C5

C0

QFP44

NC

40

4x47pF

39

3413231302928

R7R6R5R4R3R2R1

NC

NC

NC

16

22

R4R2R5R1R7

VCC

K

RP1

NET_15

27

R0

VSS

17

ODCO

36

OSCI

37

IRQ

VX

43

42

VCC

R5

RP

2

C15

C14

C13

C12

C11

C10C9C8C7C6C5C4C3C2C1C0

C16

JUPERS SETTINGS

JP1 1-2: PC/XT

JP1

3
2
1

C
VC

C6

+

1uF

C1

.

B

TELCOM

TC54VC4502EC

1

C17

R6

100K

44

7

1819202123

24.252615141312111098

C9C8C7C6C5C4C3C2C1

C17

C16

C15

C14

C13

C12

C11

C10

NC

33

F
10u

VCC

38

RST

41

EKC1

EKC

EKD

KC

6

KD

4

3

5

35

2x2K

R4R3R2

C4

1

VCC

R1

C3

C2

2x4.7K

K

A

K

HOST_PS2DAT

HOST_PS2CLOC

EXTERNAL_KBD_PS2DATA

EXTERNAL_KBD_PS2CLOC

MECHANICALS FOR THE K25C81-P

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

8

40 21

1 20

A

H

G

F

D

Seating
Plane

B

L

C

J

N

M

K

Notes:

1. Positional tolerance of leads (D) shall be
within 0.25 mm (0.010) at maximum material
condition, in relation to the seating plane and
each other.

2. Diminsion L is to the center of the leads when
the leads are formed parallel.

3. Dimension B does not include mold flash.

MILLIMETERS INCHES

MIN MAX

DIM

A 51.69 52.45

B

13.72

C

3.94

D

0.36

1.02

F

G

2.54 BSC 0.100 BSC

H

1.65

J

0.20 0.008

K

2.92 0.015

L

15.24 BSC 0.600 BSC

0

M

0

N

0.51

MIN MAX

2.065

2.035

0.540

0.560

14.22

5.08 0.155 0.200

0.56 0.014

0.022

1.52 0.040 0.060

2.16 0.085

0.065

0.38

0.015

0.1353.43

0

0

0

15 0 15

1.02 0.020 0.040

MECHANICALS FOR THE K25C81-FN

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

9

44

(Note 1)

Z

C

+

G1

M

0.25 (0.010) T-LSMSNSP

L

(Note 1) 44

G

N

44

Leads

PLCC

Y BRK

M

D

M

0.18 (0.007) T LSM

B

NSP

0.18 (0.007) T L

U

S

S

--

M

NSP

SMS

S

-

-

Note 1

W

Z1

1

P

0.18 (0.007) T-LSMSNSP

A

0.18 (0.007) T-LSMSNSP

R

+

E

J

Detail S

S

-

M

M

0.010 (0.004)

T

Seating Plane

V

-

-

Notes:

1. Due to space limitation, the chip
is represented by a general (smaller)
case outline drawing rather than
showing all 44 leads.

2. Datums L, M, N, and P determine where
the top of the lead shoulder exits plastic
body at mold parting line

3. DIM G1, true position to be measured
at Datum T, Seating Plane

4. DIM R and U do not include mold
protusion. Allowable mold protusion is

0.25 (0.010) per side.

5. Dimensioning and tolerancing per Ansi
Y14.5M, 1982

6. Controlling dimension: Inch

D

H

X

0.18 (0.007)

0.18 (0.007)TT

S

S

View D-D

G1

0.25 (0.010) T

M

LSMSNSP

-

M

NSP

-

M

S

NSP

LSM

LSM

S

S

-

-

S

-

S

-

K1

K

M

Detail S

0.18 (0.007)

F

0.18 (0.007)

LSMSNSP

T

-

M

DIM

A
B
C
E
F
G
H
J
K
R
U
V

W

X
Y

Z
G1
K1
Z1

LSM

NSP

T

S

--

MILLIMETERS INCHES

MAX MIN MAX

MIN

17.40 17.65

17.65 0.685 0.695

17.40

4.20 4.57 0.165 0.180

2.29 2.79 0.090 0.110

0.33 0.48 0.013 0.019

1.27 BSC 0.050 BSC

0.66 0.81 0.026 0.032

0.51 - 0.020 -

0.64 - 0.025 -

16.51 16.66 0.650 0.656

16.51 16.66 0.650 0.656

1.21 0.042 0.048

1.07

1.07 1.21 0.042 0.048

1.07 1.42 0.042 0.056

- 0.50 - 0.020

00

2 10 2 10

15.50 16.00 0.610 0.630

1.02 - 0.040 -

00

0

2 10 2 10

-

0.685

S
S

0.695

0

0

MECHANICALS FOR THE K25C81-FB

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

10

L

L

Datum
Plane

A

H

C
Seating
Plane

33 23

34

44

1

D

A

M

0.20 (0.008) C

0.05 (0.002) A-B

S

M

0.20 (0.008) H

Detail C

E

C

H

Detail A

A-B

A-B

W

G

22

12

S

D

S

A-B

B

M

0.20 (0.008) C

0.05 (0.002) A-B

S

D

S

A-B

V

M

0.20 (0.008) H

B

Detail A

B

A,B,D

11

Notes

1. Dimensioning and tolerancing per Ansi
Y14.5-M, 1982

S

S

D

F

S

S

D

Base Metal

JN

M

T

R

D

M

0.20 (0.008) C

Section B-B

S

S

D

A-B

K

Q

X

M

Detail C

Datum

H

Plane

0.01 (0.004)

M

2. Controlling dimension: Millimeter

3. Datum Plane "H" is located at the
bottom of the lead and is coincident
with the lead where the lead exits
the plastic body at the bottom of the
parting line.

4. Datums -A-, -B-, and -D- to be determined
at Datum Plane -H-.

5. Dimensions S and V to be determined
at seating plane -C-.

6. Dimensions A and B do not include
Mold protusion. Allowable protusion
is 0.25 (0.010) per side. Dimensions
A and B do include mold mismatch
and are determined at Datum Plane -H-.

7. Dimension D does not include Danbar
protrusion. Allowable Danbar
protrusion is 0.08 (0.003) total in
excess of the D dimension
at Maximum Material Condition.
Danbar cannot be located on the
lower radius or the foot.

MILLIMETERS INCHES

MIN MAX MIN MAX

DIM

A 9.90 10.10
B

9.90 10.10

2.45 0.083 0.096

C

2.10

D

0.30 0.45 0.012 0.018

E

2.00 2.10 0.079 0.083

0.30 0.40 0.012 0.016

F
G

0.80 BSC 0.031 BSC

H

0.25 0.010

-

J

0.23

0.13

K

0.65

L

8.00 REF 0.315 REF

0

M

5 10 5 10

N

0.17 0.005 0.007

0.13

0

Q

0 7 0 7

R

0.13 .30 0.005 0.012

S

13.45 0.530

12.95 0.510

T

0.13 0.005

0

0

U

12.95

13.45

V
W

0.40 0.016

X

1.6 REF

0.398

0.390

0.398

0.390

-

0.009

0.005

0.026

0.0370.95

0

0

0

0

0

0

0.510

0.063 REF

0

-

0.530

--

0

-

--

ELECTRICAL SPECIFICATIONS

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

11

Absolute Maximum Ratings
Ratings Symbol Value Unit

Supply Voltage Vdd -0.3 to +7.0 V
Input Voltage Vin Vss -0.3 to Vdd +0.3 V
Current Drain per Pin I 25 mA
(not including Vss or Vdd)
Operating Temperature Ta T low to T high ° C
K25C81 40 to +85
Storage Temperature Range Tstg -65 to +150 ° C

Thermal Characteristics
Characteristic Symbol Value Unit

Thermal Resistence Tja ° C per W

Plastic 60
DIP -60
Plcc 70

DC Electrical Characteristics (Vdd=5.0 Vdc +/-10%, Vss=0 Vdc, Temperature range=T low to T high unless otherwise noted)
Characteristic Symbol Min Typ Max Unit

Output Voltage (I load<10µA) Vol 0.1 V

Voh Vdd–0.1
Output High Voltage (I load=0.8mA) Voh Vdd–0.8 V
Output Low Voltage (I load=1.6mA) Vol: 0.4 V
Input High Voltage Vih 0.7xVdd Vdd V
Input Low Voltage Vil Vss 0.2xVdd V
Supply Current Idd 4.7 7.0 mA
I/O Ports Hi-Z Leakage Current Iil +/-10 µA
Input Current Iin +/- 1 µA
I/O Port Capacitance Cio 8 12 pF

Control Timing (Vdd=5.0 Vdc +/-10%, Vss=0 Vdc, Temperature range=T low to T high unless otherwise noted)
Characteristic Symbol Min Max Unit

Frequency of Operation fosc MHz

Crystal Option 4.0
External Clock Option dc 4.0

Copyright Semtech, 1997-2001
DOC5-C81-DS-105

www.semtech.com

12

For sales information
and product literature,
contact:

HID & System Mgmt Division
Semtech Corporation
568 Broadway
New York, NY 10012

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

212 226 2042 Telephone
212 226 3215 Telefax

Semtech Western Regional Sales
805-498-2111 Telephone
805-498-3804 Telefax

Semtech Central Regional Sales
972-437-0380 Telephone
972-437-0381 Telefax

Semtech Eastern Regional Sales
203-964-1766 Telephone
203-964-1755 Telefax

Semtech Asia-Pacific Sales Office
[phone] Telephone
[phone] Telefax

Semtech Japan Sales Office
[phone] Telephone
[phone] Telefax

Semtech Korea Sales Sales
[phone] Telephone
[phone] Telefax

Northern European Sales Office
[phone] Telephone
[phone] Telefax

Southern European Sales Office
[phone] Telephone
[phone] Telefax

Central European Sales Office
[phone] Telephone
[phone] Telefax

Copyright 1997-2001 Semtech Corporation. All rights reserved.
KeyCoder, FlexiCoder and Self-Power Management are trademarks
of Semtech Corporation. Semtech is a registered trademark of
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.