Nad C-725-BEE Service Manual

NAD

SERVICE MANUAL

C 725BEE

STEREO

C 725BEE

STEREO

RECEIVER



RECEIVER

TABLE OF CONTENTS

DESCRIPTION P A G E

SERVICE CAUTION…………………………………………………………..3-4

REAR PANEL/FRONT PANEL VIEW………………………………………..5

SPECIFICATIONS…………………………………………………………6-7

WIRING DIAGRAM………………………………………………………………8

BLOCK DIAGRAM……………………………………………………. …….9-18

ALIGNMENT PROCEDURE........................................................19

SCHEMATICS……………………………………………………………....20-23

PCB LAYOUT……………………………………………………………….24-28

TROUBLE SHOOTING GUIDE…………………......................................29

ELECTRICAL PARTS LIST…………………………………………….30-46

EXPLODED VIEW……………………………………………………………..47

EXPLODED VIEW PARTS LIST……………………………………………....48

C725BEE PACKING ACCESSORY AND PARTS LIST.............................49



PRODUCT SAFETY SERVICING GUIDELINES

CAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN
ANY WAY. NEVER PERFORM CUSTOMIZED INSTALLATIONS
WITHOUT MANUFACTURER’S APPROVAL. UNAUTHORIZED
MODIFICATIONS WILL NOT ONLY VOID THE WARRANTY, BUT
MAY LEAD TO YOUR BEING LIABLE FOR ANY RESULTING
PROPERTY DAMAGE OR USER INJURY.

SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU
ARE THOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING
SAFETY CHECKS AND SERVICING GUIDELINES. TO DO
OTHERWISE, INCREASES THE RISK OF POTENTIAL HAZARDS
AND INJURY TO THE USER.

WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR
PROTECTION FROM AC LINE SHOCK.

SAFETY CHECKS

AFTER THE ORIGINAL SERVICE PROBLEM HAS BEEN
CORRECTED. A CHECK SHOULD BE MADE OF THE
FOLLOWING.

SUBJECT : FIRE & SHOCK HAZARD

1. BE SURE THAT ALL COMPONENTS ARE POSITIONED IN
SUCH A WAY AS TO AVOID POSSIBILITY OF ADJACENT
COMPONENT SHORTS. THIS IS ESPECIALLY IMPORTANT
ON THOSE MODULES WHICH ARE TRANSPORTED TO AND
FROM THE REPAIR SHOP.

2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVE
DEVICES SUCH AS INSULATORS, BARRIERS, COVERS,
SHIELDS, STRAIN RELIEFS, POWER SUPPLY CORDS, AND
OTHER HARDWARE HAVE BEEN REINSTALLED PER
ORIGINAL DESIGN. BE SURE THAT THE SAFETY PURPOSE
OF THE POLARIZED LINE PLUG HAS NOT BEEN DEFEATED.

3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLE
COLD SOLDER JOINTS, SOLDER SPLASHES OR SHARP
SOLDER POINTS. BE CERTAIN TO REMOVE ALL LOOSE
FOREIGN PARTICLES.

4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR
DETERIORATION TO PARTS AND COMPONENTS. FOR
FRAYED LEADS, DAMAGED INSULATION (INCLUDING AC
CORD). AND REPLACE IF NECESSARY FOLLOW ORIGINAL
LAYOUT, LEAD LENGTH AND DRESS.

5. NO LEAD OR COMPONENT SHOULD TOUCH A RECEIVING
TUBE OR A RESISTOR RATED AT 1 WATT OR MORE. LEAD
TENSION AROUND PROTRUDING METAL SURFACES MUST
BE AVOIDED.

6. ALL CRITICAL COMPONENTS SUCH AS FUSES,
FLAMEPROOF RESISTORS, CAPACITORS, ETC. MUST BE
REPLACED WITH EXACT FACTORY TYPES, DO NOT USE
REPLACEMENT COMPONENTS OTHER THAN THOSE
SPECIFIED OR MAKE UNRECOMMENDED CIRCUIT
MODIFICATIONS.

7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM AN
AC LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OF
THE CABINET, (THE CHANNEL SELECTOR KNOB, ANTENNA
TERMINALS. HANDLE AND SCREWS) TO BE SURE THE SET
IS SAFET TO OPERATE WITHOUT DANGER OF ELECTRICAL
SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER
DURING THIS TEST USE AN AC VOLTMETER, HAVING 5000
OHMS PER VOLT OR MORE SENSITIVITY, IN THE
FOLLOWING MANNER; CONNECT A 1500 OHM 10 WATT
RESISTOR, PARALLELED BY A .15 MFD, 150V AC TYPE
CAPACITOR BETWEEN A KNOWN GOOD EARTH GROUND
(WATER PIPE, CONDUIT, ETC.) AND THE EXPOSED
METALLIC PARTS, ONE AT A TIME.
MEASURE THE AC VOLTAGE ACROSS THE COMBINATION
OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR.
REVERSE THE AC PLUG AND REPEAT AC VOLTAGE
MEASUREMENTS FOR EACH EXPOSED METALLIC PART.

VOLTAGE MEASURE MUST NOT EXCEED 75 VOLTS R.M.S.
THIS CORRESPONDS TO 0.5 MILLIAMP AC ANY VALUE
EXCEEDING THIS LIMIT CONSTITUTES A POTENTIAL
SHOCK HAZARD AND MUST BE CORRECTED IMMEDIATELY.

SUBJECT : GRAPHIC SYMBOLS

THE LIGHTNING FLASH WITH ARROWHEAD SYMBOL, WITHIN AN
EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE USER TO THE
PRESENCE OF UNINSULATED “DANGEROUS VOLTAGE” WITHIN THE
PRODUCT’S ENCLOSURE THAT MAY BE OF SUFFICIENT MAGNITUDE TO
CONSTITUTE A RISK OF ELECTRIC SHOCK.

THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS
INTENDED TO ALERT THE USER TO THE PRESENCE OF IMPORTANT
OPERATING AND MAINTENANCE (SERVICING) INSTRUCTIONS IN THE
LITERATURE ACCOMPANYING THE APPLIANCE.

SUBJECT : TIPS ON PROPER INSTALLATION

1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS,
CUBBYHOLE OR CLOSELY FITTING SHELF SPACE. OVER
OR CLOSE TO HEAT DUCT, OR IN THE PATH OF HEATED
AIR FLOW.

2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS:
OUTDOOR PATIO INSTALLATIONS WHERE DEW IS A
FACTOR, NEAR STEAM RADIATORS WHERE STEAM
LEAKAGE IS A FACTOR, ETC.

3. AVOID PLACEMENT WHERE DRAPERIES MAY OBSTRUCT
REAR VENTING. THE CUSTOMER SHOULD ALSO AVOID THE
USE OF DECORATIVE SCARVES OR OTHER COVERINGS
WHICH MIGHT OBSTRUCT VENTILATION.

4. WALL AND SHELF MOUNTED INSTALLATIONS USING A
COMMERCAL MOUNTING KIT MUST FOLLOW THE FACTORY
APPROVED MOUNTING INSTRUCTIONS A PRODUCT
MOUNTED TO A SHELF OR PLATFORM MUST RETAIN ITS
ORIGINAL FEET (OR THE EQUIVALENT THICKNESS IN
SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS
THE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERS
MUST NOT TOUCH ANY PARTS OR WIRING. PERFORM
LEAKAGE TEST ON CUSTOMIZED INSTALLATIONS.

5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A
PRODUCT ON SLOPING SHELF OR A TILTED POSITION,
UNLESS THE PRODUCT IS PROPERLY SECURED.

6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE
ON ITS MOUNTING TO THE CART. CAUTION THE
CUSTOMER ON THE HAZARDS OF TRYING TO ROLL A CART
WITH SMALL CASTERS ACROSS THRESHOLDS OR DEEP
PILE CARPETS.

7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR
STAND WHICH HAS NOT BEEN LISTED BY UNDERWRITERS
LABORATORIES, INC. FOR USE WITH THEIR SPECIFIC
MODEL OF TELEVISION RECEIVER OR GENERICALLY
APPROVED FOR USE WITH T.V.’S OF THE SAME OR
LARGER SCREEN SIZE.

8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION
CORDS, EXPLAIN THAT A FOREST OF EXTENSIONS
SPROUTING FROM A SINGLE OUTLET CAN LEAD TO
DISASTROUS CONSEQUENCES TO HOME AND FAMILY.



SERVICING PRECAUTIONS

CAUTION : Before servicing the A/V Receiver covered by this
service data and its supplements and addends, read and follow the
SAFETY PRECAUTIONS. NOTE : if unforeseen circumstances
create conflict between the following servicing precautions and any
of the safety precautions in this publication, always follow the safety
precautions.

Remember Safety First:

General Servicing Precautions

1. Always unplug the A/V Receiver AC power cord from the AC
power source before:
(1) Removing or reinstalling any component, circuit board,

module, or any other assembly.

(2) Disconnecting or reconnecting any internal electrical plug or

other electrical connection.

(3) Connecting a test substitute in parallel with an electrolytic

capacitor.
Caution : A wrong part substitution or incorrect polarity installation
of electrolytic capacitors may result in an explosion hazard.

2. Do not spray chemicals on or near this A/V Receiver or any of its
assemblies.

3. Unless specified otherwise in this service data, clean electrical
contacts by applying an appropriate contact cleaning solution to
the contacts with a pipe cleaner, cottontipped swab, or
comparable soft applicator.
Unless specified otherwise in this service data, lubrication of
contacts is not required.

4. Do not defeat any plug/socket B+ voltage interlocks with which
instruments covered by this service manual might be equipped.

5. Do not apply AC power to this A/V Receiver and/or any of its
electrical assemblies unless all solid-state device heat sinks are
correctly installed.

6. Always connect test instrument ground lead to the appropriate
ground before connecting the test instrument positive lead. Always
remove the test instrument ground lead last.

Insulation Checking Procedure

Disconnect the attachment plug from the AC outlet and turn the
power on. Connect an insulation resistance meter(500V) to the
blades of the attachment plug. The insulation resistance between
each blade of the attachment plug and accessible conductive parts
(Note 1) should be more than 1M-ohm.
Note 1 : Accessible Conductive Parts including Metal panels, Input
terminals, Earphone jacks, etc.

Electrostatically Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by
static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical Es
devices are integrated circuits and some field effect transistors and
semiconductor chip components.
The following techniques should be used to help reduce the
incidence of component damage caused by static electricity.

1. Immediately before handling any semiconductor component or
semiconductor-equipped assembly, drain off any electrostatic
charge on your body by touching a known earth ground.
Alternatively, obtain and wear a commercially available
discharging wrist strap device, which should be removed for
potential shock reasons prior to applying power to the unit under
test.

2. After removing an electrical assembly equipped with ES devices,
place the assembly on a conductive surface such as aluminum
foil, to prevent electrostatic charge buildup or exposure of the
assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ES
devices.

4. Use only an antistatic solder removal device. Some solder
removal devices not classified a “anti-static” can generate
electrical charges sufficient to damage ES devices.

5. Do not use freonpropelled chemicals. These can generate
electrical charge sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective
package until immediately before you are ready to install it. (Most
replacement ES devices are packaged with leads electrically
shorted together by conductive foam, aluminum foil, or
comparable conductive material).

7. lmmediately before removing the protective material from the
leads of a replacement ES device, touch the protective material to
the chassis or circuit assembly into which the device will be
installed.

Caution : Be sure no power is applied to the chassis or circuit, and
observe all other safety precautions.

8. Minimize bodily motions when handing unpackaged replacement
ES devices. (Normally harmless motion such as the brushing
together of your clothes fabric or the lifting of your foot from a
carpeted floor can generate static electricity sufficient to damage
an ES device.)



*%&/5*'*$"5*0/0'$0/530-4

'30/5 1"/&-

 

         

   

1. Power

2. Power/Standby
/Protection/Led

3. Blend

4. Info

5. Memory

6. Tuner Mode

3&"3 1"/&-



    

7. Preset

8. Tune

9. VFD

10.IR Receiver

11.Record out / Zone 2 selector

12.Volume

13.Headphone

14.Speaker A & B

15.MP input

16.Input selector

17.Tone defeat

18.Tone controls

19.Balance

           

1. +12V trigger out

2. IR in / out

3. MP input

4. CD input

5. DISC input

6. AUX input

7. TAPE input

8. REC out

9. PRE out

10.Main in

11.Sub out

12.Speaker out

13.Soft Clipping

14.ON / OFF power(AC) switch

15.Switched AC outlet

16.RS232 input

17. MP Dock data port

18.Antenna (FM)

19.Antenna(AM)

20.DAB input (230V version only)



SPECIFICATIONS

POWER AMPLIFIER SECTION
STEREO MODE

CONTINUOUS AVERAGE POWER 50 W (17 dBW)

OUTPUT INTO 8 OHMS OR 4 OHMS

(Min. power per channel, 20 Hz – 20 kHz,
with no more than rated distortion)

Rated Distortion 0.03%
(THD 20 Hz – 20 kHz)

Clipping power 52 W
(maximum continuous power per channel 4 and 8).

IHF dynamic headroom: at 8 ohms + 2.4 dB

at 4 ohms + 4.4 dB

IHF dynamic power
(maximum short term power per channel)

8 ohms: 160 W (20.4 dBW)
4 ohms: 220 W (22.0 dBW)
2 ohms: 270 W (23.2 dBW)

Damping factor > 100
(ref. 8 ohms 1 kHz)

Input Impedance R = 20 kohms

C = 1 nF

Input sensitivity (for rated output into 8 ohms) 780 mV

Voltage gain 29 dB

Frequency response 20 Hz – 20 kH

Signal / Noise ratio, A-weighted 100 dB ref. 1 W

THD + Noise < 0.03%
(Total Harmonic Distortion, 20 Hz – 20 kHz,
from 250 mW to rated output)

SMPTE I.M. < 0.01%
(Intermodulation Distortion, 60 Hz + 7 kHz, 4:1,
from 250 mW to rated output)

0.1 dB

119 dB ref. 50 W

IHF I.M. < 0.01%
(CCIF IM Distortion, 19 + 20 kHz at rated output)

Headphones Output Impedance 220 ohms



PREAMPLIFIER SECTION

LINE LEVEL INPUTS

(MP, CD, Disc, Aux, Tape)

Input impedance (R and C) 22 kohms + 100 pF

Input sensitivity (ref. rated power) 320mV

Maximum input signal > 4.5V

Signal / Noise ratio, A-weighted 97.0 dB ref. 1W
(from CD Input to Speakers Output, Volume Setting
for 500mV in , 8ohms 1W out)
Signal to noise ratio preamp out, IHF “A” weighted 110 dB re 500mV

Frequency response, 20 Hz – 20 kHz < +/-0.1 dB (tone defeat on)
< +/-0.2 dB (tone defeat off)
THD + Noise, SMPTE IM < 0.01% at 5 V out

LINE LEVEL OUTPUTS

Pre-amp output impedance 80 ohms

Tape output impedance Source Z + 1kohms

Maximum output level pre-amp out : > 11 V
Tape-out : > 10 V

CONTROLS

Treble +/- 5 dB at 10 kHz

Bass +/- 8 dB at 100 Hz

IR IN and OUT

Input Resistance > 10 kohms

Input Voltage Min 5 V

Output Resistance < 30 ohms

TRIGGER Out

Output Current 50 mA

Output Voltage 12 V

DIMENSIONS AND WEIGHTS

Net Weight 9.4 kg ( 20.7 Ib)
Shipping Weight 11 kg ( 22 Ib)

DIMENSION (W×H×D) 435× 149 ×396MM



COPYRIGHT C 2008
NAD ELECTRONIC
C725BEE AC OUTPUT BOARD

CZ58

18AWG UL1672#

1672#22AWG

UL1672#18AW G

CB58

To AC Outlet

CB57

C725 BEE POWERBOARD

CB51

CB52

3266#18AWG

3266#22AWG

WIRING DIAGRAM

To Power Swicth

CB56

CB55

To AC Cord

CB45

CB47

CB49

CB54

CB53

CB59

COPYRIGHT C 2008 NAD ELECTRONICS

UL2468#26AWG

UL1015#14AWG black
UL1015#16AW G red,white

UL2468#26AWG

COPYRIGHT C 2008 NAD ELECTRONIC

C725 BEE MAINBOARD

TUNER MODULE

C725BEE RS232 BOARD

CB32

IN MODULE

CZ310

CB35

CB311

FPC-1.25-17P-220MM

UL2547# 26AWG

UL1691#24AWG

UL1691#24AWG

CZ311

CZ37

UL2468#26AWG

CZ36

FPC-1.25-20P-600MM

CZ35

C725 BEE TRANSFORMER

C725BEE STANDBY

CZ46 CZ45

HEADPHONEBOARD

CZ710

UL2468 #26AWG

UL2468 #26AWG

UL2468#26AWG

CB710

COPYRIGHT C 2008 NAD ELECTRONICS

C725 BEE KEYBOARD

CZ703

CZ709

CZ38

CB46

CB33

OUT MODULE

UL2468#26AWG

CB38

CZ702

CZ705

CZ701

UL2547#26AWG

CZ34

CZ704

C725 BEE POTBOARD

CB31

COPYRIGHT C 2008

NAD C725BEE

NAD ELECTRONIC

NAD



HCF4094

IC32

BLOCK DIAGRAM

MCU

IC703

IP SEL

TONE DEFEAT

SPEAKER B

SPEAKER A

STANDBY

KEY

KEYBOARD SECTION

VFD

CD

TUNE

DISC

AUX

TAPE

MP

REC OUT

SUBOUT

PREOUT

INPUT SELECTOR

IC31 TC9164

RECOUT SELECT SWITCH

Q301

2SK303

RELAY

RL310

SOFT
CLIPPING

PREAMP
MODULE

CB32

RT34

BALANCE

POWERAMP

LINEAR

TONE
DEFEAT

RL39

TONE
CONTROL

RT32&RT31

+-46V

VOLUME
CONTROL

RT33

ISC

CIRCUIT

ISC TRIG

SWITCHING POWER

+5.5V

UNIT PRO.

PRO.

MODULE

AC DET

LINEAR

MAINBOARD SECTION

RL12/1

RELAY

RL12/2
RELAY

POWERBOARD SECTION

+5.5V

SPEAKER A

SPEAKER B

MAIN IN



MCU CONNECTION DIAGRAM

TO STANDBY BOARD

TO MP BOARD

TO MP LED D719

CZ711
TO POWER BOARD

TUNER MODULE

1234567

IC710

3A
3B
4Y
4A
4B

VCC

74HC86

GND3Y

IR RECEIVER

FM-6038TM2-5AN

2Y
2B
2A

1Y
1B
1A

1

2

1

2

CON2
CZ707

3

2

1

CZ706
CON2

+5.8V

IC704

RESET

MR
GND
RESET

VDD

TPS3825-50DBVT

IC702

D722
1N4148

Q734
C1815

4

5

+5.8V

DGND

57

58

60

59

64

62

61

R773

33

1MEG
R774

18.432 MHz
Y701

3

1

2

D723
1N4148

CZ708

12345678910

1112

1314

47

R796

47

R797

CNVss
CE

Reset

R786
15k

DGND

+5.8V

1

2

3
4
5

6
7

8

9
10
11
12
13
14
15
16

P9363P92

P100

VREF

AVCC

P91
P90
CNVSS
P87/XCIN
P86/XCOUT
RESET
XOUT

VSS

XIN
VCC
P85/NMI
P84/INT2
P83/INT1
P82/INT0
P81
P80

P7717P7618P7519P7420P7321P7222RXD2/P7123TXD2/P7024TXD1/P6725RXD1/P6626P6527P6428P3329P3230P3131P30

R798 47

R799 47

R768 47

R769 47

Q702
C1815

R770 47

AVSS

51

P102

P0249P0150P00

P10752P10653P10554P10455P10356P101

R701 47K

SDA/P20
SCL/P21

RXD0/P62
TXD0/P63

M30281F6HP

32

48

P03

47

P15

46

P16

45

P17

44
43
42

P22

41

P23

40

P24

39

P25

38

P26

37

P27

36

P60

35

P61

34
33

IC703

IC705

8

Vdd

7

WP

6

SCL

5

SDA

24C16

KEY

TO DAB MODULE

1

A0

2

A1

3

A2

4

Vss

CZ702
TO PREAMP SCH

IC706

R713

3

B

2

C

R710

1

A

EC12E1220801-F20

OP SEL DATA

OP SEL CLK

OP SEL STB2

Unit Protect

IP SEL STB

IP SEL DATA

IP SEL CLK

1011121314151617181920

IC701

16-BT-130GINK

1

F1

IR OUT

IR IN

R763

10

9

10

TO IPOD

11

10

12

R764

13
14
15

16

IC707
CD4094

IC709 SP232EEP-L

123456789

16

15

2

1

3

D

OE

STR

CLK

VCC

Q14Q25Q36Q47Q514Q613Q712Q811QS9QS10GND



DGND

OP SEL CLK

OP SEL DATA

OP SEL STB1

16

15

2

1

3

IC711
CD4094

8

D

OE

STR

CLK

VCC

Q14Q25Q36Q47Q514Q613Q712Q811QS9QS10GND

8

DGND

R2OUT
T2IN
T1IN
R1OUT
R1IN
T1OUT
GND
VCC

R2IN

T2OUT

53

16G52Q16

V-

C2-

C2+

C1-

V+

C1+

55

TSB54TSA

60

61

58

62

59

63

64

DA56CP57CS

VH

VDD

OSC

LGND

PGND

RESET

8

7
6

5
4
3

2

1

69

F2

MCU
30281FA
KEY BOARD IC703

3

I/O

Port P04Port P1

Ports

Internal Peripheral Functions

Timer

Timer A0 (16 bits)
Timer A1 (16 bits)
Timer A2 (16 bits)
Timer A3 (16 bits)
Timer A4 (16 bits)
Timer B0 (16 bits)
Timer B1 (16 bits)
Timer B2 (16 bits)

3-phase PWM

M16C/60 series 16-bit CPU Core

8

Port P2

Output Compare (8 channels)

Registers

R2

R2

R3

R3

A0

A0

A1

A1

FR

FB

SB

Port P3

Timer S

Input Capture (8 channels)

A-D converter

(10bits x 13 channels)

DMAC (2 channels)

R0LR0H

R0LR0H

R1LR1H

R1LR1H

4

Port P68Port P7

8

Serial Ports

U(S)ART/SIO (channel 0)
U(S)ART/SIO (channel 1)

U(S)ART/SIO/I2C/IEbus

(channel 2)

SIO (channel 3)

Multi-master I2C BUS

Program Counter

PC

Stack Pointers

ISP

USP

Vector Table

INTB

Flag Register

FLG

Multiplier

8

Port P8

Port P94Port P10

System Clock Generator

Xin-Xout

Xcin-Xcout

PLL frequency synthesizer

Ring Oscillator

Watchdog Timer

Low voltage detect

Memory

Flash ROM

Flash ROM

(Data Flash)

RAM

8

11

CD4094
KEYBOARD:IC707 IC711
MAINBOARD:IC32



IC709
keyboard,SP232EEP

1

2

+V

3

-1C

TUPNI V5+

Fu01

61

1

+1C

Fu1.0

3

-1C

61+1C

CCV

51

DNG

41

TUO1T

4

+2C

Fu1.0

5

-2C

CCV

2

V01+ ot V5+

relbuoD egatloV

V01- ot V01+

retrevnI egatloV

+V

Fu1.0

6

-V

fu1.0

4

+2C

5

-2C

6

-V

7

TUO2T

31

NI1R

11

21

TUO1R

11

NI1T

01

NI2T

98

TUO2RNI2R

NI1T

01

NI2T

21 31

TUO1R

TUO2R NI2R

smhoK004

smhoK004

1R

2R

51DNG

1T

2T

smhoK5

smhoK5

41

7

89

TUO1T

TUO2T

NI1R



24C16

KEY BOARD IC705

FUNCTIONAL BLOCK DIAGRAM

WP

PIN CONFIGURATION

8-Pin PDIP

A0
A1
A2

GND

1
2
3
4

8

VCC

7

WP

6

SCL

5

SDA



PROCESSOR SUPERVISORY CIRCUIT
TPS3825
KEY BOARD IC704
BLOCK DIAGRAM:

Vdd

Watchdog

Timer Logic

Reset
Logic

Reset

Reset

†

+
_

Transition

Detector

MR

WDI

‡

