TDA Bridge public doc (PDF)

TDA 7293 or 7294 bridged
poweramp project

Bridged poweramp project with TDA 7294 - 2

Schematics, images, PCB,
and another images about
TDA729x bridge project

This project made for instrument amplifier project not for home HI-FI users. The amplifiers on this documents are assembled and working very well. The TDA Bridge poweramp have more than enough output power for keyboards or guitars. Marshall and for
example Carsbro using this solution on their amplifiers (Marshall mode Four, and Carlsbro GLX100). The PCB of Bridged TDA is very easy to assemble, and very stable for
long therm and heavy usage.

BRIDGE APPLICATION
Another application suggestion
is the BRIDGE
3
-
configuration, where two TDA7294 are used, as
shown by the schematic diagram of figure 25.
In this application, the value of the load must not
be lower than 8 Ohm for dissipation and current
capability reasons.
A suitable field of application includes HI-FI/TV
subwoofers realizations.
The main advantages offered by this solution are:

Schematics for TDA 729x bridge amp project
Schematic of the bridged TDA poweramp

Figure 25: Bridge Application Circuit

+Vs
0.22µF

2200µF

7
3

Vi
0.56µF

6
14

22µF

4
10

22K

2

1

The Bridge-Parallel is not recommended. Very hard to build and assemble, the PCB is
large, great heatshink and high-power transformer required.

TDA7294

9

15

680

8

20K
22K

22µF

10K

30K

0.56µF

-Vs
0.22µF

2200µF

1N4148
10
22µF

9

15

8

TDA7294

3

Images (on Google Piacasa) about this project:
7294 bridged • 7293 bridged and paralleled • The soft start • The power supply

13
+

22K

ST-BY/MUTE

English blog and PCB order: http://custompcb.blogspot.com/
Hungarian blog and PCB order: http://diyguitarpa.blogspot.com/
The Youtube Channel • Picasa gallery • Email: gitarfogas@gmail.com

- High power performances with limited supply
voltage level.
Bridged poweramp project with TDA 7294
- Considerably high output power even with high
load values (i.e. 16 Ohm).
The characteristics shown by figures 27 and 28,
measured with loads respectively 8 Ohm and 16
Ohm.
With Rl= 8 Ohm, Vs = ±25V the maximum output
power obtainable is 150 W, while with Rl=16
Ohm, Vs = ±35V the maximum Pout is 170 W.

+

22K

6
14

2

1
4

7

13

22µF
22K
680
D93AU015A

Schematics, images, PCB, and another images about TDA729x bridge project . . . . . . . . . . . 2
Schematic of the bridged TDA poweramp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Images about TDA7294 bridged poweramp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Schematic of speaker protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Schematic of power supply and the soft-strart for toroid transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The assembled poweramp and speaker protection PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Images about the power supply and soft-start for poweramp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1 - Bridged
2 - Bridged + paralel

13/17

More power: the paralel TDA project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Schematic of the bridged-paralleled TDA7293 poweramp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Images about TDA7293 bridged-paralleled poweramp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
The assembled poweramp and speaker protection PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Document last modified and saved: 13 October 2011 11:57 AM

1

12

6

9
Bridged powerampSTBY
project
with TDA 10uF
7294

Clip Detect

STBY GND

5

1N4148

U6
TDA7293

Boot loader

Bootstrap

Boot loader

Amp. Left

C45
100n

S2
C21

1000uF

C47
100n

Mute

C48
100n

MUTE SW

SGND

C67

10

C23
1000uF

-Vs

In-

C66
10uF

4

3

2

-Vs

8

+Vs

In+

7

Buffer DRV

11

+Vs (Power)

-Vs (Power)

Amp. Right

C22

C46
100n

Out

15

22K
R11

14

R25
10K

13

14

-Vs (Power)

+Vs (Power)

Out

15

13

Buffer DRV

In-

8

2

In+

5

D6

Schematics for TDA 729x bridge amp project
Schematic of speaker protection
11

3

SGND

STBY GND

4

+Vs

Images about TDA 729x bridge amp project
Images about TDA7294 bridged poweramp

Mute

-Vs

10

R23
30K

Bootstrap

6

12

1

U5
TDA7293

9
5
- Detect
STBY
Clip

7

Bridged poweramp project with TDA 7294 - 4

C

+Vs

C24
1000uF

F1

1000uF

4A 28V

+24V
R31
4.7K

B

LED

R29
2.2K

R32
1.2K

LED

K2

K1

S1

AC Input ~15V

D3

D4

LS1

SW

9.2K R30
D8
1N4148

R38
56K

R39
56K

R40
56K

400W 4Ohm

R43
10

R41
56K
C74
4.7uF

1N4148
D9

C75
33uF

LS2

RELAY

RELAY

D10

1N4148

400W 4Ohm

UPC1237
U11

1
2
3
4
5
6
7
8

A
C72

C73
22n

330uF

R42 56K

1

10uF
C70

2

6

2X400W gainclone
TDA7293

6.8K R44

3

4

Document last modified and saved: 13 October 2011 11:57 AM

5

Bridged poweramp project with TDA 7294 - 6

7 -

Schematics for TDA 729x bridge amp project
Schematic of power supply and the soft-strart for toroid transformer

7

Integrated circuit

Integrated circuit
U

U
Trimmer potentiometer

d

Diode

TR

Power

D

e

Resistor

h

R

m

Q

R

Dual transistor or JFET

+
C

b

J
f

I/O

Q

c

c
R

C
Cb

U

+
C

C

+

+
C

a

a

R
C

Jumper

Electrolic capacitor

C

+

J

+

C+

Input

m
k

+
+
C

R

+
+
C

R

+

+

I/O

I/O

U

D

R
+

I/O

I/O

D

+
+

I/O

S

R

+
C

Relay

R

Relay

+

S

8

Good quailty non-electrolic
polarized capacitor,
for like Tantal

7

Input

6

k

-60V Preamp
5

R

2

C

-Vout

+
C

LM337

h

Vin

C

4

+
C

3

Power Supply for
Poweramp and preamps

C118
100uF 63V

+

3

10 1W
2

R24
220

c

R19

~ 50V

1

U10

R

C114

D

100uF 100V

+

C110

R
f
R
e
R
R
g

2200uF 100V

+

a

2200uF 100V
C109

KBPC1010

A

b

C103
47n

J

C116
47uF 63V

2

+

C99
47n

D26

GND

~ 15V

4

D25
30V 2W

47n
C102

C

KBL04

C101
47n

1

3

A

+

+

2

C98
47n

ADJ

D21

C97
47n

D24
30V 2W

1

4

C100
47n

3

47n

1

C96

+
C

D23
30V 2W
~220V

+

~ 50V

~ 15V

R
g

C115
47uF 63V

D22
30V 2W

KBL04

R

R

C112
4700uF

c

2

C

D20

C

C95
47n

3

4

C117
100uF 63V

a

100uF 100V

R23
220

C

U8

b

2

C113

R

+
+
C

C

D18

C93
47n

C108
2200uF 100V

B

R

L2

1
4

2200uF 100V

C76
100n

3

47n

C107

C94
47n

+ 22V (Relay, LED)

KBL04

+60V Preamp

+

C92

3

R1

~10V

LM317

+Vout

Single transistor or JFET

C

b
1

10 1W

Vin

ADJ

B

2

1

R17

~15V

+
+

R

-15V

Q6 BC560C

C

-16V

R

2

R

-Vout

L1

LM337

C75
100n

R

Vin

C86
47uF

R

3

10 1W

U9

b

C69
100n

R

R22
12K

1

C111
4700uF

2

C82
2200uF

R18

3

D19

C74
100n

ADJ

1
4

C80
2200uF

+ 22V (Relay, LED, UPC1237)

KBL04

R

C106
10uF

R

C73
100n

~15V (AC Detect for protection)

R

C91
47n

C105
10uF

L2

C72
100n

R

~ 15V

C90
47n

Q

C88
47uF

D17
16V 2W

~ 50V

R
C

C87
47uF

D16
16V 2W

15...200W

TDA7294

~ 35V

R21
12K

C71
100n

R1

+16V

C85
47uF

Q

3

1

S4

+Vout

TDA7294

100n

LM317

U7

L1

Vin

C70

Q

PowerAmp -VEE

C81
2200uF

TDA7294

C

2

10 1W
C79
2200uF

+
+
C

R2

R16
C68
100n

with protection

R14
4.7K 5W

C63
10000uF

2 X TDA7294 Bridge

C62
10000uF

ADJ

3

GBPC5008

~ 20V

C

R
TDA7294

BC550C

+

Q5

+15V

~ 10V

C

ADJ

D15
10V 2W

2

+

+

+10V

C66
100n

C83
100uF

1

1

3

LM317 +Vout

U6

-V

Vin

AC

2

C78
C65
2200uF 100n

Relay -

C77
2200uF

C64

+ V,
Relay +

100n

+

D14

10000uF

R13
4.7K 5W

+

4

C61

UPC1237

C60
10000uF

+

R15 10 1W

PowerAmp +VCC
~220V

Q

~ 10V

Q

D

I/O channel, connector for
input/output, VCC, VEE, etc...

C104
10uF

D

C67
100n

Non-polarized capacitor,
C ceramic, or some good quality
like WIMA capacitors

C89
47n

Power

C84
47uF
15...200W

P

S3
~ 20V

-

d

C

~ 35V

Powertransistor or powerfet

R2

+9V

R20
12K

Integrated circuit

BC550C

~ 50V

D

Potentiometer

8

Q4

2X200W Bridge poweramp
http://microprojects.rentahost.net

6

C

5

-

4

I/O

3

R

2

Schematics for TDA 729x bridge amp project
The assembled poweramp and speaker protection PCB

+

1

Bridged poweramp project with TDA 7294

Document last modified and saved: 13 October 2011 11:57 AM

Bridged poweramp project with TDA 7294 - 8

9 -

Bridged poweramp project with TDA 7294

Images about TDA 729x bridge amp project
Images about the power supply and soft-start for poweramp

More power:
the paralel TDA
project
The Bridge-Parallel project is
not recommended
for average users.
Very hard to build and assemble, the PCB is large, great heatshink and
high-power transformer required. The power is more than 2x300W, but
not stable and quiet like a simple paralleled amplifier. The cheaper “gainclone” TDA7294 not useful for this parallel version, the 7293 or 7294s
have higher costs. Not only the one “gainclone” have higher price, 8
circuits required to try this.
Make sure that you have enought knowledge and devices to done
this if you decide to try out.

Document last modified and saved: 13 October 2011 11:57 AM

Bridged poweramp project with TDA 7294 - 10

11 -

Bridged poweramp project with TDA 7294

Schematics for TDA 7293 bridge-paralel amp project
Schematic of the bridged-paralleled TDA7293 poweramp
1

2

C13
1000uF

C33
100n

3
C34
100n

1000uF
C14

4

C35
100n

C15
1000uF

5
-Vs

C36
100n

1000uF
C16

6

+Vs

C37
100n

C17
1000uF

7
C38
100n

1000uF
C18

8

C39
100n

C19
1000uF

C40
100n

1000uF
C20

C29 10p

100n

100n

C62

C63

C22
S2
C21

1000uF

100n

100n

C64

C65

R28
2.2K

D2

BC640

-Vs

+Vs

8

7

11

STBY GND

13

D

3
4

SGND

R10
22K

10

Mute

C8
10uF T

9

STBY
TDA7293
U4

1

Buffer DRV

Boot loader

-Vs (Power)

+Vs (Power)

Clip Detect

C4
470p

2

InIn+

12

5

Bootstrap

R20
2.2 2W

-Vs (Power)

13
+Vs (Power)

15
R19
2.2 2W

5

Clip Detect

Out

R16
680

C61

47uF

MUTE SW

C12
22uF T

47uF

LED

1000uF

C52
100n

4A 28V

C25

100n
C44

STBY GND

1

12
Boot loader

1000uF

MUTE SW

SGND

-Vs

+Vs

In-

C68
10uF

10

C69
10uF

4
3
2

C28

C54
100n

S3

Mute

C

9

8

C53
100n

1000uF

STBY

In+

7

Buffer DRV
11

22K
R12

6
+Vs (Power)

Out

Bootstrap

Clip Detect

-Vs (Power)

R26
10K

C26

F1

1000uF

14

U8
TDA7293

13

Bootstrap

6

12

C50
100n

C24

5

D7
1N4148

-Vs (Power)

In-

+Vs

5

15

-Vs

In+

R24
30K

14

Out

+Vs (Power)

2

Clip Detect

13

2

SGND

Boot loader

3

11

4

3

+Vs

4

Mute

U7
TDA7293

Buffer DRV

1
10

-Vs

C66
10uF

7

-Vs

+Vs
C23
1000uF

In-

C67

10

STBY

STBY GND

1
STBY GND

SGND

9

10uF

8

C48
100n

Mute

9

8

C47
100n

STBY

In+

7

6

12
Boot loader

R25
10K

Bootstrap

Out

15

22K
R11

14

Clip Detect

Buffer DRV

1N4148

14

-Vs (Power)

5

U6
TDA7293

15

13

5

D6

11

Out

+Vs (Power)

Bootstrap

Clip Detect

R23
30K

14

Q2

100n

100n
C42

C32
10p

14

Out

C60
C43

C10
22uF T

15

11

C11
22uF T

R9
22K

6

TDA7293
U3

Buffer DRV

7

8
STBY

Bootstrap

9

R8
22K

6

R14
680

Mute

Boot loader

10
R15
680

-Vs

SGND

12

R6
22K

+Vs

In+

4

STBY GND

STBY GND
1

3

10uF T
IN
C7
C6 10uF T

9

TDA7293
U2

In-

1

-Vs

+Vs

8

7

11

13

Buffer DRV

Boot loader

10

10p

2

R22 44K

-Vs (Power)

U5
TDA7293

C45
100n
C46
100n

STBY

R5
22K

C3
470p

R21 44K

6

12
Boot loader

Buffer DRV

11

In-

+Vs

In+

8

2

SGND

STBY GND

1
3

-Vs

4

Mute

7

10

STBY

Mute

4

47uF

R27
2.2K

LED D1

SGND

3

C59

BC640

9

Clip Detect

C2
470p

2

C31

15

100n
C41

C

5

6

R18
2.2 2W

InIn+

12

R17
2.2 2W

Out

Bootstrap

14

5

+Vs (Power)

15
14

Q1

47uF C58

22uF T

-Vs (Power)

-Vs (Power)

+Vs (Power)

15

11
Buffer DRV

7

C9

Clip Detect

C30
10p

+Vs (Power)

TDA7293
U1

Out

R4
22K

13

STBY

Bootstrap

9

R13
680

Mute

R3
22K

6

10

SGND

Boot loader

R1
22K

In+

12

4

+Vs

8
3

10uF T
IN
C5

In-

-Vs

2

STBY GND

C1

1

D

R2 22K

13

R7 22K
470p

C27

1000uF

1000uF

+24V

LED

K2

K1

S1

D4

LS1

SW

10uF
C70

C49
100n

3
V
OUT

GND

C51
100n

MG1
C71
10uF

R38
56K

R39
56K

R40
56K

R43
10
C74
4.7uF

1N4148
D9

C75
33uF

D10

1N4148

1
2
3
4
5
6
7
8

C72

C73
22n

330uF

R42 56K

2

U10B

7

5
LM324

2

LM324

A

D11
1N4004

IRF640

100K

NTK1

5.6k

10k NTH4G1

+

C56

10
R37
100K

U10C

8

13

LM324

12

9

U10D

D12
1N4004

IRF640

14
LM324

A

Q5

C57

6

7

+

1.2K

100n

IRF640

5

A

MG3

10n

47K

-

12V FAN

R33

D5
LED

R45

4

-

12V FAN

MG2
Q4

TR1

C76

R36

6.8K R44

3

100n

1

100n

6

2X400W gainclone
TDA7293

+

C55

TR2
10k

400W 4Ohm

UPC1237
U11

A

U10A

LS2

RELAY

RELAY

Q3

R35
100K

400W 4Ohm

R41
56K

R34
100K

3

9.2K R30
D8
1N4148

1

1 V
IN

11

AC Input ~15V

B
U9
78L12

t

R32
1.2K

D3

4

LED

R29
2.2K

2

R31
4.7K

B

D13
1N4004

A
-

12V FAN

8

Document last modified and saved: 13 October 2011 11:57 AM

GND

-V

L1
R1

C

R2

C

D

C

I/O
+

C

i

Q

o

LED

7812

C

R

S

g

U+

JJ

d

s

C

D

g

Q

d

C

C

s

C

D

g

4 X IRF640

C

R

FAN

C

R

C

c

d

FAN

Q

s

c

C

C

U

D
R
+

+

Relay

C

R
R

C

h

U-

C

I/O

C+

C

Jumper

U-

-

C

U-

J

I/O

J

D

h

c

c

b

b

I/O

f

c

Inputs

g

C

C

R1

C

C

Trimmer potentiometer

Resistor

Powertransistor or powerfet

Single transistor or JFET

Dual transistor or JFET

Diode

TR

R

Q

Q

Q

D

C

C

c

Q

f1

C

C

R

clip led

a

C

c

Q

C

+

U

U

h

f1

P

e

b

U-

C

a J

C

R1

U-

R

U-

b

C

C

C

C

g1

C

Potentiometer

C

C

C

+

Power IC

Integrated circuit

Integrated circuit

Integrated circuit

C

Q

c g

g

Q

R

U

R

J

Good quailty non-electrolic
polarized capacitor,
for like Tantal

Electrolic capacitor

C

C

Power

Non-polarized capacitor,
C ceramic, or some good quality
like WIMA capacitors

NTK

C

C

J

+

Relay

s

U+

e1

L2

+

S

Q

d

g1

C

C

Q

C

Q

C

C

U+

C

C

e1

e1

R2

R

J C

C

C

C

c

Q

C

b

g1
C

C

R2

2X350W Bridge parallel poweramp
http://microprojects.rentahost.net

+

PWM Out

D

g

g1

C

R

+

I/O channel, connector for
input/output, VCC, VEE, etc...

FAN

Q

C

C

J

C

LM324

U

C

C

e

f (input)

c

Q

b

a

e1

L2

+

Connector

c

C

U-

clip led

a

C

Q

13 -

Fuse

C

C

C

b

+

C

J

U+

C

C

L1

+

R

J

D

R
R
R
R

c

C

R

Q

+

R

C

L1

R

C

C

c

g

L2

b

R

AC

+

+

+
UPC1237

+
R

Relay -

+

+ V,
Relay +

+

+

+

R

c

+

I/O

+

+
+

+

+

I/O

+

R

R

+

+

R

R

+

R
+

Q

+

+

with protection

+

+

R

+

R

R

R

+

R
+

+

+

+

R
+

+

R

+

+

+

+

R

R

TR

+

+ +

2 X TDA7293 Bridge/Parallel

+

+

+

+

R

R

TR

R

R

R

+

+

R

+

+

c

+

R

R

+

J

R
+

+

Visit the Picasa gallery of this project:
+

+
+

+

https://picasaweb.google.com/105028544937175433650/My2x400WRackPACircuit
+

Images about TDA 7293 amp project
Images about TDA7293 bridged-paralleled poweramp

R

Bridged poweramp project with TDA 7294 - 12
Bridged poweramp project with TDA 7294

PCB for TDA 7293 bridge amp project
The assembled poweramp and speaker protection PCB

+

+

I/O

R
R

I/O

Document last modified and saved: 13 October 2011 11:57 AM