Datasheet CXA2500N, CXA2500M Datasheet (Sony)

Dual REC/PB Preamplifier

Description

The CXA2500M/N is a dual recording/playback preamplifier system bipolar IC which has been developed for the low voltage operating cassette tape recorder.

Features

• Low quiescent current (VCC = 2V)

PB: ICC = 3.2mA (typ.)

REC: ICC = 5.2mA (typ.)

• Very few external parts

• Built-in Metal/Normal selection switch

• Small switching noise due to internal transient

muting

Applications

3V headphone radio cassette recorders

Structure

Bipolar silicon monolithic IC

Bock Diagram

Absolute Maximum Ratings (Ta = 25°C)

• Supply voltage VCC 7V

•Operating temperature Topr –20 to +75 °C

• Storage temperature Tstg –65 to +150 °C

• Allowable power dissipation PD

CXA2500M 600 mW CXA2500N 470 mW

Operating Conditions

Supply voltage PB VCC 1.2 to 3.5 V

REC VCC 1.6 to 3.5 V

– 1 –

E94806B8Y

Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.

CXA2500M/N

REFERENCE

MIC INPUT (A)

PB PRE

INPUT (A)

PB NF (A)

PB OUTPUT (A)

PB EQ

SWITCH (A)

TUNER

INPUT (A)

LINE

OUTPUT (A)

REC DRIVE

INPUT (A)

REC DRIVE

OUTPUT (A)

AGC TIME

CONSTANT

TAPE/TUNER

SELECTOR

GROUND

MIC INPUT (B)

PB PRE

INPUT (B)

PB NF (B)

PB OUTPUT (A)

PB EQ

SWITCH (B)

TUNER

INPUT (B)

LINE

OUTPUT (B)

REC DRIVE

INPUT (B)

REC DRIVE

OUTPUT (B)

V

CC

PB/REC

SELECTOR

6dB

22dB

12dB

–0.3dB

20.5dB

MIC

GCA

PB

LINE

REC

AMP

REF

PB/

REC

NORM/ METAL

TAPE/

TUNER

AGC

LINE

AMP

PB

GCA

MIC

REC

AGC DET

2

3

4

5

6

7

8

9

10

11

12

13

1415

16

17

18

19

20

21

22

23

24

1

CXA2500M

24 pin SOP (Plastic)

CXA2500N

24 pin SSOP (Plastic)

– 2 –

CXA2500M/N

Pin Description Pin voltage is during VCC = 2V

No.

223MIC IN (A)

MIC IN (B)

0.93V MIC preamplifier input

PB preamplifier input

PB equalizer circuit negative feedback

PB preamplifier output

PB equalizer switch

0.93V

PB PRE IN (A) PB PRE IN (B)

PB-NF (A) PB-NF (B)

PB OUT (A) PB OUT (B)

PB EQ SW (A) PB EQ SW (B)

3

22

4

21

5

20

6

19

Symbol

Voltage

(Typ.)

Equivalent circuit Description

510

10k

20k

VCC

Vref

2

23

510

VCC

Vref

22

3

510

VCC

Vref

510

4

21

VCC

20

5

VCC

6

19

– 3 –

CXA2500M/N

No.

718TUNER IN (A)

TUNER IN (B)

0.93V Tuner input

Line amplifier output

REC drive input

REC drive output

Reference voltage output

0.58V

0.93V

1.0V

0.93V

LINE OUT (A) LINE OUT (B)

REC AMP IN (A) REC AMP IN (B)

REC AMP OUT (A) REC AMP OUT (B)

REF

8

17

9

16

10 15

1

Symbol

Voltage

(Typ.)

Equivalent circuit Description

40k

4k

VCC

Vref

40k

18

7

142

40k

VCC

8

17

10k

4k

VCC

Vref

16

9

VCC

10

15

VCC

1

– 4 –

CXA2500M/N

No.

11 AGC TC 0.37V AGC time constant

Tape/tuner selection During Tape/Normal: 0V During Tape/Metal: 0.5V During Tuner Mode: 2.0V

PB/REC selection During PB = 0V During REC = 2.0V

0.5V

(Open)

0V

(2.0V)

TAPE/TUNER

PB/REC

12

13

Symbol

Voltage

(Typ.)

Equivalent circuit Description

1k

VCC

11

150k

VCC

142

50k

12

VCC

142

13

– 5 –

CXA2500M/N

Electrical Characteristics VCC = 2.0V, f = 1kHz, Ta = 25°C, unless otherwise specified.

Item

Icq1

Icq2

Icq3

Icq4

Vref

Gvo

Gvc1

Gvc2

CB

THD

Vom

Vno

RR

A

B

OFF

ON

PB

REC

PB

REC

PB

C

A

C

B

C

OFF

A

OFF

ON

OFF

ON

OFF

B

A

B

A

B

A

dBm

Io

V1

e8, e17

Vcc = 2.0V

No signal, Tape

Vcc = 2.0V

No signal, Mic Rec

Vcc = 2.0V

No signal, Tuner

Vcc = 2.0V

No signal, Tuner Rec

Vcc = 2.0V

No signal, Tape

Vo = –15dBm

THD = 1%

Rg = 2.2kΩ

fr = 100Hz

Vr = –30dBm

1.8

3.8

1.3

2.8

0.78

54

28.5

25.5

–2.0

—

190

—

27.5

3.2

5.2

2.8

4.2

0.93

65

30.8

27.2

0

0.3

300

72

35

5.5

7.2

4.7

6.2

1.05

—

33.0

29.0

+2.0

1.05

—

125

—

mA

V

dB

%

mV

µV

dB

Symbol

SW condition Input condition

Measure

-ment

point

Measurement

conditions

Min. Typ. Max. Unit

S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 Vin1 Vin2 Vin3 Unit

Tape playback

quiescent current

MIC recording

quiescent current

Radio playback

quiescent current

Radio pecording

quiescent current

Reference

voltage

(1) PLAYBACK MODE

Open loop

voltage gain

Close loop

voltage gain 1

Close loop

voltage gain 2

Channel

balance

Total harmonic

distortion

Maximum output

voltage

Output noise

voltage

Ripple rejection

– 6 –

CXA2500M/N

Gvc

CB

THD

Vom

Vno

RR

Gvc

CB

THD

Vno

W ALC

Vo ALC

CB ALC

RR

A

B

A

B

ON

REC

A

C

OFF

ON

OFF

ON

OFF

A

B

A

B

A

OFF

B

A

B

A

B

A

C

A

–50

–60

–30

dBm

e10, e15

Vin = –30dBm

THD = 1%

Rg = 10kΩ

fr = 100Hz

Vr = –30dBm

Vo = –15dBm

Vin = –50dBm

BW = 30 to 20kHz

The input range

when the output

level varies ±3dB

from the standard

input level

(Vin = –60dBm)

Vin = –60dBm

fr = 100Hz

Vr = –30dBm

17.8

–1.5

—

380

—

24

58.5

–1.5

—

230

–2

–5

19.5

0

0.1

600

280

33

61.8

0

1.5

3

39

340

0

3

21.2

1.5

0.5

—

360

—

65.0

1.5

4.5

4.7

—

470

+2

—

dB

%

mV

µV

dB

%

mV

dB

mV

dB

S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 Vin1 Vin2 Vin3 Unit

Item Symbol

SW condition Input condition

Measure

-ment

point

Measurement

conditions

Min. Typ. Max. Unit

(2) RADIO RECORDING: -

Voltage gain

Channel balance

Total harmonic

distortion

Maximum output

voltage

Output noise

voltage

Ripple rejection

(3) MIC RECORDING: -

Voltage gain

Channel

balance

Total harmonic

distortion

Output noise

voltage

ALC width

ALC voltage

ALC balance

Ripple rejection

– 7 –

CXA2500M/N

Measurement Circuit

REF

MIC

IN (A)

PB PRE

IN (A)

PB/MIC

NF (A)

PB

OUT (A)

METAL

SW (A)

TUNER

IN (A)

LINE

OUT (A)

REC

IN (A)

REC

OUT (A)

AGC TC

TAPE/

RADIO SW

GND

MIC

IN (B)

PB PRE

IN (B)

PB/MIC

NF (B)

PB

OUT (B)

METAL

SW (B)

TUNER

IN (B)

LINE

OUT (B)

REC

IN (B)

REC

OUT (B)

V

CC

REC/PB

SW

Vin1

1kHz

S5

S7

1µ

Vin2

1kHz

1µ

2.2k

330

33µ

S9

A

B

100k

15k

22k

1µ

Vin3

1kHz

A

B

10k

1µ

10k

1µ

e8

10k

0.0047µ

e10

4.7µ

S13

A

B

ABC

S4

TUNER

METAL PB

NORMAL PB

10k

S3

PB

S2

I

0

47µ

A

B

Vr

2V

10k

0.0047µ

e15

400 to 30kHz

BPF

e17

1µ

1kHz

Vin3

10k

1µ

15k

100k

330

A

B

S12

22k

33µ

2.2k

1µ

1kHz

Vin2

1µ

1kHz

Vin1

S6

100µ

V1

S11

A

B S10

S8

2V

S1

VCC

2.2k

I

11

2

3

4

5

6

7

8

9

10

11

12

13

1415

16

17

18

19

20

21

22

23

24

1

0.01µ

C

REC

400 to 30kHz

BPF

400 to 30kHz

BPF

400 to 30kHz

BPF

– 8 –

CXA2500M/N

Application Circuit

6dB 22dB

12dB

–0.3dB

20.5dB

MIC

GCA

PB

LINE

REC

AMP

REF

PB/

REC

NORM/

METAL

TAPE/

RADIO

AGC

LINE

AMP

PB

GCA

MIC

REC

AGC

DET

1µ

A CH

1000p

MIC IN (A)

330

33µ

15k

330k

39k

0.01µ

22k

RADIO IN (A)

1µ

TO POWER AMP (A)

1µ

10k

0.0047µ

3.3M

47µ

22µ

2.2k

RADIO

TAPE/METAL

TAPE/NORM

10k

22µ

PB

47µ

10k

0.0047µ

1µ

TO POWER AMP (B)

1µ

RADIO IN (B)

22k

15k

330k

0.01µ

39k

330

1000p

MIC IN (B)

1µ

BIAS

100µ

REC

PB

1µ

VCC

33µ

0.01µ

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

1

0.01µ

REC

Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for

any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same.

– 9 –

CXA2500M/N

Description of Operation

REF Pin (Pin 1)

A low impedance pin for outputting the internal reference voltage, which is fixed at 0.93V regardless of supply voltage variation.

LINE OUT Pin (Pin 8)

This output pin outputs signal from any selected source (MIC, Tape or Tuner) to the subsequent stages such as Dolby NR or power amplifier for further signal processing. It is internally biased at 0.58V so as to achieve maximum dynamic swing at minimum supply voltage of 1.2V. The change of DC potential at this pin that may result from any changeover of PB/REC or Tape/Tuner switch was set to be minimum, thus reducing any potential occurence of switching noise.

REC Out Pin (Pin 10)

This recording driver output pin is internally biased at 1.0V to achieve maximum signal swing at minimum supply voltage of 1.6V during the recording mode. The REC OUT will be momentally muted during the changeover of PB/REC or Tape/Tuner modes, so as to prevent mis-recording of any undesired switching noise. The muting period is determined by the values of R and C at Pins 12 or 13.

AGC TC Pin (Pin 11)

This is the external pin for AGC filter during the MIC Recording mode. The attack time is determined by the 1kΩ resistor inside the IC and the external electrolytic capacitor. The recovery time is determined by both external resistor and electrolytic capacitor at Pin 11.

Notes on Operation

1. The following table shows the potential at Pins 12 and 13 and the associated operating states of the

amplifier. Each of the pins, when at the same potential as Pin 14, has H level, and when at the same potential as Pin 24, has L level.

System Control Operation Table

Control pins

Amplifier operating state

MIC AMP AGC DET GCA AMP PB AMP EQ SWITCH LINE AMP REC AMP

OFF OFF OFF OFF

ON

OFF

ON

OFF

OFF OFF OFF OFF

ON ON ON

OFF

OFF OFF OFF OFF OFF OFF

ON

OFF

ON ON ON

ON OFF OFF

ON

OFF OFF OFF OFF OFF OFF

ON ON

Operating

mode

Playback

(Normal)

Playback

(Metal)

Tuner

Mode

MIC

Recording

Tuner

Recording

Pin 13 L H Pin 12 L FLOAT H L, FLOAT H

– 10 –

CXA2500M/N

2. PB Mode: To reduce the PB amplifier DC output offset, it is recommended that 39kΩ resistor be connected as shown in the Application Circuit. However, too low this resistor value may affect the low frequency portion of the PB frequency response. The inter-relationship of the RC values in the playback equalization network is as shown below:

During Normal PB mode, Gain G1 = 20 log (R2 + R5)/R5 3dB cut-off frequency, f1 = 1/(2 × 3.1416 × C1 × R2)

During Metal PB mode, Gain G2 = 20 log (R2//R3 + R5)/R5 3dB cut-off frequency, f2 = 1/(2 × 3.1416 × C1 × R2//R3)

3. Use of RC at Tape/Tuner and PB/REC pins: The purpose of the external RC components at the switch inputs is to create an internal mute pulse so as to mute the REC OUT momentally during the switching operation. By doing so, the switching click noise that may appear at REC OUT can be reduced. The selection of the RC values affects the duration of the mute pulse. It is recommended to use resistor of 2.2kΩ and below at Tape/Tuner pin, i.e Pin 12. These RC components may be removed if such internal pop noise countermeasure is not required.

R1

330k

C1

0.01µ

IN

R2

15k

R3 22k

R5

330

REF

R4

39k

C2

33µ

PB

+

–

55 50

40

30

Voltage [dB]

CXA2500 TAPE PB: GV, THD vs f VO = –15dBm VCC = 2V

45

35

25

10 100 1k 10k 100k

f

1 f2

f [Hz]

NORMAL

METAL

G1 G2

GV (dB)

– 11 –

CXA2500M/N

Package Outline Unit: mm

CXA2500M

CXA2500N

SONY CODE EIAJ CODE JEDEC CODE

M

PACKAGE STRUCTURE

MOLDING COMPOUND LEAD TREATMENT LEAD MATERIAL PACKAGE WEIGHT

EPOXY/PHENOL RESIN SOLDER PLATING

COPPER ALLOY / 42ALLOY

24PIN SOP (PLASTIC)

15.0 – 0.1

+ 0.4

1 12

1324

1.270.45 ± 0.1

5.3 – 0.1

+ 0.3

7.9 ± 0.4

0.2 – 0.05

+ 0.1

0.5 ± 0.2

0.1 – 0.05

+ 0.2

0.15

1.85 – 0.15

+ 0.4

6.9

± 0.12

SOP-24P-L01 ∗SOP024-P-0300-A

0.3g

SONY CODE

EIAJ CODE

JEDEC CODE

SSOP-24P-L01 SSOP024-P-0056

PACKAGE MATERIAL LEAD TREATMENT LEAD MATERIAL PACKAGE MASS

EPOXY RESIN SOLDER/PALLADIUM

42/COPPER ALLOY

PACKAGE STRUCTURE

PLATING

0.1g

24PIN SSOP(PLASTIC)

0.1 ± 0.1

0° to 10°

0.5 ± 0.2

DETAIL

A

∗5.6 ± 0.1

24

∗7.8 ± 0.1

13

0.65

12

1

7.6 ± 0.2

0.1

1.25 – 0.1

+ 0.2

A

0.13

M

NOTE: Dimension “∗” does not include mold protrusion.

b=0.22 – 0.05

+ 0.1

0.15 – 0.02

+ 0.05

(0.22)

(0.15)

0.15 – 0.01

DETAIL B : SOLDER DETAIL B : PALLADIUM

+ 0.03

b=0.22 ± 0.03

B

b

NOTE : PALLADIUM PLATING

This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).