AN7531SA-2

AN7531SA

Headphone amplifier IC for portable equipment

■ Overview

AN7531SA is an audio signal processing IC in which bass boost amplifiers, ALC circuit and beep circuit are built in the headphone amplifiers for use in portable equip- ment. Its headphone output block is using the center amplifier method which eliminates the need for coupling capacitor so that the circuit is most suitable for rational- ization of audio circuit.

■ Features

• Output coupling capacitor is not required (Center am- plifier method)

• Built-in bass boost amplifiers

• ALC circuit

• Built-in mute circuit

• Built-in beep circuit

• With mixed output pin of power amplifier

■ Applications

• Portable CD and MD players, etc.

■ Block Diagram

SSOP024-P-0300A

Unit: mm

6.5 ± 0.3

1 12

24 13

5.5 ± 0.3 7.5 ± 0.3

(0.50) 0.50

Seating plane Seating plane

0.2 ± 0.1 0.65 ± 0.100.65 ± 0.10 1.5 ± 0.20.1 ± 0.1

(0.50) 0° to 10°

0.15 + 0.10− 0.05

241 232 223 214 205 196 187 178 169 1510 1411 1312

BST SW

Standby SW

C-amp.

SW

Mute SW

ATT SW

ALC det.

Bias Beep

Note) *1: Except for the operating ambient temperature and storage temperature, all ratings are for Ta= 25°C.

*2: Without signal.

*3: Ta= 75°C, mounted on standard board (Refer to the Application Notes).

■ Absolute Maximum Ratings

Parameter Symbol Rating Unit

Supply voltage ^*2 V_CC 4.6 V

Supply current I_CC 200 mA

Power dissipation ^*3 P_D 370 mW

Operating ambient temperature ^*1 T_opr −25 to +75 °C

Storage temperature ^*1 T_stg −55 to +125 °C

■ Recommended Operating Range

■ Pin Descriptions

Pin No. Description

13 Attenuation SW 14 ch.1 input pin 15 ch.2 input pin 16 GND (input) 17 Beep sound input pin 18 Mute time-constant pin 19 Mute control pin 20 Standby control pin 21 Bias output pin 22 Bias input pin 23 Bass boost control pin 24 Bass boost amplifier output pin

Pin No. Description

1 Bass boost amplifier NF 2 ch.1 and ch.2-mixed output pin 3 Ripple filter

4 Center amplifier output control SW

5 Supply pin

6 ch.2 output pin

7 Center amplifier output pin 8 ch.1 output pin

9 GND (output)

10 Mixed output pin of power amplifier 11 ALC input pin

12 ALC detection pin

Parameter Symbol Range Unit

Supply voltage V_CC 1.8 to 4.5 V

Parameter Symbol Conditions Min Typ Max Unit

Standby current I_STB V_IN= 0 mV, STB: On  0.1 5 µA

Quiescent current 1 I_CQ1 V_IN= 0 mV, C-CUP: On  1.5 3.0 mA

Quiescent current 2 I_CQ2 V_IN= 0 mV, C-CUP: Off  2.0 4.0 mA

Voltage gain 1 G_V1 V_OUT= −22 dBV, ATT: On 5.5 8.3 10.5 dB

Voltage gain 2 G_V2 V_OUT= −22 dBV, ATT: Off 14 15.9 18 dB

Channel balance CB V_OUT= −22 dBV −1.0 0 1.0 dB

Maximum output power P_O THD = 10%, VCC= 2 V 5.0 9.0  mW

Total harmonic distortion THD V_OUT= −12.2 dBV  0.1 0.5 %

Output noise voltage V_NO R_g= 600 Ω  −94.5 −88 dBV

Channel cross-talk CT V_OUT= −12.2 dBV 30 50  dB

Ripple rejection RR V_CC= 1.8 V, fr= 100 Hz, Vr= −20 dBV 64 72  dB

Mute attenuation MT V_OUT= −12.2 dBV 68 78  dB

Beep sound output voltage V_BEEP V_BEEP-IN= 0 dBV −56 −51 −46 dBV Boosting amount B_ST V_OUT= −30 dBV, f = 100 Hz 9.7 11.7 13.7 dB

ALC detection level V_ALC V_IN= −20 dBV −41.5 −39.5 −37.5 dBV

Note) Condition: V_CC= 2.4 V, RL= 16 Ω, f = 1 kHz, Rg= 10 kΩ, STB: On, Mute: Off, C-CUP: Off, ATT: Off, ALC: Off, BST: Off

*1: Measurement using A curve filter

*2: Measurement using 30 kHz LPF

■ Application Notes

1. P_D Ta curves of SSOP024-P-0300A

P_D Ta

Power dissipation PD (mW)

0

0 25

Ambient temperature T_a (°C)

50 75 100 125

100 200 300 400 500 600

390 700 800 900

740

Mounted on standard board

(glass epoxy: 50 mm × 50 mm × t0.08 mm) Rth(j-a)= 135.1°C/W

Independent IC without a heat sink Rth(j-a) = 256.4°C/W

■ Electrical Characteristics at T

= 25°C

■ Application Notes (continued)

I_CC VCC (STB: 0 V, Mute: On) I_CC VCC

I_CC VCC (ALC: On, ATT: On) I_{CC7, 8} VCC

I_CC PO I_CQ VSTB

0.0 4.0

1.0 3.0 5.0

Power supply voltage V_CC (V) Power supply current ICC (mA)

1.0 2.0 3.0

4.5 2.5

1.5 2.0 3.5 4.0

0.5 1.5 3.5

2.5

VIN = 0 mV RL= 16 Ω Rg= 10 kΩ STB = 0 V/VCC

Mute = 0 V/VCC

ALC = Off BST = Off ATT = On/off CCUP = Off/on

ICC1 (C-CUP) STB = 0 V, ICC2 (BTL) STB = 0 V ICC4 (BTL) Mute = On

ICC3 (C-CUP) Mute = On

0.0 4.5

1.0 3.0 5.0

Power supply voltage V_CC (V) Power supply current ICC (mA)

1 3

4.5 2.5

1.5 2.0 3.5 4.0

2 4

0.5 1.5 3.5

2.5

VIN = 0 mV RL= 16 Ω Rg = 10 kΩ STB = VCC

Mute = 0 V ALC = Off BST = On/off ATT = On/off CCUP = Off

ICC5 (SEPP) ICC6 (BTL)

ICC (BTL) BST = On ICC (SEPP) BST = On

0.0 4.0

1.0 3.0 5.0

Power supply voltage V_CC (V) Power supply current ICC (mA)

1.0 2.0 3.0

4.5 2.5

1.5 2.0 3.5 4.0

0.5 1.5 3.5

2.5 VIN= 0 mV RL= 16 Ω Rg= 10 kΩ STB = VCC

Mute = 0 V

ALC = On/off BST = Off ATT = On/off CCUP = Off/on

ICC (BTL) ATT = On

ICC (C-CUP) ALC = On ICC (C-CUP) ATT = On

ICC (BTL) ALC = On

5 15

1.0 3.0 5.0

Power supply voltage V_CC (V) Power supply current ICC (mA)

4.5 2.5

1.5 2.0 3.5 4.0

6 7 8 9 10 11 12 13 14

VOUT = 0.5 mV f = 1 kHz RL = 16 Ω Rg= 10 kΩ STB = VCC

Mute = 0 V

ALC = Off BST = Off ATT = On/off CCUP = Off

ICC7 (SEPP) ICC8 (BTL)

1

10.00 1.00

0.10 0.01

10 100

Output power P_O (mW) VCC = 2.4 V

f = 1 kHz RL = 16 Ω Both ch. input Rg = 10 kΩ

STB = VCC

Mute = 0 V ALC = Off BST = Off ATT = Off CCUP = Off

Power supply current ICC (mA)

ICC (C-CUP) ICC (BTL)

0.0 3.0

0.0

Standby voltage V_STB (V) Power supply current ICC (mA)

2.5 0.5

0.5 1.0 1.5 2.0 2.5

1.0 1.5 2.0

VCC= 2.4 V VIN = 0 mV RL= 16 Ω Rg= 10 kΩ Mute = 0 V

ALC = Off BST = Off ATT = Off CCUP = Off

P_O , THD  VIN (ALC: On) G_V frequency

Beep  VIN G_V VCC

0 110

1.0 3.0 5.0

Power supply voltage V_CC (V) Maximum output power PO (mW)

4.5 2.5

1.5 2.0 3.5 4.0

10 20 30 40 50 60 70 80 90 100

f = 1 kHz THD = 10%

RL= 16 Ω Both ch. input Rg= 10 kΩ STB = VCC

Mute = 0 V

ALC = Off BST = Off ATT = Off CCUP = Off

Ch.1, Ch.2

0.01

100.00 10.00

1.00 0.10

10

1

0.1 100

Output power P_O (mW)

Total harmonic distortion THD (%)

VCC= 2.4 V f = 1 kHz RL= 16 Ω Both ch. input Rg= 10 kΩ A-curve filter

STB = VCC

Mute = 0 V ALC = Off BST = Off ATT = Off CCUP = Off

100 Hz ch.1, ch.2 10 kHz ch.1, ch.2

1 kHz ch.1, ch.2

−50 0

−70 0

Input voltage V_IN (dBV)

Output voltage VO (dBV) Total harmonic distortion THD (%)

−45

0 10

−60

−40

−35

−30

−25

−20

−15

−10

2 4 6 8

−5

−50 −40 −30 −20 −10

VO (ALC : Off)

THD (ALC : Off)

THD (ALC : On) VO (ALC : On)

VCC = 2.4 V f = 1 kHz RL= 16 Ω Both ch. input Rg= 10 kΩ STB = VCC

Mute = 0 V ALC = Off/on BST = Off ATT = Off CCUP = Off

Output voltage GV (dBV)

100k 10k

1k

10 100

Frequency f (Hz)

−40

−10

−35

−30

−25

−20

−15

VCC= 2.4 V VIN= −46 dBV RL= 16 Ω Both ch. input Rg= 10 kΩ STB = VCC

Mute = 0 V ALC = Off BST = On/off ATT = Off CCUP = Off GV (BST : On)

GV (BST : Off)

−100 0

0 1 600

Beep input voltage V_BEEP-IN (mV[p-p]) Beep output voltage VBEEP (dBV)

−90 200

−80

−70

−60

−50

−40

−30

−20

−10

400 600 800 1 000 1 200 1 400 VBEEP (ch.1 Mute : Off)

VBEEP (ch.2 Mute : Off) VCC= 2.4 V VIN= 0 mV RL= 16 Ω Rg= 10 kΩ

STB = VCC

Mute = 0 V/VCC

ALC = Off BST = Off ATT = Off CCUP = Off

0 20

Power supply voltage V_CC (V) Output voltage gain GV (dB)

2 4 6 8 10 12 14 16 18

VOUT = −20 dB f = 1 kHz RL = 16 Ω Both ch. input Rg = 10 kΩ

STB = VCC

Mute = 0 V ALC = Off BST = Off ATT = On/off CCUP = Off

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 GV1 (ch.1 ATT : Off), GV1 (ch.2 ATT : Off)

GV2 (ch.1 ATT : On), GV2 (ch.2 ATT : On)

■ Application Notes (continued)

P_O VCC THD  PO

RR  VCC V_TH-STB VCC

V_TH-MUTE VCC V_TH-ALC , V_TH-BST VCC

Channel crosstalk CT (dB)

100k 10k

1k

10 100

Frequency f (Hz) 0

100

10 20 30 40 50 60 70 80 90

0 100

10 20 30 40 50 60 70 80 90

CT (ch.1) MT (ch.1) MT (ch.2)

CT (ch.2) VCC= 2.4 V

VOUT = −20 dBV RL= 16 Ω Both ch. input Rg= 10 kΩ A-curve filter STB = VCC

Mute = 0 V/VCC

ALC = Off BST = Off ATT = Off CCUP = Off

Mute effective MT (dB) Channel crosstalk CT (dB)

1 000

10 100

Input voltage V_IN (mV) 0

100

10 20 30 40 50 60 70 80 90

CT (ch.1) MT (ch.1) MT (ch.2)

CT (ch.2) VCC= 2.4 V

f = 1 kHz RL= 16 Ω Both ch. input Rg= 10 kΩ A-curve filter

STB = VCC

Mute = 0 V ALC = Off BST = Off ATT = Off CCUP = Off

0 100

10 20 30 40 50 60 70 80 90

Mute effective MT (dB)

50 90

1.0 3.0 5.0

Power supply voltage V_CC (V) Ripple rejection ratio RR (dB) ⁶⁰

70 80

4.5 2.5

1.5 2.0 3.5 4.0

55 65 85

75

Vr = −20 dBV fr= 100 Hz THD = 10%

RL= 16 Ω Both ch. input Rg= 10 kΩ A-curve filter

STB = VCC

Mute = 0 V ALC = Off BST = Off ATT = Off CCUP = Off RR (ch.1), RR(ch.2)

0 2

1.0 3.0 5.0

Power supply voltage V_CC (V) Standby thereshold voltage VTH-STB (V)

0.5 1 1.5

4.5 2.5

1.5 2.0 3.5 4.0

VIN= 0 mV RL= 16 Ω Rg= 10 kΩ Mute = 0 V ALC = Off BST = Off ATT = Off CCUP = Off

0 2

1.0 3.0 5.0

Power supply voltage V_CC (V) Mute thereshold voltage VTH-MUTE (V)

0.5 1 1.5

4.5 2.5

1.5 2.0 3.5 4.0

VIN = 0 mV RL= 16 Ω Rg= 10 kΩ STB = VCC

ALC = Off BST = Off ATT = Off CCUP = Off

0.0 2.0

1.0 3.0 5.0

Power supply voltage V_CC (V)

ALC thereshold voltage VTH-ALC (V) BST thereshold voltage VTH-BST (V)

0.5 1.0 1.5

0 2

0.5 1 1.5

4.5 2.5

1.5 2.0 3.5 4.0

STB = V^CC Mute = 0 V ATT = Off CCUP = Off VIN= 0 mV

RL= 16 Ω Rg= 10 kΩ

VTH-ALC

VTH-BST

■ Application Notes (continued)

CT, MT  frequency CT, MT  VIN

■ Application Circuit Examples

1. Center output method (without output capacitor) 1) At bass boosting

241 232 223 214 205 196 187 178 169 1510 1411 1322 µF

22 µF 0.22 µF

10 µF

47 kΩ 12

BST SW

Standby SW

C-amp.

SW

Mute SW

ATT SW

ALC det.

Bias Beep

16 Ω

V_CC

16 Ω 0.1 µF

SP2 Standby Mute

SP1 Off

ALC On On

Off

Off On On ATT

Off On

BST Off

1 µF

10 µF

0.068 µF

2.2 µF0.068 µF

10 kΩ 10 kΩ

Beep In2 In1

0.0 4.0

1.0 3.0 5.0

Power supply voltage V_CC (V)

CCUP thereshold voltage VTH-CCUP (V) ATT thereshold voltage VTH-ATT (V)

1.0 2.0 3.0

0 2

0.5 1 1.5

4.5 2.5

1.5 2.0 3.5 4.0

0.5 1.5 3.5

2.5

VIN = 0 mV RL= 16 Ω Rg = 10 kΩ STB = VCC

Mute = 0 V ALC = Off BST = Off

VTH-ATT

VTH-CCUP

■ Application Notes (continued)

■ Application Circuit Examples (continued)

1. Center output method (without output capacitor) (continued) 2) No bass boosting

241 232 223 214 205 196 187 178 169 1510 1411 1322 µF

22 µF 0.22 µF

10 µF 12

BST SW

Standby SW

C-amp.

SW

Mute SW

ATT SW

ALC det.

Bias Beep

16 Ω V_CC

16 Ω 0.1 µF

SP2 Standby Mute

SP1 Off

ALC On On

Off

Off On On ATT

Off

1 µF

10 kΩ 10 kΩ

Beep In2 In1

241 232 223 214 205 196 187 178 169 1510 1411 1322 µF

22 µF 0.22 µF

10 µF

47 kΩ 12

BST SW

Standby SW

C-amp.

SW

Mute SW

ATT SW

ALC det.

Bias Beep

16 Ω V

16 Ω 0.1 µF

SP2 Standby Mute

SP1 Off

On On

Off

Off On On ATT

Off On

BST Off

1 µF 470 µF 470 µF

10 µF

0.068 µF

2.2 µF0.068 µF

10 kΩ 10 kΩ

Beep In2 In1

2. Output transformer less (OTL) (Output capacitors are necessary)