ST TS4995 User Manual

Features

TS4995

1.2 W fully differential audio power amplifier
with selectable standby and 6 dB fixed gain

■ Differential inputs

■ 90 dB PSRR @ 217 Hz with grounded inputs

■ Operates from V

■ 1.2 W rail-to-rail output power @ V

= 2.5 V to 5.5 V

CC

CC

=5 V,

THD+N=1%, F=1 kHz, with an 8 Ω load

■ 6 dB integrated fixed gain

■ Ultra-low consumption in standby mode

(10 nA)

■ Selectable standby mode (active low or active

high)

■ Ultra-fast startup time: 10 ms typ. at V

■ Available in 9-bump flip chip (300 mm bump

CC

=3.3 V

diameter)

■ Ultra-low pop and click

Applications

■ Mobile phones (cellular / cordless)

■ PDAs

■ Laptop / notebook computers

■ Portable audio devices

Description

The TS4995 is an audio power amplifier capable
of delivering 1.2 W of continuous RMS output
power into an 8 Ω load at 5 V. Thanks to its
differential inputs, it exhibits outstanding noise
immunity.

TS4995 - Flip chip 9

Pin connections (top view)

Gnd

Gnd

V

V

Bypass Stdby

Bypass Stdby

V

V

765

765

O-

O-

8

8

IN+

IN+

1

1

9

9

2

2

V

V

CC

CC

V

V

O+

O+

4

4

V

V

3

3

IN-

IN-

Stdby Mode

Stdby Mode

The TS4995 features an internal fixed gain at 6dB
which reduces the number of external
components on the application board.

The device is equipped with common mode
feedback circu itry allowing outputs to be always
biased at V

/2 regardless of the input common

CC

mode voltage.
The TS4995 is specifically designed for high

quality audio applications such as mobile phones
and requires few external components.

An external standby mode control reduces the
supply current to less than 10 nA. A STBY MODE
pin allows the standby pin to be active high or
low. An internal thermal shutdown protection is
also provided, making the device capable of
sustaining short-circuits.

March 2008 Rev 3 1/26

www.st.com

26

Contents TS4995

Contents

1 Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 3

2 Typical application schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.1 Differential configuration principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.2 Common mode feedback loop limitations . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.3 Low frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.4 Power dissipation and efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.5 Decoupling of the circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.6 Wake-up time t

4.7 Shutdown time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.8 Pop performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.9 Single-ended input configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

WU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

5 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

6 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2/26

TS4995 Absolute maximum ratings and operating conditions

1 Absolute maximum ratings and operating conditions

Table 1. Absolute maximum ratings (AMR)

Symbol Parameter Value Unit

(2)

(1)

(4)

(5)

(3)

6V

GND to V

CC

V

200 °C/W

200 V

1.5 kV

V

CC

V

in

T

oper

T

stg

T

R

thja

P

diss

ESD

Supply voltage
Input voltage
Operating free air temperature range -40 to + 85 °C
Storage temperature -65 to +150 °C
Maximum junction temperature 150 °C

j

Thermal resistance junction to ambient
Power dissipation Internally limited W
MM: machine model
HBM: human body model

Latch-up Latch-up immunity 200 mA

- Lead temperature (soldering, 10sec) 260 °C

1. All voltage values are measured with respect to the ground pin.

2. The magnitude of input signal must never exceed V

3. The device is protected in case of over temperature by a thermal shutdown activated at 150° C.

4. Machine model: a 200 pF cap is charged to the specified voltage, then discharged directly between two pins of the device
with no external series resistor (internal resistor < 5 Ω), done for all couples of pin combinations with other pins floating.

5. Human body model: 100 pF discharged through a 1.5 kΩ resistor between two pins of the device, done for all couples of pin
combinations with other pins floating.

Table 2. Operating conditions

+ 0.3 V / GND - 0.3 V.

CC

Symbol Parameter Value Unit

V

Supply voltage 2.5 to 5.5 V

CC

Standby mode voltage input:

V

SM

Standby Active LOW
Standby Active HIGH

=GND

V

SM

VSM=V

CC

V

Standby voltage input:

V

STBY

T

SD

R

L

R

thja

1. The minimum current consumption (I
temperature range.

Device ON (V
Device OFF (V

=GND) or Device OFF (VSM=VCC)

SM

=GND) or Device ON (VSM=VCC)

SM

Thermal shutdown temperature 150 °C
Load resistor ≥ 4 Ω
Thermal resistance junction to ambient 100 °C/W

) is guaranteed when V

STBY

1.5 ≤ V

GND ≤ V

= GND or VCC (the supply rails) for the whole

STB Y

STBY
STBY

≤ VCC
≤ 0.4

(1)

V

3/26

Typical application schematics TS4995

2 Typical application schematics

Table 3. External component descriptions

Component Functional description

C

s

C

b

C

in

Supply bypass capacitor that provides power supply filtering.
Bypass capacitor that provides half supply filtering.
Optional input capacitor that forms a high pass filter together with Rin.

= 1 / (2 x π x Rin x Cin)

(F

cl

Figure 1. Typical application

Optional

Vin­P1

P2
Vin+

Cin1

330nF
Cin2

330nF

3

1

8

TS4995

Vin-

Vin+

BYPASS

BIAS

VCC

2

Cs1
1uF

TS4995 FlipChip

Vcc

Vo-

7

Vo+

+

5

8 Ohms

1uF

3

STDBY

2

1

Cbypass1

VCC

4/26

4

STDBY / Operation

STBY

STDBY MODE

9

2

3

GND

6

STDBY MODE

1

TS4995 Electrical characteristics

3 Electrical characteristics

Table 4. VCC = +5V, GND = 0V, T

= 25°C (unless otherwise specified)

amb

Symbol Parameter Test conditions Min. Typ. Max. Unit

Supply current No input signal, no load 4 7 mA

I

CC

I

THD + N

PSRR

Standby current

STBY

Differential output offset

V

oo

voltage

V

Input common mode voltage 0 4.5 V

IC

Output power THD = 1% Max, F= 1kHz, RL = 8Ω 0.8 1.2 W

P

o

Total harmonic distortion +
noise

Power supply rejection ratio

IG

with inputs grounded

(1)

CMRR Common mode rejection ratio

SNR Signal-to-noise ratio

GBP Gain bandwidth product R

No input signal, V
No input signal, V

No input signal, R

Po = 850mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω 0.5 %

F = 217Hz, R = 8Ω, Cin = 4.7µF, Cb =1µF
V

= 200mV

ripple

F = 217Hz, RL = 8Ω, Cin = 4.7µF, Cb =1µF

= 200mV

V

ic

PP

A-weighted filter

= 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz 100

R

L

= 8Ω 2MHz

L

= VSM = GND, RL = 8Ω

STBY

= VSM = VCC, RL = 8Ω

STBY

= 8Ω 0.110mV

L

PP

75

10 1000 nA

(2)

90 dB

60 dB

20Hz ≤ F ≤ 20kHz, RL = 8Ω

Unweighted

Output voltage noise

V

N

A-weighted
Unweighted, standby
A-weighted, standby

Z

Input impedance 15 20 25 kΩ

in

11

7

3.5

1.5

µV

- Gain mismatch 5.5 6 6.5 dB

t

Wake-up time

WU

1. Dynamic measurements - 20*log(rms(V

2. Guaranteed by design and evaluation.

3. Transition time from standby mode to fully operational amplifier.

(3)

Cb =1µF 15 ms

)/rms (V

out

ripple

)). V

is the super-imposed sinus signal relative to VCC.

ripple

dB

RMS

5/26

Electrical characteristics TS4995

Table 5. VCC = +3.3V (all electrical values are guaranteed with correlation measurements at

2.6V and 5V), GND = 0V , T

= 25°C (unless otherwise specified)

amb

Symbol Parameter Test conditions Min. Typ. Max. Unit

I

Supply current No input signal, no load 3 7 mA

CC

I

THD + N

PSRR

Standby current

STBY

Differential output offset

V

oo

voltage

V

Input common mode voltage 0.4 2.3 V

IC

P

Output power THD = 1% max, F= 1kHz, RL = 8Ω 300 500 mW

o

Total harmonic distortion +
noise

Power supply rejection ratio

IG

with inputs grounded

(1)

CMRR Common mode rejection ratio

SNR Signal-to-noise ratio

GBP Gain bandwidth product R

Output voltage noise

V

N

No input signal, V
No input signal, V

No input signal, R

Po = 300mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω 0.5 %

F = 217Hz, R = 8Ω, Cin = 4.7µF, Cb =1µF
V

= 200mV

ripple

F = 217Hz, R
Vic = 200mV

= 8Ω, Cin = 4.7µF, Cb =1µF

L

PP

A-weighted filter

= 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz 100

R

L

= 8Ω 2MHz

L

20Hz ≤ F ≤ 20kHz, R

Unweighted
A weighted
Unweighted, standby
A weighted, standby

= VSM = GND, RL = 8Ω

STBY

= VSM = VCC, RL = 8Ω

STBY

= 8Ω 0.110mV

L

PP

75

10 1000 nA

(2)

90 dB

60 dB

= 8Ω

L

11

7

µV

3.5

1.5

dB

RMS

Z

Input impedance 15 20 25 kΩ

in

- Gain mismatch 5.5 6 6.5 dB
Wake-up time

t

WU

1. Dynamic measurements - 20*log(rms(V

2. Guaranteed by design and evaluation.

3. Transition time from standby mode to fully operational amplifier.

(3)

Cb =1µF 10 ms

)/rms (V

out

ripple

)). V

is the super-imposed sinus signal relative to VCC.

ripple

6/26

TS4995 Electrical characteristics

Table 6. VCC = +2.6V, GND = 0V, T

= 25°C (unless otherwise specified)

amb

Symbol P arameter Test condition s Min. Ty p. Max. Unit

I

Supply current No input signal, no load 3 7 mA

CC

I

STBY

THD + N

PSRR

CMRR

Standby current

Differential output offset

V

oo

voltage

V

Input common mode voltage 0.6 1.5 V

IC

P

Output power THD = 1% max, F= 1kHz, RL = 8Ω 200 300 mW

o

Total harmonic distortion +
noise

Power supply rejection ratio

IG

with inputs grounded

(1)

Common mode rejection
ratio

SNR Signal-to-noise ratio

GBP Gain bandwidth product R

Output voltage noise

V

N

No input signal, V
No input signal, V

No input signal, R

Po = 225mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω 0.5 %

F = 217Hz, R = 8Ω, Cin = 4.7μF, Cb =1µF
V

= 200mV

ripple

F = 217Hz, RL = 8Ω, Cin = 4.7μF, Cb =1µF

= 200mV

V

ic

PP

A-weighted filter

= 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz 100

R

L

= 8Ω 2MHz

L

20Hz ≤ F ≤ 20kHz, R

Unweighted
A weighted
Unweighted, standby
A weighted, standby

= VSM = GND, RL = 8Ω

STBY

= VSM = VCC, RL = 8Ω

STBY

= 8Ω 0.1 10 mV

L

PP

75

10 1000 nA

(2)

90 dB

60 dB

= 8Ω

L

11

7

3.5

1.5

µV

dB

RMS

Z

Input impedance 15 20 25 kΩ

in

- Gain mismatch 5.5 6 6.5 dB

Wake-up time

t

WU

1. Dynamic measurements - 20*log(rms(V

2. Guaranteed by design and evaluation.

3. Transition time from standby mode to fully operational amplifier.

(3)

Cb =1µF 10 ms

)/rms (V

out

ripple

)). V

is the super-imposed sinus signal relative to VCC.

ripple

7/26

Electrical characteristics TS4995

Figure 2. THD+N vs. output power Figure 3. THD+N vs. output power

10

RL = 8

Ω

G = 6dB
F = 20Hz
Cb = 1μF
BW < 125kHz

1

Tamb = 25°C

0.1

THD + N (%)

0.01
1E-3 0.01 0.1 1

Output power (W)

Vcc=5V

Vcc=3.3V

Vcc=2.6V

10

RL = 8

Ω

G = 6dB
F = 20Hz
Cb = 0
BW < 125kHz

1

Tamb = 25°C

0.1

THD + N (%)

0.01
1E-3 0.01 0.1 1

Output power (W)

Vcc=5V

Vcc=3.3V

Vcc=2.6V

Figure 4. THD+N vs. output power Figure 5. THD+N vs. output power

10

RL = 16
G = 6dB
F = 20Hz
Cb = 1μF
BW < 125kHz

1

Tamb = 25°C

Ω

Vcc=5V

Vcc=3.3V

Vcc=2.6V

10

RL = 16
G = 6dB
F = 20Hz
Cb = 0
BW < 125kHz

1

Tamb = 25°C

Ω

Vcc=5V

Vcc=3.3V

Vcc=2.6V

0.1

THD + N (%)

0.01
1E-3 0.01 0.1 1

Output power (W)

0.1

THD + N (%)

0.01
1E-3 0.01 0.1 1

Output power (W)

Figure 6. THD+N vs. output power Figure 7. THD+N vs. output power

10

RL = 4

Ω

G = 6dB
F = 1kHz
Cb = 1μF
BW < 125kHz
Tamb = 25°C

1

THD + N (%)

0.1
1E-3 0.01 0.1 1

Output power (W)

Vcc=5V

Vcc=3.3V

Vcc=2.6V

10

RL = 4

Ω

G = 6dB
F = 1kHz

Vcc=5V

Cb = 0
BW < 125kHz
Tamb = 25°C

Vcc=3.3V

1

THD + N (%)

0.1
1E-3 0.01 0.1 1

Vcc=2.6V

Output power (W)

8/26