NXP Semiconductors TFA9810 User Manual

TFA9810

Stereo full-bridge audio ampliﬁer 2 x 12 W

Rev. 03 — 20 February 2008 Product data sheet

1. General description

The TFA9810 is a two-channel power comparator for high-efﬁciency class D audio ampliﬁer systems. It contains two full-bridge Bridge-Tied Load (BTL) power stages, drive logic, protection control logic and full differential input comparators. By using this power comparator a compact closed-loop self-oscillating digital ampliﬁer system or open-loop system can be built. The TFA9810 does not require a heat sink and operates using an asymmetrical supply voltage.

2. Features

n Stereo full-bridge power comparator for class D audio ampliﬁer applications n No external heat sink required n Operating voltage range: asymmetrical from 8 V to 20 V n Thermally protected n Zero dead-time switching n Current-limiting (no audible interruptions)

3. Applications

n Self-oscillating or open-loop class D audio ampliﬁer applications n Flat-panel television sets n Flat-panel monitors n Multimedia systems n Wireless speakers n High-end CRT television sets

4. Quick reference data

Table 1. Quick reference data

= 25°C; VP = 12 V; f

amb

Symbol Parameter Condition Min Typ Max Unit

off

= 550 kHz; Figure 33 unless otherwise speciﬁed

osc

supply voltage VP = V off-state current off mode - 110 200 µA quiescent current with load, ﬁlter and

snubbers connected

output power efﬁciency

output power 2 x 9 W into 8 Ω; P

o=Po(nom)

DDPx

− V

SSPx

81220V

-3545mA

87 89 - %

NXP Semiconductors

TFA9810

Audio ampliﬁer 2 x 12 W

Table 1. Quick reference data

= 25°C; VP = 12 V; f

amb

osc

…continued

= 550 kHz; Figure 33 unless otherwise speciﬁed

Symbol Parameter Condition Min Typ Max Unit

o(RMS)

RMS output power RL = 8 Ω; VP = 12 V;

- 9.5 - W THD = 10 %;Twochannel driven; no heat sink required.

output power VP = 12 V; RL = 8 Ω ----

THD = 10 % 8.5 9.5 - W THD = 1 % 6.5 7.5 - W

= 14 V; RL= 8 Ω;

-15-W THD = 10 %; thermally limited

= 16 V; RL= 8 Ω;

-15-W THD = 10 %; thermally limited

= 12 V; RL= 6 Ω;

-12-W THD = 10 %; thermally limited

= 12 V; RL = 4 Ω;

-15-W THD = 10 %; thermally limited

5. Ordering information

Table 2. Ordering information

Type number Package

Name Description Version

TFA9810T SO32 SO32: plastic small outline package; 32 leads; body width 7.5 mm SOT287-1

Product data sheet Rev. 03 — 20 February 2008 2 of 29

NXP Semiconductors

6. Block diagram

TFA9810

Audio ampliﬁer 2 x 12 W

DDA1

IN1P

IN1N

SSA1

DIAG

TEST

SO/OL

ENABLE

CDELAY

DDA2

IN2P IN2N

SSA2

TFA9810

2 3

PROTECTION

REFERENCE

15 14

COMPARATOR 1

OVP UVP OCP OTP ODP

COMPARATOR 2

CONTROL

LOGIC

CONTROL

LOGIC

CONTROL

LOGIC

CONTROL

LOGIC

DRIVER

HIGH

DRIVER

LOW

STABI1

DRIVER

HIGH

DRIVER

LOW

DRIVER

HIGH

DRIVER

LOW

STABI2

DRIVER

HIGH

DRIVER

LOW

DDP1

SSP1

DDP2

SSP2

27 25

22 24

BOOT1P V

DDP1

OUT1P

SSP1

BOOT1N

OUT1N

STAB1

BOOT2P V

DDP2

OUT2P

SSP2

BOOT2N

OUT2N

STAB2

HEATSPREADER

1161732

SSD(HW)

n.c.

010aaa016

Fig 1. Block diagram

Product data sheet Rev. 03 — 20 February 2008 3 of 29

NXP Semiconductors

7. Pinning information

7.1 Pinning

TFA9810

Audio ampliﬁer 2 x 12 W

SSD(HW)

ENABLE OUT1P CDELAY V

SSD(HW)

1 2

IN1P STAB1

IN1N V

DDA1

SSA1

SO/OL BOOT1P

7 8

TFA9810

n.c. V

DIAG OUT2P

TEST BOOT2P

SSA2

DDA2

IN2N V

IN2P STAB2

SO32

010aaa017

32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17

SSD(HW)

SSP1

BOOT1N OUT1N

DDP1 DDP2

OUT2N BOOT2N

SSP2

SSD(HW

)

Fig 2. Pin conﬁguration

The SO32 package has four corner leads. These leads (1, 16, 17, and 32) are internally connected to the die pad and must be connected to V

in the application. Together with

SSA

the applied copper area on the Printed Circuit Board (PCB) these leads determine the ambient temperature, which affects the thermal resistance of the junction.

7.2 Pin description

Table 3. Pin description

Symbol Pin Description

SSD(HW)

IN1P 2 Positive input comparator channel 1 IN1N 3 Negative input comparator channel 1 V

DDA1

SSA1

SO/OL 6 SO/OL input enables self-oscillating / open-loop conﬁguration ENABLE 7 Enable input to switch between SLEEP and OPERATING CDELAY 8 CDELAY input determines the switch on/off timing n.c. 9 Not connected DIAG 10 Diagnostic output; open drain TEST 11 Test signal input; for testing purposes only V

SSA2

DDA2

Product data sheet Rev. 03 — 20 February 2008 4 of 29

1, 16, 17,32Negative digital supply voltage and handle wafer

4 Positive analog supply voltage channel 1 5 Negative analog supply voltage channel 1

12 Negative analog supply voltage channel 2 13 Positive analog supply voltage channel 2

NXP Semiconductors

TFA9810

Audio ampliﬁer 2 x 12 W

Table 3. Pin description

Symbol Pin Description

IN2N 14 Negative input comparator channel 2 IN2P 15 Positive input comparator channel 2 STAB2 18 Decoupling of internal 11 V regulator for channel 2 drivers V

SSP2

BOOT2N 20 Bootstrap high-side driver negative output channel 2 OUT2N 21 Negative output channel 2 BOOT2P 22 Bootstrap high-side driver positive output channel 2 OUT2P 23 Positive output channel 2 V

DDP2

DDP1

OUT1P 26 Positive output channel 1 BOOT1P 27 Bootstrap high-side driver positive output channel 1 OUT1N 28 Negative output channel 1 BOOT1N 29 Bootstrap high-side driver negative output channel 1 V

SSP1

STAB1 31 Decoupling of internal 11 V regulator for channel 1 drivers

8. Functional description

…continued

19 Negative power-supply voltage channel 2

24 Positive supply voltage power channel 2 25 Positive power supply voltage channel 1

30 Negative supply voltage power channel 1

8.1 General

The TFA9810 is a dual-switching power comparator. It is the main building block for a stereo high-efﬁciency Class D audio power ampliﬁer system. It contains two full-bridge BTL power stages, drive logic, protection-control logic and full differential input comparators and references (see Figure 1). By using this power comparator a compact closed-loop self-oscillating digital ampliﬁer system or open-loop system can be built. A second-order low-pass ﬁlter converts the Pulse Width Modulation (PWM) output signal into an analog audio signal across the speaker.

8.2 Interfacing

The pins ENABLE and SO/OL control the operating mode of the TFA9810. Both the ENABLE and the SO/OL pins refer to V

When the SO/OL pin is connected to V

SSD(HW)

SSA

the SO/OL pin is ﬂoating the TFA9810 is in open-loop mode. The TEST pin needs to be connected to V

Table 4. SO/OL connections

Interfacing SO/OL connected to Conﬁguration

SSD(HW)

Open Open-loop

the TFA9810 is in self-oscillating mode: when

in both situations.

DDA

Self-oscillating

The device has two modes: SLEEP and OPERATING.

Product data sheet Rev. 03 — 20 February 2008 5 of 29

NXP Semiconductors

In SLEEP mode the TFA9810 is not biased and has a very low supply current. When the TFA9810 is set to OPERATING mode the device is started via the start-up

sequence, which provides a pop-free start-up behavior. After start-up the reference voltages STAB are present and the outputs start switching.

Table 5. Start-up

Interfacing ENABLE [V] Mode

ENABLE < 0.8 V SLEEP ENABLE > 3 V OPERATING

8.3 Input comparators

The input stages have a differential input and are optimized for low noise and low offset. This results in maximum ﬂexibility in the application.

8.3.1 Operating in self-oscillating conﬁguration

The inputs (IN1P,IN1N, IN2P, IN2N) of the comparators are internally set to a voltage level of 0.5VP, but only during the start-up sequence. In operating mode the inputs are high-ohmic.

TFA9810

Audio ampliﬁer 2 x 12 W

8.3.2 Operating in open-loop conﬁguration

No internal voltages are applied to the inputs. The input pins (IN1P, IN1N, IN2P, IN2N) are pulled down to V

level by internal resistors.

SSA

8.4 Diagnostic

The DIAG output is an open-drain output. The maximum current is 2 mA. Whenever one of the protections is triggered the DIAG output is activated low. The DIAG output refers to V

SSD

8.5 Protections

Overtemperature, overcurrent, overvoltage, undervoltage, overdissipation sensors, and window protection are included in the TFA9810. When one of these sensors exceeds its threshold level either the output power stage is switched off and the outputs (OUT1N, OUT1P, OUT2N, OUT2P) become ﬂoating, or the TFA9810 shuts down and starts up immediately.

• OverTemperature Protection (OTP)

If the junction temperature (Tj) exceeds a threshold level of about 150 °C then the outputs become ﬂoating. The device will start switching again after 5 µs and when the temperature is below 150 °C. This is thermal limitation without audible interruptions.

• OverCurrent Protection (OCP)

If the output current exceeds the maximum output current threshold level the output becomes ﬂoating. The device will start switching again after 5 µs. This is current limitation without audible interruptions.

Product data sheet Rev. 03 — 20 February 2008 6 of 29

NXP Semiconductors

• OverVoltage Protection (OVP)

• UnderVoltage Protection (UVP)

• OverDissipation Protection (ODP)

• Window Protection (WP)

TFA9810

Audio ampliﬁer 2 x 12 W

When the supply voltage applied to the TFA9810 exceeds the maximum supply voltage threshold level the device will shut down. The device will restart when the supply voltage is within the operating range.

When the supply voltage applied to the TFA9810 falls below the minimum supply voltage threshold level the device will shut down. The device will restart when the supply voltage is within the operating range.

The ODP in the TFA9810 is a combination of two protections. Exceeding a temperature threshold level of 135 °C an internal pre-warning is generated. When an overcurrent is detected during the pre-warning the device will shut down. When the ENABLE pin is high the TFA9810 will restart automatically. The restart sequence (switch-off → switch-on) will take 200 ms to 500 ms.

During start-up, if one of the outputs is shorted to VSSor VDDthe device will not start. This is an effective measure to protect the device against shorts between the outputs (beforethe ﬁlter) and the groundor supply lines. The supply must be switchedoff prior to removing any short. The WP protects the device against failure during board assembly.

Table 6. Overview protections

Protections Symbol Condition DIAG Outputs Recovering

OTP T OCP I OVP VP > 20 V LOW Floating Restart (switch-off → switch-on when VP< 20 V) UVP V ODP T

WP OUTX > V

> 150 °C LOW Floating Automatic, after 5 µs and Tj < 150 °C

> I

ORM

< 8 V LOW Floating Restart (switch-off → switch-on when VP> 8 V)

> 135 °C and IO > I

- 1 V or

OUTX < V

DDA SSA

+ 1 V

LOW Floating Automatic, after 5 µs and IO < I

LOW Floating Restart (switch-off → switch-on when

ORM

LOW

< 135 °CorIO<I

ORM

)

Product data sheet Rev. 03 — 20 February 2008 7 of 29

NXP Semiconductors

8.6 Start-up sequence

ENABLE

STAB1

CDELAY

TFA9810

Audio ampliﬁer 2 x 12 W

V IN x

FLOATING

OUT x

AUDIO

DIAG

SLEEP START-UP OPERATING FAULT RESTART OPERATING SHUT-DOWN SLEEP

Fig 3. Start-up sequence

9. Internal circuitry

PWM

AUDIO

1,16, 17, 32

FLOATING

PWM

AUDIO

010aaa018

DDA

22 V

SSA

010aaa024

Fig 4. Internal circuitry 0001

Product data sheet Rev. 03 — 20 February 2008 8 of 29

NXP Semiconductors

TFA9810

Audio ampliﬁer 2 x 12 W

135 kΩ

DDA1

5.5 V

Fig 5. Internal circuitry 0002

Fig 6. Internal circuitry 0003

DDA1

135 kΩ

110 kΩ

SSA

22 V

010aaa026

5.5 V

DDA1

SSA1

010aaa025

50 µA

hvp

SSA1

SSA

010aaa027

Fig 7. Internal circuitry 0004

Product data sheet Rev. 03 — 20 February 2008 9 of 29

+ 20 hidden pages

NXP Semiconductors TFA9810 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

1. General description

2. Features

3. Applications

4. Quick reference data

5. Ordering information

6. Block diagram

7. Pinning information

7.1 Pinning

7.2 Pin description

8. Functional description

8.1 General

8.2 Interfacing

8.3 Input comparators

8.4 Diagnostic

8.5 Protections

8.6 Start-up sequence

9. Internal circuitry