NXP Semiconductors TFA9810 8. Functional description

TFA9810_3 © NXP B.V. 2008. All rights reserved.

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

NXP Semiconductors TFA9810

Audio ampliﬁer 2 x 12 W

8. Functional description

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 VSSD(HW).

When the SO/OL pin is connected to VSSA the TFA9810 is in self-oscillating mode: when

the SO/OL pin is ﬂoating the TFA9810 is in open-loop mode.

The TEST pin needs to be connected to VDDA in both situations.

The device has two modes: SLEEP and OPERATING.

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

VSSP2 19 Negative power-supply voltage channel 2

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

VDDP2 24 Positive supply voltage power channel 2

VDDP1 25 Positive power supply voltage channel 1

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

VSSP1 30 Negative supply voltage power channel 1

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

Table 3. Pin description

…continued

Symbol Pin Description

Table 4. SO/OL connections

Interfacing

SO/OL connected to Conﬁguration

VSSD(HW) Self-oscillating

Open Open-loop

Contents

Main 1. General description 2. Features 4. Quick reference data TFA9810 Stereo full-bridge audio amplier 2 x 12 W Rev. 03 20 February 2008 Product data sheet Audio amplier 2 x 12 W = 25 5. Ordering information = 12 V; f = 550 kHz; Figure 33 unless otherwise specied Product data sheet Rev. 03 20 February 2008 3 of 29 6. Block diagram Fig 1. Block diagram 7. Pinning information 7.1 Pinning Fig 2. Pin conguration 7.2 Pin description 8. Functional description 8.1 General 8.2 Interfacing 8.3 Input comparators 8.3.1 Operating in self-oscillating conguration 8.3.2 Operating in open-loop conguration 8.4 Diagnostic 8.5 Protections Page Product data sheet Rev. 03 20 February 2008 8 of 29 NXP Semiconductors TFA9810 9. Internal circuitry Fig 4. Internal circuitry 0001 8.6 Start-up sequence Fig 3. Start-up sequence Product data sheet Rev. 03 20 February 2008 9 of 29 NXP Semiconductors TFA9810 Fig 5. Internal circuitry 0002 Fig 7. Internal circuitry 0004 Fig 6. Internal circuitry 0003 NXP Semiconductors TFA9810 Fig 8. Internal circuitry 0005 Fig 10. Internal circuitry 0007 Fig 9. Internal circuitry 0006 Fig 11. Internal circuitry 0008 Fig 12. Internal circuitry 0009 Fig 14. Internal circuitry 0011 Fig 13. Internal circuitry 0010 Audio amplier 2 x 12 W Fig 15. Internal circuitry 0012 Fig 18. Internal circuitry 0015 Fig 16. Internal circuitry 0013 Fig 17. Internal circuitry 0014 Fig 19. Internal circuitry 0016 Fig 20. Internal circuitry 0017 Fig 22. Internal circuitry 0019 Fig 21. Internal circuitry 0018 10. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). 11. Thermal characteristics 12. Characteristics = 25 12.1 Static characteristics In accordance with the Absolute Maximum Rating System (IEC 60134). 12.2 Dynamic characteristics = 25 = 12 V; f = 550 kHz; Figure 33 unless otherwise specied = 12 V; R 12.3 AC characteristics measured in a typical application = 25 = 8 = 25 = 12 V; R 13. Quality specication 14. Application information 14.1 Output power estimation 14.2 Output current limiting ------------------------------------------------------3 A +()+ DSon Rs (1) RL = 4 (2) RL = 6 (3) RL= 8 14.3 Speaker conguration and impedance 14.4 Differential input 14.5 Single-ended input 14.6 Curves measured in a typical application Fig 29. Input conguration for single-ended input Fig 30. Gain as a function of frequency VP= 12 V, Vi = 100 mV 14.7 Typical application diagram TFA9810 VP=12V,R Fig 32. Total harmonic distortion as a function of output power Fig 31. Total harmonic distortion + noise as a function of frequency VP=12V,R Fig 33. Typical application diagram TFA9810 Fig 34. Typical application diagram TFA9810 with externally adjusted switch-on time 14.8 Typical application: bill of materials 14.9 Snubber network 15. Test information 16. Package outline Fig 35. Package outline SOT287-1 (SO23) SO32: plastic small outline package; 32 leads; body width 7.5 mm SOT287-1 17. Revision history 18. Legal information 18.1 Data sheet status 18.2 Denitions 18.3 Disclaimers 18.4 Trademarks 20. Contents