NXP Semiconductors TFA9812 - page 23

TFA9812_2 © NXP B.V. 2009. All rights reserved.

Preliminary data sheet Rev. 02 — 22 January 2009 23 of 66

NXP Semiconductors TFA9812

BTL stereo Class-D audio ampliﬁer with I2S input

The selected PWM switching frequency is 400 kHz by default and can be set to 350 kHz,

700 kHz and 750 kHz in I2C control mode. In Legacy mode 400 kHz is the only option and

this scales linearly if 32 kHz or 48 kHz is used as fs.

Remark: The selected sample frequency, fs (selected) must be equal to the sample

frequency (fs) in I2C control mode.

Remark: The performance of AM radio reception can sometimes be improved by

selecting non-interfering frequencies for the PWM signal.

8.6 Class-D ampliﬁcation

The Class-D power ampliﬁcation of the PWM signal is carried out in two BTL power

stages. The output signal voltage level is determined by the values on the VDDP pins.

The power ampliﬁers can be explicitly put into 3-state mode by using the pin ENABLE as

shown in Table 19. The ENABLE pin is functional in Legacy mode and in I2C mode.

[1] Can be overruled by a forced 3-state in Sleep or Fault mode.

8.7 Protection mechanisms

The TFA9812 has a wide range of protection mechanisms to facilitate optimal and safe

application. All of these are active in both I2C and Legacy control modes.

The following protections are included in the TFA9812:

•Thermal Foldback (TF)

•OverTemperature Protection (OTP)

•OverCurrent Protection (OCP)

•OverVoltage Protection (OVP)

•UnderVoltage Protection (UVP)

•Window Protection (WP)

•Lock Protection (LP)

•UnderFrequency Protection (UFP)

•OverFrequency Protection (OFP)

•Invalid BCK Protection (IBP)

•DC-blocking

•ESD

The reaction of the device to the different fault conditions differs per protection.

Table 19. ENABLE pin functionality

ENABLE pin value Function

0 Output stages in 3-state mode.

1 Switching enabled [1].

Contents

Main 1. General description 2. Features 2.1 General features TFA9812 Rev. 02 22 January 2009 Preliminary data sheet BTL stereo Class-D audio amplier with I2S input NXP Semiconductors TFA9812 2.2 DSP features 3. Applications 4. Quick reference data =12V,V =0V,V = 3.3 V, ,f 5. Ordering information 6. Block diagram Fig 1. TFA9812 block diagram TFA9812 Preliminary data sheet Rev. 02 22 January 2009 6 of 66 7. Pinning information 7.1 Pinning 4 STABA O 1.8 V analog stabilizer output 5 REFA P Analog reference voltage 6V 7 TEST1 I T est signal input 1. F or test pur poses only (connect to V 8V TFA9812HN Page NXP Semiconductors TFA9812 8. Functional description 8.1 General Page 8.2.3 I2S master/slave modes and MCLK/BCK clock modes Page NXP Semiconductors TFA9812 8.3 Power-up/power-down 8.3.1 Power-up 8.3.2 Power-down 8.4 Digital audio data input 8.4.1 Digital audio data format support Remark: Only MSB-rst formats are supported. TFA9812_2 NXP B.V. 2009. All rights reserved. Fig 4. Serial interface input and output formats control mode 8.4.2 Digital audio data format control 8.5 Digital signal-processing features 8.5.1 Equalizer Page Page Preliminary data sheet Rev. 02 22 January 2009 20 of 66 8.5.2 Digital volume control Fig 7. T ransfer functions f or several center frequencies f Fig 8. Transfer functions for several gain factors G 8.5.3 Soft mute and mute 8.5.4 Output signal and word-select polarity control 8.5.5 Gain boost and clip level control 8.5.6 Output power limiter 8.5.7 PWM control for performance improvement Page 8.7.1 Thermal foldback 8.7.2 Overtemperature protection 8.7.3 Overcurrent protection 8.7.4 Overvoltage protection 8.7.5 Undervoltage protections 8.7.8 Lock protection 8.7.9 Underfrequency protection 8.7.10 Overfrequency protection 8.7.11 Invalid BCK protection 8.7.12 DC blocking 8.7.13 Overview protections Table 21 shows the overview of the protections. 9. I2C bus interface and register settings 9.1 I2C bus interface Voltage values applied to the I2C bus device address pins are interpreted as described in Table 23. 9.2 I2C bus TFA9812 device addresses 9.3 I2C write cycle description 9.4 I2C read cycle description 9.5 Top-level register map Reserved registers or bits will be indicated by RSD. 9.5.1 Interpolator settings and soft mute 9.5.2 Volume control 9.5.3 Digital input format 9.5.4 Equalizer conguration 9.5.5 Equalizer settings For word1 for equalizer 'yy' see Figure 9 For word2 for equalizer 'yy' see Figure 9 Page 9.5.6 PWM signal control 9.5.7 Digital-in clock conguration 9.5.8 Thermal foldback control 9.5.9 TFA9812 temperature 9.5.10 Miscellaneous status 9.6 Overview of functional control in each control mode D = xed control setting, determined by default I 10. Internal circuitry D = xed control setting, determined by default I Page Page 11. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). 12. Thermal characteristics In accordance with the Absolute Maximum Rating System (IEC 60134). 13. Characteristics 13.1 DC Characteristics = 400 kHz, 24-bit I = V = 0 V, V Page Page 13.2 AC characteristics < 0.1 = 3.3 V, T , R , f 13.3 Timing 14. Application information 14.1 Output power estimation 14.2 Output current limiting 14.3 Speaker conguration and impedance 14.4 Typical application schematics 14.4.1 I2S slave mode and Legacy control mode Fig 13. Simplied application diagram for I2S slave mode and Legacy control mode 14.4.2 I2S slave mode and I2C control mode Fig 14. Simplied application diagram for I2S slave mode and I2C control mode 14.4.3 I2S master mode and Legacy control mode Fig 15. Simplied application diagram for I2S master mode and Legacy control mode 14.4.4 I2S master mode and I2C control mode Fig 16. Simplied application diagram for I2S master mode and I2C control mode 14.5 Curves measured in typical application a. VP = 12 V; RL = 2 6 b. VP = 12 V; RL = 2 8 VP = 12 V; PO = 1 W (1) RL = 6 15 H / 680 F (2) RL = 8 15 H / 680 F Fig 19. Gain as a function of frequency Fig 20. Gain as a function of AVOL VP = 12 V; RL = 8 ; fi = 1 kHz (1) 0 dB (2) 24 dB gain boost VP = 12 V; Vripple = 500 mV (RMS) reference to ground; No input signal (1) RL = 8 (2) RL = 6 Fig 21. SVRR as a function of frequency Fig 22. S/N ratio as a function of output power VP = 15 V; 20 kHz AES17 lter (1) RL = 2 8 (2) RL = 2 6 Fig 23. Output power as a function of time a. VP = 15 V; RL = 2 6 BTL; fi = 1 kHz b. VP = 20 V; RL = 2 8 BTL; fi = 1 kHz (1) Tact(th_fold) = 125 C (2) Tact(th_fold) = 105 C (3) Tact(th_fold) = 90 C a. VP = 12 V; RL = 2 6 ; fi = 1 kHz; THD = 1 % b. VP = 12 V; RL = 2 6 ; fi = 1 kHz; THD = 10 % VP = 12 V; fi = 1 kHz; Power dissipation in junction only VP = 12 V; fi = 1 kHz; po = (2 Po) / (2 Po + Pd) VP = 12 V; PO = 1 W Fig 27. Channel separation as a function of frequency 15. Package outline Fig 28. Package outline SOT619-8 (HVQFN48) SOT619-8 Page 17. Revision history 18. Legal information 18.1 Data sheet status 18.2 Denitions 18.3 Disclaimers 18.4 Trademarks 20. Contents