Audio Amplifiers Forum - Recent Threads

TPA3116D2 SYNC pin in Master/Save mode.

Rajeev Huralikoppi — Thu, 16 May 2013 19:48:59 GMT

Hi,

The TPA3116D2 datasheet suggests using Master/Slave operation to synchronize multiple devices. The schematic shows two devices driving a stereo and a subwoofer signals. Does the synchronization work properly across from one master to 7 other slaves located on multiple boards? I am particularly concerned about the signal delays and how to compensate them.

Regards

--Rajeev

LM4675 driving headphone question.

peter zhu2 — Sat, 18 May 2013 18:37:04 GMT

Hi, Expert:

In one of my project, LM4675 is used for drive speaker, and it also needs to support headphone. Can i use LM4675 to drive headphone? I am not sure about this, because the datasheet only mentions speaker.

Thanks

Peter

Looking for a recommendation for a single supply op amp for a audio preamplifier

Sid Tryzbiak — Fri, 17 May 2013 21:17:39 GMT

Looking for a recommendation for a single supply op amp for an audio preamplifier. Most seem to be dual supply voltage.

TAS5731 / Questions

S.Satoshi — Wed, 06 Mar 2013 11:10:55 GMT

Hi,

Our customer start to evaluate TAS5731 and now we received some questions for specifications. Can you check following questions and give your comments?

1, Can you provide the minimum OCP threshold? The minimum value in characterization data should be preferable.

It should be just for reference only and so we understand that it will not be guaranteed value.

Please prepare it for both BTL and PBTL configuration if it's difference between BTL and PBTL.

2, We can not find description about following register. Please explain about them if TAS5731 really has these register.

0x62: IDF post scale
0x63: Second left-channel mixer
0x64: Second right-channel mixer

Best Regards,

Sonoki / Japan Disty

Interfacing with a TI LM4950 10 watt power amp.

Sid Tryzbiak — Fri, 17 May 2013 16:25:14 GMT

I have a sound chip with a fixed line out supplying audio at about 200mv.

I built the LM4950 7.5 watt mono-BTL power amp as shown in the data sheet with a voltage divider to provide half of the 12 volt supply voltage to the Shutdown pin.

Audio sounds good but not very loud. Should this 200 mv line out be able to drive the 7.5 watt chip to full output? Can I get there by changing the gain resistors on the LM4950 or do I need to put a preamp between the Line out and the LM4950?

Thanks,

Sid

TPS65951 Audio Section

shekhar SAINI97194 — Fri, 17 May 2013 12:17:26 GMT

Hello,

In our application we need on board mic, speaker (not earpiece) and headset mic and headset speaker.

We are doing above by using interface available in TPS65951:

On board

Mic: MIC.MAIN.P,MIC.MAIN.M

Speaker: Predrive outputs for 8 ohm speaker with class D amplifier (mono)

Headset:

Mic: HSMIC.P, HSMIC.M

Speaker: HSOL,HSOR

We need headset speaker and headset mic detection in the above explained application. We are using GPIO2 as suggested in TRM for headset speaker detection but for mic detection we are planning to use GPIO1 for it.

Would it be possible to use GPIO1 for the headset mic detection? If yes, is it possible to switch between on board and headset by software?

tas5717 no sound. No errors in register 0x03

alex camilo — Wed, 24 Apr 2013 20:04:35 GMT

I've wired up a circut containing a 5717 to the mc57xxPISA that came with my tas5717 evk. I can connect over i2c and register 0x00 reads as 0x6c.

I set the ch1 vol 1 and 2 to 1.0 and set the master volume to max using the tas57xx GUI and then unchecked shutdown and mute. On the board provided with the EVK this resulted in audio coming out of the attached speakers. When I tried this on my circuit i got no audio.

The Error register 0x02 is zero. However when i read 0x01 i get 0xc1 (Datasheet says it should be all zeroes)

Is there anything I'm missing. anything else I should check?

TAS5708 failing

siavash rezaei1 — Fri, 17 May 2013 20:18:50 GMT

Hi,

Recently, we designed an Audio amplifier based on TAS5708. They all work great when they work!

However, sometime they just die. Sometimes they die during power up, sometimes when they are play music, and sometime when just sitting there with NO SIGNAL!

This has happened with all supply voltages 12V, 20V, 24V. Sometimes they die in 5 minutes, and sometime in 30 minutes. The ones that get passed 1 hour tend to live.

In short, I have not been able to narrow down the cause of this failure. BUT the one thing they all have in common is that when this happens, the impedance of the HIZ pin drops from about 90KOhm to around 0.88 kOhm

I'm also suspicious about the authenticity of the chips because they were not assembled by us, and they can be found for cheap on Alibaba. So I'm afraid the company that made the boards for us, might have used chips from unauthorized sellers (contrary to what they tell us). They are a North America company with factories in China.

If any of the above rings a bell or if you have any comments, please let me know. These failures are pretty embarrassing for our company.

I can supply more info (i.e. schematic, layout ) on demand.

Regards,

keeping TAS5352ADDV permanently supplied with PVDD but not GVDD

Christoph Apel — Wed, 15 May 2013 08:20:42 GMT

Hello,

in our application we switch off 12V while the device is in standby. But PVDD (15V to 24V) is always on.

Looking at the datasheet of TAS5352ADDV this should not be a problem, right ?

I just want to double check that there is no reliability issue or anything we may overlook.

thanks and regards,

Christoph

opa2132 pre-amp into a opa4134

Chris Bryant — Thu, 16 May 2013 16:24:08 GMT

I have a board made that takes a opa2132 as a pre-amp and its output into the input of a opa4134. All amps work great, but when connecting the 2132 output into the 4134 inputs sll you get elc noice and no music. Seperatly the amps all work great but not connectined together. I have tried a 1k and 10k resistrs between the amps with still no luck. Any body have ifes'a

TPA3106D1 dying with FAULT high

Matt Jenkins — Fri, 17 May 2013 09:53:01 GMT

I have a pair of TPA3106D1 chips arranged as a stereo pair. The circuit is pretty much the same as the one in the data sheet with the exception of a T filter on the output instead of a simple LC filter to give a sharper cut-off. Power supply is 19V, speakers are 4 ohm.

I built it up yesterday and all was fine - really nice crystal clear sound, absolutely perfect.

Today I come to turn the test rig on and nothing. The fault pin on both chips are HIGH indicating a short circuit on the output. There is no short circuit on the output. Even with no speakers connected the fault pins are both HIGH.

Does anyone have any clue as to what this might be?

Can INA331 be used in the signal amplification of the microphone electret capsule(with built-in FET)?

Marius kwok — Wed, 27 Mar 2013 03:01:34 GMT

Hello,

My application is to amplify the 1mV order mic electret capsule signal of bandwidth 20Hz to 22kHz in a gain of 1000.
The mic and the whole circuit are required to biased by the resistor with a 3V supply voltage, so INA331 is chosen for this application.
Is the attachment circuit correctly use of INA311? Or any modification is required? If I use the configuration given in the attachment, how small the noise value be calculated & evaluated and required using this voltage reference(Vref) IC that I should choose? could you please suggest the voltage reference suitable for this application?
The R in the figure may vary from 1k to 11k depending on the different brand of mic.

Thank you very much in advance for any expertise advices, comments and feedback.

how to parallel TPA3122D2 outputs to single speaker? and power-on pop avoidance

achoox4 — Tue, 16 Apr 2013 23:09:06 GMT

My first question is merely about saving unecessary passive parts; the second is an actual problem:

1. Paralleled outputs:

I've got the TPA3122D2 setup with the example circuit from the datasheet, and it performs OK with single-ended stereo inputs. I've used mostly 8-ohm speakers, with both the EVM default 470uF output caps, as well as 2200uF for deeper bass, 100 uF for wideband speakers, and single-digit uF for tweeters.

As I'm getting closer to the final product configuration, I settled on a single 4-ohm woofer to produce mixed L+R bass, in the vein of a subwoofer.

(I originally pondered a BTL .setup for a central 8-ohm woofer, but in the single attempt so far the DRV134 I used appeared to melt while its electrolytics exploded. Reversed PS polarity?)

I'm planning to use one IC for the pair of wideband L and R speakers, and another with both channels driving the bass, to have more total power before I reach the individual devices' high-THD (etc.) parts of the various performance graphs.

A. The obvious circuit to use is to mix L and R before the inputs, then go through the 1uF input coupling cap into the 3122, and then add all the usual components at the outputs sized for 8-ohm devices (incl. 2200uF caps for lowest bass) before connecting to the + pin of the single 4-ohm speaker. Can I leave out (1 of the pair of) any of those parts and connect the L and R sides of the circuits (in and/or out) nearer the IC? E.g. can I use a single 1uF input cap and connect the input pins? Or can I connect the outputs before the filter cap, or even before the inductor?

B. If the answer to (A) is a Yes of any sort, is it any different when the output filter caps are 100 uF? (To give each wideband speaker its own 3122 as well.)

C. There's a TI app note somewhere about power supply pumping in class-D amps, especially during similar L/R signals. Perhaps less useful because there may not be that much difference between L and R in the bass frequencies (I do intend to low-pass filter before the bass's 3122 to avoid a crossover network), I considered running L and R through the 3122 separately and joining just before the speaker. Is that even possible (not to mention, do any of the savings from (1) apply?), or does the effective voltage difference between the outputs require additional components to mix?

I thought I saw an app note some time ago that described which of the non-duplication in (1) could be done, but I cannot find it now.

2. How to avoid the earth-shattering POP whenever I power it up?

Is there an RC circuit or similar with which to drive Shutdown or Mute such that there is no loud pop when powering up? So far, my debug setup consist of a full-up power source, such that the supply voltage has a step up, as opposed to the final product's unregulated transformer PS which is switched at the mains, which would, I assume, produce a slightly slower rate of rise - so that might make a difference. But trying to defeat it, I've experimented with hardwiring either Shutdown or Mute to the "off" state, powering up, then switching the respective input to the "on" state - and depending on which I do, I get the POP either when powering up, or controlling to "on" - I've not managed a POP-free startup.

Are Shutdown/Mute only intended for use with a (micro)controller setup which is powered up before the 3122, controls the 3122 power, and can therefore drive the high-active Mute high before the 3122 is powered up?

Or should this work with a single plainly-switched power supply, and I'm just doing it wrong?

Is it just that my switch just to rough, and the smooth action of an RC circuit is needed?

TAS5731 / How to calculate output level

S.Satoshi — Wed, 08 May 2013 14:00:02 GMT

Hi,

Our customer hope to know how to calculate output level of D-AMP with I2S input. The condition and setting should be 0dB volume and other effects are not worked. We think the PVDD voltage, input level of signal and PWM-Modulation-Limit(0x10) are included to calculate.

Your advice will be appreciated.

Best Regards,

Sonoki

LM4752 application question.

Chen Bogey — Tue, 05 Mar 2013 16:00:43 GMT

Dear Sir

Good days,

May we check if LM4752 have other reference design circuit or application note& layout guide ?

due to i just can find datasheet in website.

Another question is may TI have I2S input 100W mono speaker driver? selection guide seem just only 25W.

and my customer want to use in woofer,

Best regards,

Bogey

Headphone output TAS5706

Saurabh Patel — Tue, 14 May 2013 09:19:05 GMT

Hi,

Speaker output is working with TAS5706.

Now I want audio output on headphone. We have connected HPSEL pin GND.

In this case what register do i need to chagne?

I have enable HP mode by changing system control register but still no output on headphone.

-Saurabh

Frame slip error on TAS5706B

Saurabh Patel — Sat, 04 May 2013 08:21:09 GMT

Hi,

Can you explain about Frame slip error ERROR STATUS REGISTER (0x02)?

How to fixe this issue?

MCLK = 64 * fs is valid for 48000 sampling frequency? If it is true then what about MCLK limit mentioned in TAS5706B data sheet?

Data sheet page number 7

"MCLK is the clock master input. The input frequency of this clock can range from 4.9 MHz to 49 MHz"

Saurabh.

TAS5711 and CP2114

Josef Obermayr — Mon, 06 May 2013 13:35:23 GMT

Hello,

I'm using TAS5711 Evalboard and I want to get it running in combination with Silicon Labs CP2114 (USB to I²S).
I checked I²S signals (MCLK, SCLK, LRCLK, SDIN) by oscilloscope and they look fine, but I don't get any sound out of it.
Analog input (by using analog to I²S converter on MC57xxPSIA-Board) is working.

TAS5711 datasheet states (page 11 and 25): SCLK must be 32/48 or 64 x Samplerate
So if sample rate is 48 kHz the maximum SCLK = 64 x 48 kHz = 3.072 MHz

CP2114 datasheet states (page 7): SCLK frequency (SYSCLK = 49.152 MHz) = 3.511 MHz

So could it be a clock synchronisation/mismatch issue, or do you have any other idea ?

Best regards,
Josef

P.S: Link to CP2114 datasheet
http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2114.pdf

AC coupling the output of a LME49724

lester davis — Mon, 13 May 2013 18:44:47 GMT

I'm using the typical application circuit in a design, under what conditions do I need to AC couple the output of the LME49724?

TPA6130A2 in Single Ended Configuration

Pierre SCHLOSSER — Fri, 03 May 2013 05:50:09 GMT

Hello,

I have a problem to be sure to do the right configuration for single ended input in the TPA6130A2 audio amplifier when I look at technical documentation from TI. I think there is an opposite information between TPA6130A2 datasheet and TPA6130A2EVM User Guide (SLOU185 document).

In the USER Guide of The TPA6130A2EVM, for single ended operation, the signal to ground is LINM and you enter your single ended input to LINP (see schematic in page 7 of SLOU185 document). In datasheet, it is written in page 3, to ground LINP and to enter the single ended signal in LINM. What's wrong?

For example, in TPA6140A2 datasheet, you have to enter in IN- the single ended input and ground the IN+ signal input (I assume that IN- of TPA6140A2 is LINM of TPA6130A2).

So please, could you confirm that: on TPA6130A2, in single ended input configuration, I have to ground XXXINP and enter in XXXINM? (opposite of schematic in page 7 of SLOU185 document)? Do I have to ground the input with a capacitor or Can I wire directly my input to analog ground? (Note that I don't want to invert my signal, phase = 0° and not 180° from original signal)

Moreover, I think the names of signals shall be corrected from RIGHTINM to RIGHTINN & same thing for left channel (N = negative, P = Positive, What mean M???) -> It will be more clear and as others TI datasheets ;) -> or do as TPA6140A2 RIGHTIN+ and RIGHTIN- would be a good solution.

I thank you in advanced. Best regards.

TPA3118D2 output signal problem

Chee Ho Kar — Sat, 11 May 2013 20:31:18 GMT

Hi all, I am using TPA3118D2 to design a 2.1 audio board, I follow the application circuit, and output filter components are same as the EVM BOM list. But the output signal has a 400kHz 800mVpp noise even the board has no signal input. (It seem the LC filter cannot cut all PWM)

I already test my power supply and input signal on EVM board, it work prefectly. So, what will cause this problem?

TPA3116D2 quiescent current clarification?

Gary Marsh1 — Sun, 05 May 2013 14:10:32 GMT

Hi,

In the TPA3116D2 datasheet, at the top of page 6, the typical quiescent current of the device is specified - 20mA typ @ 12V, 32mA typ @ 24V with no filter or load. The AMx and MODSEL pin settings aren't specified, and I imagine they'd make a significant impact on quiescent current. Could you specify the pin settings for that test?

Thanks!

TAS5706 Audio data verification

Paul Lee — Sat, 27 Apr 2013 12:46:19 GMT

Hi,

How I verify that data is coming to TAS5706 is or not?

What care should be taken for chip initialization and clocking the chip?

How can we set TAS5706 as master codec?

Thanks,

Paul

LM3886 staggered bend inversion

Torje Nikolai Thorsen — Mon, 06 May 2013 14:52:37 GMT

Dear all,

I would like to invert the staggered pin bend of the LM3886 chip for production optimization purposes. An inverted bend would allow mounting the chips horizontally under the PCB instead of vertically, which has a lot of advantages in my application.

However, this exotic bending seems to be quite a tricky task to do efficiently, especially since the chips are delivered with staggered, bent pins.

Is it possible to buy chips with straight pins? Or maybe even chips with inverted bending?

Best regards,
Torje N. Thorsen
Wrangler and R&D engineer

TPA3123D2 Clicking noise and hot inductors in BTL mode

Mark Antonucci — Tue, 21 Aug 2012 17:09:18 GMT

Hello.

My name is Mark

I'm in the process of bringing up a 2.1 amplifier using two TPA3123D2 devices.

One chip does my left and right channels into 8 Ohms and the other is in BTL mode and will be driving 4 Ohms.

I'm having two issues:

1. After looking at the posts in this forum I can see that you don't recommend driving 4 Ohms in BTL mode while looking for high power. (correct?)

I looked at table 4 in the data sheet when I was choosing the speaker for the BTL amp figuring it could be used at 4 Ohms. Did I miss something?

2. I get a clicking sound in my outputs. The click is about 1 Hz. (I can measure again). I'm getting the clicking in all my amps but I can see that the output of the BTL is the source. (This is with no audio applied to the circuit.) The BTL has a disurbance on it's output and is big enough that it leaks through the power supply into the L R amp circuit.

If I spray the BTL side with freeze spray, I can make the click go away until I power cycle the circuit.

I'm running the BTL without a speaker attached but it also exhibits the same issue with a speaker attached.

I suspect I may have a problem with the filters on the BTL amp. I'll study it closer tonight. Have you seen this clicking noise before? Am I correct in thinking the amp may be protecting its self?

I'll provide more information if needed.

Thanks for yout time!,
Mark