If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

# TPA5050 FRAME DELAY CONTROL

Other Parts Discussed in Thread: TPA5050, TPA5052, TPA5051

Hi

We have questions about frame delay control.

For frame delay control, maximum number of delay samples is defined as 8191.

If we get the audio delay (in samples) which is greater than 8191, the audio delay would be limited to 8191.

1. If the audio delay (in samples) is greater than 8191, the actual delay time is limited as 8191/Fs?

Let me explain using following example.

If Fs=192kHz, Delay Frames = 1, Frame Rate = 59.94Hz, we can get Audio Delay samples = 3200 samples. (Delay samples < 8191)
So, we can get actual delay time as 3200/192khz=16.6ms.

In other case, if Fs=96khz, Delay Frames=1, Frame Rate=59.94Hz, we can get Audio Delay samples = 1601 samples. (Delay samples < 8192)

So, we can get actual delay time as 1601/96khz = 16.6ms that is the same delay as the previous calculation with fs=192khz and
it can be said that the delay time is independent on audio sample rate.

But, if Fs=192khz, Delay Frames = 3, Frame Rate = 59.94Hz, we can get Audio Delay samples = 9609 (Delay samples > 8191).

The audio delay samples is limited by 8191, we get actual delay time as 8191/192khz = 42.66ms.

So, the actual delay time is dependent on audio sample rate.

Is my understanding correct?

2. Do you have any other lip-sync delay IC which can handle more delay samples than TPA5050 can.

BestRegards

• Hi, na,

1. Effectively, the audio delay (in samples) is limited to 8191. Even if the audio delay samples are greater than 8191, the maximum number of delayed samples is 8191 for the TPA5050.

2. Our lip-sync devices are the TPA5050, TPA5051 and TPA5052. However, they have a similar behavior.

Best regards,
Luis Fernando Rodríguez S.
• Hi Luis

We understand the audio delay (in samples) is limited to 8191 even if we use FRAME DELAY REGISTERS.

Please let me confirm the following?

1. If we try to set the audio delay (in samples) that is greater than 8191 in FRAME DELAY control (0x06 D7=1),
what is happen? Is the following idea correct?

Using following formula
Audio Delay (in samples) = int [# Delay Frames × (1/Frame Rate) × Audio Sample Rate]

If we try to set Fs=192khz, Delay Frames = 3, Frame Rate = 59.94Hz, we can get Audio Delay samples = 9609 ( > 8191).
So, the audio delay samples is limited by 8191 and we will get actual delay time as 8191/192khz = 42.66ms.

2. Is the maximum delay time that TPA5050 and TPA5052 can handle the same?

3. What is the purpose of selecting Frame rate (50Hz/59.94Hz) in Frame Delay registers?

BestRegards
• Hi, na,

1. Effectively, due to the limitations of the TPA5050, it is not possible to get more samples than 8191. So, even if the result of the formula provides 9609 (> 8191), the result would be the max delay (8191). So, as you mentioned, the actual delay time is 42.66ms.

2. That's correct. The TPA5050 and TPA5052 handle the same maximum delay time. The samples are limited to 8191.

3. Frame rate is used to modify the Audio Delay (in samples). The Frame Rate will determine if the Audio Delay is greater or not:

int [# Delay Frames × (1/Frame Rate) × Audio Sample Rate]

Best regards,
Luis Fernando Rodríguez S.

• Hi Luis

We understood the way of Audio Delay setting and that effect.

There are two ways to control delay, using Audio Delay registers and using Frame Delay registers.

Is that delay applicable to Lch and Rch each?

If Fs = 192KHz and maximum samples (8191) are assumed,
Lch : 8191/192Khz = 42.6msec delayed
Rch : 8191/192Khz = 42.6msec delayed

Is our understanding correct?

Bestregards
• Hi, na,

Exactly. The TPA5050 allows delay of up to 170.4ms/ch with fs = 48 KHz (8191/48KHz = 170.4ms) and 42.6ms / ch with fs = 192KHz (8191 / 192KHz = 42.6ms). If more delay is needed, the devices can be connected in series.

Best regards,
Luis Fernando Rodríguez S.
• Hi Luis

I found suspicious description about the allowable delay in TPA5051.

According to the datasheet, TPA5051 has [Right/Left] delay upper register (5bits ) and [Right/Left] delay lower register (8bits), so the total number of bit is 13bits/ch.

Its register function is the same as TPA5050 which can accept maximum 8191 samples but TPA5051 only accepts 4095 samples.

Why does TPA5051 accept only 4095 samples as maximum number of delay samples?

BestRegards
• Hi, na,

Effectively, the TPA5051 accepts the half of samples (4095). The difference in this case is the quantity of channels that it can accept. The TPA5051 accepts two serial audio inputs. So, it is a tradeoff between channels vs delay. The TPA5051 allows delay of up to 85 ms/ch while the TPA5051 accepts up to 170 ms/ch.

Best regards,
Luis Fernando Rodríguez S.
• Hi Luis

OK. We understand that the TPA5051 can accepts the half of samples (4095/ch).

Can you check following s?

1. TPA5051 has total 13 bits for the audio delay registers? We can see 14bits (D13:D0) as the
audio delay registers in Table 4 in the datasheet. Is this error?

2. What is relationship between Audio Delay register bits and number of samples?

D13:D1=0, D0=1 -> 1 sample
D13:D2=0, D1=1, D0=0 -> ?
D13:D2=0, D1=1, D0=1 -> ?
...
D13:D0=1 -> 4095 samples

BestRegards
• Hi, na,

1. There's a mistake in Table 4. The bits should be D0 - D12. It is similar to the TPA5050: 5 bits for right delay upper and 8 bits for right delay lower.

2. Regarding the relationship between Audio Delay register bits and number of samples. It is a sample per bit. However, it is limited to 4095 samples. So, once the value 0111 1111 1111 is reached, the samples cannot be higher.

Best regards,
Luis Fernando Rodríguez S.