PCM6260-Q1: Schematic review

Hi Lakshmi,

Could you please tell me the maximum current of VBAT_IN、AVDD、IOVDD、BSTVDD？Is there any requirement for ripple voltage and power-on suquence?

Thanks

Hi Lakshmi,

We select PCM6260-Q1 at present.However，the I/O level of our SOC is 1.2V,level conversion is required.Could you please recommend ADC chip of 1.2V I/O level？Whether the chip will be developed later？

Thanks

Hi Lakshmi,

We select PCM6260-Q1 at present.However，the I/O level of our SOC is 1.2V,level conversion is required.Could you please recommend ADC chip of 1.2V I/O level？Whether the chip will be developed later？

Thanks

Hi Rubin,

There is currently a device TAA5412-Q1 in PREVIEW status on ti.com. This stereo ADC can support 1.2V i/o level.

Thanks and Regards,

Lakshmi Narasimhan

Hi Lakshmi,

TAA5412-Q1 has 2 ADC channels.Is there any device that supports 6 ADC channels?

Thanks

Hi Lakshmi,

Rubin is an engineer from ZTE. Could you help answer the above question?

Could you please tell me the maximum current of VBAT_IN、AVDD、IOVDD、BSTVDD？Is there any requirement for ripple voltage and power-on suquence?

Thanks

Brs

Jayden

Hi Rubin,

We currently don't have a 6-channel ADC that supports 1.2V I/O levels.

Thanks and Regards,

Lakshmi Narasimhan

Regarding the query:

Jayden Qiu said:

Could you please tell me the maximum current of VBAT_IN、AVDD、IOVDD、BSTVDD？Is there any requirement for ripple voltage and power-on suquence?

The VBAT_IN pin is a monitoring pin for the VBAT_IN voltage, hence consumes very less current. The AVDD/IOVDD/BSTVDD current consumption values are as per the electrical table mentioned in the datasheet:

For power supply sequencing requirement, we can refer to section 10 of the datasheet:

Thanks and Regards,

Lakshmi Narasimhan

Hi Lakshmi,

Do you have plan to develop a 6-channel ADC that supports 1.2V I/O level?

Thanks

Hi Lakshmi,

Are there ripple requirements for these power supplies?

Thanks

Rubin Chen said:

Do you have plan to develop a 6-channel ADC that supports 1.2V I/O level?

Hi Rubin,

Currently I don't think a 6-channel ADC that supports 1.2V I/O level is planned.

Thanks and Regards,

Lakshmi Narasimhan

Rubin Chen said:

Are there ripple requirements for these power supplies?

Hi Rubin,

The datasheet specifies the PSRR of the device. We can refer to the same.

Thanks and Regards,

Lakshmi Narasimhan

Hi Lakshimi，

PSRR looks like a feature of a device.I want to know the requirement of ripple requirements：Whether LDO or DCDC is used for power supply. The voltage ripple that supplies power to the device cannot exceed (？) mV.

Thanks

Hi Rubin,

There is no ripple requirement specifically mentioned in the datasheet. However, there is a recommended operating voltage range, we would need to ensure that the supply does not violate this range.

Thanks and Regards,

Lakshmi Narasimhan

Hi Lakshmi,

Currently, 3.3 V to1.2 V can only be implemented through level conversion IC.
Can you help me evaluate whether this solution is risky?Especially the audio interface such as TDM/I2S.

Thanks

Hi Rubin,

As you have pointed out, to interface the device with 1.2V SoC, we would need a level translator to move to 1.8V/3.3V logic level (depending on device IOVDD).

Thanks and Regards,

Lakshmi Narasimhan

Hi Lakshmi,

Could you help support schematic review?

Please focus on microphone input circuits.The following figure shows the microphone used by us.

R1-R6 will be replaced by 680 Ω later.

Thanks

adc_pcm6260_s0_20240806.pdf

Hi Rubin,

Can you once confirm the voltage rating of the capacitors used for the BST_OUT and MICBIAS pins?

Based on the input connections, the device is intended to be used in AC-coupled, single-ended configuration, please correct me if my understanding is wrong?

Thanks ang Regards,

Lakshmi Narasimhan

Hi Lakshmi,

voltage rating of capacitors:

C14=25V，C17=16V，C22=50V，C13=25V.

I think the microphone circuit in the following figure is a circuit that requires single-end input AC coupling.

Thanks

Hi Rubin,

In the attached schematic, the INM looks to be directly shorted to GND.

As per the PCM6260-Q1 datasheet, the recommendation for AC-coupled single-ended input is as shown below:

Thanks and Regards,

Lakshmi Narasimhan

Hi Lakshmi,

In the red area in Figure 1, MICBIAS needs to be used to supply power to the right side of the AC coupling capacitor.
In the blue area in Figure 2, MICBIAS needs to be used to supply power to the left side of the AC coupling capacitor.

I think if I want to supply power to the microphone through MICBIAS, I need to supply power like Figure 2.What do you think?

Thanks

Figure 1:

Figure 2:

Hi Rubin,

The resistor highlighted in Figure 2 (left side of AC-coupling capacitor) would power the microphone with the MICBIAS voltage.

The resistors highlighted in Figure 1 (right side of AC-coupling capacitor) are meant to provide bias to the input pins of the PCM6260.

Thanks and Regards,

Lakshmi Narasimhan

Hi Lakshmi,

The resistor highlighted in Figure 2 (left side of AC-coupling capacitor) would power the microphone with the MICBIAS voltage.

——Do you recommend power the microphone via the MICBIAS voltage？

The resistors highlighted in Figure 1 (right side of AC-coupling capacitor) are meant to provide bias to the input pins of the PCM6260.

——What are the functions of providing bias to the input pins of the PCM6260？

Thanks

Hi Rubin,

The microphone can be biased using the MICBIAS pin voltage.

The external bias to input pins of PCM6260 is to keep the device from directly seeing negative signal swing.

Alternatively, the device can be used for DC-coupled microphone input, as shown below:

Thanks and Regards,

Lakshmi Narasimhan

Hi Lakshmi,

The external bias to input pins of PCM6260 is to keep the device from directly seeing negative signal swing.

——What is the impact of seeing negative signal swing?

Another question:

What's the function of VBAT_IN?When does the VBAT_IN need to be used?

Thanks.

Hi Rubin,

The device input pins are not designed to accept a negative voltage input. In the Absolute Maximum table, the minimum value is -0.3V. Values lower than this are at risk of damaging the device.

VBAT_IN is only used as part of the diagnostic feature set. It is a measurement of the battery voltage commonly found in automotive systems in order to determine if the input pins are shorted to VBAT.

Best regards,
Jeff McPherson

Hi Lakshmi,

The manufacturer of the microphone recommends AC coupling to avoid ADC affecting the operation of the microphone.

Please help review attached schematic diagram，especially the circuits of the input connection:

①Figure 1 shows the microphone used by the CH1-CH4，the circuits of the input connection shows as figure 2，I will use MICBIAS as power of microphone.

②CH4-CH6 Input differential signal，the circuits of the input connection shows as figure 3.

Thanks.

Figure 1:

Figure 2:

Figure 3:

adc_pcm6260_s0_20240828.pdf

Hi Jeff,

Can you provide a reference design for the PCM6260?

Thanks