TPS61220 with AFE4404

Samuel Conti

Other Parts Discussed in Thread: TPS61220, AFE4404, TPS62740

Hello,

I use the TPS61220 step-up converter to supply the AFE4404 TX_SUP pin. Vin of TPS61220 is from 3V3 to 4V2. Its output is 4V3.

My question is when the TPS61220 is disabled. I saw in the datasheet when the chip is disabled, there is even so a voltage (between 2V5 and 3V5 : figure 12 page 7 of the datasheet). As well as theTPS61220 is disabled, is the AFE4404 supplied ? is there a current consumption by the AFE4404 with this low voltage ?

Thank you,

Sam,

over 9 years ago

0 Lakeishia Brown over 9 years ago

TI__Prodigy 230 points

Hi Sam,

We have received your inquiry about the TPS61220, and will get back to you shortly.

Best Regards,
Lakeishia

0 Praveen Aroul over 9 years ago

TI__Mastermind 49986 points

Hi Sam,

The recommended voltage range for the transmitter supply is 3 - 5.25V.
When the voltage level is below 3V (between 2.5V and 3V) what are the receiver and IO_SUP voltages?

0 Jasper Li over 9 years ago

TI__Mastermind 46905 points

there is a body diode in the high side MOSFET form SW to VOUT. the VOUT will be (VIN-Vdiode) when the device is disable. the Vdiode is approximately 0.4~0.7, depend on the load condition.

0 Samuel Conti over 9 years ago in reply to Praveen Aroul

Intellectual 510 points

Hi,

The voltage on IO_SUP is 0V. In fact I have the TPS61220 to supply TX_SUP + LED of a SFH7051 and a TPS62740 to supply RX_SUP and IO_SUP. So the "Enable" pins of these 2 DC/DC converters are drived at the same time by the same signal. So when TPS61220 is disabled TPS62740 is disabled and same when enabled.

About the last reply and the internal diode, if I understand, the current flow through the internal diode. So the AFE4404 consumes current even if the chip is diable ? is it true ?

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TPS61220 with AFE4404