questions regarding one alkaline battery (1.5v)

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achao1104
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questions regarding one alkaline battery (1.5v)

Dialog,

In my case, we are very sensitive in cost of device, that is why we have to select " one alkaline battery (1.5v) " rather than other power supply.
please kindly confirm the following questions:
1) does " one alkaline battery (1.5v) " cost more energy than other power supply?
2) in board design, we connect the battery to vbat1v, so can we leave vbat3v empty(dangling) or connect vbat3v to vbat_rf (as said in datasheet)?
3) are there any limitations in using battery 1.5v?

Peter

Device:
MT_dialog
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Hi achao1104,

Hi achao1104,

1)我不确定我得到这个问题,碱性battery it will give you more operating days than a coin cell if that is what you want.

2) Just follow the configuration that is indicated by the datasheet.

3) There are a bunch of tradeoffs when choosing between buck and boost mode for example in boost mode you will have to use use the XTAL32 you cant use the RC oscillators so you will have to add an XTAL32 in your BOM, also you have to use the OTP you wont be able to boot from external devices you will have to use the OTP.

Thanks MT_dialog

achao1104
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thanks for reply.

thanks for reply.
#1 I mean one Alkaline battery only provides 1.5v (voltage) much lower than 3.0V, the question is that whether lower voltage (like 1.5v) will cost more energy than higher voltage. In other words, assuming the same capacity for 1.5v vs. 3.0v battery, the 1.5v battery will provide shorter working time?
#2 just clarify, though the Alkaline battery connected to vbat1v, we still need to connect vbat3v to vbat_rf (as said in datasheet)?
#3 it is ok to use OTP only, could you please explain more why we have to add a XTAL32?

MT_dialog
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Hi achao1104,

Hi achao1104,

1) As far as i know the 1.5v batteries will provide larger working time, i am not aware in case of the same capacitance what is the best option.

2) Yes, connect the battery to the vbat1v and the vbat3v, vbat_rf to each other. You can have a look at the keyboard reference schematic that operates under boost mode.

3) Since you are going to use the da in Boost mode the usage of the XTAL32 is mandatory

Thanks MT_dialog