Current consumption numbers - TCXO included\not included

viola · ‎2024-09-15

Hi,

I have several questions regarding current consumption numbers as they appear in the Datasheet of the STM32WLE5.

in Table 28 / Table 29 the current consumption of LORA RX/TX modes is mentioned.

I have several questions:

1. is it possible to use a TCXO on board and not supply its VDD=1.8V from PB0_VDD_TCXO pin , supply it from an external on board LDO instead?

2. if i chose to supply the TCXO VDD from PB0_VDD_TCXO pin - does the current consumption numbers ,that appear in table 28/Table 29 , include this current consumption ? if not - what is the delta current for this in each power state (RF RX , RF TX , RF not used) ?

3. is the internal on chip regulator that supply the PB0_VDD_TCXO - an LDO or SMPS ?

Thank you,

Viola

viola · ‎2024-09-17

Hi ,

Any update regarding those issues?

Thank you,

Viola

STTwo-32 · ‎2024-09-20

Hello @viola

1- Yes, you can. The TCXO supply can be provided by the STM32WL on PB0/VDDTCXO or independently to save one GPIO. Keep in mind that the HSEBYPPWR bit 23 of RCC clock control register (RCC_CR) is set and cleared by software to control the function on package pin
PB0-VDDTCXO. 0: PB0 selected; 1: VDDTCXO selected.
In addition, the voltage to apply depends on TCXO selected. Also, in that case, you’ll have a static power consumption, even when 32MHz is not needed.

2- No, table 28/29 are based on a XO oscillator. Add 1.5mA (when 32MHz runs) if TCXO is used.

3- This is an LDO, with a programmable voltage.

Best Regards.

STTwo-32

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viola · ‎2024-09-22

Hi ,

you mentioned I need to add 1.5mA due to the TCXO consumption.

1. Do you assume that the external TCXO requires 1.5mA and thats the reason you mention 1.5mA ?

or , 1.5mA is the additional current required by the STM32 VDD and its in addition to the current required by the exteranl TCXO VDD ?

2. what is the static additional current ,that you mentioned , required by the STM32 VDD when not using the 32Mhz ?

Thank You very much!

Viola

viola · ‎2024-09-24

Hi ,

Any update regarding those issues?

Thank you,

Viola