I have configured a DWM1001 module powered through 2 AAA batteries with a boost converter, I have configure it into low power mode (Responsive mode off, BLE on) and using PANS 2.0 firmware. To test robustness I ran few cycles of powering off and on the anchors network. Most of the times it worked well and the tag consumes very low power except few surges. But every once in a while the tag gets stuck in a high power consumption mode consuming 17-32mA and sometimes even more. What can cause this, please guide.
What Boost Converter are you Using?
TPS613221A : https://www.ti.com/lit/ds/symlink/tps61322.pdf?ts=1602839076884&ref_url=https%3A%2F%2Fwww.google.com%2F
I also have a 470uF with max 28uA leakage current (DCL) in parallel to the boost convertor output. Through current and voltage measurement I am seeing that sometimes the unit is entering into a short circuit mode and consuming 500mA+ currents. When i put in fresh batteries it starts consuming low power again and this short circuit condition is resolved.
1 Like
We have experienced the same issue with the same TI regulators “TPS613221A” (6.5uA Iq) and also with the “TPS6120x” (55uA Iq) when the VIN voltage was below of 0.9 or 0.5 respectively, this usually happens when you use a single AAA/AA Cell or two Cell in parallel, so if you are using the batteries in parallel recommend you to change to series connection so the high current draw event never happens even with fully discharged batteries, and by the way the 470uF Cap is very excessive choose a smaller CAP.
e.g.
Input 150uF (Tantalum) parallel 4.7uF (ceramic)
Output 22uF (ceramic) parallel 22uF (ceramic)
Inductor 4.7uH
But in order to know better, are you using Parallel connection for the batteries?
Hi @MaximosRTLS thanks for your insight. I have used 2 AAA in series to create a 3V unit. With one single cell of 1.5v I also observed the same behavior at low voltages the inductor starts to heat up and the TI regulator doesn’t work properly.
Have you experienced the same overheating/overcurrent effect with Two AAA/AA Batteries in series (3V) connection?
By the way the High current consumption event of 17-32 mA can be caused for a PANS bug when BLE is on, see the topic:
https://forum.qorvo.com/t/very-high-dwm1001-current-consumption-in-off-sleep-mode/6122/21
No the overheating issue hasn’t been observed with batteries in series as the voltage never drops too low. But what I am observing is that after working for some time (in which the DMW1001 works as expected) , after some time though the current consumption suddenly increases and the circuit starts to act as short. I checked with the multimeter and confirmed the circuit is acting as short. I am confused if this is a problem with power converter or firmware is making the DWM1001 act like that.
Hi @MaximosRTLS I am observing very high currents in range of 500mA+. I followed this post and the observations in the post have been replicated by me.
@MaximosRTLS Even while using 2 AAA batteries as 3v unit, do you think transient drops in battery voltage (during Tx/Rx) could cause this behavior in boost converter that the circuit starts acting as short cicuit?
its possible because the RX drops a High current when start to seek for a PANS network,
So I posted this event issue in the e2e forum of Texas instruments, If I get some answer I gonna post it here.
@MaximosRTLS another observation is even when the module is working properly if I switch off all anchors , the module gets stuck in a high current consumption mode consuming 25-600mA currents. Its like the module has exited the responsive mode. In responsive mode off it consumes 200-400uA.
Attaching the current output: sampling current values at 0.1 seconds, current values in mA
this is the answer ithat I get from the TI Post
Hi Maximiliano:
May you share the waveform with us? Including the Vin, Vout and SW.
I saw the current is like the pulse loading. May you check the load details?
I afraid that the battery voltage will drop a lot caused by the ESR/ESL itself, especially it’s close to fully discharged. The Iin=Vo*Io/Vin/eff. If the Vin is low, the efficiency will decrease. Thus the input current will be increase.
Best Regards
Minqiu
if you can get Vin, Vout and SW pins plots that can help us.