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Hello COMMUNITY 8))
please give me recommendations about suply
i have :
Psoc 5lp for ~16-18bit ADC and postprocessing
full Isolated dif amp (TI amc1301) for measure current shunt.
Shunt located in heavy EMI from random ultra HV sparks.
for power supply device i want use 1s Lipo 2x18650 3500mah
device shilded in metall box
i need maximum ADC perfomance for my situation , and long battery life.
in this case i have some questions:
1. can i supply PSOC (Vddd= 3.3-4.2v) direct from LIPO without LDO, or best way use buck/boost regulator for full lipo dicharge to 3.0 V , and stabil 3.3 main voltage?
2. how i understand, for accurate ADC measurement i need external Vref.
in this case i can use dual Vref ic TI REF2033 (1.65V20mA + 3.3V20mA, 6 ppm/°C , Accuracy: ±0.05% ).
REF2033 out1 Vref 3.3 -> to PSOC Vdda + amc1301 Vdd2
REF2033 out2 Vref 1.65 -> to PSOC Vref
or you can tell me a more optimal solution ?
3. isolated DCDC for isolated amp parts + 3.3 LDO to amc1301 Vdd1
ADUM6000 or any other 1:1 isolated DCDC
.
Solved! Go to Solution.
- Labels:
-
PSoC 5 Architecture
-
PSoC 5LP
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PaSv,
"16-18bit ADC" and "random ultra HV sparks" do not come along. Data collected during the sparks, has to be discarded.
PSoC5 has internal 1.024V reference, which is sufficient for 16-18-bit DelSig_ADC measurements. I don't believe that any improvement can be made using external voltage reference, particularly in noisy EMI environment.
Simple data acquisition by PSoC5 will draw about 30mA, a pair of 18650 3500mAH each will run the system for 10 days continuously. I would use batteries directly, without any DC-DC converter. Voltage variation 4.2 down to 3.3V should not be an issue.
/odissey1
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Hi,
For the first question, buck/boost regulator should improve your battery life.
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"For the first question, buck/boost regulator should improve your battery life."
But buck/boost will add noise ...
may be 3.3V LDO beter ...
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PaSv,
"16-18bit ADC" and "random ultra HV sparks" do not come along. Data collected during the sparks, has to be discarded.
PSoC5 has internal 1.024V reference, which is sufficient for 16-18-bit DelSig_ADC measurements. I don't believe that any improvement can be made using external voltage reference, particularly in noisy EMI environment.
Simple data acquisition by PSoC5 will draw about 30mA, a pair of 18650 3500mAH each will run the system for 10 days continuously. I would use batteries directly, without any DC-DC converter. Voltage variation 4.2 down to 3.3V should not be an issue.
/odissey1
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" do not come along. Data collected during the sparks, has to be discarded." for the most accurate measurement, I plan to make a double shielding box + isolated shunt ground ( isolated shunt amplifier TI amc1301 ) ....and yes big currents, I will reject with post-processing
"PSoC5 has internal 1.024V reference, which is sufficient for 16-18-bit DelSig_ADC measurements. I don't believe that any improvement can be made using external voltage reference, particularly in noisy EMI environment."
hm .. sounds good.
"Simple data acquisition by PSoC5 will draw about 30mA, a pair of 18650 3500mAH each will run the system for 10 days continuously. I would use batteries directly, without any DC-DC converter. Voltage variation 4.2 down to 3.3V should not be an issue."
ok in this case my task is a little easier:
[~50ma leds fiber optic TX]--{to PSOC GPIO}
|
[2x 18650 DC ] ------[3.3V LDO]---------------[ISOLATION 3.3V DCDC]----[3.3VLDO]-----|
| |
| | (HV+)
| (6.9mA) (6.9mA) | |
|-------------------[ AMC1301 VDD2 |ISOLATION BARIER | AMC1301 VDD1] =======|| {SHUNT}
| | |
| | (HV-)
[PSOC 5LP ADC] ---|(ADC in)
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Power consumption is the most important when you think of design any system. ADC is used for the conversion of analog to digital. A key component of the power supply is isolating the switching and circuits always required a separate power supply. If we do not use a separate power supply so sometimes we face short-circuits issues. There I have seen a huge short circuit due to combining power supply.
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"A key component of the power supply is isolating the switching and circuits always required a separate power supply."
Yes, and for separate i want use 3.3V to 3.3V DCDC Isolation module
for example https://power.murata.com/cme0303s3c.html
(Murata cme0303s3c )