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FM5324B and FM5401 - NanoVNA-H4 Battery Charger and 5 Volt Converter Circuit
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My NanoVNA-H4 has a FM5324B for the battery charger and 5 volt boost converter circuit. The schematic shows a FM5401. Does anyone know the difference?
The datasheet is not written in English. I'm trying to explain why the charging LED on my NanoVNA-H4 does not turn off at the end of charge. The battery does appear to be charging properly. The LED flashes at very low voltages and is steady on at all other times. In looking at the datasheets, it looks like pins 2-4 can be configured for several different LED configurations. Both datasheets include a state diagram and the FM5324B appears to have one additional state. Thanks, Kent AA6P |
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Kent,
I haven't opened my 1 year old H4 lately but the led flashes when charging and is on steady once there is a full charge. Pulling the usb cable extinguishes the light.? ... Larry On Fri., 25 Jun. 2021 at 5:00 p.m., Kent AA6P<kawill70@...> wrote: My NanoVNA-H4 has a FM5324B for the battery charger and 5 volt boost converter circuit. The schematic shows a FM5401. Does anyone know the difference? The datasheet is not written in English. I'm trying to explain why the charging LED on my NanoVNA-H4 does not turn off at the end of charge. The battery does appear to be charging properly. The LED flashes at very low voltages and is steady on at all other times. In looking at the datasheets, it looks like pins 2-4 can be configured for several different LED configurations. Both datasheets include a state diagram and the FM5324B appears to have one additional state. Thanks, Kent AA6P |
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The battery LED on my NanoVNA-H4 stays on steady when the battery is fully charged, and flashes when the battery is still charging. I, too, expected the LED to out or change its color from red to blue or green when the battery is charged, but upon reading "The Absolute Beginners Guide to the NanoVNA", I discovered that the red LED just stays on steady.--Rich WB2GXMSent from my MetroPCS 4G LTE Android device------ Original message------From: Kent AA6PDate: Fri, Jun 25, 2021 5:03 PMTo: [email protected];Cc: Subject:[nanovna-users] FM5324B and FM5401 - NanoVNA-H4 Battery Charger and 5 Volt Converter CircuitMy NanoVNA-H4 has a FM5324B for the battery charger and 5 volt boost converter circuit. The schematic shows a FM5401. Does anyone know the difference?
The datasheet is not written in English. I'm trying to explain why the charging LED on my NanoVNA-H4 does not turn off at the end of charge. The battery does appear to be charging properly. The LED flashes at very low voltages and is steady on at all other times. In looking at the datasheets, it looks like pins 2-4 can be configured for several different LED configurations. Both datasheets include a state diagram and the FM5324B appears to have one additional state. Thanks, Kent AA6P |
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Thanks Larry and Richard for the help. It looks like my NanoVNA-H4 is operating normally although the battery LED only flashes when the voltage is very low.
The battery LED is Blue on my NanoVNA-H4 which is a brand new unit. The system LED is also Blue. The Absolute Beginner's Guide may not be totally up to date. My smaller NanoVNA-H has a Red battery LED that is steady on while charging and it then goes out at full charge. It was the different operation on the smaller NanoVNA-H that initially prompted the question. Thanks, Kent AA6P |
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I didn't initially notice Larry's comment that pulling the USB cable extinguishes the Battery LED. My NanoVNA-H4 does not operate that way so maybe the difference is the FM5324B chip.
The Battery LED in my unit only flashes below 3.6 volts so the indicator is useful in that one regard. Otherwise, the Battery LED is steady on whenever the unit is turned on. The operation of this LED is very different with the NanoVNA-H4 and NanoVNA-H. Here is a surprise. I have an AC Outlet Power Meter and decided to check the AC wattage when charging the NanoVNA-H4. I have three different AC to USB phone charger adapters. The wattage readings were 7.8 watts, 10.7 watts, and 11.5 watts using the three different AC adapters. All readings were higher than expected. The battery charge current must be quite high. Measurements on my NanoVNA-H were all in the range of 1.5 watts to 1.7 watts. That seems much more reasonable. 73, Kent AA6P |
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On 6/26/21 4:02 PM, Kent AA6P wrote:
I didn't initially notice Larry's comment that pulling the USB cable extinguishes the Battery LED. My NanoVNA-H4 does not operate that way so maybe the difference is the FM5324B chip. Or the chargers have wildly varying efficiency or (more likely) they have weird power factor/current waveform that "fools" the power meter. In addition to the trusty Kill-A-Watt for AC, I have a couple USB power meters that are quite handy.? And, if there's still something weird looking, there's the trusty 0.1 ohm resistor and the scope to look at the current waveform. |
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Jim - I am also using the Kill-A-Watt meter. In the case of the 7.8 watt reading, the Power Factor was 0.60 along with the higher Volt-Amp reading. The three AC to USB power adapters all get quite warm during charging.
My Moto G7 phone which has a 5000 mAh battery showed 14 watts during charge. The Kill-A-Watt meter does appear to show the end of charge on my NanoVNA-H4. Last night after about an hour the wattage reading dropped about three watts. That was good to see as the LED on my NanoVNA-H4 gives no indication of end of charge. The specification on the FM5324B integrated circuit appears to show a typical charge current of 300 mA. That would represent 1.26 watts at 4.2 volts. 73, Kent AA6P |
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