CH9102 and CH343 have this VBUS pull down capability on top of CP2102N, which can be used to implement a VBUS-switch using a PMOS or to implement a VBUS discharging circuit for more reliable re-plugging enumeration. Also, the 3mm*3mm package (CH343P) has both RTS and DTR, making it the smallest (conventionally packaged) ready-to-use (no firmware coding) ESP32 downloading bridge. In addition, CH9102/343 do not suffer from the same DTR glitch during serial port opening and closing, so if reliability is not at No. 1 on your priority list, you can save the two NPN transistors as well, just connect DTR to EN and RTS to IO0. On the flip side, detection threshold on VBUS is not the same on CH9102/343 compared with CP2102N, so if you use a voltage divider to implement precision UVLO on VBUS, you need to tweak your circuit. The threshold is no longer VIO-0.7V. Learned it the hard way. Also the built-in 5V-3.3V LDO is not as capable on CH9102/343. The rated max output current is only 10mA, so consider it a signal only. OTOH, CP2102N's LDO can output 100mA, which includes its own
good info, thanks! we are using the internal regulator but NOT for other chips, just the serial chip itself as that is the lowest power mode. we do have a vbus divider, we will adjust the values as necessary thank you for letting us know its not the same. for the dual transistors, we're going to stick with them since we prefer reliability no matter what the OS does with the control lines :)
FWIW, JLC have 888 of them in stock ready for SMT pick N place today. But then again they've got 20,000+ of the various CP210 series too! What chip shortage? If you need bulk CP210whatever then just get them to SMT build a few PCBs with 100 chips per PCB then recover them all with a hot air gun on reception :)
CP2102N QFN24 package is pin to pin compatible with CP2104 of the same package. CP2104 was declared EOL a few years ago, I think they have since switched to CP2102N. And yes, I also have a very old Huzzah board with CP2104. CH9102 QFN24 is NOT pin to pin compatible, but if you only use the serial port function (not GPIOs, and you do not need a precise VBUS UVLO), they can be practically considered pin to pin compatible.
CH9102 and CH343 have this VBUS pull down capability on top of CP2102N, which can be used to implement a VBUS-switch using a PMOS or to implement a VBUS discharging circuit for more reliable re-plugging enumeration. Also, the 3mm*3mm package (CH343P) has both RTS and DTR, making it the smallest (conventionally packaged) ready-to-use (no firmware coding) ESP32 downloading bridge. In addition, CH9102/343 do not suffer from the same DTR glitch during serial port opening and closing, so if reliability is not at No. 1 on your priority list, you can save the two NPN transistors as well, just connect DTR to EN and RTS to IO0.
On the flip side, detection threshold on VBUS is not the same on CH9102/343 compared with CP2102N, so if you use a voltage divider to implement precision UVLO on VBUS, you need to tweak your circuit. The threshold is no longer VIO-0.7V. Learned it the hard way. Also the built-in 5V-3.3V LDO is not as capable on CH9102/343. The rated max output current is only 10mA, so consider it a signal only. OTOH, CP2102N's LDO can output 100mA, which includes its own
good info, thanks! we are using the internal regulator but NOT for other chips, just the serial chip itself as that is the lowest power mode. we do have a vbus divider, we will adjust the values as necessary thank you for letting us know its not the same. for the dual transistors, we're going to stick with them since we prefer reliability no matter what the OS does with the control lines :)
Good on you, working through it. Keep us all in toys. Love you guys. ♥
I have no idea what you changed but I know what you did. Customer service. Awesome!
FWIW, JLC have 888 of them in stock ready for SMT pick N place today. But then again they've got 20,000+ of the various CP210 series too! What chip shortage? If you need bulk CP210whatever then just get them to SMT build a few PCBs with 100 chips per PCB then recover them all with a hot air gun on reception :)
thanks for the purchase tip - there are cp2012n in stock, but the price is 3x what it used to be - its not practical to spend $2 on a USB serial chip!
I thought the ESP32 Hazzah uses the CP2104 and not the CP2102
CP2102N QFN24 package is pin to pin compatible with CP2104 of the same package. CP2104 was declared EOL a few years ago, I think they have since switched to CP2102N. And yes, I also have a very old Huzzah board with CP2104. CH9102 QFN24 is NOT pin to pin compatible, but if you only use the serial port function (not GPIOs, and you do not need a precise VBUS UVLO), they can be practically considered pin to pin compatible.
@@bskull3232 your insights on these series of chips is quite fascinating reading
Did you test the CH9102 driver in windows 7? The driver worked ok in win 10 but did not work in win 7 for me.
W7 has been eol for more than 2 years
@@UNVIRUSLETALE However, W7 is still widely used.