[neonixie-l] Re: Supertex HV5522 supply current
Antoine I am using the HV5522 on my clock and multimeter projects. Using both SPI (for the HV5522) and I2C bus level shift. The voltage for the HV5522 is the same that powers the boost converter. I tested both 9 and 12V and it works just fine. I based my design on this app note: http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf The document describes a bi-directional level shifter but it works just fine when communication is uni-directional like with the HV5522. For the FETs I chose BSS138 as they are inexpensive. Regards Tobias On 1 jun, 07:53, Antoine Vanoutryve anto...@blacktrap.net wrote: Hi Terry. Indeed I found only one schematic using 12V. Most of schematics available on Google use 5V. That's why I preferred to ask. I will use 12V with transistors then. Thank you for your reply. Antoine On 01 Jun 2012, at 13:48, Terry S wrote: The datasheet does not indicate an operating supply voltage of -0.5 to +15v, those are the absolute maximum ratings. Use the part within it's recommended ratings of 10.8 to 13.2 volts and you won't have any issues. Otherwise, all bets are off. It never ceases to amaze me when people use a part outside it's spec and then wonder why they have problems. Would you use a lawnmower to trim your hedge? Your weed whip to cut down a tree? Terry On Jun 1, 6:06 am, Pengouin anto...@blacktrap.net wrote: Hi, I intend to use Supertex HV5522 to build a Nixie clock with four IN-18 tubes. I found some schematics on the Internet. Some use 5V directly connected to HV5522 and some use higher voltages (12V) with a field effect transistor connected to a 5V MCU. I plan on using a PIC MCU running at 3.3V to drive my HV5522. The datasheet seems to indicate that I can use any voltage between -0.5V to +15 V, but the recommended voltage is 10V to 13V. Does anyone uses HV5522 connected directly in 3.3? Is it working correctly? Thanks for your help Antoine -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group athttp://groups.google.com/group/neonixie-l?hl=en-GB. signature.asc 1KVisualizarFazer download -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
[neonixie-l] Re: Supertex HV5522 supply current
On Jun 1, 12:54 pm, Adam Jacobs a...@jacobs.us wrote: I understand your point, Terry.. Which I think is the classic Slippery Slope argument. You get used to cutting corners, before you know it you're trying the same tricks at work where you design nuclear reactor cooling systems, the systems fail due to your design choices that were outside of specification, etc. Luckily for me, I take mission criticality into account when I make a design. A nixie clock project (for me) is foremost a fun chance to try new things and sandbox some experimentation. Disclaimer: I don't sell my clocks and I also don't use them in mission critical applications such as drones or heart pumps. I'm more concerned when the cut corners are in Friend or Foe detection systems :D -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
[neonixie-l] Re: Supertex HV5522 supply current
The datasheet does not indicate an operating supply voltage of -0.5 to +15v, those are the absolute maximum ratings. Use the part within it's recommended ratings of 10.8 to 13.2 volts and you won't have any issues. Otherwise, all bets are off. It never ceases to amaze me when people use a part outside it's spec and then wonder why they have problems. Would you use a lawnmower to trim your hedge? Your weed whip to cut down a tree? Terry On Jun 1, 6:06 am, Pengouin anto...@blacktrap.net wrote: Hi, I intend to use Supertex HV5522 to build a Nixie clock with four IN-18 tubes. I found some schematics on the Internet. Some use 5V directly connected to HV5522 and some use higher voltages (12V) with a field effect transistor connected to a 5V MCU. I plan on using a PIC MCU running at 3.3V to drive my HV5522. The datasheet seems to indicate that I can use any voltage between -0.5V to +15 V, but the recommended voltage is 10V to 13V. Does anyone uses HV5522 connected directly in 3.3? Is it working correctly? Thanks for your help Antoine -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
Re: [neonixie-l] Re: Supertex HV5522 supply current
Hi Terry. Indeed I found only one schematic using 12V. Most of schematics available on Google use 5V. That's why I preferred to ask. I will use 12V with transistors then. Thank you for your reply. Antoine On 01 Jun 2012, at 13:48, Terry S wrote: The datasheet does not indicate an operating supply voltage of -0.5 to +15v, those are the absolute maximum ratings. Use the part within it's recommended ratings of 10.8 to 13.2 volts and you won't have any issues. Otherwise, all bets are off. It never ceases to amaze me when people use a part outside it's spec and then wonder why they have problems. Would you use a lawnmower to trim your hedge? Your weed whip to cut down a tree? Terry On Jun 1, 6:06 am, Pengouin anto...@blacktrap.net wrote: Hi, I intend to use Supertex HV5522 to build a Nixie clock with four IN-18 tubes. I found some schematics on the Internet. Some use 5V directly connected to HV5522 and some use higher voltages (12V) with a field effect transistor connected to a 5V MCU. I plan on using a PIC MCU running at 3.3V to drive my HV5522. The datasheet seems to indicate that I can use any voltage between -0.5V to +15 V, but the recommended voltage is 10V to 13V. Does anyone uses HV5522 connected directly in 3.3? Is it working correctly? Thanks for your help Antoine -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB. signature.asc Description: Message signed with OpenPGP using GPGMail
Re: [neonixie-l] Re: Supertex HV5522 supply current
That is interesting. My guess is that there are lots of lazy engineers out there that have figured out that the part works OK on 5v. That's why experimentation is so important. If I was going to make a WAG, I'd bet that it works at 5v although probably at slower speeds. Try it with 5v if it is a huge savings in parts for your. Maybe it will work. If it doesn't, then change it to 12v. (shrug) I'm assuming this isn't a mission critical device or something that you are planning to sell, of course. I think that most people here don't have much experience with the Supertex parts, although they do look neat. I have a tube of them but haven't had a chance to try them out. -Adam On 6/1/2012 4:53 AM, Antoine Vanoutryve wrote: Hi Terry. Indeed I found only one schematic using 12V. Most of schematics available on Google use 5V. That's why I preferred to ask. I will use 12V with transistors then. Thank you for your reply. Antoine On 01 Jun 2012, at 13:48, Terry S wrote: The datasheet does not indicate an operating supply voltage of -0.5 to +15v, those are the absolute maximum ratings. Use the part within it's recommended ratings of 10.8 to 13.2 volts and you won't have any issues. Otherwise, all bets are off. It never ceases to amaze me when people use a part outside it's spec and then wonder why they have problems. Would you use a lawnmower to trim your hedge? Your weed whip to cut down a tree? Terry On Jun 1, 6:06 am, Pengouinanto...@blacktrap.net wrote: Hi, I intend to use Supertex HV5522 to build a Nixie clock with four IN-18 tubes. I found some schematics on the Internet. Some use 5V directly connected to HV5522 and some use higher voltages (12V) with a field effect transistor connected to a 5V MCU. I plan on using a PIC MCU running at 3.3V to drive my HV5522. The datasheet seems to indicate that I can use any voltage between -0.5V to +15 V, but the recommended voltage is 10V to 13V. Does anyone uses HV5522 connected directly in 3.3? Is it working correctly? Thanks for your help Antoine -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB. -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
[neonixie-l] Re: Supertex HV5522 supply current
The part is fabbed in HVCMOS, so yes, it will continue to function at some level down to where the CMOS transistor structures no longer switch -- probably well below 3 volts. But... The problem with using a part like that outside its spec is that you simply can't predict what parameters won't be met. What if it affects set-up or hold times? What if it affects output drive or input impedance? There are simply so many things that can go wrong -- internal timing conditions that might not be met. As a hobbyist, you might be forgiving of a misbehavior if it doesn't manifest itself visibly on your clock display, or you find a work around for a timing problem -- but what if this were a life critical medical or industrial application, or a mission critical military app? As an engineer or designer, your butt would be on the line should you use a part outside its specs and someone gets hurt or dies, or your drone crashes... Speaking of drones, Obama is in town today, about 6 blocks from here, speaking at Honeywell. I bet I can't even go out for lunch today without running into his entourage. Gonna be another vending machine lunch I guess. Terry -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
Re: [neonixie-l] Re: Supertex HV5522 supply current
I understand your point, Terry.. Which I think is the classic Slippery Slope argument. You get used to cutting corners, before you know it you're trying the same tricks at work where you design nuclear reactor cooling systems, the systems fail due to your design choices that were outside of specification, etc. Luckily for me, I take mission criticality into account when I make a design. A nixie clock project (for me) is foremost a fun chance to try new things and sandbox some experimentation. Disclaimer: I don't sell my clocks and I also don't use them in mission critical applications such as drones or heart pumps. If something fails because of a design choice that I made, then I make a note of it and change the experimental design. The fact is that mission criticality is just another input in the requirements phase of the design. Things like component count, size, feature set, hazard analysis. Take the time to come up with some real product requirements before you start drawing a schematic. Makes things a lot easier. -Adam W7QI On 6/1/2012 8:09 AM, Terry S wrote: The part is fabbed in HVCMOS, so yes, it will continue to function at some level down to where the CMOS transistor structures no longer switch -- probably well below 3 volts. But... The problem with using a part like that outside its spec is that you simply can't predict what parameters won't be met. What if it affects set-up or hold times? What if it affects output drive or input impedance? There are simply so many things that can go wrong -- internal timing conditions that might not be met. As a hobbyist, you might be forgiving of a misbehavior if it doesn't manifest itself visibly on your clock display, or you find a work around for a timing problem -- but what if this were a life critical medical or industrial application, or a mission critical military app? As an engineer or designer, your butt would be on the line should you use a part outside its specs and someone gets hurt or dies, or your drone crashes... Speaking of drones, Obama is in town today, about 6 blocks from here, speaking at Honeywell. I bet I can't even go out for lunch today without running into his entourage. Gonna be another vending machine lunch I guess. Terry -- You received this message because you are subscribed to the Google Groups neonixie-l group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
