Have a circuit that needs repair. Uses a TIP125 (NPN, Darlington) emitter tied to Vbb (~20VDC). Collector to load, then to ground. 1K resistor...

Have a circuit that needs repair. Uses a TIP125 (NPN, Darlington) emitter tied to Vbb (~20VDC). Collector to load, then to ground. 1K resistor (R1) pullup on Base to Vbb, and a second 1KR (R2) to the TTL controller. Problem is of course, that R2 puts the ~20VDC to the TTL output gate on a 74LS138. Trying to solve this without a driver transistor. The circuit is for a 1ms ~20V strob...

Hi, I have been using an GW Instek SFG-2110 and find that the TTL output has a fast rise time. It is about 2 ns and this could be useful for...

Hi, I have been using an GW Instek SFG-2110 and find that the TTL output has a fast rise time. It is about 2 ns and this could be useful for oscilloscope bandwidth measurements for instruments of less than 100 MHz. The TTL option seems to be missing on more expensive function generators. Any thoughts?

Working on a FPGA project and we need perhaps 30 level shifter gates. Anyone work with 3.6 to 5.0 volt interfaces that can recommend any...

Working on a FPGA project and we need perhaps 30 level shifter gates. Anyone work with 3.6 to 5.0 volt interfaces that can recommend any single part over the rest before I spend a few hours digging through Digi/Mouser/Newark's inventory? In some cases we can get away with resistors, but there is a bit of TTL level drivers needed. Thanks! John :-#)# -- (Please post followups or...

I'm tired of digging around looking for an optimal chip to level shift a pair of signals from 5V TTL (an RS-422 transceiver) to 3.3V CMOS. There...

I'm tired of digging around looking for an optimal chip to level shift a pair of signals from 5V TTL (an RS-422 transceiver) to 3.3V CMOS. There are too many devices, and no small number of them are impacted by the semiconductor shortage. But resistors are pretty available, as are Zener diodes. So, I could use a pair of resistors to simply divide the TTL output voltage to somet

I am still working with a friend on a TTL level replacement for some chips on a pinball board and we have a nice FPGA (MAX 10 based) but it...

I am still working with a friend on a TTL level replacement for some chips on a pinball board and we have a nice FPGA (MAX 10 based) but it wants (of course) 3.3V I/O. I was thinking that SN74CBT16211C (24 x IO level shifter) and a TVS arrays like the D3V3X8U9LP3810-7 with a low Ohm (1 - 10R) Flame-Proof 1/8W or less resistor on the outside world interface would do for protection. ...

If I were to use CAN bus on the test fixture I'm planning, I would need a USB cable that looks like a UART to the PC. Then I would need modules...

If I were to use CAN bus on the test fixture I'm planning, I would need a USB cable that looks like a UART to the PC. Then I would need modules to mount on the test fixture boards that provide a UART like TTL interface. A quick survey finds lots of modules with wired connectors on both ends and units in metal boxes. I would need something that requires zero programming of the unit itself. ...

2N2369 is an old standby... kind of high current (200mA), like a '3904 sped up about 2-3 times. Not well specified though, I suppose because...

2N2369 is an old standby... kind of high current (200mA), like a '3904 sped up about 2-3 times. Not well specified though, I suppose because it's so old. I'm thinking in the 20V, 50mA range, fT maybe 0.5-1GHz. Like if you wanted to make old school RTL circuits that run as fast as 74S TTL. MPSH11 looks good, and '81 looks like its complement. I've used PN3563 before (complement PN425...

Looking for a cost effective part that is better then the classic 4052 switch. Requirements: Rugged part that can handle being used by...

Looking for a cost effective part that is better then the classic 4052 switch. Requirements: Rugged part that can handle being used by hobbyists. Dip package preferred for customer replacement. +/- 12 to 15V rails. TTL Control +/- 5V signal, DC to 3 KHz waveforms. Steve

The mounting holes on PC motherboards: are they usually connected to the PCB ground plane? -- John Larkin ...

The mounting holes on PC motherboards: are they usually connected to the PCB ground plane? -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL d...

Has anybody done this? https://dl.dropbox.com/u/53724080/Circuits/Isrc_LED.JPG -- John Larkin Highland Technology...

Has anybody done this? https://dl.dropbox.com/u/53724080/Circuits/Isrc_LED.JPG -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links V...

I have a fast 3.3 volt logic level that I'd like to split into inverted and non-inverted copies with minimum time skew. I think that TI...

I have a fast 3.3 volt logic level that I'd like to split into inverted and non-inverted copies with minimum time skew. I think that TI once had a buffer with one input and complementary outputs, but I can't find a reference to that. It's probably slow and obsolete. A TTL to RS485 converter sort of works but would be slow. I could use two separate XOR gates, one as a buffer and the...

I'm updating some game board designs and was curious if there is any sort of printed guideline for replacing silicon driver transistors with...

I'm updating some game board designs and was curious if there is any sort of printed guideline for replacing silicon driver transistors with MOS? Both NPN and PNP. For example TIP122 Darlington transistors driven by another pre-driver, that is the TTL interface. I've seen many a substitute, but would like to have the theory explained so I can make better use of it and understand exact...

http://www.theregister.co.uk/2013/06/19/nuke_plants_to_keep_pdp11_until_2050/ -- John Larkin Highland Technology,...

http://www.theregister.co.uk/2013/06/19/nuke_plants_to_keep_pdp11_until_2050/ -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME the...

I have a project in mind using small Flash RAM and a cheap CPU to substitute for the old TTL level CMOS RAM used on arcade games. This has...

I have a project in mind using small Flash RAM and a cheap CPU to substitute for the old TTL level CMOS RAM used on arcade games. This has come up because the NVRAM that is currently being used is getting hard to find at prices under $7 to $9USD. Something like the M25P05-AVMN6P (512k or 64K x 8) or similar chips are $0.20 in single quantities. The size of CMOS RAM we are replacing ...

Just some thoughts that may help someone. To get started I would recommend the Nano. You just need it , a usb cable, and the IDE downloaded....

Just some thoughts that may help someone. To get started I would recommend the Nano. You just need it , a usb cable, and the IDE downloaded. The Nano has a usb chip on the module. No hassles about connecting. The pro mini does not have a usb chip, but is otherwise the same. To use it you need a usb to TTL adapter. I bought an adapter with a FDTI232 chip and could not get

Cheapest way to add USB and 5 V and 3.3V power to a RS232 PIC project Got some ebay USB To RS232 TTL PL2303HX Auto Converter Module...

Cheapest way to add USB and 5 V and 3.3V power to a RS232 PIC project Got some ebay USB To RS232 TTL PL2303HX Auto Converter Module Converter Adapter for arduino ebay object: 360750555245 Module has 5V and 3.3 V out (from the USB power). The PL2303 works 100% OK with Linux native drivers. Just connect to RS232 in and RS232 out, and power, and no need to write USB code, or get a sp...