A 42x20mm integrated breakout, boost converter and driver. This board connects to an IV-18 tube and provides 3V or 5V control via the MAX6921AUI driver chip. The necessary voltage for the VFD tube is generated automatically from the supply voltage.
This board lets you control the IV-18 tube as if it was a TTL-level device - all the high-voltage drive circuitry is contained in the vertical support riser. It runs happily off a USB 5V supply, though it will be fairly dim at 3.3V.
We design these modules ourselves and manufacture them in our workshop in Bethnal Green, London, UK, and the modules+tube ship from the UK.
You can find a datasheet for the IV-18 tube here and example code here.
Please note - options with a tube may take several days to prepare, as they are assembled on demand.
We also stock a basic breakout board for the IV-18, which you can find here.
Ordering with a tube
It's possible to order the module with an original IV-18 tube. The tubes come randomly in either black (opaque background) or silver/transparent, and are all unused original stock manufactured in the early 1990s in the Soviet Union, likely by either Sovtek or ORZEP.
The supply of tubes is very limited.
The tube displays the digits 0-9 in bright green luminescence. Each digit has a decimal point. There is a - sign and a ° symbol on the left side of the display.
The typical lifespan is about 5,000-10,000 hours, depending on how hard (how bright) the tube is run. To extend the tube lifespan, reduce the module supply to about 4.75V. To run the tube very brightly (with reduced lifespan), power the module with 5.25V.
Module pinout
- GND
- +5V: 5V or 3.3V supply (the tube will run slightly dimmer at 3.3V; consider changing R1 for an 0805 0-ohm link to increase filament power, at the expense of slightly shorter tube life)
- DIN: Connected to the MAX6921. Serial-Data Input. Data is loaded into the internal shift register on CLK’s rising edge
- CLK: Connected to the MAX6921. Serial-Clock Input. Data is loaded into the internal shift register on CLK’s rising edge. Claims to support up to 5MHz.
- LOAD: Drive high to update the display; low to disable the serial bus (equivalent to chip-select). Connected to the MAX6921. Load Input. Data is loaded transparently from the internal shift register to the output latch while LOAD is high. Data is latched into the output latch on LOAD’s rising edge, and retained while LOAD is low.
- BLANK: Drive high to turn off the display. Connected to the MAX6921. Blanking Input. High forces outputs OUT0 to OUT19 low, without altering the contents of the output latches. Low enables outputs OUT0 to OUT19 to follow the state of the output latches.
- DOUT: Data output, for chaining multiple tubes together. Connect to the DIN pin of the next module in line, and connect CLK, LOAD and BLANK together.
Tube specifications
- Luminescence: 400 cd/m2
- Filament voltage: 5V (4.3V - 5.25V)
- Filament current: 85mA (75mA - 95mA max)
- Anode-Grid voltage 50V nominal, generated by the driver module (70V max)