The TADD-3 Mini is a distribution amplifier for digital pulses. Its primary use is to distribute pulse-per-second (“PPS”) signals such as those obtained from GPS timing receivers. It is available in versions with SMA or BNC output connectors; the input connector is SMA on both. The board has all surface mount components installed; the user must solder the input, output, and power connectors, and the option jumpers.
The TADD-3 Mini has 4 outputs with coax connectors as well as provision to install an LED. Its input and outputs operate at either 3.3 or 5.0 volt logic levels, set by a jumper. With 5 volts, it delivers greater than 3.5 volts into a 50 ohm load, with rise time of less than 3ns.
The SMA board is 2.5 x 3.0 inches (63.5 x 76.2 mm) and the BNC board is 2.5 x 3.75 inches (63.5 x 95.25 mm). It requires a minimum DC input of about 5.5 volts (for 3.3 volt logic levels) or 7 volts (for 5 volt logic levels), and a maximum of 15 volts. Power consumption without loads is less than 20 ma.
Two or more TADD-3 Minis of either or both types may be stacked to create 8 or more outputs from a single input. Here are an SMA type stacked with a BNC type, and two BNC types stacked together:
How is the TADD-3 Mini different from the original TADD-3?
- 4 outputs instead of 8 (and no RS-232 outputs)
- One input rather than two
- SMA input connector
- Input is logic gate only; no comparator option
- Inverted outputs not available
- 3.3 or 5V logic level
(The BNC version is more expensive than the SMA model because BNC connector cost has risen greatly in the last couple of years and are now more than 4x the price of SMAs.)