TLN-864 Switching Comparator

Combination of a comparator and switch

The TLN-864 Switching Comparator combines a comparator and an analogue switch. A typical comparator has two inputs (A & B) and produces an output that is high (H) if A > B, and low (L) if A < B. Rather than using fixed voltages for the H and L states, the TLN-864 allows the voltages to be manually set using two front panel pots. For example, H can be -1V and L can be +3V. In addition, two front panel jacks allow any external signal to be used for the H and L states. For example, H could be the SINE wave output from an oscillator and L could be the inverted output from a sample and hold module. Anything goes in, anything goes out. Reversing attenuators are used on the A, B, H, and L inputs so that all input signals can be scaled and inverted. When nothing is plugged into the A, B, H, and L inputs, the front panel pot is used to select a fixed voltage reference from -5V to +5V.

The switching portion of the comparator has two modes of operation. The first mode (HL:X) is a 2-to-1 switch in which the signals at A and B determine which of H and L appear at output X. In other words:

If ( A > B )
X = H
else
X = L

The Y output is not used in this mode.

The second mode (H:XY) is a 1-to-2 switch in which the signals at A and B determine whether H appears at the X or Y output. In other words:

If ( A > B )
X = H
else
Y = H

The L input is not used in this mode.
The panel controls are as follows:

• LEVEL A: reversing attenuator for A input (normalled to +5V reference).
• LEVEL B: reversing attenuator for B input (normalled to +5V reference).
• LEVEL H: reversing attenuator for H input (normalled to +5V reference).
• LEVEL L: reversing attenuator for L input (normalled to +5V reference).
• MODE: selects the switch mode, 2-to-1 or 1-to-2.
• LED: indicates if A is greater than B.

The TLN-864 makes a great companion to the TLN-865 Trigger Extractor & Window Comparator.

Required PCBs are available at SynthCube!
https://synthcube.com/cart/tellun-corporation-diy-pcbs

http://www.tellun.com/motm/diy/tln864/TLN-864.html