The reason why TC9400 V/F converter is very useful in the laboratory are because it’s portable, battery-operated, and low cost frequency source. Both pulse and square-wave outputs are provided by the TC9400. A triangular waveform can also be generated by adding an op-amp integrator. The outputs can be frequency-modulated via the FM input.
WIDE FREQUENCY RANGE PULSE GENERATOR circuit schematic

[Circuit’s schematic diagram source: Microchip Application Note]