The generation of symmetrical triangles at frequencies above 50 kHz is usually accomplished by conversion of a square wave by means of a fast (op-amp) integrator. If a voltage swing of about 20 v pk-pk is required, the choice is restricted to a fast op-amp driven by a good 20 v pk-pk square wave. Other circuits have been designed, but are not simple, or output voltage swing and/or frequency effective. A novel fixed frequency triangular waveform generator is driven directly by a TTL square wave at the input, and generates typically 16 v pk-pk triangles at frequencies up to some MHz, with a quite fair linearity. It uses only one NAND open collector gate, or one open collector inverter, as a fast integrator with grain, and is simple and cost saving.