9.2.4.2.1 N-Channel Oscillator Circuit

The oscillation frequency is determined by R5 and C5. The default configuration oscillates around 10kHz (depending on RC component tolerances). For further information on selecting these RC values, please see the Engineers Cookbook Circuit entitled Oscillator Circuit (SNOA990). Do note that R5 does present an AC load to the oscillator output, and should be sized appropriately to minimize the peak charging currents of C5 (use large resistors and small capacitors).

The output amplitude is roughly equivalent to the V_LOAD voltage minus the TLV1805 output saturation (approximately 300mV). With a maximum supply voltage of 40V for the TLV1805, the oscillator circuit is capable of generating up to 39Vpp!

The TLV1805 oscillator typically starts oscillating when V_LOAD reaches 2.8V, though full specified operation does not occur until 3.3V.

For more information, please see the TLV1805-Q1 Evaluation Module Users Guide TLV1805-Q1 Evaluation Module Users Guide (SNOU158).