The square-wave period is determined by the
RC time constant of the capacitor C1 and resistor R4. The maximum
frequency is limited by propagation delay of the device and the capacitance load at the
output. The low input bias current allows a lower capacitor value and larger resistor
value combination for a given oscillator frequency, which can help to reduce BOM cost
and board space. TI recommends that R4 be over several kilo-ohms to minimize loading of
the output.