Temperature compensated oscillators are provided. The oscillator comprises an oscillator circuit and a temperature compensation module. The temperature compensation module reduces temperature induced errors in the frequency of oscillation of the oscillator by providing a temperature compensation signal to the oscillator circuit based on a temperature sensor output. The temperature compensation module comprises a low pass filter configured to reduce noise in the temperature compensation signal. The low pass filter is such that, using Laplace representations of transfer functions, the transfer function H(s) of the filter is equivalent to the transfer function of a closed loop configuration in which a module having an open loop transfer function G(s) is configured to generate an output from the closed loop configuration by applying the open loop transfer function G(s) to an error between an input to the closed loop configuration and the output from the closed loop configuration.