This application relates to analogue-to-digital converters (ADCs). An ADC 200 has a first converter (201) for receiving an analogue input signal (AIN) and outputting a time encode signal (DT), such as a pulse-width-modulated (PWM) signal, based on input signal and a first conversion gain setting (GIN). In some embodiments the first converter has a PWM modulator (401) for generating a PWM signal such that the input signal is encoded by pulse widths that can vary continuously in time. A second converter (202) receives the time encoded signal and outputs a digital output signal (DOUT) based on the time encoded signal (DT) and a second conversion gain setting (GO). The second converter may have a first PWM-to-digital modulator (403). A gain allocation block (204) generates the first and second conversion gain settings based on the time encoded signal (DT). The gain allocation block (204) may have a second PWM-to-digital modulator (203) which may be of lower latency and/or lower resolution that the first PWM-to-digital modulator (403).