Patent attributes
A PWM controlled current source includes a selection input, a modulation input, a switchable current source which can be switched by means of a signal at a control terminal and whose current output is configured for connection to a load, and an inverter circuit including an input node and an output coupled to the control terminal. The inverter circuit has a capacitance conditioned by elements of the inverter circuit. A start signal can be supplied to the input node in dependence on a selection signal at the selection input, which controls the switchable current source via the inverter circuit. The PWM controlled current source also includes a voltage-to-current converter that generates a current derived from a modulation signal at the modulation input and supplies it to the input node. The supplied current disconnects the switchable current source after a time period predetermined by the conditioned capacitance.