In some examples, a device includes a curvature-correction circuit including a first current source configured to generate a PTAT electrical current. In some examples, the curvature-correction circuit also includes three or more programmable current sources configured to generate three or more programmable electrical currents. In some examples, the curvature-correction circuit is configured to generate a PWL electrical current based on the PTAT electrical current and the three or more programmable electrical currents. In some examples, the device also includes a reference voltage circuit configured to generate a reference voltage signal based on the PWL electrical current.