A current reference based on bandgap technology with wide input voltage range by using 0.18µm BCD process

A current reference with 8∼25V input voltage range has been designed by using CSMC's 0.18µm BCD process. Based on the bandgap technology, the temperature coefficient of the current reference was obtained to be 105.9∼110.7 ppm/°C over the temperature range of −40∼125°C when the input voltage was 8∼25V. The total quiescent current of the current reference is 9.02µA and 22.55µA when the input voltage is 8V and 25V, respectively. Moreover, the PSR (power supply rejection) at low frequency is −56.2dB ∼ −28.1dB, when the input voltage is between 8V and 25V. This current reference has been successfully applied in a white LED driver chip.