| 摘要 |
A flash driver to limit a load current for a flash comprises a dc/dc converter (DCDC) having a first input (IN1) to re ceive an input voltage (Vin) and an output (OUT) to supply an output voltage (Vout). The dc/dc converter is designed to convert the input voltage (Vin) to the output voltage (Vout). Furthermore the flash driver has an adjustable current source (Iadj) connected between the output (OUT) and a load terminal (LT). A first control unit (CTRL_1) is connected to the first input (IN1) and coupled to the adjustable current source (Iadj), and is designed to compare the input voltage (Vin) to a threshold (Vth) and, if the comparison indicates the input voltage (Vin) being smaller than the threshold value (Vth), adjust the adjustable current source (Iadj) such that the input voltage (Vin) is equal or greater than the threshold value (Vth). A second control unit (CTRL_2) is coupled to the adjustable current source (Iadj) and the dc/dc converter (DCDC) and is designed to detect a voltage drop over the adjustable current source (Iadj) and to set the dc/dc converter (DCDC) to control the conversion of input voltage (Vin) to the output voltage (Vout) depending on the detected voltage drop. |
