| 摘要 |
A voltage regulator comprising: a first voltage divider (R10,R11) having a first voltage divider input, a first voltage divider output and a first output/input voltage ratio; a second voltage divider (R12,R13) having a second voltage divider input, a second voltage divider output and a second output/input voltage ratio; a first comparator (122) for comparing a voltage at said first voltage divider output to a predetermined voltage; a first transistor (126) responsively coupled to said comparator (122) and coupled to an impedance (R14) to switchably insert said impedance into said second voltage divider to change the second output/input ratio; a second transistor (120); and a pulse-width-modulated signal means (106,108,112,116,118) coupled to the first and the second voltage divider outputs; the pulse-width-modulated signal means having an output (OUT) to switch said second transistor (120) with a pulse-width-modulated signal having a duty cycle responsive to the outputs of the first and second voltage dividers. <IMAGE> |
