Patent ID: 8432140

Claim:
A dual mode boost regulator in an integrated circuit device ( 102 ), comprising: a power source terminal ( 134 ); a power source common terminal ( 142 ); an inductor terminal ( 136 ); a external transistor gate control terminal ( 138 ); a voltage output terminal ( 140 ); a boost regulator mode select terminal ( 126 ); a voltage sense terminal ( 141 ); a transistor switching control circuit ( 108 ) having a mode select input coupled to the boost regulator mode select terminal ( 126 ); a first power transistor ( 124 ) coupled between the inductor terminal ( 136 ) and the voltage output terminal ( 140 ), and controlled by the transistor switching control circuit ( 108 ); a voltage feedback circuit ( 106 ) coupled between the voltage output terminal ( 140 ) and the transistor switching control circuit ( 108 ), and having at least one input coupled to at least one voltage reference; a start-up circuit ( 110 ); an oscillator ( 112 ) coupled to the start-up circuit ( 110 ) and the transistor switching control circuit ( 108 ); a second power transistor ( 116 ) coupled between the inductor terminal ( 136 ) and the power source common terminal ( 142 ), and controlled by the transistor switching control circuit ( 108 ); a first voltage measurement device ( 114 ) having an output coupled to the transistor switching control circuit ( 108 ); a second voltage measurement device ( 115 ) having a first differential input coupled to the inductor terminal ( 136 ) and a second differential input coupled to the voltage sense terminal ( 141 ); and a mode selection switch ( 118 ) having a common coupled to an input of the first voltage measurement device ( 114 ), a first input coupled to the inductor terminal ( 136 ) and a second input coupled to an output of the second voltage measurement device ( 115 ); wherein when a low power boost regulator mode is selected through the boost regulator mode select terminal ( 126 ) the first power transistor ( 124 ) and the second power transistor ( 116 ) are active and controlled by the transistor switching control circuit ( 108 ), and the input of the voltage measurement device ( 114 ) is coupled to the inductor terminal ( 136 ) through the mode selection switch ( 118 ); and when a high power boost regulator mode is selected through the boost regulator mode select terminal ( 126 ) the first power transistor ( 124 ) and the second power transistor ( 116 ) are inactive, and the input of the first voltage measurement device ( 114 ) is coupled to the output of the second voltage measurement device ( 115 ) through the mode selection switch ( 118 ).