Tin Wai Wong

US Patent:

7279961, Oct 9, 2007

Filed:

Nov 21, 2005

Appl. No.:

11/284780

Inventors:

Johnny Chan - Fremont CA, US
Tin Wai Wong - Fremont CA, US
Ken Kun Ye - Fremont CA, US

Assignee:

Atmel Corporation - San Jose CA

International Classification:

G05F 1/10
G05F 3/02

US Classification:

327540, 327536, 363 60

Abstract:

A charge pump generates a voltage higher than an intermediate voltage and a regulator circuit provides a first regulated voltage higher than the intermediate voltage. A second stage includes a regulator stage using the first voltage to provide the intermediate voltage from the first voltage. A charge pump provides a pump output voltage. The pump output voltage is divided and the divided voltage is presented to a first comparator that compares it with a reference voltage. The first comparator drives the gate of a first MOS transistor to regulate the pump output voltage to a regulated voltage related to the reference voltage. The regulated voltage is presented to a second comparator that compares it with the reference voltage. The second comparator drives the gate of a second MOS transistor to downconvert the regulated output voltage to an intermediate voltage related to the reference voltage.

US Patent:

7145318, Dec 5, 2006

Filed:

Nov 21, 2005

Appl. No.:

11/284779

Inventors:

Johnny Chan - Fremont CA, US
Tin Wai Wong - Fremont CA, US
Ken Kun Ye - Femont CA, US

Assignee:

Atmel Corporation - San Jose CA

International Classification:

G05F 3/16
G05F 1/40

US Classification:

323316, 323280, 327539

Abstract:

A first voltage divider includes a first resistor having a first resistance coupled to a positive voltage reference in series with a second resistor having a second resistance and coupled to ground. A second voltage divider includes a third resistor having the first resistance coupled to the positive voltage potential in series with a fourth resistor having the second resistance, and a fifth resistor having a third resistance and coupled to a negative voltage. A comparator has an inverting input coupled to the junction of the first and second resistors and a non-inverting input coupled to the junction of the third and fourth resistors. The first and third resistors are equal and the second and fourth resistors are equal. The fifth resistor has a value chosen to drop a voltage equal to the target voltage to be regulated when the voltage regulator output is equal to that target voltage.