US 7,532,445 B2
Transient voltage clamping circuit
Sakti Pada Rana, Singapore (Singapore); Swarnali Rana, legal representative
Assigned to STMicroelectronics Asia Pacific Pte Ltd., Singapore (Singapore)
Appl. No. 10/498,727
PCT Filed Dec. 14, 2001, PCT No. PCT/SG01/00253
§ 371(c)(1), (2), (4) Date Jan. 23, 2006,
PCT Pub. No. WO03/052898, PCT Pub. Date Jun. 26, 2003.
Prior Publication US 2006/0181822 A1, Aug. 17, 2006
Int. Cl. H02H 3/22 (2006.01); H02H 9/00 (2006.01)
U.S. Cl. 361—56  [327/536; 327/539; 363/37; 361/111] 23 Claims
OG exemplary drawing
 
10. A power circuit for a motor disk drive that receives power on a plurality of power lines coupled to the power circuit, the power circuit comprising:
a plurality of DMOS transistor pairs coupled between a voltage potential and a ground reference potential, each DMOS transistor pair coupled to a respective power line; and
a voltage clamping circuit coupled to the voltage potential and the ground reference potential and comprising:
a power transistor having a first terminal coupled to the voltage potential, a second terminal coupled to the ground reference potential, and a gate terminal;
an amplifier circuit having an input coupled to a voltage reference node and an output coupled to the gate terminal of the power transistor;
a pull-down circuit coupled to the voltage potential and the ground reference potential and having an output coupled to the gate terminal of the power transistor; and
a voltage reference circuit coupled to the voltage potential and the ground reference potential and having an output coupled to the voltage reference node on which the voltage reference circuit generates a first reference voltage.