Boost converter with integrated high power discrete FET and low voltage controller

• US 8,008,897 B2
• Filed: 06/11/2007
• Issued: 08/30/2011
• Est. Priority Date: 06/11/2007
• Status: Active Grant

• Current Assignee: Alpha & Omega Semiconductor, Ltd.
• Original Assignee: Alpha & Omega Semiconductor, Ltd.
• Inventors: Cheng, Wai-Keung Peter, Chang, Allen
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US11/761,301
• Publication Number:
  US 20080304305A1
• Time in Patent Office: 1,541 Days
• Field of Search: 323/220, 323/222, 323/282, 323/283, 323/351, 257/676, 257/777
• US Class Current: 323/222
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 25/16 the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/12032 Schottky diode
• CPC Class Codes: H01L 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A boost converter for high power and high output voltage applications includes a low voltage controller integrated circuit and a high voltage, vertical, discrete field effect transistor, both of which are packed in a single package.

Claims

1. A boost converter, comprising:

a low voltage controller integrated circuit (IC) mounted to a first die pad;

an external high voltage, vertical, discrete field effect transistor (FET) mounted to a second die pad, the external high voltage vertical discrete FET having a gate coupled to the low voltage controller IC and a bottom drain facing and in electrical contact with the second die pad; and

an external high voltage Schottky diode mounted to the second die pad, the external high voltage Schottky diode having an anode facing and in electrical contact with the second die pad, whereby the anode of the Schottky diode is coupled to a drain of the high voltage, vertical, discrete FET through the second die pad;

wherein the IC, FET, and Schottky diode are formed on separate semiconductor chips;

wherein the low voltage controller IC and the external high voltage vertical discrete FET are configured as part of a boost converter circuit that boosts an input voltage to a higher output voltage,

wherein the first and second die pads are separate die pads that are electrically isolated from each other and are packaged together side by side in a single package.

2. The boost converter of claim 1, wherein the low voltage controller integrated circuit includes a pulse-wide modulation (PWM) controller.

3. The boost converter of claim 1, wherein the low voltage controller IC includes an internal sense device.

4. The boost converter of claim 3, wherein the internal sense device includes a resistor or transistor.

5. The boost converter of claim 4 wherein the internal sense device includes a field effect transistor.

6. The boost converter of claim 1 wherein the high voltage, vertical, discrete field effect transistor is attached to the second die pad using a conductive epoxy.

7. The boost converter of claim 6, wherein the low voltage controller IC includes an internal current sense device.

8. The boost converter of claim 7 wherein the internal current sense device includes a resistor or transistor.

9. The boost converter of claim 7 wherein the internal current sense device includes a field effect transistor.

10. The boost converter of claim 1, wherein the bottom-anode Schottky diode is attached to the second die pad using a conductive epoxy between the bottom anode and the second die pad.

11. The boost converter of claim 1 further comprising an external high voltage Schottky diode having an anode coupled to a drain of the high voltage, vertical, discrete FET.

12. The boost converter of claim 1 wherein the low voltage controller integrated circuit and the high voltage, vertical, discrete field effect transistor are attached to a single die pad.

13. The boost converter of claim 12, wherein the low voltage controller integrated circuit is attached on the single die pad using insulating epoxy.

14. The boost converter of claim 13, wherein high voltage, vertical, discrete field effect transistor is attached to the single die pad using conductive epoxy.

15. The boost converter of claim 12 further comprising a discrete current sense device, wherein the discrete sense device is also packed in the single die pad.

16. The boost converter of claim 15 wherein the discrete current sense device is a discrete current sense resistor.

17. The boost converter of claim 16 wherein the discrete current sense resistor is a vertical sense resistor attached to the single die pad using conductive epoxy.

18. The boost converter of claim 12 further comprising an external current sense device.

19. The boost converter of claim 18 wherein the external current sense device is an external current sense resistor.

20. The boost converter of claim 19 wherein the external current sense resistor is connected at a low-voltage side of the controller IC.

21. The boost converter of claim 19, wherein the external sense resistor is connected at a high-voltage side of the controller IC.

22. The boost converter of claim 12, wherein the high voltage, vertical, discrete field effect transistor is a bottom source discrete FET having a bottom source in electrical contact with the single die pad.

23. The boost converter of claim 6, wherein the high voltage, vertical, discrete field effect transistor is a bottom source discrete FET having a bottom source in electrical contact with the second die pad.

24. The boost converter of claim 7, wherein the high voltage, vertical, discrete field effect transistor is a bottom drain discrete FET having two separate top sources, wherein at least one of the sources is in electrical contact to the internal current sense device.