Load Transient, Reduced Bond Wires for Circuits Supplying Large Currents

• US 20140103893A1
• Filed: 10/16/2012
• Published: 04/17/2014
• Est. Priority Date: 10/16/2012
• Status: Active Grant

• Current Assignee: Dialog Semiconductor GmbH (Renesas Electronics Corporation)
• Original Assignee: Dialog Semiconductor GmbH (Renesas Electronics Corporation)
• Inventors: Nikolov, Ludmil, Bhattad, Ambreesh
• Granted Patent: US 9,239,585 B2
• Time in Patent Office: Days
• US Class Current: 323/273
• CPC Class Codes: G05F 1/575 characterised by the feedback circuit

Abstract

Circuits and methods to improve dynamic load transient performance of circuits supplying high current and having parasitic resistances are disclosed. These circuits comprise e.g. LDOs, amplifiers or buffers. The circuits and methods are characterized by including parasitic resistances, caused by bond wires, metallization of pass devices, and substrate routings, in a loop for fast transient response. Furthermore the circuits comprise a stabilization circuit within said loop and a separate pad for said loop.

Claims

1. A method to improve dynamic load transient performance of circuits supplying high current, comprising the following steps:

(1) providing an electronic circuit supplying high currents and having parasitic resistances;

(2) including parasitic resistances in a separate loop for fast loop response;

(3) implementing stabilizing circuit within said fast loop response; and

(4) deploying separate pad for the fast loop response connected to feedback voltage VFB.

2. The method of claim 1 wherein said high current comprise a range of more than 200 mA.

3. The method of claim 1 wherein said circuit is a LDO.

4. The method of claim 1 wherein said circuit is an amplifier.

5. The method of claim 1 wherein said circuit is a buffer.

6. The method of claim 1 wherein said stabilization circuit is achieved by splitting a main pass device into two unequal parts, by placing a controlled impedance in series with a smaller part of the pass device, and taking the fast feedback loop from a node between the pass device and the controlled impedance and coupling it back to a Miller capacitor.

7. The method of claim 1 wherein said parasitic resistances comprise resistances of one or more bond wires, metallization of one or more pass devices, and substrate routings.

8. The method of claim 1 wherein the resistance of a main pass transistor is not included in the loop of fast response.

9. The method of claim 1 wherein one bond wire is used.

10. The method of claim 1 wherein more than one bond wire are used.

11. A circuit to improve dynamic load transient performance of circuits supplying high current and having parasitic resistances, comprising:

a separate loop for fast transient response including the parasitic resistances;

a separate pad for the loop for fast transient response; and

a stabilizing circuit connected to said loop for fast transient response.

12. The circuit of claim 11 wherein said circuit is an LDO.

13. The circuit of claim 11 wherein said circuit is an amplifier.

14. The circuit of claim 11 wherein said circuit is a buffer.

15. The circuit of claim 11 wherein said parasitic resistances comprise resistances of one or more bond wires, metallization of one or more pass devices, and substrate routings

16. The circuit of claim 11 wherein the circuit comprises one bond wire.

17. The circuit of claim 11 wherein the circuit comprises more than one bond wire.

18. The circuit of claim 11 wherein said high current comprise a range of more than 200 mA.

19. The circuit of claim 11 wherein said loop for fast transient response comprises a capacitor.

20. The circuit of claim 11 wherein the stabilizing circuit comprises a main pass transistor and an additional pass transistor in parallel to the main pass transistor.

21. The circuit of claim 20 wherein a resistive device, having a resistance in a range between about 0.5 to 100, is deployed a drain of the additional pass transistor and an output of the circuit.

22. The circuit of claim 21 wherein the resistive device is a resistor.