Invention Grant
US07893670B2 Frequency compensation scheme for stabilizing the LDO using external NPN in HV domain
有权
用于在HV域中稳定LDO使用外部NPN的频率补偿方案
- Patent Title: Frequency compensation scheme for stabilizing the LDO using external NPN in HV domain
- Patent Title (中): 用于在HV域中稳定LDO使用外部NPN的频率补偿方案
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Application No.: US12389581Application Date: 2009-02-20
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Publication No.: US07893670B2Publication Date: 2011-02-22
- Inventor: Srinivas K. Pulijala , Scott C. McLeod
- Applicant: Srinivas K. Pulijala , Scott C. McLeod
- Applicant Address: US NY Hauppauge
- Assignee: Standard Microsystems Corporation
- Current Assignee: Standard Microsystems Corporation
- Current Assignee Address: US NY Hauppauge
- Agency: Meyertons Hood Kivlin Kowert & Goetzel, P.C.
- Agent Jeffrey C. Hood
- Main IPC: G05F1/00
- IPC: G05F1/00

Abstract:
A voltage regulator may comprise a regulator output configured to provide a regulated voltage, which may be controlled by an error amplifier based on the regulated voltage and a reference voltage. The error amplifier may control a source-follower stage to mirror a multiple of the current flowing in the source-follower stage into an internal pass device. A voltage developed by the mirror current may control an external pass device configured to deliver the load current into the regulator output. A first resistor may be configured to decouple a load capacitor coupled between the regulator output and reference ground, when the load current is below a specified value. A second resistor may be configured to create a bias current in the internal pass device even when the external pass device is close to cut-off region. A third resistor may be configured to counter the effects of negative impedance at the control terminal of the external pass device caused by the current-gain of the external pass device. A compensation capacitor and resistor may be coupled in series between the output of the error amplifier and the output of the voltage regulator to provide frequency compensation for the Miller-Effect.
Public/Granted literature
- US20100213917A1 Frequency Compensation Scheme for Stabilizing the LDO Using External NPN in HV Domain Public/Granted day:2010-08-26
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