Low Dropout Regulator Capable of On-Chip Implementation
Power management is necessary to reduce standby power consumption of low-power portable applications such as mobile phones and personal digital assistants (PDAs). A low-dropout regulator (LDO) is a type of voltage regulator that is widely utilized in power management integrated circuits. In order to give higher stability and better load transient response, however, an off-chip capacitor cannot be eliminated in conventional LDO design.
The present invention relates to an internal compensated LDO regulator, and in particular to such a regulator that does not necessarily require an off-chip capacitor to maintain stability and to improve output accuracy, load transient response and power supply rejection ratio. In addition, the performance is better than other existing commercial LDOs due to the wide loop-gain bandwidth provided by an HKUST patented frequency compensation technique (US6,208,206). Also, the error amplifier inside the invented regulator is a two-stage high-gain amplifier, and the voltage buffer is eliminated to improve the minimum supply voltage requirement.
1. Stable, accurate and low noise power without an off-chip capacitor
2. Superior performance to conventional low-dropout regulator with no-capacitor feature on line regulation, load regulation, power supply rejection radio and load transient response
3. Resolved technology compatibility and can be easily integrated with other circuits
- Battery-operated portable electronic devices such as cellular phones, PDAs and discmans, laptop computers
Patent Number: US7205827B2
Application Number: US2003739115A
Inventor: Leung, Ka Nang | Mok, Kwok Tai
Priority Date: 23 Dec 2002
Priority Number: US7205827B2
Application Date: 19 Dec 2003
Publication Date: 17 Apr 2007
IPC Current: G05F000110 | G05F0001575 | G05F000302
US Class: 327540 | 323280 | 323316
Assignee Applicant: The Hong Kong University of Science & Technology
Title: Low dropout regulator capable of on-chip implementation
Usefulness: Low dropout regulator capable of on-chip implementation
Summary: Used in a power management integrated circuit of a low-power portable application e.g. personal digital assistant (PDA), and mobile phone.
Novelty: Low-dropout regulator for power management integrated circuit, has damping-factor-control unit including negative gain stage with feedback capacitor connected between input and output of negative gain stage
Electronics
3C/Gadgets
19 Dec 2003
US 7205827
TTC.PA.179
Hong Kong
