Back to Search
Start Over
A 100-mA, 99.11% Current Efficiency, 2-mVpp Ripple Digitally Controlled LDO With Active Ripple Suppression.
- Source :
- IEEE Transactions on Very Large Scale Integration (VLSI) Systems; Feb2017, Vol. 25 Issue 2, p696-704, 9p
- Publication Year :
- 2017
-
Abstract
- Digital low-dropout (DLDO) regulators are gaining attention due to their design scalability for distributed multiple voltage domain applications required in state-of-the-art system-on-chips. Due to the discrete nature of the output current and the discrete-time control loop, the steady-state response of the DLDO has inherent output voltage ripple. A hybrid DLDO (HD-LDO) with fast response and stable operation across a wide load range while reducing the output voltage ripple is proposed. In the HD-LDO, a DLDO and a low current analog ripple cancellation amplifier (RCA) work in parallel. The output dc of the RCA is sensed by a 2-bit analog-to-digital converter, and the digitized linear stage current is fed into the DLDO as an error signal. During load transients, a gear-shift controller enables fast transient response using dynamic load estimation. The DLDO suppresses the output dc of the RCA within its current resolution. With this arrangement, a majority of the dc load current is provided by the DLDO and the RCA supplies ripple cancellation current. The HD-LDO is designed and fabricated in a 180-nm CMOS technology, and occupies 0.697 mm2 of the die area. The HD-LDO operates with an input voltage range of 1.43-2.0 V and an output voltage range of 1.0-1.57 V. At 100-mA load current, the HD-LDO achieves a current peak efficiency of 99.11% and a settling time of 15 clock periods with a 0.5-MHz clock for a current switching between 10 and 90 mA. The RCA suppresses fundamental, second, and third harmonics of the switching frequency by 13.7, 13.3, and 14.1 dB, respectively. [ABSTRACT FROM AUTHOR]
- Subjects :
- ANALOG-to-digital converters
SYSTEMS on a chip
VOLTAGE regulators
Subjects
Details
- Language :
- English
- ISSN :
- 10638210
- Volume :
- 25
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- IEEE Transactions on Very Large Scale Integration (VLSI) Systems
- Publication Type :
- Academic Journal
- Accession number :
- 127949087
- Full Text :
- https://doi.org/10.1109/TVLSI.2016.2596708