A > 89% efficient LED driver with 0.5V supply voltage for applications requiring low average current

Author

Saadeh, Wala ; Tekeste, Temesghen ; Perrott, M.H.

Author_Institution

Masdar Inst. of Sci. & Technol., Abu Dhabi, United Arab Emirates

fYear

2013

fDate

11-13 Nov. 2013

Firstpage

273

Lastpage

276

Abstract

A modified boost converter topology is proposed to achieve better than 89% efficiency as an LED driver for applications in which low supply voltage and low average current are desired such as in a photoplethysmographic (PPG) heart rate (HR) monitor device. The approach embraces pulsing of the LED current, and allows a highly digital implementation for varying LED brightness based on Pulse Density Modulation (PDM). Measured results indicate that the LED driver, which is implemented in 180nm CMOS along with an external inductor, achieves an output current range of 28uA to 1.3mA with 6 current settings while maintaining >89% efficiency over a supply voltage range of 0.5 to 0.6V.

Keywords

CMOS integrated circuits; cardiology; driver circuits; light emitting diodes; network topology; photoplethysmography; power convertors; CMOS; LED driver; PDM; PPG heart rate monitor device; low average current; modified boost converter topology; photoplethysmographic heart rate; pulse density modulation; supply voltage; CMOS integrated circuits; Current measurement; Heart rate; Inductors; Light emitting diodes; MOS devices; Voltage measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Circuits Conference (A-SSCC), 2013 IEEE Asian

Conference_Location

Singapore

Print_ISBN

978-1-4799-0277-4

Type

conf

DOI

10.1109/ASSCC.2013.6691035

Filename

6691035