A 250 mW class D design with direct battery hookup in a 90 nm process [audio band switching amplifier]

Author

Forejt, Brett ; Rentala, Vijay ; Burra, Gangadhar ; Arteaga, Jose

Author_Institution

Texas Instruments Inc., TX, USA

fYear

2004

fDate

3-6 Oct. 2004

Firstpage

169

Lastpage

172

Abstract

A "battery connect" compatible class D (switching) amplifier which is fully integrated in a 90 nm digital CMOS process is presented. The integration of the amplifier requires no additional masks, processing, or cost. This paper includes a brief description of the circuit techniques that enable direct battery connection and allow support for the 4.6 V_P2P output swing using devices that operate solely with low gate voltages. The achieved SNR over an audio (20 Hz to 20 kHz) bandwidth is 84 dB and the total harmonic distortion (THD) is better than 0.05% at full power. The power supply rejection (PSR), which is a crucial parameter in modules connected directly to the battery, is measured at greater than 58 dB at 217 Hz. The area of the switching amplifier is <0.77 mm², where the power devices occupy approximately half the total.

Keywords

CMOS integrated circuits; audio-frequency amplifiers; power amplifiers; switching circuits; 20 Hz to 20 kHz; 217 Hz; 250 mW; 4.6 V; 90 nm; audio bandwidth; audio power amplifiers; class D switching amplifier; digital CMOS process; direct battery connection amplifier; low gate voltage devices; power supply rejection; Area measurement; Bandwidth; Batteries; CMOS process; Circuits; Costs; Distortion measurement; Low voltage; Power supplies; Total harmonic distortion;

fLanguage

English

Publisher

ieee

Conference_Titel

Custom Integrated Circuits Conference, 2004. Proceedings of the IEEE 2004

Print_ISBN

0-7803-8495-4

Type

conf

DOI

10.1109/CICC.2004.1358767

Filename

1358767