Abstract: This audio bridge-tied load (BTL) amplifier application note describes a unique architecture that minimizes the differential output distortion and noise (THD+N). 무료 웹 세미나에 등록하여, 오디오 시스템 관련 문제들을 어떻게 정의하고 측정, 해결하는 지에 대해 배워보십시오. Low-voltage systems driving loudspeakers often employ a bridged-amplifier configuration that effectively doubles the voltage swing at the transducer (speaker). In a typical bridge-amplifier circuit (Figure 1), an AC-coupled inverting stage with gain drives one side of the speaker. It also drives a second unity-gain inverting amplifier, which drives the other side of the speaker. Figure 1. This conventional bridged amplifier features two amplifiers in tandem. Bridged amplifiers usually incorporate a matched pair of amplifiers, but the first amplifier dominates overall performance because its output noise and distortion are replicated in the second amplifier. You can eliminate this drawback by placing the two amplifiers in a non-cascaded configuration, in which one is inverting and the other in non-inverting (Figure 2). Both amplify the same input signal, so neither one reproduces noise, distortion, or clipping introduced by the other. Figure 2. This circuit optimizes the Figure 1 configuration by apportioning gain between the two amplifiers. As a key improvement in Figure 2, DC bias for the non-inverting circuit is derived from the inverting amplifier's source resistor. (Bias is required because the input is AC coupled). Using the other amplifier's source resistor as a bias source lowers the component count and eliminates signal injection into the high-impedance bias source (VCC/2, applied to the top amplifier's non-inverting input). Another advantage in Figure 2 is the elimination of DC gain in the non-inverting amplifier. For the circuit shown, C2 sets the -3dB point at half the input cutoff frequency, and R1/C1 sets the input highpass cutoff frequency at 100Hz. A similar version of this article appeared in the November 19, 2001 issue of Electronic Design magazine. 의견을 보내주세요! 위 내용이 도움이 되셨나요? 여러분의 의견을 기다립니다 — Maxim은 보내주신 정정이나 제안사항을 반영하고 있습니다. 이 페이지를 평가하고 의견을 보내주십시오. 자동 업데이트 관심있는 분야의 애플리케이션 노트가 나올 때 자동으로 업데이트 받고 싶으세요? 그렇다면 EE-Mail™을 신청하십시오. 추가 정보   APP 1122: Jun 24, 2002 MAX4167 셧다운 기능이 내장된 고출력 구동, 정밀, 저전력, 단일 전원, Rail-to-Rail I/O Op 앰프 전체 데이터 시트 (PDF, 1.2MB) 무료 샘플 MAX4168 셧다운 기능이 내장된 고출력 구동, 정밀, 저전력, 단일 전원, Rail-to-Rail I/O Op 앰프 전체 데이터 시트 (PDF, 1.2MB) 무료 샘플 MAX4337 셧다운/뮤트 기능이 내장된 SC70/SOT23-8 50mA IOUT Rail-to-Rail I/O Op 앰프 전체 데이터 시트 (PDF, 548kB) 무료 샘플 MAX4338 셧다운/뮤트 기능이 내장된 SC70/SOT23-8 50mA IOUT Rail-to-Rail I/O Op 앰프 전체 데이터 시트 (PDF, 548kB) 무료 샘플 MAX4366 셧다운 기능이 내장된 330mW, 초소형, 오디오 전력 증폭기 전체 데이터 시트 (PDF, 608kB) MAX4369 UCSP 패키지로 제공되는 듀얼, Rail-to-Rail, 고출력 구동 Op 앰프 전체 데이터 시트 (PDF, 404kB)   다운로드, PDF 형식 (39kB)  AN1122, AN 1122, APP1122, Appnote1122, Appnote 1122