Abstract: A discrete-component external charge pump enables the PFM-controlled DC-DC converter of Figure 1 to generate dual outputs with moderate regulation and high efficiency. The circuit accepts input voltages between 2V and 12V (typically 5V) and delivers simultaneous 0mA to 100mA outputs at ±12V (Figure 2). Efficiencies range between 80% and 90%. A discrete-component external charge pump enables the PFM-controlled dc-dc converter of Figure 1 to generate dual outputs with moderate regulation and high efficiency. The circuit accepts input voltages between 2V and 12V (typically 5V) and delivers simultaneous 0mA to 100mA outputs at ±12V (Figure 2). Efficiencies range between 80% and 90%. Figure 1. An external charge pump (C3, C5, D1, and D3) enables this dc-dc step-up converter to generate ±12V dual outputs. Figure 2. "Pseudoregulation" stabilizes the -12V output in Figure 1. IC1 regulates 12V via its V+ terminal, but the -12V output has no direct feedback connection. Nevertheless, changes in -12V load current are coupled via "flying capacitor" C3, where they affect the switching frequency just as 12V load changes do-via current-limited, minimum-off-time, pulse-frequency modulation of the chip's internal switching MOSFET. The resulting pseudo-regulation is impressive: a load change of 10mA to 100mA at either output causes only a 4% change in the negative output (from -11.36V to -10.96V). 관련 부품   APP 974: Oct 01, 1996 MAX761 12V/15V 또는 전압 조정 가능, 고효율, Low-IQ, 스텝 업 DC-DC 컨버터 전체 데이터 시트 (PDF, 136kB) 무료 샘플 자동 업데이트 관심 분야의 애플리케이션 노트가 나올 때 자동으로 업데이트를 원하십니까? 그렇다면 EE-Mail™을 신청하십시오. We Want Your Feedback! 의견을 보내주세요! 위 내용이 도움이 되셨나요? 여러분의 의견을 기다립니다 — Maxim은 보내주신 정정이나 제안사항을 반영하고 있습니다. 이 페이지를 평가하고 의견을 보내주십시오.   다운로드, PDF 형식 (29kB)  AN974, AN 974, APP974, Appnote974, Appnote 974