摘要： 本应用程序说明演示如何形成负降压开关稳压器从升压开关控制器、 使用 MAX1771，高效率、 升压的直流-直流控制器在脉冲频率调制 （PFM） 模式下运行。Maxim > Design support > App notes > Automotive > APP 945 Maxim > Design support > App notes > Power-Supply Circuits > APP 945 Keywords: step down regulator, PWM, PFM, negative step-down regulator, DC-DC, dc-dc Jan 31, 2002 APPLICATION NOTE 945 Step-Up Controller Forms Negative Step-Down Regulator Abstract: This application note demonstrates how to form a negative step-down switching regulator from a step-up switching controller, using the MAX1771, a high-efficiency, step-up DC-DC controller operating in pulse-frequency modulation (PFM) mode. A similar version of this article appeared in the September 6, 1999 issue of EE Times magazine. Positive step-down switc……