在TD1484技术手册的典型应用电路图(Fig13)中,D1(可选项)确实是肖基二级管,功能描述部分有解释:
Optional Schottky Diode
During the transition between high-side switch and
low-side switch, the body diode of the lowside power
MOSFET conducts the inductor current. The forward
voltage of this body diode is high. An optional Schottky
diode may be paralleled between the SW pin and
GND pin to improve overall efficiency. Table 1 lists
example Schottky diodes and their Manufacturers.
Part Number Voltage/Current Vendor
B130 30V, 1A Diodes, Inc.
SK13 30V, 1A Diodes, Inc.
MBRS130 30V, 1A International Rectifier
这里说加入D1也许能够提高同步整流的整体效率,个人觉得加入D1只是提高可靠性(简化控制)而已,对整体效率影响很小!所以大部分低电压同步整流应用方案因成本方面考虑都不会加。 |