电压型逆变器集成电路形式高效轨道器-Voltage-Inve

2011-04-01 15:43:42来源: 互联网 关键字:集成电路  形式  高效
A switched-capacitor voltage inverter configured as a "rail splitter" (IC1 in Figure 1) provides a bipolar (dual-rail) local power supply that is useful in single-rail systems featuring one or more dual-rail ICs. Moreover, the tiny SOT-23 package and associated components require very little board area.


Figure 1. This compact and efficient charge-pump circuit implements a local dual-rail supply for single-rail systems.

After power is applied, the flying capacitor (C2) connects alternately across the storage capacitors C3/C4 and C5/C6. This action equalizes the voltages on those capacitors and draws current from VIN or VOUT as required to maintain VOUT ≈ ½VIN.

If the loads across VIN-VOUT and VOUT-0V are equal, the IC sits in a quiescent state and draws about 36µA. To keep VOUT at the mid-rail level, the flying capacitor needs only to supply the difference current caused by unbalanced loads. Efficiency is degraded by the IC's quiescent current for load currents below 100µA, but above 1mA the efficiency is greater than 90%—an excellent feature for low-power or battery-powered applications. (Voltage error and efficiency vary with the load current, as shown in Figures 2 and 3.)


Figure 2. The output voltage error in Figure 1 increases with load current.


Figure 3. Efficiency also increases with load current in Figure 1.

This switched-capacitor circuit provides better regulation than that of a simple voltage divider, and better efficiency than that of a simple combination of divider and op-amp buffer. Its main drawback is the increase in output noise with load (see Table 1). VIN is restricted (by the IC specifications) to a maximum of 5.5V, which is the maximum voltage allowed between pins 2 and 4 or between pins 1 and 4.

RLOAD
(Ω)
INPUT CURRENT
(µA)
VOUT
ERROR
(mV)
OUTPUT
CURRENT
(µA)
RIPPLE
(mVP-P)
EFFICIENCY
(%)
36.5
10M 36.5 0.25 0.34
10M 37.7 2.5 3.32
100k 48.9 0.1 25 25.56
10k 156 1.4 250 ~1 80.04
1k 1240 13.5 2490 ~5 99.72
470 2630 28.5 5260 ~8 98.83
100 11,410 126.9 23,700 ~30 98.71

A similar idea appeared in the August 1, 1997 issue of EDN.

关键字:集成电路  形式  高效

编辑:神话 引用地址:http://www.eeworld.com.cn/mndz/2011/0401/article_6515.html
本网站转载的所有的文章、图片、音频视频文件等资料的版权归版权所有人所有,本站采用的非本站原创文章及图片等内容无法一一联系确认版权者。如果本网所选内容的文章作者及编辑认为其作品不宜公开自由传播,或不应无偿使用,请及时通过电子邮件或电话通知我们,以迅速采取适当措施,避免给双方造成不必要的经济损失。

上一篇:高效率升压转换器提供48V的IP电话-High-Effici
下一篇:正弦和修正逆变器的区别

关注eeworld公众号 快捷获取更多信息
关注eeworld公众号
快捷获取更多信息
关注eeworld服务号 享受更多官方福利
关注eeworld服务号
享受更多官方福利
推荐阅读
全部
集成电路
形式
高效

小广播

独家专题更多

东芝在线展会——芯科技智社会创未来
东芝在线展会——芯科技智社会创未来
2017东芝PCIM在线展会
2017东芝PCIM在线展会
TI车载信息娱乐系统的音视频解决方案
TI车载信息娱乐系统的音视频解决方案
汇总了TI汽车信息娱乐系统方案、优质音频解决方案、汽车娱乐系统和仪表盘参考设计相关的文档、视频等资源
电子工程世界版权所有 京ICP证060456号 京ICP备10001474号 电信业务审批[2006]字第258号函 京公海网安备110108001534 Copyright © 2005-2017 EEWORLD.com.cn, Inc. All rights reserved