欢迎访问ic37.com |
会员登录 免费注册
发布采购

SC1182CSW 参数 Datasheet PDF下载

SC1182CSW图片预览
型号: SC1182CSW
PDF下载: 下载PDF文件 查看货源
内容描述: 可编程同步DC / DC转换器,双低压差线性稳压控制器 [PROGRAMMABLE SYNCHRONOUS DC/DC CONVERTER, DUAL LOW DROPOUT REGULATOR CONTROLLER]
分类和应用: 转换器控制器
文件页数/大小: 12 页 / 132 K
品牌: SEMTECH [ SEMTECH CORPORATION ]
 浏览型号SC1182CSW的Datasheet PDF文件第4页浏览型号SC1182CSW的Datasheet PDF文件第5页浏览型号SC1182CSW的Datasheet PDF文件第6页浏览型号SC1182CSW的Datasheet PDF文件第7页浏览型号SC1182CSW的Datasheet PDF文件第9页浏览型号SC1182CSW的Datasheet PDF文件第10页浏览型号SC1182CSW的Datasheet PDF文件第11页浏览型号SC1182CSW的Datasheet PDF文件第12页  
PROGRAMMABLE SYNCHRONOUS DC/DC  
CONVERTER, DUAL LOW DROPOUT  
REGULATOR CONTROLLER  
SC1182/3  
August 25, 1998  
as small as possible. This loop contains all the high  
LAYOUT GUIDELINES  
current, fast transition switching. Connections should  
be as wide and as short as possible to minimize loop  
inductance. Minimizing this loop area will a) reduce  
EMI, b) lower ground injection currents, resulting in  
electrically “cleaner” grounds for the rest of the system  
and c) minimize source ringing, resulting in more reli-  
able gate switching signals.  
Careful attention to layout requirements are necessary  
for successful implementation of the SC1182/3 PWM  
controller. High currents switching at 200kHz are pre-  
sent in the application and their effect on ground plane  
voltage differentials must be understood and mini-  
mized.  
1). The high power parts of the circuit should be laid  
out first. A ground plane should be used, the number  
and position of ground plane interruptions should be  
such as to not unnecessarily compromise ground plane  
integrity. Isolated or semi-isolated areas of the ground  
plane may be deliberately introduced to constrain  
ground currents to particular areas, for example the  
input capacitor and bottom FET ground.  
3). The connection between the junction of Q1, Q2 and  
the output inductor should be a wide trace or copper  
region. It should be as short as practical. Since this  
connection has fast voltage transitions, keeping this  
connection short will minimize EMI. The connection  
between the output inductor and the sense resistor  
should be a wide trace or copper area, there are no  
fast voltage or current transitions in this connection  
and length is not so important, however adding unnec-  
essary impedance will reduce efficiency.  
2). The loop formed by the Input Capacitor(s) (Cin), the  
Top FET (Q1) and the Bottom FET (Q2) must be kept  
12V IN  
5V  
10  
1
2
24  
AGND  
GATE1  
LDOS1  
LDOS2  
VCC  
GATE2  
LDVO  
VID0  
23  
22  
21  
20  
19  
18  
17  
16  
15  
14  
13  
2.32k  
3
Cin  
+
4
Q1  
Q2  
1.00k  
VID1  
0.1uF  
0.1uF  
5
5mOhm  
VID2  
Vout  
6
OVP  
VID3  
4uH  
+
7
P W R G O O D  
CS-  
VID4  
Cout  
8
VO SENSE  
EN  
9
CS+  
10  
11  
12  
PGNDH  
DH  
BSTH  
BSTL  
DL  
PGNDL  
SC1182/3  
RA1  
Heavy lines indicate  
high current paths.  
5V  
Vo Lin1  
Q3  
+
+
RB1  
Cout Lin1  
Cin Lin  
For SC1182, RA1, RA2, RB1 and RB2  
are not required. LDOS1 connects to  
Vo Lin1, LDOS2 connects to Vo Lin2  
RA2  
Vo Lin2  
Q4  
+
RB2  
Cout Lin2  
Layout diagram for the SC1182/3  
8
© 1998 SEMTECH CORP.  
652 MITCHELL ROAD NEWBURY PARK CA 91320