参数资料
型号: SG3845D
厂商: MICROSEMI CORP-ANALOG MIXED SIGNAL GROUP
元件分类: 稳压器
英文描述: CURRENT MODE PWM CONTROLLER
中文描述: 1 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO14
封装: ROHS COMPLIANT, PLASTIC, SOIC-14
文件页数: 11/12页
文件大小: 216K
代理商: SG3845D
C
U R R E N T
-M
O D E
PWM C
O N T R O L L E R
SG1844/SG1845 Series
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
11
Copyright 2000
Rev. 1.4 4/00
P
R O D U C T I O N
D
A T A
S
H E E T
T Y P I C A L A P P L I C AT I O N C I R C U I T S
Pin numbers referenced are for 8-pin package and pin numbers in parenthesis are for 14-pin package.
FIGURE 17.
— ISOLATED MOSFET DRIVE
FIGURE 16.
— BIPOLAR TRANSISTOR DRIVE
Current transformers can be used where isolation is required
between PWM and Primary ground. A drive transformer is then
necessary to interface the PWM output with the MOSFET.
The 1844/45 output stage can provide negative base current to
remove base charge of power transistor (Q
) for faster turn off. This
is accomplished by adding a capacitor (C
) in parallel with a resistor
(R
1
). The resistor (R
1
) is to limit the base current during turn on.
FIGURE 14.
— CURRENT SENSE SPIKE SUPPRESSION
FIGURE 15.
— MOSFET PARASITIC OSCILLATIONS
A resistor (R
) in series with the MOSFET gate reduce overshoot and
ringing caused by the MOSFET input capacitance and any inductance
in series with the gate drive. (Note: It is very important to have a
low inductance ground path to insure correct operation of the I.C.
This can be done by making the ground paths as short and as wide
as possible.)
The RC low-pass filter will eliminate the leading edge current spike
caused by parasitics of Power MOSFET.
V
CC
V
IN
7 (12)
7 (11)
6 (10)
5 (8)
3 (5)
R
C
R
S
Q1
I
PK
I
PK(MAX)
=1.0V
R
S
SG1844/45
V
CC
V
IN
7 (12)
7 (11)
6 (10)
5 (8)
R
S
Q1
SG1844/45
3 (5)
R
1
SG1844/45
3 (5)
5 (8)
6 (10)
7 (11)
R
S
Q1
V
C1
C
1
R
1
R
2
V
IN
V
C
I
B
+
V
C
R
2
V
R
1
||R
2
_
V
CC
V
IN
7 (12)
7 (11)
6 (10)
5 (8)
3 (5)
SG1844/45
Isolation
Boundary
C
R
R
S
N
S
N
P
Q1
V
GS
Waveforms
+
_
50% DC
+
_
25% DC
I
PK
=
V (PIN 1) - 1.4
3R
S
N
P
N
S
相关PDF资料
PDF描述
SG3845DM CURRENT MODE PWM CONTROLLER
SG3845J CURRENT MODE PWM CONTROLLER
SG3845M CURRENT MODE PWM CONTROLLER
SG3845N CURRENT MODE PWM CONTROLLER
SG3845Y CURRENT MODE PWM CONTROLLER
相关代理商/技术参数
参数描述
SG3845DM 功能描述:IC REG CTRLR ISO PWM CM 8-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,000 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:1MHz 占空比:50% 电源电压:9 V ~ 10 V 降压:无 升压:是 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:8-TSSOP(0.173",4.40mm 宽) 包装:带卷 (TR)
SG3845J 制造商:Microsemi Corporation 功能描述:SG3845J - Bulk
SG3845M 功能描述:IC REG CTRLR ISO PWM CM 8-DIP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:100% 电源电压:8.2 V ~ 30 V 降压:无 升压:无 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:0°C ~ 70°C 封装/外壳:8-DIP(0.300",7.62mm) 包装:管件 产品目录页面:1316 (CN2011-ZH PDF)
SG3845N 制造商:Microsemi Corporation 功能描述:SG3845N - Bulk
SG3845Y 制造商:Microsemi Corporation 功能描述:CURRENT MODE PWM CNTRLR 200MA 8CDIP - Bulk