參數(shù)資料
型號(hào): SG2844DM
廠商: MICROSEMI CORP-ANALOG MIXED SIGNAL GROUP
元件分類: 穩(wěn)壓器
英文描述: CURRENT MODE PWM CONTROLLER
中文描述: 1 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO8
封裝: ROHS COMPLIANT, PLASTIC, SOIC-8
文件頁(yè)數(shù): 11/12頁(yè)
文件大?。?/td> 216K
代理商: SG2844DM
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
相關(guān)PDF資料
PDF描述
SG2844J CURRENT MODE PWM CONTROLLER
SG2844M CURRENT MODE PWM CONTROLLER
SG2844N CURRENT MODE PWM CONTROLLER
SG2844Y CURRENT MODE PWM CONTROLLER
SG2845D CURRENT MODE PWM CONTROLLER
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SG2844J 制造商:Microsemi Corporation 功能描述:SG2844J - Bulk
SG2844M 功能描述:IC PWM CURRENT MODE 8DIP RoHS:是 類別:集成電路 (IC) >> PMIC - AC-DC 轉(zhuǎn)換器,離線開關(guān) 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- 輸出隔離:隔離 頻率范圍:61kHz ~ 71kHz 輸入電壓:9.4 V ~ 28 V 輸出電壓:12V 功率(瓦特):- 工作溫度:-40°C ~ 125°C 封裝/外殼:SC-74,SOT-457 供應(yīng)商設(shè)備封裝:6-TSOP 包裝:帶卷 (TR)
SG2844N 制造商:Microsemi Corporation 功能描述:SG2844N - Bulk
SG2844Y 制造商:Microsemi Corporation 功能描述:SG2844Y - Bulk
SG2845D 制造商:Microsemi Corporation 功能描述:SG2845D - Bulk