SG3843M Microsemi Analog Mixed Signal Group, SG3843M Datasheet - Page 12
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SG3843M
Manufacturer Part Number
SG3843M
Description
IC PWM CURRENT MODE 8DIP
Manufacturer
Microsemi Analog Mixed Signal Group
Datasheet
1.SG3842M.pdf
(14 pages)
Specifications of SG3843M
Pwm Type
Current Mode
Number Of Outputs
1
Frequency - Max
500kHz
Duty Cycle
100%
Voltage - Supply
8.2 V ~ 30 V
Buck
No
Boost
No
Flyback
Yes
Inverting
No
Doubler
No
Divider
No
Cuk
No
Isolated
Yes
Operating Temperature
0°C ~ 70°C
Package / Case
8-DIP
Frequency-max
500kHz
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
SG3843MR
SG3843MR
SG3843MR
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
SG3843M
Manufacturer:
LINFIN
Quantity:
5 510
SG1842/SG1843 Series
12
Softstart and adjustable peak current can be done with the external
circuitry shown above.
The oscillator is programmed by the values selected for the timing
components R
calculation of the component values.
FIGURE 19. — ADJUSTABLE BUFFERED REDUCTION OF CLAMP LEVEL
I
t
where; V
SOFTSTART
C
PK
minimum line and maximum load conditions.
=
V
R
CS
S
R
R
= -ln 1 -
2
1
EAO
FIGURE 21. — OSCILLATOR CONNECTION
T
Where: V
SG1842/43
MPSA63
and C
Discharge
≡ voltage at the Error Amp Output under
8 (14)
Current
4 (7)
2 (3)
1 (1)
T
. Refer to application information for
V
5
2.8V
1.1V
CS
EAO
= 1.67
WITH SOFTSTART
R
- 1.3
1
R
SG1842/43
+R
1
2
I
d
= 8.2mA
R
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
T Y P I C A L A P P L I C A T I O N C I R C U I T S
1
5 (9)
R
+R
1
R
R
2
5V
1
1
+R
7 (12)
R
C
and V
2
2
8 (14)
4 (7)
U R R E N T
P
C
R O D U C T I O N
C.S.MAX
7 (11)
6 (10)
5 (8)
3 (5)
V
CC
R
C
T
= 1V (Typ.)
T
- M
V
IN
Q1
V
I
R
O D E
CS
S
P W M C
D
Precision duty cycle limiting as well as synchronizing several 1842/
1843's is possible with the above circuitry.
Error amplifier is capable of sourcing and sinking current up to 0.5mA.
A T A
O N T R O L L E R
FIGURE 20. — EXTERNAL DUTY CYCLE CLAMP AND
R
S
FIGURE 22. — ERROR AMPLIFIER CONNECTION
i
R
R
H E E T
A
B
R
f =
f =
F
6
2
³ 10K
R
MULTI-UNIT SYNCHRONIZATION
R
(R
F
A
A
(continued)
+ 2R
R
8
1.44
2 (3)
1 (1)
+ 2R
B
TIMER
B
555
B
)C
4
1
2.5V
SG1842/43
3
SGX842/43
To other
8 (14)
4 (7)
SG1842/43
0.5mA
Copyright © 2000
5 (9)
Rev. 1.6a 10/04