SG3844Y SEMICOA, SG3844Y Datasheet - Page 10

• Manufacturer Part Number: SG3844Y
• Manufacturer: SEMICOA

Specifications of SG3844Y

• Pwm Type: Current Mode PWM Controller
• Number Of Pwm Outputs: 1
• On/off Pin: No
• Adjustable Output: No
• Switching Freq: 500kHz
• Duty Cycle: 50%
• Output Current: 200mA
• Synchronous Pin: No
• Rise Time: 50ns
• Fall Time: 50ns
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 8
• Package Type: CDIP
• Lead Free Status / Rohs Status: Not Compliant

10
SG1844/SG1845 Series
OSCILLATOR
The oscillator of the 1844/45 family of PWM's is programmed by
the external timing components (RT, CT) as shown in Figure 13.
FIGURE 12 — OSCILLATOR TIMING CIRCUIT
R
GND
F ≈
T
V
/C
REF
R
1.86
T
T
C
T
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
where R
C
T
U R R E N T
P
≥ 5kΩ
A P P L I C A T I O N I N F O R M A T I O N
R
C
R O D U C T I O N
T
T
- M
O D E
P W M C
D
100K
A T A
10K
1K
100
FIGURE 13 — OSCILLATOR FREQUENCY vs. R
O N T R O L L E R
S
H E E T
1K
Oscillator Frequency - (Hz)
10K
T
100K
FOR VARIOUS C
Copyright © 2000
Rev. 1.6c
1M
T