SG3845DM Microsemi Analog Mixed Signal Group, SG3845DM Datasheet - Page 10

• Manufacturer Part Number: SG3845DM
• Description: IC PWM CURRENT MODE 8SOIC
• Manufacturer: Microsemi Analog Mixed Signal Group

Specifications of SG3845DM

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 500kHz
• Duty Cycle: 50%
• Voltage - Supply: 8.2 V ~ 30 V
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 8-SOIC
• Frequency-max: 500kHz
• Lead Free Status / RoHS Status: Lead free / RoHS 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