sg6741a Fairchild Semiconductor, sg6741a Datasheet - Page 3

• Manufacturer Part Number: sg6741a
• Description: Sg6741a ? Highly Integrated Green-mode Pwm Controller
• Manufacturer: Fairchild Semiconductor

© 2008 Fairchild Semiconductor Corporation
SG6741A • Rev. 1.0.1
Marking Information
Pin Definitions
Pin #
※marking for SG6741ASZ
※marking for SG6741ASY
Pin Configuration
1
2
3
4
5
6
7
8
SENSE
Name
GATE
GND
VDD
NC
FB
HV
RI
SG6741ATP
XXXXXXXXYWWV
Description
Ground.
Feedback. The signal from the external compensation circuit is fed into this pin. The PWM duty
cycle is determined in response to the signal on this pin and the current-sense signal on SENSE
pin.
No Connection.
Startup Input. For startup, this pin is pulled HIGH to the line input or bulk capacitor via resistors.
Reference Setting. A resistor connected from the RI pin to GND pin provides a constant current
source, which determines the center PWM frequency. Increasing the resistance reduces PWM
frequency. Using a 26KΩ resistor for R
Current Sense. The sensed voltage is used for peak-current-mode control and cycle-by-cycle
current limiting.
Power Supply. The internal protection circuit disables PWM output as long as V
OVP trigger point.
Driver Output. Totem-pole output driver. Soft driving waveform is implemented for improved EMI.
ZXYTT
6741A
TPM
GND
FB
NC
HV
Figure 4. Pin Configuration
Figure 3. Top Mark
3
I
T: S = SOP
P: Z =Lead Free
XXXXXXXX: Wafer Lot
Y: Year; WW: Week
V: Assembly Location
F: Fairchild logo
Z: Plant code
X: 1 digit year code
Y: 1 digit week code
TT: 2 digits die run code
T: Package type (S = SOP)
P: Y=Green package
M: Manufacture flow code
results in a 65kHz center PWM frequency.
Null=regular package
GATE
VDD
SENSE
RI
DD
exceeds the
www.fairchildsemi.com