sg5842jasz-f116 Fairchild Semiconductor, sg5842jasz-f116 Datasheet - Page 2

• Manufacturer Part Number: sg5842jasz-f116
• Description: Sg5842 ? Highly Integrated Green-mode Pwm Controller
• Manufacturer: Fairchild Semiconductor

Highly Integrated Green-Mode PWM Controller
MARKING DIAGRAMS
ORDERING INFORMATION
Part Number
SG5842JASZ
SG5842JADZ
SG5842ASZ (Preliminary)
SG5842ADZ (Preliminary
PIN DESCRIPTIONS
1
2
3
4
5
6
7
8
© System General Corp.
Version 1.4.2 (IAO33.0026.B6)
Pin No. Symbol
SG5842HATP
XXXXXXXXYWWV
GND
FB
VIN
RI
RT
SENSE
VDD
GATE
Function
Ground
Feedback
Start-up Input
Reference
Setting
Temperature
Detection
Current Sense
Power Supply
Driver Output
OTP Latch OVP Latch Frequency Hopping Pb-Free
Yes
Yes
Yes
Yes
H:
T: D = DIP, S = SOP
P:
XXXXXXXX:
Y: Year; WW: Week
V: Assembly Location
Null = regular package
Z = Lead Free
J = with Frequency Hopping
Null = without Frequency
Description
Ground.
The signal from the external compensation circuit is fed into this pin. The PWM duty cycle is
determined in response to the signal from this pin and the current-sense signal from Pin 6. If FB
voltage exceeds the threshold, the internal protection circuit disables PWM output after a
predetermined delay time.
For start-up, this pin is pulled high to the rectified line input via a resistor. Since the start-up
current requirement of the SG5842A/JA is very small, a large start-up resistance can be used
to minimize power loss.
A resistor connected from the RI pin to GND pin provides a constant current source. This
determines the center PWM frequency. Increasing the resistance reduces PWM frequency.
Using a 26KΩ resistor results in a 65KHz center PWM frequency.
For over-temperature protection. An external NTC thermistor is connected from this pin to the
GND pin. The impedance of the NTC decreases at high temperatures. Once the voltage of the
RT pin drops below a fixed limit, PWM output is latched off.
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 if V
The totem-pole output driver for the power MOSFET, which is internally clamped below 18V.
Yes
Yes
Yes
Yes
Hopping
Wafer Lot
Yes
Yes
No
No
- 2 -
GND
VIN
FB
PIN CONFIGURATION
RI
www.sg.com.tw • www.fairchildsemi.com
Product Specification
Package
8-Pin SOP
8-Pin DIP
8-Pin SOP
8-Pin DIP
DD
is over-voltage.
October 30, 2007
SG5842A/JA
GATE
SENSE
VDD
RT