SG6859 Fairchild Semiconductor, SG6859 Datasheet - Page 2

• Manufacturer Part Number: SG6859
• Description: Low Cost Green-Mode PWM Controller
• Manufacturer: Fairchild Semiconductor

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Low Cost Green-Mode PWM Controller for Flyback Converters
MARKING DIAGRAMS
ORDERING INFORMATION
PIN DESCRIPTIONS
© System General Corp.
Version 1.2.1(IAO33.0067.B2)
Part Number
SG6859TZ
SG6859DZ
GATE
VDD
NC
SENSE
RI
NC
FB
GND
Name
XXXXXXXXYWWV
SG6859TP
AAJMW
1 / (6)
2 / (5)
3
4 / (4)
5 / (3)
6
7 / (2)
8 / (1)
Pin No.
DIP-8(SOT-26)
Pb-Free
AAJ:
M: Mask Version
W: Week code A~Z=W1~W26
Driver Output
Supply
Analog Input
Analog
Input/Output
Analog Input
Supply
Type
: Lead Free Package
T: D=DIP
P:
XXXXXXXX: Wafer Lot
Y: Year; WW: Week
V: Assembly Location
SG6859
Z =Lead Free
Null=Regular Package
A~Z=W27~W52
The totem-pole output driver for driving the power MOSFET.
Power supply.
NC pin.
Current sense. This pin senses the voltage across a resistor. When the voltage
reaches the internal threshold, PWM output is disabled. This activates
over-current protection. This pin also provides current amplitude information for
current-mode control.
A resistor connected from the RI pin to ground will generate a constant current
source for the SG6859. This current is used to charge an internal capacitor, to
determine the switching frequency. Increasing the resistance will reduce the
amplitude of the current source and reduce the switching frequency. A 95kΩ
resistor R
NC pin.
Feedback. The FB pin provides the output voltage regulation signal. It provides
feedback to the internal PWM comparator, so that the PWM comparator can
control the duty cycle.
Ground.
Function
Package
6-Pin SOT-26
8-Pin DIP-8
i
results in a 50uA constant current I
- 2 -
www.sg.com.tw
SENSE
GATE
PIN CONFIGURATION
GND
VDD
NC
FB
RI
i
SOT-26
and a 70kHz switching frequency.
DIP-8
Product Specification
• www.fairchildsemi.com
September 28, 2007
GATE
SENSE
VDD
GND
NC
RI
FB
SG6859