SG6980DZ Fairchild Semiconductor, SG6980DZ Datasheet - Page 15

• Manufacturer Part Number: SG6980DZ
• Description: IC PFC CTRLR AVERAGE CURR 16DIP
• Manufacturer: Fairchild Semiconductor

Specifications of SG6980DZ

• Mode: Average Current
• Frequency - Switching: 65kHz
• Current - Startup: 10µA
• Voltage - Supply: 12.5 V ~ 20 V
• Operating Temperature: -20°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: 16-DIP (0.300", 7.62mm)
• Output Voltage: 0.3 V to 25 V
• Switching Frequency: 68 KHz
• Operating Temperature Range: - 20 C to + 125 C
• Mounting Style: Through Hole
• Duty Cycle (max): 98 %
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Single-Stage PFC Controller
Gate Drivers
SG6980D output stages are fast totem-pole gate drivers.
The output driver is clamped by an internal 18V Zener
diode to protect the power MOSFET.
Over-Temperature Protection
SG6980D provides an OTP pin for over-temperature
protection. A constant current is output from this pin. If RI
is equal to 24k , the magnitude of the constant current is
50µA. An external NTC thermistor must be connected
from this pin to ground. When the OTP voltage drops
below 1.2V, SG6980D shuts down. SG6980D auto restarts
when the OTP voltage is higher than 1.4V.
Protections & Built-in Latch Circuit
The SG6980D provides full protection functions to prevent
the power supply and the load from being damaged. The
protection features include:
PFC Feedback Over-Voltage Protection. When the PFC
feedback voltage exceeds the over-voltage threshold, the
SG6980D inhibits the PFC switching signal. This
protection prevents the PFC power converter from
operating abnormally while the FB pin is open.
PFC Feedback Under-Voltage Protection. The SG6980D
stops the PFC switching signal whenever the PFC feedback
voltage drops below the under-voltage threshold. This
protection feature is designed to prevent the PFC power
converter from experiencing abnormal conditions while the
FB pin is shorted to ground.
VDD Over-Voltage Protection. The built-in clamping
circuit clamps V
over-voltage threshold.
RI Pin Open / Short Protection. The RI pin is used to set the
switching frequency and internal current reference. If the
RI pin is shorted or open, SG6980D turns off.
© System General Corp.
Version 1.0.1 (IAO33.0071.B0
DD
whenever the V
DD
voltage exceeds the
- 15 -
PCB Layout
The SG6980D has a single ground pin. High sink currents
in the output cannot be returned separately. Good
high-frequency or RF layout practices should be followed.
Avoid long PCB traces and component leads. Locate
decoupling capacitors near the SG6980D. A resistor of 5 ~
20 : is recommended for connecting in series from the
output to the gate of the MOSFET.
Isolating the interference between the PFC and PWM
stages is also important. Figure 7 shows an example of the
PCB layout. The ground trace 1 is connected from the
ground pin of SG6980D to the decoupling capacitor, which
should be low impedance and as short as possible. The
ground trace 2 provides a signal ground. It should be
connected directly to the decoupling capacitor C
to the ground pin of the SG6980D. The ground trace 3 is
independently tied from the decoupling capacitor to the
PFC output capacitor C
capacitor C
switching. To provide a good ground reference and reduce
the switching noise of both the PFC and PWM stages, the
ground traces 6 and 7 should be located very near and be
low impedance.
The ICS pin is connected directly to R
improve noise immunity. (Beware that it may incorrectly
be connected to the ground trace 2). The IMP and IPK pins
should be connected directly via the resistors R
another terminal of R
O
is the major ground reference for power
www.sg.com.tw • www.fairchildsemi.com
FIG. 7 PCB Layout
S
.
O
. The ground in the output
Product Specification
September 17, 2007
S
through R
SG6980D
2
DD
and R
and/or
3
P
to
to