SG6742HL/HR — Highly Integrated Green-Mode PWM Controller
April 2009
SG6742HL/HR
Highly Integrated Green-Mode PWM Controller
Features
High-Voltage Startup
Low Operating Current: 2.7mA
Linearly Decreasing PWM Frequency to 22KHz
Frequency Hopping to Reduce EMI Emission
Fixed PWM Frequency: 100KHz
Peak-Current-Mode Control
Cycle-by-Cycle Current Limiting
Leading-Edge Blanking (LEB)
Synchronized Slope Compensation
Internal Open-Loop Protection
GATE Output Maximum Voltage Clamp: 18V
V
DD
Under-Voltage Lockout (UVLO)
V
DD
Over-Voltage Protection (OVP)
Programmable Over-Temperature Protection (OTP)
Internal Latch Circuit (OVP, OTP)
Internal-Sense, Short-Circuit Protection
Built-in 6ms Soft-Start Function
Constant Power Limit (Full AC Input Range)
Internal OTP Sensor with Hysteresis
Description
The highly integrated SG6742HL/HR PWM controller
provides several features to enhance the performance
of flyback converters.
To minimize standby power consumption, a proprietary
green-mode function provides off-time modulation to
linearly decrease the switching frequency at light-load
conditions. To avoid acoustic-noise problems, the
minimum PWM frequency is set above 22KHz. This
green-mode function enables the power supply to meet
international power conservation requirements. With the
internal high-voltage startup circuitry, the power loss
due to bleeding resistors is eliminated. To further
reduce power consumption, SG6742HL/HR is
manufactured using the BiCMOS process, which allows
an operating current of 2.7mA.
SG6742HL/HR integrates a frequency-hopping function
internally that helps reduce EMI emission of a power
supply with minimum line filters. Its built-in synchronized
slope compensation achieves stable peak-current-mode
control. The proprietary, internal line compensation
ensures constant output power limit over a wide AC
input voltage range, from 90V
AC
to 264V
AC
.
SG6742HL/HR provides many protection functions. In
addition to cycle-by-cycle current limiting, the internal
open-loop protection circuit ensures safety should an
open-loop or output short-circuit failure occur. PWM
output is disabled until V
DD
drops below the UVLO lower
limit, when the controller starts up again. As long as V
DD
exceeds ~25V, the internal OVP circuit is triggered.
SG6742HL/HR is available in an 8-pin SOP package.
Applications
General-purpose switch-mode power supplies and
flyback power converters, including:
Power Adapters
Open-Frame SMPS
Ordering Information
Part
Number
SG6742HLSY
SG6742HRSY
Operating
Temperature
Range
-40 to +105°C
-40 to +105°C
OLP
Function
Latch
Restart
Package
8-Lead Small Outline Package (SOP)
8-Lead Small Outline Package (SOP)
Eco
Status
Green
Green
Packing
Method
Tape & Reel
Tape & Reel
For Fairchild’s definition of “green” Eco Status, please visit:
http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2008 Fairchild Semiconductor Corporation
SG6742HL/HR • Rev. 1.0.4
www.fairchildsemi.com
SG6742HL/HR — Highly Integrated Green-Mode PWM Controller
Marking Information
F
- Fairchild Logo
Z - Plant Code
X - 1-Digit Year Code
Y - 1-Digit Week Code
TT - 2-Digit Die Run Code
T - Package Type (S=SOP)
P - Y: Green Package
M - Manufacture Flow Code
ZXYTT
6742HR
TPM
ZXYTT
6742HL
TPM
Figure 3. Top Mark
Pin Configuration
SOP-8
GND
FB
NC
HV
1
2
3
4
8
7
6
5
GATE
VDD
SENSE
RT
Figure 4. Pin Configuration (Top View)
Pin Definitions
Pin #
1
2
3
4
5
6
7
8
Name
GND
FB
NC
HV
RT
SENSE
VDD
GATE
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 on this pin and the current-sense signal on the SENSE pin.
No connection.
For startup, this pin is pulled high to the line input or bulk capacitor via resistors.
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.
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
DD
exceeds the
OVP trigger point.
The totem-pole output driver. Soft driving waveform is implemented for improved EMI.
© 2008 Fairchild Semiconductor Corporation
SG6742HL/HR • Rev. 1.0.4
www.fairchildsemi.com
3
SG6742HL/HR — Highly Integrated Green-Mode PWM Controller
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device
reliability. The absolute maximum ratings are stress ratings only.
Symbol
V
VDD
V
FB
V
SENSE
V
RT
V
HV
P
D
Θ
JA
T
J
T
STG
T
L
DC Supply Voltage
(1, 2)
Parameter
FB Pin Input Voltage
SENSE Pin Input Voltage
RT Pin Input Voltage
HV Pin Input Voltage
Power Dissipation (T
A
＜50°C)
Thermal Resistance (Junction-to-Air)
Operating Junction Temperature
Storage Temperature Range
Lead Temperature (Wave Soldering or IR, 10 Seconds)
Human Body Model,
JEDEC:JESD22-A114
Charged Device Model,
JEDEC:JESD22-C101
All pins except HV pin
All pins except HV pin
Min.
-0.3
-0.3
-0.3
Max.
30
7.0
7.0
7.0
500
400
141
Unit
V
V
V
V
V
mW
°C/W
°C
°C
°C
-40
-55
+125
+150
+260
4.0
ESD
kV
1.5
Notes:
1. All voltage values, except differential voltages, are given with respect to the network ground terminal.
2. Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device.
© 2008 Fairchild Semiconductor Corporation
SG6742HL/HR • Rev. 1.0.4
www.fairchildsemi.com
4
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