March 2010
FAN6754
Highly Integrated Green- Mode PWM Controller
Brownout and VLimit Adjustment by HV Pin
Features
Description
The highly integrated FAN6754 PWM controller
provides several features to enhance the performance
of flyback converters. To minimize standby power
High-Voltage Startup
AC Input Brownout Protection with Hysteresis
Monitor HV to Adjust VLimit
consumption,
a
proprietary green-mode function
provides off-time modulation to continuously decrease
the switching frequency under light-load conditions.
Low Operating Current: 1.7mA
Linearly Decreasing PWM Frequency to 22KHz
Frequency Hopping to Reduce EMI Emission
Fixed PWM Frequency: 65KHz
Under zero-load and very light-load conditions,
FAN6754 saves PWM pulses by entering deep burst
mode. This burst mode function enables the power
supply to meet international power conservation
requirements.
Peak-Current-Mode Control
FAN6754 integrates
a frequency-hopping function
Cycle-by-Cycle Current Limiting
internally to reduce EMI emission of a power supply
with minimum line filters. Built-in synchronized slope
compensation is accomplished by proprietary HV
monitor to adjust VLimit for constant output power limit
over universal AC input range. Also, the gate output is
clamped at 13V to protect the external MOSFET from
over-voltage damage.
Leading-Edge Blanking (LEB)
Internal Open-Loop Protection
GATE Output Maximum Voltage Clamp: 13V
VDD Under-Voltage Lockout (UVLO)
VDD Over-Voltage Protection (OVP)
Programmable Over-Temperature Protection (OTP)
Latch Circuit (OVP, OTP)
Other protection functions include AC input brownout
protection with hysteresis and VDD over-voltage
protection. For over-temperature protection, an external
NTC thermistor can be applied to sense the external
switcher’ s temperature. When VDD OVP are activated,
an internal latch circuit is used to latch-off the controller.
The latch mode is reset when the VDD supply is
removed.
Open-Loop Protection (OLP); Restart for MR, Latch
for ML
Built-in 8ms Soft-Start Function
FAN6754 is available in an 8-pin SOP package.
Applications
General-purpose switch-mode power supplies and
flyback power converters, including:
Power Adapters
Ordering Information
Operating
Temperature
Range
Eco
Status
Part Number
Package
Packing Method
FAN6754MRMY
FAN6754MLMY
-40 to +105°C
Green
8-Pin, Small Outline Package (SOP)
Tape & Reel
For Fairchild’s definition of Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2010 Fairchild Semiconductor Corporation
FAN6754 • Rev. 1.0.2
www.fairchildsemi.com