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CR6848
Novel Low Cost Green-Power PWM Controller
Features
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Low Cost, PWM&PFM&CRM
universal AC input
Low Start-up Current (about 10µA)
Low Operating Current (about 2mA)
Current Mode Operation
Under Voltage Lockout (UVLO)
Built-in Synchronized Slope
Compensation
Programmable PWM Frequency
Leading edge Blanking on Sense input
Constant output power limiting for
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Cycle-by-cycle current limiting
Clamped gate output voltage 16.5V
Over voltage protect 26.7V
High-Voltage CMOS Process with ESD
SOT-23-6L、SOP-8 & DIP-8 Pb-Free
Packaging
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Compatible with SG5701 & SG5848 &
LD7535 &OB22632/63
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Applications
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Switching AC/DC Adaptor
Battery Charger
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Open Frame Switching Power Supply
384X Replacement
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General Description
The CR6848 is a highly integrated low cost
edge blanking circuit on current sense input
could remove the signal glitch due to
snubber circuit diode reverse recovery and
current mode PWM controller, which is ideal
for small power current mode of offline
AC-DC fly-back converter applications.
Making use of external resistors, the IC
changes the operating frequency and
automatically enters the PFM/CRM under
light-load/zero-load conditions. This can
minimize standby power consumption and
achieve green-power functions. With a very
low start-up current, the CR6848 could use
a large value start-up resistor (1.5Mohm).
Built-in synchronized slope compensation
enhances the stability of the system and
avoids sub-harmonic oscillation. Dynamic
peak limiting circuit minimizes output power
change caused by delay time of the system
over a universal AC input range. Leading
thus
greatly
reduces
the
external
component count and system cost in the
design. Pulse-by-pulse current limiting
ensures safe operation even during
short-circuit.
The CR6848 offers more protection like
OVP (Over Voltage Protection) and OCP
(Over current protection). The CR6848’s
output driver is clamped to maximum 16.5V
to protect the power MOSFET. Excellent
EMI performance is achieved soft switching
control at the totem pole gate driver output.
CR6848 is offered in SOT-23-6, SOP-8 and
DIP-8 packages.
Dec, 2006
V1.5
1/14
Chengdu Chip-Rail Tech.Co.Ltd.
http://www.chiprail.com