UCC2817A Datasheet, PDF (1/33 Pages) Texas Instruments – BiCMOS POWER FACTOR PREREGULATOR

UCC2817A, UCC2818A
UCC3817A, UCC3818A
ą
SLUS577B − SEPTEMBER, 2003 − REVISED FEBRUARY 2006
BiCMOS POWER FACTOR PREREGULATOR
FEATURES
D Controls Boost Preregulator to Near-Unity
Power Factor
D Limits Line Distortion
D World Wide Line Operation
D Over-Voltage Protection
D Accurate Power Limiting
D Average Current Mode Control
D Improved Noise Immunity
D Improved Feed-Forward Line Regulation
D Leading Edge Modulation
D 150-µA Typical Start-Up Current
D Low-Power BiCMOS Operation
D 12-V to 17-V Operation
DESCRIPTION
The UCC3817A and the UCC3818A family
provides all the functions necessary for active
power factor corrected preregulators. The
controller achieves near unity power factor by
shaping the ac input line current waveform to
correspond to that of the ac input line voltage.
Average current mode control maintains stable,
low distortion sinusoidal line current.
Designed in Texas Instrument’s BiCMOS process,
the UCC3817A/UCC3818A offers new features
such as lower start-up current, lower power
dissipation, overvoltage protection, a shunt UVLO
detect circuitry, a leading-edge modulation
technique to reduce ripple current in the bulk
capacitor and an improved, low-offset (±2 mV)
current amplifier to reduce distortion at light load
conditions.
BLOCK DIAGRAM
VCC
15
OVP/EN 10
SS 13
VAOUT 7
VSENSE 11
7.5 V
VOLTAGE
− ^{ERROR AMP}
+
VFF 8
X2
X
÷ MULT
X
MIRROR
2:1
IAC 6
MOUT 5
16 V (FOR UCC3817A ONLY)
7.5 V
REFERENCE
9 VREF
1.9 V −
+
0.33 V
CURRENT
AMP
−
+
ENABLE
ZERO POWER
−
+
8.0 V + OVP
−
−
+
OSC
PWM
CLK
SQ
PWM
LATCH
RR
UVLO
16 V/10 V (UCC3817A)
10.5 V/10 V (UCC3818A)
VCC
CLK
OSCILLATOR
−
+
16 DRVOUT
1 GND
2 PKLMT
4
3
12 14
CAI
CAOUT RT CT
UDG-03122
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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Copyright  2006, Texas Instruments Incorporated
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