UCC28501DW ,BiCMOS PFC/PWM Combination Controllermaximum ratings over operating free-air temperature (unless otherwise noted)Supply Voltage VCC . . ..
UCC28510DW ,Advanced PFC/PWM Combination ControllersELECTRICAL CHARACTERISTICST = –40°C to 105°C for the UCC2851x, T = T , VCC = 12 V, R = 156 kΩ, R = ..
UCC28510DW ,Advanced PFC/PWM Combination ControllersMAXIMUM RATINGS †over operating free-air temperature (unless otherwise noted)Supply voltage VCCIdl ..
UCC28511DW ,Advanced PFC/PWM Combination Controllersmaximum ratings” may cause permanent damage to the device. These are stress ratings only, andfuncti ..
UCC28511DWR ,Advanced PFC/PWM Combination ControllersMAXIMUM RATINGS †over operating free-air temperature (unless otherwise noted)Supply voltage VCCIdl ..
UCC28511N ,Advanced PFC/PWM Combination ControllersELECTRICAL CHARACTERISTICST = –40°C to 105°C for the UCC2851x, T = T , VCC = 12 V, R = 156 kΩ, R = ..
UPA1716G-E2 ,Pch enhancement type power MOS FETapplications of notebook computers. PACKAGE DRAWING (Unit : mm)
UPA1717G ,SWITCHING P-CHANNEL POWER MOS FET INDUSTRIAL USEFEATURES• Low on-state resistanceRDS(on)1 = 33 mΩ MAX. (VGS = - 10 V, ID = - 3 A)6.0 ±0.314RDS(on)2 ..
UPA1717G-E1 ,P-channel enhancement type power MOS FETFEATURES• Low on-state resistanceRDS(on)1 = 33 mΩ MAX. (VGS = - 10 V, ID = - 3 A)6.0 ±0.314RDS(on)2 ..
UPA1717G-E2 ,P-channel enhancement type power MOS FETELECTRICAL CHARACTERISTICS (TA = 25 °C, All terminals are connected.)CHARACTERISTICS SYMBOL TEST CO ..
UPA1720 ,SWITCHING N-CHANNEL POWER MOS FET INDUSTRIAL USEFEATURES• Low On-ResistanceRDS(on)1 = 25.0 mΩ MAX. (VGS = 10 V, ID = 4.0 A)RDS(on)2 = 33.0 mΩ MAX. ..
UPA1720G ,SWITCHING N-CHANNEL POWER MOS FET INDUSTRIAL USEELECTRICAL CHARACTERISTICS (TA = 25 °C, All terminals are connected.)CHARACTERISTICS SYMBOL TEST CO ..
UCC28501DW
BiCMOS PFC/PWM Combination Controller
��������� ��������� ��������� ��������
��������� ��������� ��������� ��������
SLUS419C − AUGUST 1999 − REVISED NOVEMBER 2001
������ �������
����������� ����������
FEATURES Combines PFC and Downstream Converter
Controls Controls Boost Preregulator to Near-Unity
Power Factor Accurate Power Limiting Improved Feedforward Line Regulation Peak Current-Mode Control in Second Stage Programmable Oscillator Leading-Edge/Trailing-Edge Modulation for
Reduced Output Ripple Low Start-up Supply Current Synchronized Second Stage Start-Up, with
Programmable Soft-start Programmable Second Stage Shutdown
DESCRIPTIONThe UCC2850x family provides all of the control
functions necessary for an active power-factor-
corrected preregulator and a second-stage dc-to- dc
converter. The controller achieves near-unity power
factor by shaping the ac input line current waveform to
correspond to the ac input-line voltage using average
current-mode control. The dc-to-dc converter uses
peak current-mode control to perform the step-down
power conversion.
The PFC stage is leading-edge modulated while the
second stage is trailing-edge synchronized to allow for
minimum overlap between the boost and PWM
switches. This reduces ripple current in the bulk-output
capacitor.In order to operate with over three-to-one
range of input-line voltages, a line feedforward (VFF) is
used to keep input power constant with varying input
voltage. Generation of VFF is accomplished using IAC in
conjunction with an external single-pole filter. This not
only reduces external parts count, but also avoids the
use of high-voltage components, offering a lower-cost
solution. The multiplier then divides the line current by
the square of VFF.
The UCC2850x PFC section incorporates a low
offset-voltage amplifier with 7.5-V reference, a
highly-linear multiplier capable of a wide current range,
a high-bandwidth, low offset-current amplifier, with a
novel noise-attenuation configuration, PWM
comparator and latch, and a high-current output driver.
Additional PFC features include over-voltage
protection, zero-power detection to turn off the output
when VAOUT is below 0.33 V and peak current and
power limiting.
The dc-to-dc section relies on an error signal generated
on the secondary-side and processes it by performing
peak current mode control. The dc-to-dc section also
features current limiting, a controlled soft-start, preset
operating range with selectable options, and 50%
maximum duty cycle.
The UCC28500 and UCC28502 have a wide UVLO
threshold (16.5 V/10 V) for bootstrap bias supply
operation. The UCC28501 and UCC28503 are
designed with a narrow UVLO range (10.5 V/10 V) more
suitable for fixed bias operation. The UCC28500 and
UCC28501 have a narrow UVLO threshold for PWM
stage (to allow operation down to 75% of nominal bulk
voltage), while the UCC28502 and UCC38503 are
configured for a much wider operation range for the
PWM stage (down to 50% of bulk nominal voltage).
Available in 20-pin N and DW packages.
