The UCC28019 8-pin active Power Factor Correction (PFC) controller uses the boost topology operating in Continuous Conduction Mode (CCM)

UCC28019

Manufacturer Part NumberUCC28019
DescriptionThe UCC28019 8-pin active Power Factor Correction (PFC) controller uses the boost topology operating in Continuous Conduction Mode (CCM)
ManufacturerTexas Instruments
UCC28019 datasheet
 


Specifications of UCC28019

Uvlo Thresholds On/off(v)10.5/9.5Operating Supply(max)(v)22
Startup Current(ma)0.1Operating Supply Current(ma)7
Vref(v)5Vref Tol(%)2
Duty Cycle(max)(%)99.3Practical Operating Frequency(max)(mhz)0.65
Pin/package8PDIP, 8SOIC  
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Power Supply
The UCC28019 operates from an external bias supply. It is recommended that the device be powered from a
regulated auxiliary supply. This device is not intended to be used from a bootstrap bias supply. A bootstrap bias
supply is fed from the input high voltage through a resistor with sufficient capacitance on VCC to hold up the
voltage on VCC until current can be supplied from a bias winding on the boost inductor. The minimal hysteresis
on VCC would require an unreasonable value of hold-up capacitance.
During normal operation, when the output is regulated, current drawn by the device includes the nominal run
current plus the current supplied to the gate of the external boost switch. Decoupling of the bias supply must take
switching current into account in order to keep ripple voltage on VCC to a minimum. A ceramic capacitor with a
minimum value of 0.1 F is recommended from VCC to GND with short, wide traces.
VCC
10.5V
ON
VCC
9.5V
OFF
Controller
UVLO
Soft-Start
State
PWM
OFF
Ramp
State
The device bias operates in several states. During startup, VCC Under-Voltage LockOut (UVLO) sets the
minimum operational dc input voltage of the PFC controller. There are two UVLO thresholds. When the UVLO
turn-on threshold is exceeded, the controller turns ON. If VCC falls below the UVLO lower turn-off threshold, the
controller turns OFF. During UVLO, current drawn by the device is minimal. After the device turns on, Soft Start
(SS) is initiated and the output is ramped up in a controlled manner to reduce the stress on the external
components and prevents output voltage overshoot. During soft start and after the output is in regulation, the
device draws its normal run current. If any of several fault conditions is encountered or if the device is put in
Standby with an external signal, the device draws a reduced standby current.
Copyright © 2007, Texas Instruments Incorporated
VCC
I
VCC
Soft-
Run
Fault/Standby
Start
Regulated
OFF
Ramp
Figure 19. Device Supply States
Product Folder Link(s):
UCC28019
UCC28019
SLUS755B – APRIL 2007 – REVISED DECEMBER 2007
I
VCC(ON)
I
<2.9mA
VCC(stby)
I
<200µA
VCC(start)
Run
UVLO
Regulated
OFF
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