UCC2819, UCC3819

PROGRAMMABLE OUTPUT

POWER FACTOR PREREGULATOR

SLUS482A - APRIL 2001 REVISED JANUARY 2002

www.ti.com

Controls Boost Preregulator to Near-Unity
Power Factor

World Wide Line Operation

Over-Voltage Protection

Accurate Power Limiting

Average Current Mode Control

Improved Noise Immunity

Improved Feed-Forward Line Regulation

Leading Edge Modulation

150-

A Typical Start-Up Current

Low-Power BiCMOS Operation

10.8-V to 17-V Operation

Programmable Output Voltage (Tracking
Boost Topology)

description

The UCC2819/UCC3819 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 UCC3819 offers new features such as lower start-up
current, lower power dissipation, overvoltage protection, a shunt UVLO detect circuitry and a leading-edge
modulation technique to reduce ripple current in the bulk capacitor.

The UCC3819 allows the output voltage to be programmed by bringing out the error amplifier noninverting input.

Available in the 16-pin D, DW, N, and PW packages.

block diagram

UDG-01009

VREF

DRVOUT

GND

CAI

VCC

OVP/EN

VAOUT

1.9 V

PKLMT

7.5 V

REFERENCE

UVLO

16 V/10 V

10.5 V/10 V

VCC

OSCILLATOR

PWM

LATCH

PWM

CAOUT

VOLTAGE
ERROR AMP

8.0 V

VSENSE

VFF

IAC

MOUT

MIRROR

2:1

ENABLE

OVP

MULT

OSC

CLK

CURRENT

AMP

0.33 V

ZERO POWER

VAI

(UCC2819)

(UCC3819)

2002, Texas Instruments Incorporated

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.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

D, DW, N, and PW PACKAGES

(TOP VIEW)

GND

PKLMT

CAOUT

CAI

MOUT

IAC

VAOUT

VFF

DRVOUT
VCC
CT
VAI
RT
VSENSE
OVP/EN
VREF

UCC2819, UCC3819

PROGRAMMABLE OUTPUT

POWER FACTOR PREREGULATOR

SLUS482A - APRIL 2001 REVISED JANUARY 2002

www.ti.com

absolute maximum ratings over operating free-air temperature (unless otherwise noted)

Supply voltage, VCC

18 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gate drive current, continuous

0.2 A

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gate drive current

1.2 A

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input voltage, CAI, MOUT

8 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input voltage, PKLMT

5 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input voltage, VSENSE, OVP/EN, VAI

10 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input current, RT, IAC, PKLMT

10 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maximum negative voltage, DRVOUT, PKLMT, MOUT

0.5 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power dissipation

1 W

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and

functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied.
Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

AVAILABLE OPTIONS

PACKAGE DEVICES

D PACKAGE

DW PACKAGE

N PACKAGE

PW PACKAGE

C to 70

UCC3819D

UCC3819DW

UCC3819N

UCC3819PW

C to 85

UCC2819D

UCC2819DW

UCC2819N

UCC2819PW

The D, DW, and PW packages are available taped and reeled. Add TR suffix to device type (e.g. UCC3819DTR) to

order quantities of 2500 devices per reel.

electrical characteristics

, T

= 0

C to 70

C for the UCC3819, 40

C to 85

C for the UCC2819, VCC = 12 V,

= 22 k

, C

= 270 pF, (unless otherwise noted)

supply current

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Supply current, off

VCC = (VCC turnon threshold 0.3 V)

150

300

Supply current, on

VCC = 12 V,

No load on DRVOUT

UVLO

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

VCC turnon threshold

9.7

10.2

10.8

VCC turnoff threshold

9.4

9.7

UVLO hysteresis

0.3

0.5

voltage amplifier

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

VIO

VAOUT = 2.75 V,

VCM = 3.75 V

VAI bias current

VAOUT = 2.75 V,

VCM = 3.75 V

200

VSENSE bias current

VSENSE = VREF,

VAOUT = 2.5 V

200

CMRR

VCM = 1 V to 7.5 V

Open loop gain

VAOUT = 2 V to 5 V

High-level output voltage

IL = 150

5.3

5.5

5.6

Low-level output voltage

IL = 150

150

UCC2819, UCC3819

PROGRAMMABLE OUTPUT

POWER FACTOR PREREGULATOR

SLUS482A - APRIL 2001 REVISED JANUARY 2002

www.ti.com

electrical characteristics

, T

= 0

C to 70

C for the UCC3819, 40

C to 85

C for the UCC2819, VCC = 12 V,

= 22 k

, C

= 270 pF, (unless otherwise noted)

over voltage protection and enable

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Over voltage reference

VREF

+0.48

VREF

+0.50

VREF

+0.52

Hysteresis

300

500

600

Enable threshold

1.7

1.9

2.1

Enable hysteresis

0.1

0.2

0.3

current amplifier

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Input offset voltage

VCM = 0 V,

VCAOUT = 3 V

Input bias current

VCM = 0 V,

VCAOUT = 3 V

100

Input offset current

VCM = 0 V,

VCAOUT = 3 V

100

Open loop gain

VCM = 0 V,

VCAOUT = 2 V to 5 V

Common-mode rejection ratio

VCM = 0 V to 1.5 V,

VCAOUT = 3 V

High-level output voltage

IL = 120

5.6

6.5

6.8

Low-level output voltage

IL = 1 mA

0.1

0.2

0.5

Gain bandwidth product

See Note 1

2.5

MHz

voltage reference

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Input voltage, (UCC3819)

TA = 0

C to 70

7.387

7.5

7.613

Input voltage, (UCC2819)

TA = 40

C to 85

7.369

7.5

7.631

Load regulation

IREF = 1 mA to 2 mA

Line regulation

VCC = 10.8 V to 15 V,

See Note 2

Short-circuit current

VREF = 0 V

oscillator

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Initial accuracy

TA = 25

100

115

kHz

Voltage stability

VCC = 10.8 V to 15 V

Total variation

Line, temp,

See Note 1

120

kHz

Ramp peak voltage

4.5

5.5

Ramp amplitude voltage
(peak to peak)

3.5

4.5

NOTES: 1. Ensured by design, Not production tested.

2. Reference variation for VCC < 10.8 V is shown in Figure 2.

UCC2819, UCC3819

PROGRAMMABLE OUTPUT

POWER FACTOR PREREGULATOR

SLUS482A - APRIL 2001 REVISED JANUARY 2002

www.ti.com

electrical characteristics

, T

= 0

C to 70

C for the UCC3819, 40

C to 85

C for the UCC2819, VCC = 12 V,

= 22 k

, C

= 270 pF, (unless otherwise noted)

peak current limit

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

PKLMT reference voltage

PKLMT propagation delay

150

350

500

multiplier

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

IMOUT, high line, low power output

current, (0

C to 85

IAC = 500

A, VFF = 4.7 V,

VAOUT = 1.25 V

IMOUT, high line, low power output

current, (40

C to 85

IAC = 500

A, VFF = 4.7 V,

VAOUT = 1.25 V

IMOUT, high line, high power output

current

IAC = 500

A, VFF = 4.7 V,

VAOUT = 5 V

105

IMOUT, low line, low power output

current

IAC = 150

A, VFF = 1.4 V,

VAOUT = 1.25 V

IMOUT, low line, high power output

current

IAC = 150

A, VFF = 1.4 V,

VAOUT = 5 V

268

300

346

IMOUT, IAC limited

IAC = 150

A, VFF = 1.3 V,

VAOUT = 5 V

250

300

400

Gain constant (K)

IAC = 300

A, VFF = 3 V,

VAOUT = 2.5 V

0.5

1.5

1/V

ero c rrent

IAC = 150

A, VFF = 1.4 V,

VAOUT = 0.25 V

IMOUT, zero current

IAC = 500

A, VFF = 4.7 V,

VAOUT = 0.25 V

IMOUT, zero current, (0

C to 85

IAC = 500

A, VFF = 4.7 V,

VAOUT = 0.5 V

IMOUT, zero current, (40

C to 85

IAC = 500

A, VFF = 4.7 V,

VAOUT = 0.5 V

3.5

Power limit (IMOUT x VFF)

IAC = 150

A, VFF = 1.4 V,

VAOUT = 5 V

375

420

485

feed-forward

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

VFF output current

IAC = 300

140

150

160

gate driver

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Pullup resistance

IO = 100 mA to 200 mA

Pulldown resistance

IO = 100 mA

Output rise time

CL = 1 nF,

RL = 10

VDRVOUT = 0.7 V to 9 V

Output fall time

CL = 1 nF,

RL = 10

VDRVOUT = 9 V to 0.7 V

Maximum duty cycle

100

Minimum controlled duty cycle

At 100 kHz

zero power

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Zero power comparator threshold

Measured on VAOUT

0.20

0.33

0.50

UCC2819, UCC3819

PROGRAMMABLE OUTPUT

POWER FACTOR PREREGULATOR

SLUS482A - APRIL 2001 REVISED JANUARY 2002

www.ti.com

pin descriptions

CAI: (current amplifier noninverting input) Place a resistor between this pin and the GND side of current-sense
resistor. This input and the inverting input (MOUT) remain functional down to and below GND.

CAOUT: (current amplifier output) This is the output of a wide bandwidth operational amplifier that senses line
current and commands the PFC pulse-width modulator (PWM) to force the correct duty cycle. Compensation
components are placed between CAOUT and MOUT.

CT: (oscillator timing capacitor) A capacitor from CT to GND sets the PWM oscillator frequency according to:

[

0.6

The lead from the oscillator timing capacitor to GND should be as short and direct as possible.

DRVOUT: (gate drive) The output drive for the boost switch is a totem-pole MOSFET gate driver on DRVOUT.
Use a series gate resistor to prevent interaction between the gate impedance and the output driver that might
cause the DRVOUT to overshoot excessively. See characteristic curve (Figure 13) to determine minimum
required gate resister value. Some overshoot of the DRVOUT output is always expected when driving a
capacitive load.

GND: (ground) All voltages measured with respect to ground. VCC and REF should be bypassed directly to
GND with a 0.1-

F or larger ceramic capacitor.

IAC: (current proportional to input voltage) This input to the analog multiplier is a current proportional to
instantaneous line voltage. The multiplier is tailored for very low distortion from this current input (I

IAC

) to

multiplier output. The recommended maximum I

IAC

is 500

MOUT: (multiplier output and current amplifier inverting input) The output of the analog multiplier and the
inverting input of the current amplifier are connected together at MOUT. As the multiplier output is a current, this
is a high-impedance input so the amplifier can be configured as a differential amplifier. This configuration
improves noise immunity and allows for the leading-edge modulation operation. The multiplier output current

is limited to 2

IAC

. The multiplier output current is given by the equation:

MOUT

IAC

VAOUT

VFF

where K

is the multiplier gain constant.

OVP/EN: (over-voltage/enable) A window comparator input that disables the output driver if the boost output
voltage is a programmed level above the nominal or disables both the PFC output driver and resets SS if pulled
below 1.9 V (typ).

PKLMT: (PFC peak current limit) The threshold for peak limit is 0 V. Use a resistor divider from the negative side
of the current sense resistor to VREF to level shift this signal to a voltage level defined by the value of the sense
resistor and the peak current limit. Peak current limit is reached when PKLMT voltage falls below 0 V.

RT: (oscillator charging current) A resistor from RT to GND is used to program oscillator charging current. A
resistor between 10 k

and 100 k

is recommended. Nominal voltage on this pin is 3 V.

UCC2819, UCC3819

PROGRAMMABLE OUTPUT

POWER FACTOR PREREGULATOR

SLUS482A - APRIL 2001 REVISED JANUARY 2002

www.ti.com

pin descriptions (continued)

VAI: (voltage amplifier non-inverting input) This input can be tied to the VREF or any other voltage reference
(

7.5 V) to set the boost regulator output voltage.

VAOUT: (voltage amplifier output) This is the output of the operational amplifier that regulates output voltage.
The voltage amplifier output is internally limited to approximately 5.5 V to prevent overshoot.

VCC: (positive supply voltage) Connect to a stable source of at least 20 mA between 10 V and 17 V for normal
operation. Bypass VCC directly to GND to absorb supply current spikes required to charge external MOSFET
gate capacitances. To prevent inadequate gate drive signals, the output devices are inhibited unless V

VCC

exceeds the upper under-voltage lockout voltage threshold and remains above the lower threshold.

VFF: (feed-forward voltage) The RMS voltage signal generated at this pin by mirroring 1/2 of the I

IAC

into a single

pole external filter. At low line, the VFF roll should be 14 V.

VSENSE: (voltage amplifier inverting input) This is normally connected to a compensation network and to the
boost converter output through a divider network.

VREF: (voltage reference output) VREF is the output of an accurate 7.5-V voltage reference. This output is
capable of delivering 20 mA to peripheral circuitry and is internally short-circuit current limited. VREF is disabled
and remains at 0 V when V

VCC

is below the UVLO threshold. Bypass VREF to GND with a 0.1-

F or larger

ceramic capacitor for best stability. Please refer to Figures 8 and 9 for VREF line and load regulation
characteristics.

APPLICATION INFORMATION

The UCC3819 is based on the UCC3818 PFC preregulator. For a more detailed application information for this
part, please refer to the UCC3818 datasheet product folder.

The main difference between the UCC3818 and the UCC3819 is that the non-inverting input of the voltage error
amplifier is made available to the user through an external pin (VAI) in the UCC3819. The SS pin and function
were eliminated to accommodate this change.

The benefit of VAI pin is that it can be used to dynamically change the PFC output voltage based on the line
voltage (RMS) level or other conditions. Figure 1 shows one suggested implementation of the tracking boost
PFC converter as this approach is sometimes referred to. The VAI pin is tied to the VFF pin and hence output
voltage scales up with the line voltage. The benefit of this approach is that at lower line voltages the output
voltage is lower and that leads to smaller boost inductor value, lower MOSFET conduction losses and reduced
component stresses. In order for this feature to work, the downstream converter has to operate over a wider
input range.

UCC2819, UCC3819

PROGRAMMABLE OUTPUT

POWER FACTOR PREREGULATOR

SLUS482A - APRIL 2001 REVISED JANUARY 2002

www.ti.com

APPLICATION INFORMATION

Figure 2

7.45

7.50

7.55

7.60

7.40

VCC Supply Voltage V

VREF

Reference V

ltage

REFERENCE VOLTAGE

SUPPLY VOLTAGE

Figure 3

REFERENCE VOLTAGE

REFERENCE CURRENT

7.495

7.500

7.505

7.510

7.490

VREF

Reference V

ltage

IVREF Reference Current mA

Figure 4

MULTIPLIER OUTPUT CURRENT

VOLTAGE ERROR AMPLIFIER OUTPUT

0.0

1.0

2.0

3.0

4.0

5.0

200

250

350

100

300

150

IAC = 150

IAC = 300

IAC = 500

I MO

Multiplier Output Current

VAOUT Voltage

Error Amplifier

Output V

Figure 5

MULTIPLIER GAIN

VOLTAGE ERROR AMPLIFIER OUTPUT

1.0

2.0

3.0

4.0

5.0

0.7

1.1

1.3

1.5

0.5

0.9

IAC = 300

IAC = 500

IAC = 150

Multiplier

Gain

VAOUT Voltage

Error Amplifier

Output V

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enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
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TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI's standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.

TI assumes no liability for applications assistance or customer product design. Customers are responsible for
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Mailing Address:

Texas Instruments
Post Office Box 655303
Dallas, Texas 75265

2001, Texas Instruments Incorporated

IMPORTANT NOTICE

Mailing Address:

Texas Instruments
Post Office Box 655303
Dallas, Texas 75265

2001, Texas Instruments Incorporated

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: UCC2819ADR

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: UCC2819ADR