TEXAS INSTRUMENTS UCC28C4x-EP Technical data

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BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS

UCC28C4x-EP

SGLS352B – DECEMBER 2006 – REVISED MAY 2007

FEATURES

• Low Operating Current of 2.3 mA at 52 kHz

• Controlled Baseline • Fast 35 ns Cycle-by-Cycle Overcurrent

– One Assembly/Test Site, One Fabrication

Limiting

Site • ± 1 A Peak Output Current

– Extended Temperature Performance of • Rail-to-Rail Output Swings With 25 ns Rise

–55 ° C to 125 ° C and 20 ns Fall Times

• Enhanced Diminishing Manufacturing Sources • ± 1% Initial Trimmed 2.5 V Error Amplifier

(DMS) Support Reference

• Enhanced Product-Change Notification • Trimmed Oscillator Discharge Current

• Qualification Pedigree

(1)

• New Undervoltage Lockout Versions

• Enhanced Replacements for UC2842A Family • MSOP-8 Package Minimizes Board Space

With Pin-to-Pin Compatibility

• 1 MHz Operation

• 50 µ A Standby Current, 100 µ A Maximum

(1) Component qualification in accordance with JEDEC and

industry standards to ensure reliable operation over an extended temperature range. This includes, but is not limited to, Highly Accelerated Stress Test (HAST) or biased 85/85, temperature cycle, autoclave or unbiased HAST, electromigration, bond intermetallic life, and mold compound life. Such qualification testing should not be viewed as justifying use of this component beyond specified performance and environmental limits.

APPLICATIONS

• Switch Mode Power Supplies

• DC-to-DC Converters

• Board Mount Power Modules

DESCRIPTION

The UCC28C4x family are high performance current mode PWM controllers. They are enhanced BiCMOS versions with pin-for-pin compatibility to the industry standard UC284xA family and UC284x family of PWM controllers. In addition, lower startup voltage versions of 7 V are offered as UCC28C40 and UCC28C41.

Providing necessary features to control fixed frequency, peak current mode power supplies, this family offers several performance advantages. These devices offer high frequency operation up to 1 MHz with low start up and operating currents, thus minimizing start up loss and low operating power consumption for improved efficiency. The devices also feature a fast current sense to output delay time of 35 ns, and a ± 1 A peak output current capability with improved rise and fall times for driving large external MOSFETs directly.

The UCC28C4x family is offered in 8-pin package SOIC (D).

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.

PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

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Note:Toggleflip-flopusedonlyinUCC28C41,UCC28C44,andUCC28C45.

UCC28C4x-EP BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS

SGLS352B – DECEMBER 2006 – REVISED MAY 2007

AVAILABLE OPTIONS

MAXIMUM UVLO

DUTY CYCLE ON/OFF

14.5 V/9 V UCC28C42MDREP

100% 8.4 V/7.6 V UCC28C43MDREP

–55 ° C to 125 ° C

7 V/6.6 V UCC28C40MDREP

14.5 V/9 V UCC28C44MDREP

50% 8.4 V/7.6 V UCC28C45MDREP

7 V/6.6 V UCC28C41MDREP

(1) D (SOIC-8) packages are available taped and reeled. Add R suffix to device type (e.g., UCC28C42DREP) to order quantities of 2500

devices per reel. Tube quantities are 75 for D packages (SOIC-8).

(2) Product Preview

FUNCTIONAL BLOCK DIAGRAM

SOIC-8

SMALL OUTLINE

(1)

(D)

(2)

(2) (2)

(2)

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UCC28C4x-EP

BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS

SGLS352B – DECEMBER 2006 – REVISED MAY 2007

Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)

Supply voltage

Output current, I Output energy, capacitive load 5 µ J

Voltage rating V

Error amplifier output sink current 10 mA

Operating junction temperature range

Storage temperature range –65 150 ° C

stg

Lead temperature (soldering, 10 s) 300 ° C

(1) 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. (2) All voltages are with respect to ground. Currents are positive into and negative out of the specified terminals. (3) Long-term high temperature storage and/or extended use at maximum recommended operating conditions may result in a reduction of

overall device life. See http://www.ti.com/ep_quality for additional information about enhanced plastic packaging.

peak ± 1 A

OUT

(1) (2)

MIN MAX UNIT

VDD 20 V Max I

30 mA

COMP, CS, FB –0.3 6.3 OUT –0.3 20 RT/CT –0.3 6.3 VREF 7

(3)

–55 150 ° C

Dissipation Ratings

PACKAGE

( ° C/W) POWER RATING ABOVE TA= 25 ° C POWER RATING POWER RATING POWER RATING

D 176 710 mW 5.68 mW/ ° C 454 mW 369 mW 142 mW

TA< 25 ° C DERATING FACTOR TA= 70 ° C TA= 85 ° C TA= 125 ° C

Recommended Operating Conditions

MIN MAX UNIT

OUT

(1)

OUT

OUT(ref

(1)

(1) It is not recommended that the device operate under conditions beyond those specified in this table for extended periods of time.

Input voltage 18 V Output voltage range 18 V Average output current 200 mA

(1)

)

Reference output current –20 mA Operating junction temperature –55 150 ° C

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ACS +

COM

,0Vv VCSv 900 mV

UCC28C4x-EP BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS

SGLS352B – DECEMBER 2006 – REVISED MAY 2007

Electrical Characteristics

UCC28C4x

Reference

Oscillator

Error Amplifier

VOL

PSRR Power-supply rejection ratio V

Current Sense

PSRR Power-supply rejection ratio V

Output

(1)

= 15 V

, RT= 10 k Ω , CT= 3.3 nF, C

VDD

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Output voltage, initial accuracy TA= 25 ° C , I Line regulation V Load regulation 1 mA to 20 mA 3 25 mV Temperature stability Total output variation Output noise voltage 10 Hz to 10 kHz, TA= 25 ° C 50 µ V Long term stability 1000 hours, TA= 125 ° C Output short circuit –30 –45 –55 mA

Initial accuracy

Voltage stability V Temperature stability T Amplitude RT/CT pin peak to peak 1.9 V

Discharge current

Feedback input voltage, initial accuracy V Feedback input voltage, total variation V Input bias current –0.1 –2 µ A Open-loop voltage gain V Unity gain bandwidth 1.5 MHz

Output sink current V Output source current V High-level output voltage V Low-level output voltage V

Gain

Maximum input signal V

Input bias current –0.1 –2 µ A CS to output delay 35 70 ns COMP to CS offset V

low (R

OUT

high (R

OUT

pull-down) I

DS(on)

pull-up) I

DS(on)

= 0.1 µ F and no load on the outputs, TA= TJ= –55 ° C to 125 ° C for the

= 1 mA 4.9 5 5.1 V

OUT

= 12 V to 18 V 0.2 20 mV

(2) (2)

(2)

TA= 25 ° C TA= Full Range

DD MIN

TA= 25 ° C, RT/CT = 2 V RT/CT = 2 V

COMP COMP

OUT

DD FB FB FB FB

TA= 25 ° C TA= Full Range

FB DD

SINK SOURCE

(3)

= 12 V to 18 V 0.2 2.85 %

(2)

to T

MAX

(4)

= 2.5 V, TA= 25 ° C 2.475 2.500 2.525 V = 2.5 V 2.45 2.50 2.55 V

= 2 V to 4 V 65 90 dB

= 12 V to 18 V 60 dB = 2.7 V, V = 2.3 V, V = 2.3 V, R = 2.7 V, R

(5) (6)

= 1.1 V 2 14 mA

COMP

= 5 V –0.5 –1 mA

COMP

= 15 k to GND 5 6.8 V

LOAD

= 15 k to VREF 0.1 1.1 V

LOAD

(5) (6)

< 2.4 V 0.9 1 1.1 V

= 12 V to 18 V

(2) (5)

= 0 V 1.15 V

= 200 mA 5.5 15 Ω

= 200 mA 10 25 Ω

4.82 5.18 V

50.5 53 55 kHz

50.5 57 KHz

2.85 3 3.15 V/V

2.825 3.15 V/V

0.2 0.4 mV/ ° C

7.7 8.4 9 mA

7.2 8.4 9.5 mA

70 dB

5 25 mV

1 2.5 %

(1) Adjust V (2) Not production tested.

above the start threshold before setting at 15 V.

(3) Output frequencies of the UCC28C41, UCC28C44, and UCC28C45 are one-half the oscillator frequency. (4) Oscillator discharge current is measured with RT= 10 k Ω to V (5) Parameter measured at trip point of latch with V

= 0 V.

REF

(6) Gain is defined as

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1 2 3 4

8 7 6 5

COMP

RT/CT

VREF VDD OUT GND

PDIP (P) or SOIC (D) PACKAGE

(TOP VIEW)

Electrical Characteristics (continued)

= 15 V , RT= 10 k Ω , CT= 3.3 nF, C

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Rise tIme TA= 25 ° C, C Fall time TA= 25 ° C, C

Undervoltage Lockout (UVLO)

Start threshold UCC28C43-EP, UCC28C45-EP 7.8 8.4 9 V

Minimum operating voltage UCC28C43-EP, UCC28C45-EP 7 7.6 8.2 V

PWM

Maximum duty cycle UCC28C40-EP, UCC28C44-EP, %

Minimum duty cycle 0%

Current Supply

START-UP

Start-up current V Operating supply current V

BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS

SGLS352B – DECEMBER 2006 – REVISED MAY 2007

= 0.1 µ F and no load on the outputs, TA= TJ= –55 ° C to 125 ° C for the UCC28C4x

VDD

= 1 nF 25 50 ns

LOAD

= 1 nF 20 40 ns

LOAD

UCC28C42-EP, UCC28C44-EP 13.5 14.5 15.5

UCC28C40-EP, UCC28C41-EP 6.5 7 7.5 UCC28C42-EP, UCC28C44-EP 8 9 10

UCC28C40-EP, UCC28C41-EP 6.1 6.6 7.1

UCC28C42-EP, UCC28C43-EP, 94 96 UCC28C45-EP, UCC28C41-EP

= UVLO start threshold (–0.5 V) 50 100 µ A

= V

= 0 V 2.3 3 mA

UCC28C4x-EP

47 48

Pin Assignments

COMP: This pin provides the output of the error amplifier for compensation. In addition, the COMP pin is

frequently used as a control port by utilizing a secondary-side error amplifier to send an error signal across the secondary-primary isolation boundary through an opto-isolator.

CS: The current-sense pin is the noninverting input to the PWM comparator. This is compared to a signal proportional to the error amplifier output voltage. A voltage ramp can be applied to this pin to run the device with a voltage mode control configuration.

FB: This pin is the inverting input to the error amplifier. The noninverting input to the error amplifier is internally trimmed to 2.5 V ± 1%.

GND: Ground return pin for the output driver stage and the logic-level controller section. OUT: The output of the on-chip drive stage. OUT is intended to directly drive a MOSFET. The OUT pin in the

UCC28C40, UCC28C42, and UCC28C43 is the same frequency as the oscillator, and can operate near 100% duty cycle. In the UCC28C41, UCC28C44, and the UCC28C45, the frequency of OUT is one-half that of the oscillator due to an internal T flipflop. This limits the maximum duty cycle to <50%.

RT/CT: Timing resistor and timing capacitor. The timing capacitor should be connected to the device ground using minimal trace length.

VDD: Power supply pin for the device. This pin should be bypassed with a 0.1 µ F capacitor with minimal trace lengths. Additional capacitance may be needed to provide hold up power to the device during startup.

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UCC28C4x-EP BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS

SGLS352B – DECEMBER 2006 – REVISED MAY 2007

VREF: 5-V reference. For stability, the reference should be bypassed with a 0.1 µ F capacitor to ground using

the minimal trace length possible.

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