Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - voltage regulators - DC DC switch controllers SOIC 8

UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP

CURRENT-MODE PWM CONTROLLER

SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

D Controlled Baseline

− One Assembly/Test Site, One Fabrication

Site

D Extended Temperature Performance of

−55°C to 125°C

D Enhanced Diminishing Manufacturing

Sources (DMS) Support

D Enhanced Product Change Notification

D Qualification Pedigree

†

D Optimized for Off-line and DC-to-DC

Converters

D Low Start Up Current (<0.5 mA)

D Trimmed Oscillator Discharge Current

†

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.

D Automatic Feed Forward Compensation

D Pulse-by-Pulse Current Limiting

D Enhanced Load Response Characteristics

D Under-Voltage Lockout With Hysteresis

D Double Pulse Suppression

D High Current Totem Pole Output

D Internally Trimmed Bandgap Reference

D 500 kHz Operation

D Low R

Error Amp

description

The UC1842A/3A/4A/5A family of control ICs is a pin-for-pin compatible improved version of the UC3842/3/4/5

family. Providing the necessary features to control current mode switched mode power supplies, this family has

the following improved features. Start up current is guaranteed to be less than 0.5 mA. Oscillator discharge is

trimmed to 8.3 mA. During under voltage lockout, the output stage can sink at least 10 mA at less than 1.2 V

for V

over 5 V.

The difference between members of this family are shown in the table below.

PART NUMBER UVLO ON UVLO OFF MAXIMUM DUTY CYCLE

UC1842A 16 V 10 V <100%

UC1843A 8.5 V 7.9 V <100%

UC1844A 16 V 10 V <50%

UC1845A 8.5 V 7.9 V <50%

ORDERING INFORMATION

‡

PACKAGE

‡

ORDERABLE

PART NUMBER

TOP-SIDE

MARKING

−55°C to 125°C SOP − D Tape and reel UC1842AMDREP 1842AME

−55°C to 125°C SOP − D Tape and reel UC1843AMDREP 1843AME

−55°C to 125°C SOP − D Tape and reel UC1844AMDREP 1844AME

−55°C to 125°C SOP − D Tape and reel UC1845AMDREP 1845AME

‡

Package drawings, standard packing quantities, thermal data, symbolization, and PCB design

guidelines are available at www.ti.com/sc/package.

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 PACKAGE

(TOP VIEW)

COMP

SENSE

REF

OUTPUT

GND

Summary of content (15 pages)

PAGE 1
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 D Controlled Baseline D D D D D D D † D D D D D D D D D − One Assembly/Test Site, One Fabrication Site Extended Temperature Performance of −55°C to 125°C Enhanced Diminishing Manufacturing Sources (DMS) Support Enhanced Product Change Notification Qualification Pedigree† Optimized for Off-line and DC-to-DC Converters Low Start Up Current (<0.
PAGE 2
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 block diagram NOTES: 1. Toggle flip flop used only in 1844A and 1845A.
PAGE 3
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†‡ VCC voltage (low impedance source) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 V VCC voltage (ICC mA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 4
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 electrical characteristics, TA = −55_C to 125_C for the UC184xAM-EP, VCC = 15 V (see Note 1), RT = 10 kΩ, CT = 3.3 nF, and TA = TJ (unless otherwise stated) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS Error Amplifier Section Input voltage COMP = 2.5 V 2.
PAGE 5
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 electrical characteristics, TA = −55_C to 125_C for the UC184xAM-EP, VCC = 15 V (see Note 1), RT = 10 kΩ, CT = 3.
PAGE 6
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 PARAMETER MEASUREMENT INFORMATION During UVLO, the Output is low. Figure 2. Under Voltage Lockout Peak Current (Is) is determined by the following formula: IsmaxȀ 1V RS A small RC filter may be required to suppress switch transients. Figure 3.
PAGE 7
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 PARAMETER MEASUREMENT INFORMATION Error Amplifier Open-Loop Frequency Response Output Saturation Characteristics Figure 5 Figure 4 APPLICATION INFORMATION Oscillator Frequency vs Timing Resistance Maximum Duty Cycle vs Timing Resistor Figure 6.
PAGE 8
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 APPLICATION INFORMATION High peak currents associated with capacitive loads necessitate careful grounding techniques. Timing and bypass capacitors should be connected close to pin 5 in a single point ground. The transistor and 5k potentiometer are used to sample the oscillator waveform and apply an adjustable ramp to pin 3. Figure 7.
PAGE 9
UC1842A-EP, UC1843A-EP, UC1844A-EP, UC1845A-EP CURRENT-MODE PWM CONTROLLER SGLS134D − SEPTEMBER 2002 − REVISED JANUARY 2013 APPLICATION INFORMATION Power Supply Specifications 1. 2. 3. 4. 5. Input Voltage 95VAC to 130VAC (50 Hz/60 Hz) Line Isolation 3750 V Switching Frequency 40 kHz Efficiency, Full Load 70% Output Voltage: A. +5V, ±5%; 1A to 4A Load B. +12V, ±3%; 0.1A to 0.3A Load Ripple voltage: 100 mV P-P Max C. −12V, ±3%; 0.1A to 0.3A Load Ripple voltage: 100 mV P-P Max Figure 9.
PAGE 10
PACKAGE OPTION ADDENDUM www.ti.
PAGE 11
PACKAGE OPTION ADDENDUM www.ti.com 31-May-2014 (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device.
PAGE 12
PACKAGE MATERIALS INFORMATION www.ti.com 11-Jan-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant UC1842AMDREP SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 4.0 12.0 Q1 UC1843AMDREP SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 4.0 12.0 Q1 UC1844AMDREP SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 4.0 12.
PAGE 13
PACKAGE MATERIALS INFORMATION www.ti.com 11-Jan-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) UC1842AMDREP SOIC D 8 2500 367.0 367.0 35.0 UC1843AMDREP SOIC D 8 2500 367.0 367.0 35.0 UC1844AMDREP SOIC D 8 2500 367.0 367.0 35.0 UC1845AMDREP SOIC D 8 2500 367.0 367.0 35.
PAGE 14
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.