Datasheet

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

UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ

CURRENT-MODE PWM CONTROLLER

SGLS164 – APRIL 2003

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

D Extended Temperature Performance of

–40°C to 125°C

D Optimized for Off-line and DC to DC

Converters

D Low Start Up Current (<0.5 mA)

D Trimmed Oscillator Discharge Current

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 UC2842A/3A/4A/5A family of control ICs is a pin for pin compatible improved version of the UC2842/3/4/5

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

UC2842A 16 V 10 V <100%

UC2843A 8.5 V 7.9 V <100%

UC2844A 16 V 10 V <50%

UC2845A 8.5 V 7.9 V <50%

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 8-PIN PACKAGE

(TOP VIEW)

COMP

SENSE

REF

OUTPUT

GND

D 14-PIN PACKAGE

(TOP VIEW)

COMP

SENSE

REF

OUTPUT

GND

PWR GND

Summary of content (17 pages)

PAGE 1
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 D Extended Temperature Performance of D 8-PIN PACKAGE (TOP VIEW) –40°C to 125°C D Optimized for Off-line and DC to DC D D D D D D D D D D D Converters Low Start Up Current (<0.
PAGE 2
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 ORDERING INFORMATION† TA 40°C to 125°C –40°C ORDERABLE PART NUMBER PACKAGE‡ TOP-SIDE MARKING SOIC-8 – D8 Tape and reel UC2842AQD8R 2842AQ SOIC-8 – D8 Tube UC2842AQD8 2842AQ SOIC-14 – D Tape and reel UC2842AQDR 2842AQ SOIC-14 – D Tube UC2842AQD 2842AQ SOIC-8 – D8 Tape and reel UC2843AQD8R 2843AQ SOIC-8 – D8 Tube UC2843AQD8 2843AQ SOIC-14 – D Tape and reel UC2843AQDR 2843AQ SOIC-14 – D Tu
PAGE 3
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 Ordering Information UC 284 4 A Q D R TAPE and REEL INDICATOR PACKAGE D = Plastic SOIC, 14 pin D8 = Plastic SOIC, 8 pin AUTOMOTIVE TEMPERATURE RANGE INDICATOR IMPROVED PERFORMANCE INDICATOR PRODUCT OPTION 2 through 5 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3
PAGE 4
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†‡ VCC voltage (low impedance source) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 V VCC voltage (ICC mA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 5
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 electrical characteristics, TA = –40_C to 125_C, 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 2.45 Input bias current Open loop voltage gain (AVOL) VO = 2 V to 4 V Unity gain bandwidth See Note 2 PSRR VCC = 12 V to 25 V Output sink current FB = 2.7 V, COMP = 1.
PAGE 6
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 electrical characteristics, TA = –40_C to 125_C, 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 PWM Section Maximum duty cycle UC2842A, UC2843A 94 96 100 UC2844A, UC2845A 47 48 50 Minimum duty cycle 0 % % Total Standby Current Start-up current Operating supply current FB = 0 V, SENSE = 0 V 0.3 0.
PAGE 7
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 PARAMETER MEASUREMENT INFORMATION During UVLO, the Output is low. Figure 2. Under Voltage Lockout Peak Current (Is) is Determined By The Formula: IsmaxȀ 1.0V RS A small RC filter may be required to supress switch transients. Figure 3.
PAGE 8
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 PARAMETER MEASUREMENT INFORMATION Error Amplifier Open-Loop Frequency Response Output Saturation Characteristics Figure 5 Figure 4 AP PLICATION INFORMATION Oscillator Frequency vs Timing Resistance Figure 6.
PAGE 9
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 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 10
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 APPLICATION INFORMATION Power Supply Specifications 1. 2. 3. 4. 5. Input Voltage 95VAC to 130VAC (50Hz/60Hz) Line Isolation 3750V 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 11
PACKAGE OPTION ADDENDUM www.ti.
PAGE 12
PACKAGE OPTION ADDENDUM www.ti.com 26-Aug-2013 TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
PAGE 13
PACKAGE MATERIALS INFORMATION www.ti.com 9-Dec-2010 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 UC2842AQD8R SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 4.0 12.0 Q1 UC2843AQD8R SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 4.0 12.0 Q1 UC2845AQD8R SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 4.0 12.
PAGE 14
PACKAGE MATERIALS INFORMATION www.ti.com 9-Dec-2010 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) UC2842AQD8R SOIC D 8 2500 367.0 367.0 35.0 UC2843AQD8R SOIC D 8 2500 367.0 367.0 35.0 UC2845AQD8R SOIC D 8 2500 367.0 367.0 35.
PAGE 15
PAGE 16
PAGE 17
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.