TEXAS INSTRUMENTS UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ Technical data
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ
CURRENT-MODE PWM CONTROLLER
SGLS164 – APRIL 2003
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 8-PIN PACKAGE
COMP
V
FB
I
SENSE
RT/C
T
(TOP VIEW)
1
2
3
4
8
7
6
5
V
REF
V
CC
OUTPUT
GND
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
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
5 V.
Error Amp
O
D 14-PIN PACKAGE
(TOP VIEW)
COMP
I
SENSE
R
NC
V
FB
NC
NC
T/CT
1
2
3
4
5
6
7
14
13
12
11
10
9
8
V
REF
NC
V
CC
V
C
OUTPUT
GND
PWR GND
CC
over
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%
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 Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Copyright 2003, Texas Instruments Incorporated
1
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ
CURRENT-MODE PWM CONTROLLER
SGLS164 – APRIL 2003
block diagram
ORDERING INFORMATION
T
A
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
°
–40°C to 125°C
†
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines
are available at www.ti.com/sc/package.
SOIC-14 – D Tube UC2843AQD 2843AQ
°
SOIC-8 – D8 Tape and reel UC2844AQD8R 2844AQ
SOIC-8 – D8 Tube UC2844AQD8 2844AQ
SOIC-14 – D Tape and reel UC2844AQDR 2844AQ
SOIC-14 – D Tube UC2844AQD 2844AQ
SOIC-8 – D8 Tape and reel UC2845AQD8R 2845AQ
SOIC-8 – D8 Tube UC2845AQD8 2845AQ
SOIC-14 – D Tape and reel UC2845AQDR 2845AQ
SOIC-14 – D Tube UC2845AQD 2845AQ
PACKAGE
‡
ORDERABLE
PART NUMBER
†
TOP-SIDE
MARKING
NOTES: 1. A = DIL-8 Pin Number. B = SO-14 Pin Number.
2
2. Toggle flip flop used only in 2844A and 2845A.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Ordering Information
284
UC
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ
CURRENT-MODE PWM CONTROLLER
SGLS164 – APRIL 2003
4
Q
D
A
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
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ
CURRENT-MODE PWM CONTROLLER
SGLS164 – APRIL 2003
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
voltage (low impedance source) 30 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V
CC
V
voltage (ICC mA) self limiting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
Output current, I
±1 A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
O
†‡
Output energy (capacitive load) 5 µJ. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Inputs (pins 3, 5) –0.3 V to 6.3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Error Amp Output Sink current 10 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Dissipation at T
Package thermal impedance, θ
Storage temperature range, T
< +25_C (D package) 1 W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A
(see Note 1): D (8-pin) package 97°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . .
JA
stg
–65_C to 150_C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature soldering 1,6 mm (1/16 inch) from case for 10 seconds 260_C. . . . . . . . . . . . . . . . . . . . . . .
†
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.
‡
Unless otherwise indicated, voltages are reference to ground and currents are positive into and negative out of the specified terminals.
NOTE 1: 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 on enhanced plastic packaging.
electrical characteristics, TA = –40_C to 125_C, VCC = 15 V (see Note 1), RT = 10 kΩ, CT = 3.3 nF, and
T
= TJ (unless otherwise stated)
A
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Reference Section
Output voltage
Line regulation voltage VIN = 12 V to 25 V 6 20 mV
Load regulation voltage IO = 1 mA to 20 mA 6 25 mV
T emperature stability See Notes 2 and 3 0.2 0.4
Total output variation voltage Line, Load, Temp. 4.9 5.1 V
Output noise voltage
Long term stability 1000 hours, See Note 2
Output short-circuit current –30 –100 –180 mA
Oscillator Section
Initial accuracy See Note 4
Voltage stability VCC = 12 V to 25 V 0.2 1 %
T emperature stability TA = MIN to MAX, See Note 2 5 %
Amplitude peak-to-peak V pin 7, See Note 2 1.7 V
Discharge current V pin 7 = 2 V, See Note 5
TJ = 25_C, IO = 1 mA
f = 10 Hz to 10 kHz,
See Note 2
TJ = 25_C
TA = 125_C
TJ = 25_C
TJ = 25_C
TJ = Full range 7.5 8.8
4.95 5.0 5.05 V
mV/_C
50
5 25 mV
47 52 57 kHz
7.8 8.3 8.8
µV
mA
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
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
T
= TJ (unless otherwise stated)
A
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Error Amplifier Section
Input voltage COMP = 2.5 V 2.45 2.5 2.55 V
Input bias current –0.3 –1
Open loop voltage gain (A
Unity gain bandwidth See Note 2
PSRR VCC = 12 V to 25 V 60 70 dB
Output sink current FB = 2.7 V, COMP = 1.1 V 2 6 mA
Output source current FB = 2.3 V, COMP = 5 V –0.5 –0.8 mA
V
high
OUT
V
low
OUT
Current Sense Section
Gain See Notes 6 and 7 2.85 3 3.15 V/V
Maximum input signal COMP = 5 V, See Note 6 0.9 1 1.1 V
PSRR VCC = 12 V to 25 V,See Note 6 70 dB
Input bias current –2 –10
Delay to output I
Output Section (OUT)
Low-level output voltage
High-level output voltage
Rise time CL = 1 nF, See Note 2
Fall time CL = 1 nF, See Note 2
UVLO saturation VCC = 5 V, I
Undervoltage Lockout Section
Start threshold
Minimum operation voltage after turn on
VOL)
VO = 2 V to 4 V 65 90 dB
TJ = 25_C
FB = 2.3 V, RL = 15 kΩ to GND
FB = 2.7 V, RL = 15 kΩ to V
= 0 V to 2 V, See Note 2 150 300 ns
SENSE
I
= 20 mA 0.1 0.4
OUT
I
= 200 mA 15 2.2
OUT
I
= –20 mA 13 13.5
OUT
I
= –200 mA 12 13.5
OUT
= 10 mA 0.7 1.2 V
OUT
REF
TJ = 25_C
TJ = 25_C
UC2842A,
UC2844A
UC2843A,
UC2845A
UC2842A,
UC2844A
UC2843A,
UC2845A
0.7 1 MHz
5 6 V
0.7 1.1 V
50 150 ns
50 150 ns
15 16 17
7.8 8.4 9
9 10 11
7 7.6 8.2
µA
µA
V
V
V
V
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
5
Loading...