UC2825A-EP

Manufacturer Part NumberUC2825A-EP
DescriptionThe UC2825A-EP pulse width modulation (PWM) controller is an improved version of the standard UC2825
ManufacturerTexas Instruments
UC2825A-EP datasheet
 


Specifications of UC2825A-EP

Frequency(max)(khz)1000Uvlo Thresholds On/off(v)9.6
Pin/package16SOICOperating Temperature Range(c)-40 to 125,-55 to 125
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FEATURES
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Improved Version of the UC2825 PWM
Compatible With Voltage-Mode or
Current-Mode Control Methods
Practical Operation at Switching Frequencies
to 1 MHz
50-ns Propagation Delay to Output
High-Current Dual Totem-Pole Outputs
(2-A Peak)
Trimmed Oscillator Discharge Current
Low 100-mA Startup Current
Pulse-by-Pulse Current-Limiting Comparator
Latched Overcurrent Comparator With Full
Cycle Restart
DESCRIPTION/ORDERING INFORMATION
The UC2825A-EP pulse width modulation (PWM) controller is an improved version of the standard UC2825.
Performance enhancements have been made to several of the circuit blocks. Error amplifier gain bandwidth
product is 12 MHz, while input offset voltage is 2 mV. Current-limit threshold is specified to a tolerance of 5%.
Oscillator discharge current is specified at 10 mA for accurate dead-time control. Frequency accuracy is
improved to 6%. Startup supply current, typically 100 mA, is ideal for off-line applications. The output drivers are
redesigned to actively sink current during undervoltage lockout (UVLO) at no expense to the startup current
specification. In addition, each output is capable of 2-A peak currents during transitions.
Functional improvements also have been implemented in this family. The UC2825A-EP shutdown comparator is
now a high-speed overcurrent comparator with a threshold of 1.2 V. The overcurrent comparator sets a latch that
ensures full discharge of the soft-start capacitor before allowing a restart. While the fault latch is set, the outputs
are in the low state. In the event of continuous faults, the soft-start capacitor is fully charged before discharge to
ensure that the fault frequency does not exceed the designed soft-start period. The UC2825 CLOCK pin is
CLK/LEB in the UC2825A-EP. This pin combines the functions of clock output and leading-edge blanking
adjustment and has been buffered for easier interfacing.
The UC2825A-EP has dual alternating outputs and the same pin configuration as UC2825. UVLO thresholds are
identical to the original UC2825.
Consult the application report, The UC3823A,B and UC2825A,B Enhanced Generation of PWM Controllers,
literature number SLUA125, for detailed technical and applications information.
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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.
HIGH-SPEED PWM CONTROLLER
Check for Samples:
UC2825A-EP
SUPPORTS DEFENSE, AEROSPACE,
AND MEDICAL APPLICATIONS
Controlled Baseline
One Assembly/Test Site
One Fabrication Site
Available in Military (–55°C/125°C)
Temperature Range
Extended Product Life Cycle
Extended Product-Change Notification
Product Traceability
(1) Additional temperature ranges are available - contact factory
UC2825A-EP
SGLS305D – JULY 2005 – REVISED SEPTEMBER 2010
(1)
Copyright © 2005–2010, Texas Instruments Incorporated

UC2825A-EP Summary of contents

  • Page 1

    ... CLK/LEB in the UC2825A-EP. This pin combines the functions of clock output and leading-edge blanking adjustment and has been buffered for easier interfacing. The UC2825A-EP has dual alternating outputs and the same pin configuration as UC2825. UVLO thresholds are identical to the original UC2825. Consult the application report, The UC3823A,B and UC2825A,B Enhanced Generation of PWM Controllers, literature number SLUA125, for detailed technical and applications information ...

  • Page 2

    ... S D PWM LATCH SOFT-ST ART COMPLETE CURRENT 5 V LIMIT S D RESTART R DELAY FAULT LATCH UVLO VREF 5 GOOD REF ON/OFF Product Folder Link(s): UC2825A-EP www.ti.com TOP-SIDE MARKING UC2825AQEP UC2825AMEP OUTA T 14 OUTB 12 PGND 9 A RESTART 250 A DELAY LATCH S R ...

  • Page 3

    ... SGLS305D – JULY 2005 – REVISED SEPTEMBER 2010 PIN ASSIGNMENTS DW PACKAGE (TOP VIEW) INV VREF VCC 2 15 EAOUT OUTB 3 14 CLK/LEB PGND OUTA 6 11 RAMP GND ILIM TERMINAL FUNCTIONS DESCRIPTION Product Folder Link(s): UC2825A-EP UC2825A-EP Submit Documentation Feedback 3 ...

  • Page 4

    ... DERATING FACTOR T = 70°C A ABOVE T = 25°C POWER RATING A 9.62 mW/°C 673 mW Copyright © 2005–2010, Texas Instruments Incorporated Product Folder Link(s): UC2825A-EP www.ti.com UNIT 22 V 0.5 A 2.2 A –0 –0 ±0.2 V PGND –0 +0.3 V – – ...

  • Page 5

    ... EAOUT I = –1 mA EAOUT f = 200 kHz RAMP kΩ 470 pF LEB LEB CLK/LEB RAMP 0-V to 2-V step EAOUT ILIM Product Folder Link(s): UC2825A-EP UC2825A-EP = 3.65 kΩ nF MIN TYP MAX UNIT 5.05 5.1 5. 5.03 5.17 V 0.2 0.4 mV/°C ...

  • Page 6

    ... OUT I = 200 mA OUT OUT I = 200 mA OUT VCC = V (start) – 0 Copyright © 2005–2010, Texas Instruments Incorporated Product Folder Link(s): UC2825A-EP www.ti.com = 3.65 kΩ nF MIN TYP MAX UNIT 4 100 250 ...

  • Page 7

    ... The oscillator of the UC2825A- sawtooth. The rising edge is governed by a current controlled by the RT pin and value of capacitance at the CT pin (C Selection of RT should be done first, based on desired maximum duty cycle. CT then can be chosen, based on the desired frequency (RT) and D MAX ...

  • Page 8

    ... SGLS305D – JULY 2005 – REVISED SEPTEMBER 2010 Leading-Edge Blanking (LEB) The UC2825A-EP performs fixed-frequency PWM control. The UC2825A-EP outputs are alternately controlled. During every other cycle, one output is off. Each output then switches at one-half the oscillator frequency, varying in duty cycle from 0 to less than 50%. ...

  • Page 9

    ... This results in a controlled hiccup interval for continuous fault conditions. 1.2 V FAULT 1 PWM OFF Figure 5. Soft-Start and Fault Waveforms Copyright © 2005–2010, Texas Instruments Incorporated SGLS305D – JULY 2005 – REVISED SEPTEMBER 2010 Product Folder Link(s): UC2825A-EP UC2825A-EP UDG−95106 Submit Documentation Feedback 9 ...

  • Page 10

    ... Current – A 250 Figure 7. Output V and I During UVLO Voltage Mode Oscillator C T UDG−95109 Figure 8. Control Methods Product Folder Link(s): UC2825A-EP www.ti.com 0.8 1.0 UDG−95108 V CC OUT P GND UDG−95106 Oscillator C T 1.25 V Ramp UDG−95110 From E/A Copyright © 2005–2010, Texas Instruments Incorporated ...

  • Page 11

    ... 120 4 1. Figure 10. Two-Unit Interface V SYNC V CT Figure 11. Operational Waveforms Product Folder Link(s): UC2825A-EP UC2825A-EP SGLS305D – JULY 2005 – REVISED SEPTEMBER 2010 UDG−95111 6 Slave 5 UDG−95113 UDG−95112 Submit Documentation Feedback 11 ...

  • Page 12

    ... SGLS305D – JULY 2005 – REVISED SEPTEMBER 2010 High-Current Outputs Each totem-pole output of the UC2825A-EP can deliver a 2-A peak current into a capacitive load. The output can slew a 1000-pF capacitor approximately 20 ns. Separate collector supply (VC) and power ground (PGND) pins help decouple the device analog circuitry from the high-power gate drive noise. The use of 3-A Schottky diodes (1N5120, USD245, or equivalent) (see recommended ...

  • Page 13

    ... Signal Ground Copyright © 2005–2010, Texas Instruments Incorporated Power Stage V CC OUT P GND Power Ground Figure 13. Ground Planes Product Folder Link(s): UC2825A-EP UC2825A-EP SGLS305D – JULY 2005 – REVISED SEPTEMBER 2010 VIN C BULK RTN UDG−95115 Submit Documentation Feedback 13 ...

  • Page 14

    ... Submit Documentation Feedback UC2825A-EP CLK/LEB R T Oscillator C T RAMP EAOUT 68 kW INI Error Amplifier INV ILIM Figure 14. Open-Loop Test Circuit Product Folder Link(s): UC2825A-EP www.ti.com 0 0.1 mF OUTA OUTB 1N5820 (*4) P GND GND 5 REF Copyright © 2005–2010, Texas Instruments Incorporated ...

  • Page 15

    ... Package Type Package Status UC2825AMDWREP ACTIVE SOIC UC2825AMDWREPG4 ACTIVE SOIC UC2825AQDWREP ACTIVE SOIC UC2825AQDWREPG4 ACTIVE SOIC V62/05616-01XE ACTIVE SOIC V62/05616-02XE ACTIVE SOIC (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. ...

  • Page 16

    ... In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold Customer on an annual basis. OTHER QUALIFIED VERSIONS OF UC2825A-EP : Catalog: UC2825A • • Automotive: UC2825A-Q1 NOTE: Qualified Version Definitions: Catalog - TI's standard catalog product • ...

  • Page 17

    ... TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Type Drawing UC2825AMDWREP SOIC DW PACKAGE MATERIALS INFORMATION Pins SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 16 2000 330.0 16.4 10.85 Pack Materials-Page 1 30-Aug-2010 Pin1 (mm) (mm) (mm) (mm) Quadrant 10.8 2.7 12.0 16.0 Q1 ...

  • Page 18

    ... Device Package Type UC2825AMDWREP SOIC PACKAGE MATERIALS INFORMATION Package Drawing Pins SPQ Length (mm 2000 Pack Materials-Page 2 30-Aug-2010 Width (mm) Height (mm) 346.0 346.0 33.0 ...

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    ... Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, 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 orders and should verify that such information is current and complete. All products are sold subject to TI’ ...