Document
UCC25705-Q1, UCC25706-Q1
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HIGH-SPEED VOLTAGE MODE PULSE WIDTH MODULATOR
Check for Samples: UCC25705-Q1, UCC25706-Q1
SLUSAI1 – MAY 2011
FEATURES
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• Qualified for Automotive Applications • Greater Than 4-MHz Operation • Integrated Oscillator / Voltage Feed Forward
Compensation • >4:1 Input Voltage Range • 25-ns Current Limit Delay • Programmable Maximum Duty Cycle Clamp • Optocoupler Interface • 50-µA Start-Up Current • 4.2-mA Operating Current at 1 MHz • Latch-Up Exceeds 100mA per JESD78 Class I
• Smallest Footprint of the 8-pin MSOP Package Minimizes Board Area and Height
D PACKAGE (TOP VIEW)
ILIM FB
VFF DISCH
1 2 3 4
8 VDD 7 OUT 6 GND 5 RC
DESCRIPTION
The UCC25705-Q1 and UCC25706-Q1 devices are 8-pin voltage mode primary side controllers with fast over-current protection. These devices are used as core high-speed building blocks in high performance isolated and non-isolated power converters.
UCC25705-Q1/UCC25706-Q1 devices feature a high speed oscillator with integrated feed-forward compensation for improved converter performance. A typical current sense to output delay time of 25 ns provides fast response to overload conditions. The IC also provides an accurate programmable maximum duty cycle clamp for increased protection which can also be disabled for the oscillator to run at maximum possible duty cycle.
Two UVLO options are offered. The UCC25705-Q1 with lower turn-on voltage is intended for dc-to-dc converters while the higher turn-on voltage and the wider UVLO range of the UCC25706-Q1 is better suited for offline applications.
The UCC2570x-Q1 family is offered in an 8-pin SOIC (D) package.
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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.
Copyright © 2011, Texas Instruments Incorporated
UCC25705-Q1, UCC25706-Q1
SLUSAI1 – MAY 2011
Figure 1. TYPICAL APPLICATION SCHEMATIC
++ VOUT
V -IN --
VDD 8 4 DISCH
FB 2
5 RC 3 VFF
OUT 7
6 GND ILIM 1
MODE =1
UCC2570x-Q1
TPS2829 FET DRIVER
SOFT START CIRCUIT
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ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature (unless otherwise noted)(1)(2)
Supply voltage Input voltage (VFF,RC,ILIM) Input voltage (FB) Input current (DISCH) Output current (OUT) dc Storage temperature, Tstg Junction temperature, TJ Lead temperature (soldering, 10 sec)
VALUE 15 7 15 1 ±20
–65 to 150 –55 to 150
300
UNIT V V V mA mA °C °C °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 “recommende.