application INFO available UC1825 UC2825 UC3825 High Speed PWM Controller FEATURES • • • • • • • • • • DESCRIPTION Compatible with Voltage or Current Mode Topologies The UC1825 family of PWM control ICs is optimized for high frequency switched mode power supply applications. Particular care was given to minimizing propagation delays through the comparators Practical Operation Switching Frequencies and logic circuitry while maximizing bandwidth and slew rate of the to 1MHz error amplifier. This controller is designed for use in either cur50ns Propagation Delay to Output rent-mode or voltage mode systems with the capability for input voltage feed-forward. High Current Dual Totem Pole Outputs (1.5A Peak) Protection circuitry includes a current limit comparator with a 1V threshold, a TTL compatible shutdown port, and a soft start pin Wide Bandwidth Error Amplifier which will double as a maximum duty cycle clamp. The logic is fully Fully Latched Logic with Double Pulse latched to provide jitter free operation and prohibit multiple pulses at Suppression an output. An under-voltage lockout section with 800mV of hysteresis assures low start up current. During under-voltage lockout, the outPulse-by-Pulse Current Limiting puts are high impedance. Soft Start / Max. Duty Cycle Control These devices feature totem pole outputs designed to source and sink high peak currents from capacitive loads, such as the gate of a Under-Voltage Lockout with Hysteresis power MOSFET. The on state is designed as a high level. Low Start Up Current (1.1mA) BLOCK DIAGRAM UDG-92030-2 SLUS235A - MARCH 1997 - REVISED MARCH 2004 UC1825 UC2825 UC3825 CONNECTION DIAGRAMS ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage (Pins 13, 15) . . . . . . . . . . . . . . . . . . . . . . . . 30V Output Current, Source or Sink (Pins 11, 14) DC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5A Pulse (0.5 s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0A Analog Inputs (Pins 1, 2, 7). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V (Pin 8, 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V Clock Output Current (Pin 4) . . . . . . . . . . . . . . . . . . . . . . . -5mA Error Amplifier Output Current (Pin 3) . . . . . . . . . . . . . . . . 5mA Soft Start Sink Current (Pin 8) . . . . . . . . . . . . . . . . . . . . . 20mA Oscillator Charging Current (Pin 5) . . . . . . . . . . . . . . . . . . -5mA Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1W Storage Temperature Range . . . . . . . . . . . . . . -65°C to +150°C Lead Temperature (Soldering, 10 seconds) . . . . . . . . . . 300°C DIL-16 (Top View) J or N Package PLCC-20 & LCC-20 (Top View) Q & L Packages SOIC-16 (Top View) DW Package PACKAGE PIN FUNCTION FUNCTION PIN N/C INV NI E/A Out Clock N/C RT CT Ramp Soft Start N/C ILIM/SD Gnd Out A Pwr Gnd N/C VC Out B VCC VREF 5.1V THERMAL RATINGS TABLE Package DIL-16J DIL-16N PLCC-20 LCC-20 SOIC-16 QJA 80-120 90(1) 43-75(1) 70-80 50-120(1) QJC 28(2) 45 34 20(2) 35 Q Q 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 UC1825 UC2825 UC3825 ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for , RT = 3.65k, CT = 1nF, VCC = 15V, -55°C<TA<125°C for the UC1825, –40°C<TA<85°C for the UC2825, and 0°C<TA<70°C for the UC3825, TA=TO. PARAMETERS Reference Section Output Voltage Line Regulation Load Regulation Temperature Stability* Total Output Variation* Output Noise Voltage* Long Term Stability* Short Circuit Current Oscillator Section Initial Accuracy* Voltage Stability* Temperature Stability* Total Variation* Oscillator Section (cont.) Clock Out High Clock Out Low Ramp Peak* Ramp Valley* Ramp Valley to Peak* Error Amplifier Section Input Offset Voltage Input Bias Current Input Offset Current Open Loop Gain CMRR PSRR Output Sink Current Output Source Current Output High Voltage Output Low Voltage Unity Gain Bandwidth* Slew Rate* UC1825 UC2825 MIN TOP MAX MIN TOP MAX UNITS TO = 25°C, IO = 1mA 10V < VCC < 30V 1mA < IO < 10mA TMIN < TA < TMAX Line, Load, Temperature 10Hz < f < 10kHz TJ = 125°C, 1000hrs. VREF = 0V 5.05 5.00 5.10 2 5 0.2 5.20 20 20 0.4 5.25 TJ = 2°C 10V < VCC < 30V TMIN < TA < TMAX Line, Temperature 360 TEST CONDITIONS 5.10 2 5 0.2 5.00 -15 50 5 -50 400 0.2 5 340 3.9 1V < VO < 4V 1.5V < VCM < 5.5V 10V < VCC < 30V VPIN 3 = 1V VPIN 3 = 4V IPIN 3 = -0.5mA IPIN 3 = 1mA 3 2.6 0.7 1.6 4.5 2.3 2.8 1.0 1.8 60 75 85 1 -0.5 4.0 0 3 6 0.6 0.1 95 95 110 2.5 -1.3 4.7 0 .5 5.5 12 5.15 20 20 0.4 5.20 25 -100 UC3825 4.95 -15 440 2 360 460 340 3.9 2.9 3.0 1.25 2.0 400 0.2 5 2.6 0.7 1.6 4.5 2.3 2.8 1.0 1.8 60 75 85 1 -0.5 4.0 0 3 6 0.6 0.1 95 95 110 2.5 -1.3 4.7 0.5 5.5 12 10 3 1 5.0 1.0 50 5 -50 25 -100 440 2 V mV mV mV/°C V µV mV mA 460 kHz % % kHz 2.9 3.0 1.25 2.0 V V V V V 15 3 1 5.0 1.0 mV µA µA dB dB dB mA mA V V MHz V/µs UC1825 UC2825 UC3825 ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for , RT = 3.65k, CT = 1nF, VCC = 15V, -55°C<TA<125°C for the UC1825, –40°C<TA<85°C for the UC2825, and 0°C<TA<70°C for the UC3825, TA=TJ. PARAMETERS UC1825 UC2825 MIN TOP MAX TEST CONDITIONS PWM Comparator Section Pin 7 Bias Current VPIN 7 = 0V Duty Cycle Range Pin 3 Zero DC Threshold VPIN 7 = 0V Delay to Output* Soft-Start Section Charge Current VPIN 8 = 0.5V Discharge Current VPIN 8 = 1V Current Limit / Shutdown Section Pin 9 Bias Current 0 < VPIN 9 < 4V Current Limit Threshold Shutdown Threshold Delay to Output Output Section Output Low Level IOUT = 20mA IOUT = 200mA Output High Level IOUT = -20mA IOUT = -200mA Collector Leakage VC = 30V Rise/Fall Time* CL = 1nF Under-Voltage Lockout Section Start Threshold UVLO Hysteresis Supply Current Section Start Up Current VCC = 8V ICC VPIN 1, VPIN 7, VPIN 9 = 0V; VPIN 2 = 1V 4 -1 0 1.1 -5 80 1.25 50 80 3 1 9 20 0.9 1.25 1.0 1.40 50 15 1.1 1.55 80 13.0 12.0 8.8 0.4 0.25 1.2 13.5 13.0 100 30 0.40 2.2 9.2 0.8 9.6 1.2 1.1 22 2.5 33 UC3825 MIN TOP -1 0 1.1 MAX UNITS -5 85 µA % V ns 1.25 50 80 3 1 9 20 µA mA 0.9 1.25 1.0 1.40 50 10 1.1 1.55 80 µA V V ns 0.25 1.2 13.5 13.0 10 30 0.40 2.2 500 60 V V V V µA ns 9.2 0.8 9.6 1.2 V V 1.1 22 2.5 33 mA mA 13.0 12.0 500 60 8.8 0.4 UC1825 UC2825 UC3825 Printed Circuit Board Layout Considerations High speed circuits demand careful attention to layout and component placement. To assure proper performance of the UC1825 follow these rules: 1) Use a ground plane. 2) Damp or clamp parasitic inductive kick energy from the gate of driven MOSFETs. Do not allow the output pins to ring below ground. A series gate resistor or a shunt 1 Amp Schottky diode at the output pin will serve this purpose. 3) Bypass VCC, VC, and VREF. Use 0.1µF monolithic ceramic capacitors with low equivalent series inductance. Allow less than 1 cm of total lead length for each capacitor between the bypassed pin and the ground plane. 4) Treat the timing capacitor, CT, like a bypass capacitor. Error Amplifier Circuit Simplified Schematic Open Loop Frequency Response Unity Gain Slew Rate PWM Applications Current-Mode Conventional (Voltage Mode) 5 UC1825 UC2825 UC3825 Oscillator Circuit µ Deadtime vs CT (3k RT 100k) Deadtime vs Frequency Timing Resistance vs Frequency 160 1.0nF TD (ns) 140 120 100 470pF 80 10k 100k FREQ (Hz) Synchronized Operation Two Units in Close Proximity Generalized Synchronization 6 1M UC1825 UC2825 UC3825 Forward Technique for Off-Line Voltage Mode Application Constant Volt-Second Clamp Circuit The circuit shown here will achieve a constant volt-second product clamp over varying input voltages. The ramp generator components, RT and CR are chosen so that the ramp at Pin 9 crosses the 1V threshold at the same time the desired maximum volt-second product is reached. The delay through the functional nor block must be such that the ramp capacitor can be completely discharged during the minimum deadtime. Output Section Simplified Schematic Rise/Fall Time (CL=1nF) Saturation Curves Rise/Fall Time (CL=10nF) 7 UC1825 UC2825 UC3825 Open Loop Laboratory Test Fixture UDG-92032-2 This test fixture is useful for exercising many of the As with any wideband circuit, careful grounding and byUC1825’s functions and measuring their specifications. pass procedures should be followed. The use of a ground plane is highly recommended. Design Example: 50W, 48V to 5V DC to DC Converter - 1.5MHz Clock Frequency UDG-92033-3 8 PACKAGE OPTION ADDENDUM www.ti.com 23-Nov-2005 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty Lead/Ball Finish MSL Peak Temp (3) 5962-87681012A ACTIVE LCCC FK 20 1 TBD 5962-8768101EA ACTIVE CDIP J 16 1 TBD POST-PLATE Level-NC-NC-NC A42 SNPB Level-NC-NC-NC 5962-8768101QFA ACTIVE CFP W 16 1 TBD A42 SNPB Level-NC-NC-NC 5962-8768101V2A ACTIVE LCCC FK 20 1 TBD Call TI Level-NC-NC-NC 5962-8768101VEA ACTIVE CDIP J 16 1 TBD Call TI Level-NC-NC-NC UC1825J ACTIVE CDIP J 16 1 TBD A42 SNPB Level-NC-NC-NC UC1825J883B ACTIVE CDIP J 16 1 TBD A42 SNPB Level-NC-NC-NC UC1825JQMLV ACTIVE CDIP J 16 TBD Call TI Call TI UC1825L ACTIVE LCCC FK 20 1 TBD POST-PLATE Level-NC-NC-NC UC1825L883B ACTIVE LCCC FK 20 1 TBD POST-PLATE Level-NC-NC-NC UC1825LQMLV ACTIVE LCCC FK 20 UC1825W883B ACTIVE CFP W 16 1 TBD A42 SNPB UC2825DW ACTIVE SOIC DW 16 40 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR UC2825DW/1 PREVIEW SOIC DW 16 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR UC2825DWTR ACTIVE SOIC DW 16 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR UC2825DWTRG4 ACTIVE SOIC DW 16 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR UC2825J ACTIVE CDIP J 16 1 TBD A42 SNPB Level-NC-NC-NC UC2825N ACTIVE PDIP N 16 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-NC-NC-NC UC2825NG4 ACTIVE PDIP N 16 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-NA-NA-NA UC2825Q ACTIVE PLCC FN 20 46 Green (RoHS & no Sb/Br) CU SN Level-2-260C-1 YEAR UC2825QTR ACTIVE PLCC FN 20 1000 Green (RoHS & no Sb/Br) CU SN Level-2-260C-1 YEAR UC3825DW ACTIVE SOIC DW 16 40 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR UC3825DWG4 ACTIVE SOIC DW 16 40 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR UC3825DWTR ACTIVE SOIC DW 16 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR UC3825DWTRG4 ACTIVE SOIC DW 16 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TBD Call TI Call TI Level-NC-NC-NC UC3825J ACTIVE CDIP J 16 1 TBD A42 SNPB Level-NC-NC-NC UC3825N ACTIVE PDIP N 16 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-NC-NC-NC UC3825NG4 ACTIVE PDIP N 16 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-NC-NC-NC UC3825Q ACTIVE PLCC FN 20 46 Green (RoHS & no Sb/Br) CU SN Level-2-260C-1 YEAR UC3825QTR ACTIVE PLCC FN 20 1000 Green (RoHS & no Sb/Br) CU SN Level-2-260C-1 YEAR Addendum-Page 1 PACKAGE OPTION ADDENDUM www.ti.com 23-Nov-2005 (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. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. 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. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. 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 by TI to Customer on an annual basis. Addendum-Page 2 MECHANICAL DATA MLCC006B – OCTOBER 1996 FK (S-CQCC-N**) LEADLESS CERAMIC CHIP CARRIER 28 TERMINAL SHOWN 18 17 16 15 14 13 NO. OF TERMINALS ** 12 19 11 20 10 A B MIN MAX MIN MAX 20 0.342 (8,69) 0.358 (9,09) 0.307 (7,80) 0.358 (9,09) 28 0.442 (11,23) 0.458 (11,63) 0.406 (10,31) 0.458 (11,63) 21 9 22 8 44 0.640 (16,26) 0.660 (16,76) 0.495 (12,58) 0.560 (14,22) 23 7 52 0.739 (18,78) 0.761 (19,32) 0.495 (12,58) 0.560 (14,22) 24 6 68 0.938 (23,83) 0.962 (24,43) 0.850 (21,6) 0.858 (21,8) 84 1.141 (28,99) 1.165 (29,59) 1.047 (26,6) 1.063 (27,0) B SQ A SQ 25 5 26 27 28 1 2 3 4 0.080 (2,03) 0.064 (1,63) 0.020 (0,51) 0.010 (0,25) 0.020 (0,51) 0.010 (0,25) 0.055 (1,40) 0.045 (1,14) 0.045 (1,14) 0.035 (0,89) 0.045 (1,14) 0.035 (0,89) 0.028 (0,71) 0.022 (0,54) 0.050 (1,27) 4040140 / D 10/96 NOTES: A. B. C. D. E. All linear dimensions are in inches (millimeters). This drawing is subject to change without notice. This package can be hermetically sealed with a metal lid. The terminals are gold plated. Falls within JEDEC MS-004 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 MECHANICAL DATA MPLC004A – OCTOBER 1994 FN (S-PQCC-J**) PLASTIC J-LEADED CHIP CARRIER 20 PIN SHOWN Seating Plane 0.004 (0,10) 0.180 (4,57) MAX 0.120 (3,05) 0.090 (2,29) D D1 0.020 (0,51) MIN 3 1 19 0.032 (0,81) 0.026 (0,66) 4 E 18 D2 / E2 E1 D2 / E2 8 14 0.021 (0,53) 0.013 (0,33) 0.007 (0,18) M 0.050 (1,27) 9 13 0.008 (0,20) NOM D/E D2 / E2 D1 / E1 NO. OF PINS ** MIN MAX MIN MAX MIN MAX 20 0.385 (9,78) 0.395 (10,03) 0.350 (8,89) 0.356 (9,04) 0.141 (3,58) 0.169 (4,29) 28 0.485 (12,32) 0.495 (12,57) 0.450 (11,43) 0.456 (11,58) 0.191 (4,85) 0.219 (5,56) 44 0.685 (17,40) 0.695 (17,65) 0.650 (16,51) 0.656 (16,66) 0.291 (7,39) 0.319 (8,10) 52 0.785 (19,94) 0.795 (20,19) 0.750 (19,05) 0.756 (19,20) 0.341 (8,66) 0.369 (9,37) 68 0.985 (25,02) 0.995 (25,27) 0.950 (24,13) 0.958 (24,33) 0.441 (11,20) 0.469 (11,91) 84 1.185 (30,10) 1.195 (30,35) 1.150 (29,21) 1.158 (29,41) 0.541 (13,74) 0.569 (14,45) 4040005 / B 03/95 NOTES: A. All linear dimensions are in inches (millimeters). B. This drawing is subject to change without notice. C. Falls within JEDEC MS-018 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 IMPORTANT NOTICE 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’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Amplifiers amplifier.ti.com Audio www.ti.com/audio Data Converters dataconverter.ti.com Automotive www.ti.com/automotive DSP dsp.ti.com Broadband www.ti.com/broadband Interface interface.ti.com Digital Control www.ti.com/digitalcontrol Logic logic.ti.com Military www.ti.com/military Power Mgmt power.ti.com Optical Networking www.ti.com/opticalnetwork Microcontrollers microcontroller.ti.com Security www.ti.com/security Telephony www.ti.com/telephony Video & Imaging www.ti.com/video Wireless www.ti.com/wireless Mailing Address: Texas Instruments Post Office Box 655303 Dallas, Texas 75265 Copyright 2005, Texas Instruments Incorporated