Instruction/ maintenance manual of the product UCC2891 Texas Instruments
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48-V to 3.3-V Forward Converter with Active Clamp Reset Using the UCC2891 Active Clamp Current Mode PWM Controller User's Guide December 2006 Power Supply MAN SLUU178A.
48-V to 3.3-V Forward Converter with Active Clamp Reset Using the UCC2891 Active Clamp Current Mode PWM Controller User's Guide Literature Number: SLUU178A November 2003 – Revised December 2006.
1 Introduction 2 Description User's Guide SLUU178A – November 2003 – Revised December 2006 Using the UCC2891 Active Clamp Current Mode PWM Controller The UCC2891EVM evaluation module (EVM) is a forward converter providing a 3.3-V regulated output at 30 A of load current, operating from a 48-V input.
www.ti.com 2.1 Applications 2.2 Features Description The UCC2891 is suited for use in isolated telecom 48-V input systems requiring high-efficiency and high-power density for very low-output voltage, .
www.ti.com 3 UCC2891EVM Electrical Performance Specifications 4 Schematic UCC2891EVM Electrical Performance Specifications The UCC2891EVM electrical performance specifications are listed in Table 1 .
www.ti.com + + + + Schematic Figure 1. UCC2891EVM Schematic 6 Using the UCC2891 Active Clamp Current Mode PWM Controller SLUU178A – November 2003 – Revised December 2006 Submit Documentation Feedb.
www.ti.com 5 EVM Test Setup V 2 - + J 1 + V out -V out J 9 J 10 Loo p+ Loo p- J 6 J 7 T exas I ns trum e nts H P A 03 4 U C C 2891 A c ti v e C l am p C onver te r J 3 V -C l am p J 2 Q 2 G ate J 4 SR -Q F G ate J 5 SR -Q R G ate LO A D 1 3.
www.ti.com 5.1 Output Load (LOAD1) 5.2 DC Input Source (VIN) 5.3 Network Analyzer 5.4 Recommended Wire Guage 5.5 Fan EVM Test Setup For the output load to VOUT, a programmable electronic load set to constant current mode and capable of sinking between 0A DC and 30A DC , is used.
www.ti.com 6 Power Up/Down Test Procedures Power Up/Down Test Procedures The following test procedure is recommended primarily for power up and shutting down the EVM. Whenever the EVM is running above an output load of 15 A DC , the fan should be turned on.
www.ti.com 7 Power Up/Down Test Procedures 81 79 87 83 91 89 93 85 2 6 18 26 22 10 14 I OUT - Output Current - A V IN = 36 V V IN = 72 V V IN = 48 V Percent Efficiency - % V OUT = 3.
www.ti.com t − T ime − 2.5 µ s/div V IN = 36 V I OUT = 30 A 500 mV/div 1 V peak-to-peak Input Ripple V oltage 10 -40 -60 100 1 k 10 k 100 k 0 -20 40 20 60 -120 -180 0 -60 120 60 180 V IN = 48 V I OUT = 10 A g M = -10 dB F M = 50° Gain Phase f - Frequency - Hz Gain - dB Phase - ° GAIN A ND PHA SE vs FREQUENCY t − T ime − 2.
www.ti.com t − T ime − 1 µ s/div V IN = 36 V 6.3 V , QF Gate (J5) (5 V/div) 8.4 V , QR Gate (J6) (5 V/div) SR Gate Drive t − T ime − 2.5 µ s/div V IN = 36 V I OUT = 30 A 50 mV/div 23 mV peak-to-peak Output Ripple V oltage t − T ime − 1 µ s/div V IN = 72 V 12.
www.ti.com 8 EVM Assembly Drawing and Layout EVM Assembly Drawing and Layout Figure 14 through Figure 20 show the top-side and bottom-side component placement for the EVM, as well as device pin numbers where necessary.
www.ti.com EVM Assembly Drawing and Layout Figure 15. Top Side Silk Screen Figure 16. Top Signal Trace Layer 14 Using the UCC2891 Active Clamp Current Mode PWM Controller SLUU178A – November 2003 .
www.ti.com EVM Assembly Drawing and Layout Figure 17. Internal Split Ground Plane Figure 18. Internal Signal Trace Layer SLUU178A – November 2003 – Revised December 2006 Using the UCC2891 Active C.
www.ti.com EVM Assembly Drawing and Layout Figure 19. Bottom Signal Trace Layer Figure 20. Bottom Side Component Assembly Using the UCC2891 Active Clamp Current Mode PWM Controller 16 SLUU178A – Nov.
www.ti.com 9 List of Materials List of Materials The following table lists the UCC2891EVM components corresponding to the schematic shown in Figure 1 . Table 2. List of Materials QT REF DESCRIPTION MFR PART NUMBER Y C1, C2, C4 3 Capacitor, ceramic, 2.
www.ti.com 10 References References Table 2. List of Materials (continued) QT REF DESCRIPTION MFR PART NUMBER Y R1 1 Resistor, chip, 8.45 k Ω , 1/10 W, 1%, 805 Vishay CRCW0805-8451-F R2 1 Resistor, chip, 57.6 k Ω , 1/10 W, 1%, 805 Vishay CRCW0805-5762-F R3 1 Resistor, chip, 76.
EVM IMPORT ANT NOTICE T exas Instr ument s (TI) provi des the encl osed product (s) under the f oll owing condi ti ons: This eval uati on kit bei ng sold by TI is i ntended for use for ENGI NEERING DEVELOPMENT OR EV ALUA TION PURPOSES ONL Y and is not considered by TI to be fi t f or commer cial use.
DYNAMIC W ARNINGS AND RESTRICTI ONS It is impor tant to oper ate thi s EVM wit hin t he input voltage r ange of 0 Vdc t o 72 Vdc. Exceeding t he specif ied input r ange may cause unexpected oper ati on and/or i rr eversi ble damage to the EVM.
An important point after buying a device Texas Instruments UCC2891 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Texas Instruments UCC2891 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Texas Instruments UCC2891 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Texas Instruments UCC2891 you will learn all the available features of the product, as well as information on its operation. The information that you get Texas Instruments UCC2891 will certainly help you make a decision on the purchase.
If you already are a holder of Texas Instruments UCC2891, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Texas Instruments UCC2891.
However, one of the most important roles played by the user manual is to help in solving problems with Texas Instruments UCC2891. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Texas Instruments UCC2891 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
