Texas Instruments TPS40090EVM-002 manuale d’uso

User ’s Guide 1    User ’ s G uide[...]

2 EVM IMPORT ANT NOTICE T exas Instruments (TI) provides the enclosed product(s) under the following conditions: This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EV ALUA TION PURPOSES ONL Y and is not considered by TI to be fit for commercial use. As such, the goods being provided may not be complete in terms [...]

3 DYNAMIC W ARNINGS AND RESTRICTIONS It is important to operate this EVM within the input voltage range of 0 Vdc to100 Vdc. Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM. If there are questions concerning the input range, please contact a TI field representative prior to connecting the inpu[...]

SLUU195 − June 2004 4 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A TPS40090 Multi-Phase Buck Converter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A Systems Powe r Contents 1 Introduction 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .[...]

SLUU195 − June 2004 5 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A 2 Features T able 1. TPS40090EVM−002 Performance Summary P ARAMETER TEST CONDITIONS MIN TYP MAX UNITS Input voltage range 10.5 12.0 14.0 V Output voltage set point 1.477 1.508 1.540 V Output current range V IN = 12 V 0 100 120 A[...]

SLUU195 − June 2004 6 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A TRANS_EN Figure 2. TPS40090EVM−002 Schematic Part 2 − Driver Circuit and Load T ransient Generator[...]

SLUU195 − June 2004 7 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A + + + 1.5V/100A + + + + + Figure 3. TPS40090EVM−002 Schematic Part 3 − Power Stage 4 Component Selection 4.1 Frequency of Operation The clock oscillator frequency for the TPS40090 is programmed with a single resistor from RT ([...]

SLUU195 − June 2004 8 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A 4.2 Inductance V alue The output inductor value for each phase can be calculated from the volt-second during off time, shown in equation (2). L + V OUT f I RIPPLE ǒ 1 * V OUT V IN(max) Ǔ where • I RIPPLE is usually chosen to [...]

SLUU195 − June 2004 9 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A 0 0.1 0.2 0.5 0.6 0.4 0.3 0 1 0 2 03 04 05 0 6 07 08 09 01 0 0 Duty Cycle − % I RMS_CIN(nom) − Normalized RMS Input − A N PH = 1 N PH = 2 N PH = 3 N PH = 4 N PH = 6 Figure 4. Input Ripple Current RMS V alue Overload Current [...]

SLUU195 − June 2004 10 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A where • D is the duty cycle for a single phase • N PH is the number of active phases • K (N PH ) is the intermediate function for calculation In this case, N PH =4 and D min =0.107 which yields k=0.573. The actual output r[...]

SLUU195 − June 2004 11 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A 3. T ransient consideration. An additional consideration in the selection of the output inductor and capacitance value can be derived from examining the transient voltage overshoot which can be initiated with a load step from ful[...]

SLUU195 − June 2004 12 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A With the chosen inductor described in Inductance V alue , (section 4.2, of this document) the following values are used. • R=19.6 k Ω • C=10 nF • R NTC =100 k Ω • R1=124 k Ω • R2=22.6 k Ω UDG−03136 R L DCR C [...]

SLUU195 − June 2004 13 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A 4.8 Compensation Components The TPS40090 uses peak current mode control. T ype II network is used here, which is implemented to provide one zero and two poles. The first pole is placed at the origin to improve DC regulation. The [...]

SLUU195 − June 2004 14 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A 5 T est Setup The HP A072 has the following input/output connections: 12-V input J1 (VIN) and J2 (GND), 1.5-V output J9 (VOUT) and J10 (GND). A diagram showing the connection points is shown in Figure 5. A power supply capable o[...]

SLUU195 − June 2004 15 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A 6 T est Results and Performance Data 6.1 Efficiency and Power Loss Figure 8 shows the efficiency as the load varies from 10 A to over 100 A. The ef ficiency at full load is about 84.3%. Figure 7 shows the total loss versus the lo[...]

SLUU195 − June 2004 16 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A 6.2 Closed-Loop Performance The TPS40090 uses peak current-mode control. Figure 10 shows the bode plots at 100 A of load current, where no droop function is implemented. The crossover frequency is at 89 kHz with phase margin of [...]

SLUU195 − June 2004 17 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A 6.4 T ransient Response The on-board load transient circuit enables to check the step load transient response on the same board. Simply by putting a jumper to connect Pin1 and 2 of J3, a 90-A step load is created by three 50-m ?[...]

SLUU195 − June 2004 18 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A 6.5 Start up with Pre-Biased Output In synchronous buck converter , the bottom FET discharges the pre-biased output during start-up. T o avoid this, a comparator U9 and surround components are used to pull the SYNC pin of the dr[...]

SLUU195 − June 2004 19 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A 7 Layout Considerations The PCB layout plays a critical role in the performance in a high frequency switching power supply design. Following the suggestions listed below will help to improve the performance and expedite the desig[...]

SLUU195 − June 2004 20 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A 8 EVM Assembly Drawing and PCB Layout Figure 15. T op Side Component Assembly Figure 16. Bottom Assembly[...]

SLUU195 − June 2004 21 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A Figure 17. T op Side Copper Figure 18. Internal 1 (Ground Plane)[...]

SLUU195 − June 2004 22 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A Figure 19. Internal 2 (Power Plane) Figure 20. Internal 3[...]

SLUU195 − June 2004 23 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A Figure 21. Internal 4 Figure 22. Bottom Layer Copper[...]

SLUU195 − June 2004 24 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Dr ivers Steps-Down from 12-V to 1.5-V at 100 A 9 List of Materials The following table lists the TPS40090EVM−002 components corresponding to the schematic shown in Figure 1. T able 2. List of Materials Reference Designator QTY Description Size Manufacturer Part Number C1, [...]

SLUU195 − June 2004 25 TPS40090 Multi-Phase Buck Conv erter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A Reference Designator QTY Description Size Manufacturer Part Number R27, R28, R29, R30 4 Resistor , chip, 2.2 Ω , 1/10−W , 1% 805 Std Std R31, R32,R35, R36 4 Resistor , chip, 19.6 k Ω , 1/10−W , 1% 805 Std Std R33, R34, R3[...]

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