! User’s Guide May 2002 PMP Systems Power SLVU071
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.
EVM IMPORTANT NOTICE Texas 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 EVALUATION PURPOSES ONLY and is not considered by TI to be fit for commercial use.
EVM WARNINGS AND RESTRICTIONS It is important to operate this EVM within the specified input and output ranges described in the EVM User’s Guide. 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 input power.
Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Performance Specification Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 Modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents 1−1 2−1 2−2 2−3 2−4 2−5 2−6 2−7 2−8 2−9 2−10 2−11 2−12 2−13 2−14 2−15 2−16 2−17 2−18 2−19 2−20 2−21 2−22 2−23 3−1 3−2 3−3 3−4 3−5 4−1 vi Frequency Trimming Resistor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 Connection Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 Measured Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents 1−1 1−2 1−3 1−4 1−5 4−1 Input Voltage and Output Current Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TPS54610EVM-213 Performance Specification Summary . . . . . . . . . . . . . . . . . . . . . . . . . . TPS54810EVM-213 Performance Specification Summary . . . . . . . . . . . . . . . . . . . . . . . . . . TPS54910EVM-213 Performance Specification Summary . . . . . . . . . . . . . . . . . . . . . . . . . . Output Voltage Programming . . . . . . . . . . .
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Chapter 1 This chapter contains background information for the TPS54610, TPS54810, and TPS54910 as well as support documentation for the TPS54610EVM-213, TPS54810EVM-213, and TPS54910EVM-213 evaluation modules. Performance specifications for the EVMs are given, as well as modification information. Topic Page 1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 1.2 Performance Specification Summary . . . . . . . . . . . . .
Background 1.1 Background The SLVP213 evaluation modules use the TPS54610, TPS54810, or TPS54910 synchronous buck regulators to provide an output voltage of 1.8 V from a nominal 3.3-V or 5-V input. Rated input voltage range and output current range are listed in Table 1−1. These evaluation modules are designed to demonstrate the small PCB areas that can be achieved when designing with the TPS54x10 family of regulators.
Performance Specification Summary 1.2 Performance Specification Summary A summary of the SLVP213 performance specifications is listed in Table 1−2, Table 1−3, and Table 1−4. All specifications are for an ambient temperature of 25°C, unless otherwise noted. Table 1−2. TPS54610EVM-213 Performance Specification Summary Specification Test Conditions Input voltage range Output voltage set point Output current range VIN = 5 V Line regulation IO = 0 A to 6 A Load regulation VIN = 5 V Min Typ Max 3 3.
Performance Specification Summary Table 1−3. TPS54810EVM-213 Performance Specification Summary Specification Test Conditions Input voltage range Output voltage set point Min Typ Max Units 4 5 6 V 0.9 1.8 3.3 V 0 8 A Output current range VIN = 5 V Line regulation IO = 0 A to 8 A −0.4 0.4 mV Load regulation VIN = 5 V −1.5 1.
Modifications 1.3 Modifications The SLVP213 is designed to demonstrate the small size that can be attained when designing with the TPS54x10, so many of the features which allow for extensive modifications have been omitted from this EVM. The output voltage can be changed in the range of 0.9 V to 3.3 V (2.5 V for the TPS54910) by changing the value of R4. The value of R4 for a specific output voltage can be calculated by using the following equation.
Modifications Modifying the value of C6 can change the slow start time of the SLVP213. Use the following equation to calculate the required value of C6 for a specific slow start time. With C6 left open, the slow start time is typically 3.6 ms. The slow start time cannot be made faster than 3.6 ms. T 5 mA R6 + SS 0.
Chapter 2 This chapter describes how to properly connect, set up, and use the SLVP213 evaluation module. The chapter also includes test results typical for the SLVP213 and covers efficiency, output voltage regulation, load transients, loop response, output ripple, input ripple, and start-up. Topic Page 2.1 Input/Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 2.2 Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input/Output Connections 2.1 Input/Output Connections The SLVP213 has the following four input/output connections: input, input return, output, and output return. A diagram showing the connection points is shown in Figure 2−1. A power supply capable of supplying 10 A should be connected to J2 through a pair of 20 AWG wires. The load should be connected to J1 through a pair of 16 AWG wires. The maximum load current can be reduced from 9 A if 6 A or 8 A versions of the SLVP213 are used.
Efficiency 2.2 Efficiency The SLVP213 efficiency peaks at a load current of about 2 A and then decreases as the load current increases to full load. The efficiency shown in Figure 2−2 is for 5-V (TPS54610, TPS54810) and 3.3-V (TPS54910) inputs at an ambient temperature of 25°C. The efficiency is lower at higher ambient temperatures due to temperature variation in the drain-to-source resistance of the MOSFETs.
Power Dissipation 2.3 Power Dissipation The low junction-to-case thermal resistance of the PWP package, along with a well-designed board layout, allows the SLVP213 EVMs to output full rated load current while maintaining safe junction temperatures. For the TPS54610 with a 5-V input source and a 6-A load, the junction temperature is approximately 60°C while the case temperature is approximately 55_C. The total board losses at 25°C are shown in Figure 2−3. The input voltage for the TPS54910 is 3.
Output Voltage Regulation 2.4 Output Voltage Regulation The output voltage load regulation of the SLVP213 is shown in Figure 2−4 while the output voltage line regulation is shown in Figure 2−5. Measurements are shown for an ambient temperature of 25°C. Figure 2−4. Load Regulation OUTPUT VOLTAGE vs OUTPUT CURRENT 1.83 VO − Output Voltage − V 1.82 1.81 TPS54610 TPS54910 1.8 TPS54810 1.79 1.78 1.77 0 2 4 6 IO − Output Current − A 8 10 Figure 2−5. Line Regulation OUTPUT VOLTAGE vs INPUT VOLTAGE 1.
Load Transients 2.5 Load Transients The SLVP213 response-to-load transients are shown in Figure 2−6, Figure 2−7, and Figure 2−8. The current step is from 25% to 75% of the maximum rated load. Total peak-to-peak voltage variation is as shown, including ripple and noise on the output. Figure 2−6. Load Transient Response, TPS54610 VO (AC) 100 mV/div IO 2 A/div Time Scale 10 µs/div Figure 2−7.
Loop Characteristics Figure 2−8. Load Transient Response, TPS54910 VO (AC) 100 mV/div IO 2 A/div Time Scale 10 µs/div 2.6 Loop Characteristics The SLVP213 loop response characteristics are shown in Figure 2−9 through Figure 2−14. Gain and phase plots are shown for each device at minimum and maximum operating voltage. Figure 2−9.
Loop Characteristics Figure 2−10. Measured Loop Response, TPS54610, VIN = 6 V 200 60 50 150 Gain 40 30 Phase 100 20 50 10 0 0 −10 −20 100 1k 10 k 100 k −50 1M Figure 2−11.
Loop Characteristics Figure 2−12. Measured Loop Response, TPS54810, VIN = 6 V 200 60 50 150 Gain 40 30 100 Phase 20 50 10 0 0 −10 −20 100 1k 10 k −50 1M 100 k Figure 2−13.
Output Voltage Ripple Figure 2−14. Measured Loop Response, TPS54910, VIN = 3.6 V 150 60 Phase 50 100 40 30 Gain 50 20 10 0 0 −10 −50 −20 −30 100 1k 10 k 100 k −100 1M 2.7 Output Voltage Ripple The SLVP213 output voltage ripple are shown in Figure 2−15, Figure 2−16, and Figure 2−17 for each device type. The input voltage is 3.3 V for the TPS54610 and TPS54910. The input voltage is 5 V for the TPS54810. Output current for each device is 50% of rated full load. Figure 2−15.
Output Voltage Ripple Figure 2−16. Measured Output Voltage Ripple, TPS54810 VO (AC) 10 mV/div Time Scale 1 µs/div Figure 2−17.
Input Voltage Ripple 2.8 Input Voltage Ripple The SLVP213 output voltage ripple is shown in Figure 2−18, Figure 2−19, and Figure 2−20 for each device type. The input voltage is 3.3 V for the TPS54610 and TPS54910. The input voltage is 5 V for the TPS54810. Output current for each device is 50% of rated full load. Figure 2−18. Input Voltage Ripple, TPS54610 VO (AC) 100 mV/div Time Scale 1 µs/div Figure 2−19.
Start-Up Figure 2−20. Input Voltage Ripple, TPS54910 VO (AC) 100 mV/div Time Scale 1 µs/div 2.9 Start-Up The start-up voltage waveforms of the SLVP213 are shown in Figure 2−21, Figure 2−22, and Figure 2−23. There is approximately a 9-ms delay after the input voltage rises above the 2.9-V (3.8 V for the TPS54810) startup voltage threshold until the output voltage begins to ramp up to the final value of 1.8 V.
Start-Up Figure 2−22. Measured Start-Up Waveform, TPS54810 VI 2 V/div VO 1 V/div Time Scale 5 ms/div Figure 2−23.
Chapter 3 This chapter provides a description of the SLVP213 board layout and layer illustrations. Topic 3.1 Page Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Layout 3.1 Layout The board layouts and assembly for the SLVP213 are shown in Figure 3−1 through Figure 3−5. The SLVP213 is laid out in a fashion to resemble a layer stack-up that could be encountered in a typical application. The top and bottom layers are 1.5 oz. copper, while the two internal layers are 0.5 oz. copper. The top layer contains the main power traces for VIN, VOUT, and Vphase.
Layout Figure 3−2. Internal Layer 1 Layout Figure 3−3.
Layout Figure 3−4. Bottom-Side Layout (looking from top side) Figure 3−5.
Chapter 4 The SLVP213 schematic and bill of materials are presented in this chapter. Topic Page 4.1 Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 4.2 Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic 4.1 Schematic The schematic for the SLVP213 is shown in Figure 4−1. Figure 4−1. SLVP213 Schematic U1 TPS54610, TPS54810, TPS54910 R6 28 RT VIN 71.5 kΩ VIN 27 TP9 VIN SYNCH VIN C6 26 SS/ENA VIN 0.047 µF PH C3 25 VBIAS PH 1 µF PH R5 VIN R1 C1 R2 470 pF 301 Ω 4 PWRGD PH PH TP4 R3 10 kΩ 10 kΩ C4 10 kΩ 3 PH COMP/NC PH 470 pF PH C2 12 pF PH 2 VSENSE BOOT PGND R4 9.
Bill of Materials 4.2 Bill of Materials The bill of materials for the SLVP213 is listed in Table 4−1. Table 4−1.
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