SLUU182 − March 2004
19
High-Performance Dual Synchronous Buck Conversion Using the TPS5124
Figure 15. Top Side
Figure 16. Internal 1
Страница 1: ...User s Guide 1 User s Guide...
Страница 2: ...handling or use of the goods Please be aware that the products received may not be regulatory compliant or agency certified FCC UL CE etc Due to the open construction of the product it is the user s...
Страница 3: ...rtainty as to the load specification please contact a TI field representative During normal operation some circuit components may have case temperatures greater than 50 C The EVM is designed to operat...
Страница 4: ...Results Performance Data 13 6 Layout Considerations 16 7 PCB Layout 17 8 List of Materials 19 1 Introduction The TPS5124 is a dual independent synchronous buck controller Both controllers internal to...
Страница 5: ...Load transient response recovery time IOUT falling from 8 5 A to 0 A 120 s Loop bandwidth IOUT 15 A 30 kHz Phase margin IOUT 15 A 55 Output ripple voltage IOUT 15 A 33 66 mVPP Output rise time VIN 12...
Страница 6: ...SLUU182 March 2004 6 High Performance Dual Synchronous Buck Conversion Using the TPS5124 Figure 1 HPA053 TPS5124 Controller Schematic...
Страница 7: ...max where IRIPPLE is the ripple current flowing through the inductor The ripple current affects the output voltage ripple and core losses Based on 20 ripple current and 300 kHz the inductance value is...
Страница 8: ...nput Capacitors Due to the out of phase operation the input current ripple is partially cancelled The total RMS current in the input capacitor is calculated as follows This assumes the total input cur...
Страница 9: ...le current through the input capacitor is shown in Figure 3 and can be calculated using equation 8 IincapRMS 1 T T 2 0 IOUT1 IAVG 2 dt D1 T T 2 IOUT1 IOUT2 IAVG 2 dt T 2 D2 T D1 T IOUT2 IAVG 2 dt T T...
Страница 10: ...compensator are set at 2 68 kHz The two poles fP1 and fP2 and are set at 150 kHz and 2 MHz The frequency of poles and zeros are defined by the following equations fZ1 1 2p R4 C14 fZ2 1 2p R1 C12 assum...
Страница 11: ...g high side conduction the current limit circuit terminates the high side driver pulse If the set point voltage is exceeded during low side conduction the low side pulse is extended through the next c...
Страница 12: ...ltage Protection The under voltage comparator circuit continually monitors the voltage at the INV pin If the voltage at that pin falls below 78 of the 0 85 V reference the timer begins to charge C18 I...
Страница 13: ...tion functions of the TPS5124 for troubleshooting or other purposes the OCP OVP and UVP circuits may be disabled 4 7 4 1 Disabling Overcurrent Protection OCP Remove the current limit resistors R13 and...
Страница 14: ...eration conditions IOUT Output Current A Percent Efficiency OVERALL EFFICIENCY vs OUTPUT CURRENT VOUT1 3 3 V Enabled Only Figure 6 91 89 90 92 0 3 6 9 12 15 95 93 94 96 VIN 6 5 V VIN 12 V VIN 15 V IOU...
Страница 15: ...abled Figure 8 VIN 6 5 V VIN 12 V VIN 15 V 5 2 Typical Operating Waveform Typical operating waveforms taken at VIN 12 V IOUT1 15 A and IOUT2 10 A is shown in Figure 9 5 3 Start Up Waveform Figure 10 s...
Страница 16: ...response For Channel 1 3 3 V when the load steps from 0 A to 8 5 A the overshoot and undershoot voltages are about 150 mV For Channel 2 1 5 V when the load steps from 0 A to 7 5 A the overshoot voltag...
Страница 17: ...ivers to the gate of the power MOSFETs should be as short and wide as possible to reduce stray inductance This becomes more critical if external gate resistors are not used In addition external gate r...
Страница 18: ...utput voltage sensing trace should not be placed under the inductors on the same layer The feedback components should be isolated from output components such as MOSFETs inductors and output capacitors...
Страница 19: ...SLUU182 March 2004 19 High Performance Dual Synchronous Buck Conversion Using the TPS5124 Figure 15 Top Side Figure 16 Internal 1...
Страница 20: ...SLUU182 March 2004 20 High Performance Dual Synchronous Buck Conversion Using the TPS5124 Figure 17 Internal 2 Figure 18 Bottom Side...
Страница 21: ...r 3 pin 100 mil spacing 36 pin strip 0 100 x 3 Sullins PTC36SAAN L1 L2 2 Inductor SMT 2 2 H 20 A 4 6 m 0 51 x 0 51 Vishay Siliconix IHLP5050EZ 01 Q1 Q3 2 MOSFET N channel 30 V 18 A 8 0 m PWRPAK S0 8 V...
Страница 22: ...ute 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 pro...
Страница 23: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Texas Instruments TPS5124EVM...
