NCV8851BDBGEVB

NCV8851BDBGEVB NCV8851B Automotive Grade Synchronous Buck Controller Evaluation Board User's Manual http://onsemi.com EVAL BOARD USER’S MANUAL Description Key Features • • • • • • • • • • • • The NCV8851B Evaluation Board provides a convenient way to evaluate and integrate a complete high-efficiency synchronous buck converter design. No additional components are required, other than dc supplies for the input voltage and enable pin. The board also can be connected to an external clock source to synchronize the switching frequency or for spread spectrum operation. The board is configured for a 5.0 V output with a 170 kHz switching frequency and a 4 A current limit, intended for applications requiring over 3 A of current. Additionally, modifying the NCV8851B Evaluation Board for different output voltage, switching frequency or current limit is straightforward, requiring minimal component changes. 5.0 V Output Voltage 91% Efficiency at 3 A 4 A Average Current Limit (ACL) 170 kHz Switching Frequency Average Current Mode Control Automotive Grade for up to TA = 105°C Wide Input Voltage Range of 4.5 V to 40 V Regulates through Load Dump Conditions 1.0 mA Maximum Quiescent Current in Sleep Mode Programmable Fixed Frequency – 170 kHz to 500 kHz External Clock Synchronization up to 600 kHz Easy to Modify for Other Applications VIN GND SYNC NCV8851B Output Inductor Enable Output Capacitor VOUT Figure 1. NCV8851B Evaluation Board © Semiconductor Components Industries, LLC, 2012 May, 2012 − Rev. 1 1 Publication Order Number: EVBUM2119/D NCV8851BDBGEVB Table 1. EVALUATION BOARD TERMINAL DESCRIPTIONS Terminal VIN Function Positive dc input voltage. GND Common dc return. VOUT Regulated dc output voltage. SYNC Input for external clock synchronization. EN Enable input. When disabled, the part enters sleep mode. Table 2. ABSOLUTE MAXIMUM RATINGS (Voltages are with respect to GND) Rating Value Unit Dc Supply Voltage (VIN, EN) Peak Transient Voltage (Load Dump) −0.3 to 40 45 V Dc Supply Voltage (SYNC) −0.3 to 7 V Junction Temperature (NCV8851B) −40 to 150 °C Ambient Temperature (Demo board) −40 to 105 °C Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. Table 3. ELECTRICAL CHARACTERISTICS (TA = 25°C, 4.5 V v VIN v 40 V, IOUT v 4 A, unless otherwise specified) Characteristic Conditions Typical Value Unit Output Voltage - 5.00 V Voltage Accuracy - 4 % Line Regulation IOUT = 0 A 0.02 % Load Regulation VIN = 13.2 V 0.04 % VIN = 13.2 V, IOUT = 0 A 170 kHz VIN = 13.2 V, IOUT = 100 mA, 10-90% 14 ms SYNC Frequency - 170 to 600 kHz Duty Cycle Range - 5 to 95 % OUTPUT VOLTAGE SWITCHING REGULATOR Switching Frequency Soft-start Time CURRENT LIMIT Average Current Limit - 4 A Cycle-by-cycle Overcurrent Protection - 6.4 A VIN increasing 4.3 V VIN = 13.2 V, IOUT = 100 mA VIN = 13.2 V, IOUT = 1 A VIN = 13.2 V, IOUT = 4 A 70.7 93.2 90.9 % Maximum Shutdown Current - 1.0 mA Thermal Shutdown - 180 °C GENERAL Input Undervoltage Lockout (UVLO) Efficiency http://onsemi.com 2 NCV8851BDBGEVB VIN VIN EN VIN_IC 9 12 6VOUT DBST 11 3 4 + VIN BST − CBST Q1 ROSC 5 20 GH RS VSW ROSC 6 SYNC 7 GL L Q2 + C VOUT PGND 1 8 CCOMP CC2 2 15 CC1 19 RC1 18 CFB − VIN_CS CSP CSN RF1 VFB 13 CV2 16 CSOUT VCOMP 14 17 10 RV1 RF0 CV1 AGND Figure 2. NCV8851B Application Diagram Operational Guidelines 1. Connect a dc input voltage, 4.5 V ≤ VBATT ≤ 40 V, between “VIN” and “GND”. 2. Connect a load impedance between “VOUT” and “GND”. 3. Connect a dc enable voltage, 4.5 V ≤ EN ≤ VBATT ≤ 20 V, between “EN” and “GND”. If EN must be tied to a higher voltage, a current limiting resistor is required (see below). V 4. Optionally, for external clock synchronization, connect a pulse source, SYNC, between “SYNC” and “GND”. The positive amplitude should be 1.0 V ≤ SYNC ≤ 7.0 V and negative amplitude should be -0.3 V ≤ GND ≤ 0.8 V. SYNC pulse duty cycle may range from 10% to 90%, and frequency may range from the programmed frequency (170 kHz by default) to 600 kHz. BATT SYNC EN V OUT Figure 3. Evaluation Board Connections http://onsemi.com 3 NCV8851BDBGEVB TYPICAL WAVEFORMS EN VSW VOUT VOUT Figure 4. Startup at 170 kHz, 13.2 V to 5 V Output Figure 5. SWN, VOUT at 170 kHz, 13.2 V to 5 V Output VSW VSW VOUT VOUT Figure 6. Minimum Duty Cycle at 170 kHz, 5 V Output Figure 7. Maximum Duty Cycle at 170 kHz, 5 V Output SYNC VSW VOUT VSW Figure 8. SWN, VOUT at 170 kHz, 28 V to 5 V Output Figure 9. SYNC from 170 to 600 kHz, 13.2 V to 5 V Output http://onsemi.com 4 NCV8851BDBGEVB TYPICAL PERFORMANCE 100 VOUT 99.99 %VOUT (%) IOUT 99.98 99.97 99.96 IOUT (A) 0 Figure 10. 100 mA to 3.6 A Load Step, 170 kHz, 5 V Output 100 3 4 Figure 11. 100 mA to 3.6 A Load Step, 170 kHz, 5 V Output 100 80 1.8 99.8 70 60 1.4 h 50 (%) (%) 2 2.2 90 PD (W) 40 1.0 30 20 10 0 1 IOUT (A) 0 1 2 3 4 99.6 99.4 0.6 99.2 0.2 99 5 10 15 20 25 30 35 40 VIN (V) Figure 12. Efficiency at 170 kHz, 13.2 V to 5 V Output Figure 13. Line Regulation at 170 kHz, 13.2 V to 5 V Output http://onsemi.com 5 6 EN http://onsemi.com TP8 AGND RSN1 100 1206 TP11 SYNC TP10 AGND TP9 RSN2 100 1206 RN1 OPEN GND 0603 2 12 3 RO1 51.1k 0603 10 20 1 X7R/50V 11 C2 1uF 1206 C1 0.1uF 0805 X7R/50V C3 1uF 0603 X7R Figure 14. NCV8851B Evaluation Board Schematic TSSOP20 BST 6Vout 4.7 V_FB V_COMP C_COMP C_FB CS_OUT CSN CSP PGND GATE(L) GATE(H) Vsw 0603 NCV8851B AGND ROSC SYNC EN VIN_CS VIN VIN_IC U1 R6 13 14 15 16 17 18 19 8 7 5 6 C6 1uF 0603 X7R 4 9 CC1 0603 RC2 + 0603 4.02k Q2 DPAK NTD5407 CSW1 0.1uF 0805 X7R/50V 470uF 50V CI2 Q1 DPAK NTD5407 + TP13 PGND RC1 60.4k 820 pF X5R/X7R 0603 0603 X5R/X7R CC2 100 pF DSW1 MBRA160T3 SMA 470uF 50V CI1 TP1 VIN 0603 X5R/X7R 0603 2200 pF 820 pF L1 15uH 13.7k Wurth WE−PD 0603 X5R/X7R CV1 RV1 CV2 CB1 0.1uF 0805 X7R/50V DB1 MBRA160T3 SMA 25m 2512 RS1 330uF 16V CO1 + JO1 SMB RF0 10.7k 0603 RF1 56.2k 0603 PGND TP12 2 TP7 VOUT NCV8851BDBGEVB SCHEMATIC NCV8851BDBGEVB Table 4. BILL OF MATERIALS Qty Ref Part Part Description Manufacturer Part Number 3 CSW1 0.1mF 0.1mF 50V 10% 0805 X7R ceramic SMD capacitor Kemet C0805C104K5RACTU CB1 0.1mF 0.1mF 50V 10% 0805 X7R ceramic SMD capacitor Kemet C0805C104K5RACTU C1 0.1mF 0.1mF 50V 10% 0805 X7R ceramic SMD capacitor Kemet C0805C104K5RACTU CC1 820pF 820pF 10% 0603 X7R ceramic SMD capacitor Murata Electronics North America GRM188R71H821KA01D CV2 820pF 820pF 10% 0603 X7R ceramic SMD capacitor Murata Electronics North America GRM188R71H821KA01D 1 CC2 100pF 820pF 10% 0603 X7R ceramic SMD capacitor Murata Electronics North America GCM1885C1H101JA16D 2 CI1 470mF 470mF 63V FK electrolytic SMD capacitor Panasonic - ECG EEVFK1J471M CI2 470mF 470mF 63V FK electrolytic SMD capacitor Panasonic - ECG EEVFK1J471M 1 CO1 330mF 330mF 10V 20% polymer electrolytic SMD capacitor Sanyo Electronic Components Co. 10TPE330M 1 CV1 2200pF 2200pF 10% 0603 X7R ceramic SMD capacitor Panasonic - ECG ECJ-1VB1H222K 1 C2 1mF 1mF 50V 10% 1206 X7R ceramic SMD capacitor Murata Electronics North America GCM31MR71H105KA55L 2 C3 1mF 1mF 16V 10% 0603 X7R ceramic SMD capacitor Taiyo Yuden EMK107BJ105KA-TR C6 1mF 1mF 16V 10% 0603 X7R ceramic SMD capacitor Taiyo Yuden EMK107BJ105KA-TR DSW1 MBRA160T3 1A, 60 V Schottky SMD rectifier ON Semiconductor MBRA160T3G DB1 MBRA160T3 1A, 60 V Schottky SMD rectifier ON Semiconductor MBRA160T3G JO1 SMB Vertical PCB mount gold RF connector jack Emerson Network Power Connectivity Solutions 131-3701-261 2 2 1 1 L1 15mH 15mH SMD power inductor Wurth 7447709150 2 Q1 NTD5407 40V, 38A N-channel power MOSFET ON Semiconductor NTD5407NG Q2 NTD5407 40V, 38A N-channel power MOSFET ON Semiconductor NTD5407NG 1 RC1 60.4k 60.4kW 1% 0.1W 0603 Thick-film SMD resistor Yageo Corporation RC0603FR-0760K4L 1 RC2 4.02k 4.02kW 1% 0.1W 0603 Thick-film SMD resistor Yageo Corporation RC0603FR-074K02L 1 RF0 10.7k 10.7kW 1% 0.1W 0603 Thick-film SMD resistor Yageo Corporation RC0603FR-0710K7L 1 RF1 56.2k 56.2kW 1% 0.1W 0603 Thick-film SMD resistor Yageo Corporation RC0603FR-0756K2L 1 RN1 OPEN 1% 0.1W 0603 Thick-film SMD resistor 1 RO1 51.1k 51.1kW 1% 0.1W 0603 Thick-film SMD resistor Yageo Corporation RC0603FR-0751K1L 2 RSN1 100 100W 1% 0.25W 1206 Thick-film SMD resistor Yageo Corporation RC1206FR-07100RL RSN2 100 100W 1% 0.25W 1206 Thick-film SMD resistor Yageo Corporation RC1206FR-07100RL http://onsemi.com 7 NCV8851BDBGEVB Table 4. BILL OF MATERIALS Qty Ref Part Part Description Manufacturer Part Number 1 RS1 25m 25mW 1% 2512 Thick-film SMD current sense resistor Vishay/Dale WSL2512R0250FEA 1 RV1 13.7k 13.7kW 1% 0.1W 0603 Thick-film SMD resistor Yageo Corporation RC0603FR-0713K7L 1 R6 4.7 4.75W 1% 0.1W 0603 Thick-film SMD resistor Yageo Corporation RC0603FR-074R75L 4 TP1 VCC 0.291” X 0.109” Solder terminal turret Ag over Cu Mill-Max Manufacturing Corporation 2501-2-00-44-00-00-07-0 TP7 VOUT 0.291” X 0.109” Solder terminal turret Ag over Cu Mill-Max Manufacturing Corporation 2501-2-00-44-00-00-07-0 TP12 PGND 0.291” X 0.109” Solder terminal turret Ag over Cu Mill-Max Manufacturing Corporation 2501-2-00-44-00-00-07-0 TP13 PGND 0.291” X 0.109” Solder terminal turret Ag over Cu Mill-Max Manufacturing Corporation 2501-2-00-44-00-00-07-0 TP8 AGND 0.042” Inboard pin Vector Electronics K24C 4 1 TP9 AGND 0.042” Inboard pin Vector Electronics K24C TP10 EN 0.042” Inboard pin Vector Electronics K24C TP11 SYNC 0.042” Inboard pin Vector Electronics K24C U1 NCV8851B Automotive synchronous buck controller ON Semiconductor NCV8851BG EVALUATION BOARD MODIFICATIONS Connecting EN to a Higher Voltage or VBATT Changing the switching frequency may impact dynamic characteristics. Typically, increasing the switching frequency allows the dynamic response to improve by further optimization of the compensators; however, it is advised to analyze dynamic response results of simulation whenever the switching frequency is modified. Typically, EN is tied to a logic output or low-voltage supply. However, EN can be tied to a higher voltage or to VBATT. In either case, if the supply that EN is tied to is expected to go above 20 V, a current limiting resistor is required. For convenience, RN1 is unpopulated, disconnecting EN from VBATT (via VIN) by default. To connect EN to VBATT, populate RN1 with a current limiting resistor. To connect EN to a separate higher voltage supply from VBATT, place a current limiting resistor in series with the supply. Consult the data sheet, NCV8851B/D, for selecting a current limiting resistor. Synchronizing to a Higher Frequency When connecting the SYNC input to a significantly higher frequency than that set by the program resistor, dynamic performance could be impaired. Based on empirical results, it is advised to analyze dynamic response results of simulation whenever SYNC is more than 33% higher than the programmed switching frequency. Programming the Switching Frequency to a Different Value Adjusting the Current Limit The current limit can be adjusted by using a different sense resistor for RS1. Consult the data sheet, NCV8851B/D, for selecting a different current limit. Changing the sense resistor may impact dynamic characteristics. It is advised to analyze dynamic response results of simulation whenever the sense resistor is modified. The switching frequency is programmed with a resistor, RO1, from the ROSC pin to GND. By default, the switching frequency is set to 170 kHz with a 51.1 kW resistor used for RO1. The frequency can be programmed to a different value by replacing RO1. Consult the data sheet, NCV8851B/D, for selecting a different frequency program resistor. http://onsemi.com 8 NCV8851BDBGEVB Table 5. BOM VARIATIONS The following list of BOM variations on output voltage and switching frequency have been tested. 3.3 V, 4 A 5 V, 4 A 8 V, 4 A Part 170kHz 360 kHz 500 kHz 170kHz 360 kHz 500 kHz 170 kHz 360 kHz 500 kHz Unit RO1 51.1 23.2 16.2 51.1 23.2 16.2 51.1 23.2 16.2 kW L1 15 10 10 15 15 10 22 15 15 mH CO1 330 330 330 330 330 330 330 330 330 mF RS1 25 25 25 25 25 25 25 25 25 mW RC1 60.4 60.4 60.4 60.4 60.4 60.4 60.4 60.4 60.4 kW RC2 4.02 4.02 4.02 4.02 4.02 4.02 4.02 4.02 4.02 kW CC1 820 820 820 820 820 820 820 820 820 pF CC2 100 100 100 100 100 100 100 100 100 pF RV1 13.7 27.4 27.4 13.7 27.4 27.4 13.7 13.7 13.7 kW RF0 17.4 17.4 8.66 10.7 5.36 3.57 10.0 4.99 3.32 kW RF1 54.9 54.9 27.4 56.2 28 18.7 90.9 45.3 30.1 kW CV1 2200 2200 2200 2200 2200 2200 2200 2200 2200 pF CV2 820 820 820 820 820 820 820 820 820 pF Selection of components for different operational configurations than those listed above is beyond the scope of this document and the data sheet, NCV8851B/D, should be consulted. Additionally, it is advised to analyze dynamic response results of simulation whenever variant components are used. http://onsemi.com 9 NCV8851BDBGEVB LAYOUT PLOTS Figure 15. Top Silk Screen Figure 16. Top Copper Figure 17. Bottom Copper http://onsemi.com 10 NCV8851BDBGEVB ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. 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