 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| SP6127, 2A Evaluation Board Manual Easy Evaluation for the SP6127EK1 12V Input, 0 to 2A Output Non-Synchronous Buck Converter Precision 0.60V 1% High -Accuracy Reference. Small form factor Feature Rich: Single supply operation, Overcurrent protection with auto-restart, on/off function, Preset internal soft start, Type-II internal compensation SP6127EB SCHEMATIC VIN Q1 Si2343DS 2 1 Vin Rs=1k LX C7 0.1uF 6 L1, IHLP-2525CZ 3.3uH, 30mOhm, 6A Gate C1 4.7uF 12V GND VOUT C4 22uF R1 200k, 1% 4 CZ 33pF R2 100k, 1% D1 1N4148 SP6127 3 VDR Ds MBRA340T3G RZ 2K 1.8V 0-2.0A VFB GND 5 SHDN High=Of f GND Rev 6/27/07 SP6127 Evaluation Manual Copyright 2007 Sipex Corporation USING THE EVALUATION BOARD 1) Powering Up the SP6127EB Circuit Connect the SP6127 Evaluation Board to an external +12V power supply. Connect with short leads directly to the "VIN" and "GND" posts. Connect a Load between the "VOUT" and "GND" posts, again using short leads to minimize inductance and voltage drop. 2) Measuring Output Load Characteristics It's best to GND reference scope and digital meters using the Star GND post near the output of the board. VOUT ripple can best be seen touching probe tip to the pad for COUT and scope GND collar touching Star GND post - avoid a GND lead on the scope which will increase noise pickup. 3) Using the Evaluation Board with Different Output Voltages While the SP6127 Evaluation Board has been tested and delivered with the output set to 1.80V, by simply changing one resistor, R2, the SP6127 can be set to other output voltages. The relationship in the following formula is based on a voltage divider from the output to the feedback pin FB, which is set to an internal reference voltage of 0.60V. Standard 1% metal film resistors of surface mount size 0603 are recommended. R1 Vout Vref - 1 Where R1 = 200k. For Vout = 0.60V setting, simply remove R2 from the board. R2 = Note that since the SP6127 Evaluation Board design was optimized for 12V down conversion to 1.80V, changes of output voltage and/or input voltage will alter performance from the data given in the Power Supply Data section. Using the SHDN (ON/OFF function) Feedback pin serves a dual role of ON/OFF control. The MOSFET driver is disabled when a voltage greater than 1V is applied at FB pin. Maximum voltage rating of this pin is 5.5V. The controlling signal should be applied through a small signal diode as shown on page 1. Note that under no-load condition an optional 10kOhm bleeding resistor across the output helps keep the output capacitor discharged. POWER SUPPLY DATA The SP6127EB is designed with an accurate 2% reference over line, load and temperature. Figure 1 data shows a typical SP6127 Evaluation Board efficiency plot, with efficiencies to 75% and output currents to 2A. SP6127 Load Regulation in Figure 2 shows very little change in output voltage from no load to 2A load. Figures 3 and 4 show the transient response of the SP6127 and overcurrent shutdown. Figures 5 and 6 show a controlled start-up with no load and 2A load when power is applied where the input current rises smoothly as the soft-start ramp increases. Figures 7 and 8 show the output ripple under no load and 2A load. 2 Typical Performance Characteristics SP6127 Efficiency versus Iout, Vin=12V,Ta=25C 90 Vout=1.8V SP6127 Load Regulation Vin=12V 1.810 Efficiency (%) 80 1.805 Vout (V) 0.0 0.5 1.0 Iout (A) 1.5 2.0 70 1.800 60 1.795 50 1.790 0.0 0.5 1.0 Iout (A) 1.5 2.0 Figure 1- Efficiency Figure 2- Load regulation Figure 3- Step load 1-2A, ch1: Vin ch2: Vout, ch3: Iout Figure 4- OCP shutdown, ch1: Vin ch2: Vout, ch3: Inductor current, ch4: Io Figure 5- Startup no load, ch1: Vin ch2: Vout, ch3: Iout Figure 6- Start up 2A, ch1: Vin ch2: Vout, ch3: Iout 3 Typical Performance Characteristics Figure 7- Output ripple at 0A is 32mV, ch1: Vin, ch2: Vout, ch3: Iout Figure 8- Output ripple at 2A is 15mV, ch1: Vin, ch2: Vout, ch3: Iout 4 LOOP COMPENSATION The SP6127 includes Type-II internal compensation components for loop compensation. External compensation components are not required for systems with tantalum or aluminum electrolytic output capacitors with sufficiently high ESR. Use the condition below as a guideline to determine whether or not the internal compensation is sufficient for your design. Type-II internal compensation is sufficient if the following condition is met: f ESRZERO < f DBPOLE where: f ESRZERO = 1 2. .R ESR .C OUT ................... (1) ........... (2) f DBPOLE = 1 2. . L C OUT ............ (3) Creating a Type-III compensation Network The above condition requires the ESR zero to be at a lower frequency than the doublepole from the LC filter. If this condition is not met, Type-III compensation should be used and can be accomplished by placing a series RC combination in parallel with R1 as shown below. The value of CZ can be calculated as follows and RZ selected from table 1. CZ = L C .............. (4) 1.25 x R1 fESRZERO/fDBPOLE 1X 2X 3X 5X >= 10X RZ 50K 40K 30K 10K 2K Table1- Selection of RZ 5 SP6127 Vout CP1 2pF RZ CZ CZ2 130pF RZ2 200k VFB R1 200k, 1% Error Amplif ier Figure 9- RZ and CZ in conjunction with internal compensation components form a Type-III compensation Loop Compensation for the SP6127EB L = 3.3uH, C = 22uF/5mOhm ceramic capacitor From equation (2) fESRZERO = 1.45MHz. From equation (3) fDBPOLE = 18.7 kHz. Since the condition specified in (1) is not met, Type-III compensation has to be used by adding external components RZ and CZ. Using equation (4) CZ is calculated 34pF (use 33pF). Following the guideline given in table 1, a 2kOhm RZ was used. + Vref =0.6V R2 6 PCB LAYOUT DRAWINGS Figure 10. SP6127EB Component Placement Figure 11. SP6127EB PCB Layout Top Side Figure 12. SP6127EB PCB Layout Bottom Side 7 Line No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Ref. Des. PCB U1 Q1 DS L1 D1 C1 C6 C7 CZ R1 R2 RZ VIN, VOUT, GND, GND, SHDN Qty. 1 1 1 1 1 1 1 1 1 1 1 1 1 5 Manuf. Sipex Sipex Vishay Semi On Semi Vishay MCC MURATA MURATA MURATA MURATA VISHAY/DALE VISHAY/DALE VISHAY/DALE Vector Electronic Manuf. Layout Part Number Size 146-6641-00 1.175"x1.934" SP6127EK1 TSOT-6 Si2343DS SOT-23 MBRA340T3 SMA IHLP2525CZ 6.86x6.47mm 1N4148WX SOD323 GRM21BR61E475K 0805 GRM21BR60J226M 0805 GRM18ER61E104K 0603 GRM1885C1H330JA 0603 CRCW0603200K 0603 CRCW060344K2 0603 CRCW06037K15 0603 K24C/M .042 Dia Component SP6127EB Non-synchronous Buck Controller PFET, 30V, 86mOhm Schotkky, 40V, 3A 3.3uH Coil 6A 30mOhm Fast Switching Diode 500mW 4.7 uF Ceramic X5R 25V 22uF Ceramic X5R 6.3V 0.1uF Ceramic X5R 33pF Ceramic C0G 50V 200k 100k 2.00k Test Point Post Vendor Phone Number 408-934-7500 408-934-7500 402-563-6866 602-244-6600 914-347-2474 818-701-4933 770-436-1300 770-436-1300 770-436-1300 770-436-1300 402-563-6866 402-563-6866 402-563-6866 800-344-4539 Table 2- SP6127EB List of Materials INDUCTORS - SURFACE MOUNT Inductor Specification Size Inductor Type DCR Isat mOhms (A) LxW(mm) Ht.(mm) 30.0 13.50 6.47x6.86 3.00 Shielded Inductance (uH) 3.3 Manufacturer/Part No. VISHAY Manufacturer Website www.vishay.com Capacitance( uF) 4.7 22 Manufacturer/Part No. GRM21BR61E475K GRM21BR60J226M CAPACITORS - SURFACE MOUNT Capacitor Specification Size ESR Ripple Current Voltage Capacitor Manufacturer ohms (max) (A) @20C Delta LxW(mm) Ht.(mm) (V) Type Website 0.005 2.20 2x1.25 1.25 25.0 X5R Ceramic www.murata.com 0.005 3.50 2x1.25 1.25 6.3 X5R Ceramic www.murata.com MOSFETS - SURFACE MOUNT MOSFET P-Ch Manufacturer/Part No. VISHAY Si2343DS RDS(on) ohms (max) 86.00 MOSFET Specification Qg ID Current Voltage (A) nC (Typ) nC (Max) (V) 3.1 14.0 21.0 30.0 Foot Print SOT-23 Manufacturer Website www.vishay.com Table 3- SP6127EB Suggested Components and Vendor Lists ORDERING INFORMATION Model Temperature Range Package Type SP6127EB ..............................- 40C to +125C...................SP6127 Evaluation Board SP6127EK1............................ - 40C to +125C.......................................6-pin TSOT-6 8 |
Price & Availability of SP612707
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |