ISL8502AEVAL1Z: 2A Synchronous Buck Regulator with Integrated MOSFETs

Transcription

1 Application Note 70 ISL850AEVALZ: A Synchronous Buck Regulator with Integrated MOSFETs The ISL850A is a synchronous buck controller with internal MOSFETs packaged in a small mmxmm QFN package. The ISL850A can support a continuous load of A and has a very wide input voltage range. With the switching MOSFETs integrated into the IC, the complete regulator footprint can be very small and provide a much more efficient solution than a linear regulator. The ISL850A is capable of standalone operation or it can be used in a master slave combination for multiple outputs that are derived from the same input rail. Multiple slave channels can be individually programmed such that the internal clocks are out-of-phase. This method minimizes the ripple on the input rail. The switching PWM controller drives two internal N-Channel MOSFETs in a synchronous-rectified buck converter topology. The synchronous buck converter uses voltage-mode control with fast transient response. The switching regulator provides a maximum static regulation tolerance of ±% over line, load, and temperature ranges. The output is user-adjustable by means of external resistors down to 0.6V. The output is monitored for undervoltage events. The switching regulator also has over current protection. Thermal shutdown is integrated. The ISL850A features a bidirectional Enable pin that allows the part to shut itself down and pull the enable pin low at the same time. PGOOD Rising Delay (measured from VOUT reaching regulation to PGOOD Rising) has been reduced from 50ms (typical) for ISL850 to ms (typical) for ISL850A (measured at 500kHz switching frequency). Pin Configuration PGOOD SGND EN SYNCH M/S FS 5 6 VCC ISL850A ( LD QFN) TOP VIEW COMP PVCC FB BOOT SS VIN GND 9 PGND VIN PGND VIN PGND VIN PHASE PHASE PHASE PHASE PGND Features A Continuous Output Current Integrated MOSFETs for Small Regulator Footprint Adjustable Switching Frequency, 500kHz to.mhz Tight Output Voltage Regulation, ±% Over-Temperature Wide Input Voltage Range, 5V ±0% or 5.5V to V Wide Output Voltage Range, from 0.6V Simple Single-Loop Voltage-Mode PWM Control Design Input Voltage Feed-Forward for Constant Modulator Gain Fast PWM Converter Transient Response Lossless r DS(ON) High Side and Low Side Overcurrent Protection Undervoltage Detection Integrated Thermal Shutdown Protection Power-Good Indication Adjustable Soft-Start QFN Package - Compliant to JEDEC PUB95 MO-0 QFN (Quad Flat No Leads) package outline - Near Chip Scale Package footprint, which improves PCB efficiency and has a thinner profile Pb-Free (RoHS Compliant) Applications Point of Load Applications Graphics Cards - GPU and Memory Supplies ASIC Power Supplies Embedded Processor and I/O Supplies DSP Supplies Ordering Information PART NUMBER ISL850AIRZ (Notes,, ) PART MARKING TEMP. RANGE ( C) PACKAGE (Pb-free) PKG. DWG. # 85 0AIRZ -0 to +85 Ld x QFN L.xD ISL850AEVALZ Evaluation Board NOTES:. Add -T* suffix for tape and reel. Please refer to TB7 for details on reel specifications.. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 00% matte tin plate plus anneal (e termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-00.. For Moisture Sensitivity Level (MSL), please see device information page for ISL850A. For more information on MSL please see tech brief TB6. October, 0 AN70.0 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures INTERSIL or Copyright Intersil Americas Inc. 0. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners.

2 Application Note 70 What s Inside The Evaluation Board Kit contains the following materials: The ISL850A EVAL REVD board The ISL850A datasheet This EVAL KIT document Recommended Equipment The following materials are recommended to perform testing: 0V to 5V power supply with at least 5A source current capability, battery, notebook AC adapter Two Electronic Loads capable of sinking current up to 5A Digital Multimeters (DMMs) 00MHz quad-trace Oscilloscope Signal generator (only if the SYNC function needs to be evaluated) Quick Setup Guide. Ensure that the circuit is correctly connected to the supply and loads prior to applying any power.. Connect the bias supply to VIN. Plus terminal to J(VIN) and negative return to J(GND).. Verify that all positions are ON for S, EN_all, EN_, EN_.. Turn on the power supply. 5. Verify the outputs voltages are.5v for V OUT and V OUT. Evaluating Other Output Voltages The ISL850AEVAL kit outputs are preset to.5v. For a quick evaluation of output voltages between 0.6V and V IN -.7V, the following resistors need to be changed in the feedback network as shown in Equations and : R = ( R 08 ) [( V OUT V FB ), ] (EQ. ) where R 08 = 7.kΩ; and V FB =0.6V R = ( R 08 ) [( V OUT V FB ), ] (EQ. ) where R 08 = 7.kΩ; and V FB =0.6V However, for reliable operation over the entire load and temperature range, it is highly recommended to follow the output filter and loop compensation network design guidelines as listed in the ISL850A datasheet. Frequency The ISL850AEVAL can operate at switching frequencies from 500kHz to.mhz. R 0 and R 0 are used to program the switching frequency through Equation : R 0 and ( R 0 ) = 8000 ( fosc[ khz] ) (EQ. ) TABLE. SWITCH SETTINGS SW SKIP OPERATING MODE NC No Connect EN_ALL Enable or disable V OUT and V OUT EN Enable or disable V OUT EN Enable or disable V OUT Soft-start C07, C07 can be used to adjust the soft-start time. AN70.0 October, 0

3 VIN J J VOUT J 5 6 Application Note 70 VOUT TP0 J J5 5 6 J6 J0 8 ISL850AEVALZ Schematic R6 R R 75 6 D 75 R0 R00 D00 AND REG REG ENABLE ON S OFF GROUND CONNECTIONS FOR SCOPE PROBES.7UH 7.K 0 C06 OPEN 5.9K 95.K C0 0.UF 0K 0K C0 0.UF DNP R0 C00A 0UF 0UF 5.9K 0UF C00B 0UF IKN C06 OPEN.7UH 6 C08 7PF DNP 0K DNP C0 0.UF N700 Q 0K 0 R0 70PF N700 Q6 70PF 7 C09 000PF C07 0.0UF DNP 5.9K C0 0.UF UF C0 00UF U00 7.K K R07 R08 R R R09 R0 R R R07 R08 R0 R Q Q D00 JP R05 JP R05 JP R Q R5 R Q5 P P6 TP TP TP TP05 TP0 D TP0 TP09 TP05 TP0 TP00 TP00 C07 0.0UF TP09 TP TP0 TP ON ON ON 5 67 ON L00 L00 C0 C05 C00A J9 J8 J7 U00 R00 R0 C00B C05 UF C0 00UF C K R0 95.K 0K TP0 R09 0K C08 C09 000PF 7PF 5 EP 5 6 MLFP PIN PACKAGE EP MLFP PIN PACKAGE AN70.0 October, 0

4 Application Note 70 PART NUMBER QTY UNITS ISL850EVALZREVEPCB ea SEE LABEL- RENAME BOARD TABLE. BILL OF MATERIALS REFERENCE DESIGNATOR DESCRIPTION MANUFACTURER MANUFACTURER PART PWB-PCB, ISL850EVALZ, REV E, SOIC, ROHS GRMBR7C75KA7L ea C, C CAP, SMD, 0805,.7µF, 6V, 0%, X7R, ROHS H V0-T ea C0, C0 CAP, SMD, 00, 0.µF, 6V, 0%, X7R, ROHS H V0-T ea C0, C0 CAP, SMD, 00,.0µF, 0V, 0%, X5R, ROHS H V5-T ea C08, C08 CAP, SMD, 00, 5pF, 50V, 5%, NP0, ROHS H V0-T ea C07, C07 CAP, SMD, 00, 0.05µF, 6V, 0%, X7R, ROHS H V0-T ea C0, C0 CAP, SMD, 00, 70pF, 50V, 0%, X7R, ROHS H V0-T ea C09, C09 CAP, SMD, 00, 80pF, 50V, 0%, X7R, ROHS H0-DNP 0 ea C06, C06 CAP, SMD, 00, DNP- PLACE HOLDER, ROHS H06-DNP 0 ea C, C CAP, SMD, 0805, DNP- PLACE HOLDER, ROHS H V0-T ea C00A, C00B, C00A, C00B CAP, SMD, 06, 0µF, 5V, 0%, X5R, ROHS H V0-T ea C05, C05 CAP, SMD, 0, 00µF, 0V, 0%, X5R, ROHS ea VIN CONN-GEN, BIND.POST, INSUL-RED, THMBNUT- GND ea GND CONN-GEN, BIND.POST, INSUL-BLK, THMBNUT- GND ea J7-J0 CONN-SCOPE PROBE TEST PT, COMPACT, PCB MNT, ROHS 5-6 ea J-J6, P, P CONN-TURRET, TERMINAL POST, TH, ROHS IMAGINEERING INC MURATA MURATA TAIYO YUDEN YAGEO KEMET TDK MURATA TAIYO YUDEN AVX MURATA AVX MURATA TAIYO YUDEN ISL850EVALZREVEPCB GRMBR7C75KA7L C00X7R60-0KNE GRM55R7C0KA88D ECJ-0EXC0K EMK05B70KV-F CC00KRX7R7BB0 C00C0KRACTU C005X7RC0K GRM55R6A05KE5D C00X5R00-05KNE LMK05BJ05KV-F 00ZD05KATA GRM6COG50J050AQ ECU-EH50JCQ C00COG500-50JNE ECJ-0EBC5K C00X7R60-5KNE 00YC5KATA GRM55R7C5KA0D ECJ-0EBH7K C00X7500-7KNE ECJ-0EBH8K C06X5R50-06KNE LMK5BJ07MM-T JOHNSON COMPONENTS KEYSTONE 7006 JOHNSON COMPONENTS KEYSTONE 7007 TEKTRONIX KEYSTONE 5- AN70.0 October, 0

5 Application Note 70 PART NUMBER QTY UNITS ea a) TP, TP00, TP0-TP05, TP09-TP, ea b) TP00, TP0- TP05, TP09- TP TABLE. BILL OF MATERIALS (Continued) CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS HLF ea JP-JP CONN-HEADER, X, RETENTIVE,.5mm, 0.0X 0.0, ROHS" SPC0SYAN ea JP CONN-JUMPER, SHORTING, PIN, BLACK, GOLD, ROHS N8WS-7-F-T ea D00, D00 DIODE-RECTIFIER, SMD, SOD-, P, 75V, 50mA, ROHS BAT5-T 0 ea DNP (D, D) DIODE-SCHOTTKY, SMD, SOT, P, 0V, 00mA, SINGLE DIODE PDS560-0 ea DNP (D, D) DIODE-RECTIFIER, SMD, POWER DI5, P, 60V, 5A, ROHS LTST-C70CKT ea LED, LED LED-GaAs RED, SMD, mmx.5mm, 00mW, 0mA, 0mcd, ROHS CDRH8D8NP-R7NC ea L00, L00 COIL-PWR INDUCTOR, SMD, 8.mm,.7µH, 0%,.A, ROHS, SHIELDED ISL850AIRZ ea U00, U00 IC-A BUCK REGULATOR, P, QFN, X, ROHS N700-7-F-T ea Q, Q6 TRANSISTOR, N-CHANNEL, LD, SOT-, 60V, 5mA, ROHS REFERENCE DESIGNATOR DESCRIPTION MANUFACTURER MANUFACTURER PART KEYSTONE 500 KEYSTONE 500 BERG/FCI SULLINS DIODES INC. FAIRCHILD DIODES INC. LITEON/VISHAY ROHM STANLEY ELECTRIC SUMIDA ELECTRIC, CO. INTERSIL DIODES, INC. ON SEMICONDUCTOR HLF SPC0SYAN N8WS-7-F BAT5 PDS560- LTST-C70CKT SML-0LTT86 BRH-TR CDRH8D8NP-R7NC ISL850AIRZ N700-7-F N700LTG MMBTALTG-T ea Q, Q, Q, Q5 TRANSISTOR, NPN, LD, SOT, 0V, 600mA, ROHS H /6W5-T ea R, R5 RES, SMD, 00, 6Ω, /6W, 5%, TF, ROHS H /6W5-T ea R, R6 RES, SMD, 00, 75Ω, /6W, 5%, TF, ROHS H50-00R00-/6W-T ea R00, R05, R05 H /6W-T ea R0, R0, R0, R0 RES, SMD, 00, 0Ω, /6W, 5%, TF, ROHS RES, SMD, 00, 0k, /6W, %, TF, ROHS YAGEO ROHM YAGEO VISHAY/DALE RC00JR-076RL CR00-6W-60JT ERJGEJ0750 CR00-6W-750JT CR00-6W-00T ERJ-GE0JR00 ERJ-RKF00X CR00-6W-00FT MCR0MZPF00 RC00FR-070KL CRCW000K0FKED 5 AN70.0 October, 0

6 Application Note 70 PART NUMBER QTY UNITS H50-00-/6W-T ea R0, R0 RES, SMD, 00,.k, /6W,%, TF, ROHS H /6W-T ea R08, R09, R08, R09 RES, SMD, 00, 8k,/6W, %, TF, ROHS H /6W-T ea R0 RES, SMD, 00,.99k, /6W, %, TF, ROHS H /6W-T ea R, R RES, SMD, 00, 5.9k, /6W, %, TF, ROHS H /0W-T ea R, R RES, SMD, 00, 6.0k, /0W, %, TF, ROHS H /6W-T ea R0, R0 RES, SMD, 00, 95.k, /6W, %, TF, ROHS H50-DNP 0 ea R0, R07, R00, R07 RES, SMD, 00, DNP, DNP, DNP, TF, ROHS H /0W-T ea R, R RES, SMD, 060, 0Ω, /0W, %, TF, ROHS H55-DNP 0 ea R, R RES, SMD, 5, DNP, DNP, DNP, TF, ROHS IKN00000 ea S (Install according to silkscreen) TABLE. BILL OF MATERIALS (Continued) SWITCH-DIP, SMD, P, SLIDE, SPST, LP, ROHS -0X/-SCREW ea Four corners SCREW, -0X/in, PAN, NYLON, PHILLIPS, ROHS -0X/-STANDOFF ea Four corners STANDOFF, -0X/in, F/F, HEX, NYLON, ROHS 5X8-STATIC-BAG ea Place assy in bag BAG, STATIC, 5X8, ZIPLOC, ROHS DNP 0 ea C0, C0 DO NOT POPULATE OR PURCHASE LABEL-DATE CODE ea LABEL-FOR DATE CODE AND BOM REV # REFERENCE DESIGNATOR DESCRIPTION MANUFACTURER MANUFACTURER PART VISHAY/DALE STACKPOLE ROHM YAGEO VISHAY/DALE KDA YAGEO KOA APEM KEYSTONE CRCW00K0FKED RMCF00FTK0 CR00-6W-0FT CR00-6W-80FT ERJ-RKF80X MCR0MZPF80 RC00FR-078KL CRCW008K0FKED RK7HE99F CR00-6W-99FT ERJRKF60X RC00FR-0795KL CR00-6W-95FT RK7HJT0R0F CR060-0W-0R0FT IKN D INTERSIL 0-0 INTERSIL LABEL-DATE CODE LABEL-RENAME BOARD ea RENAME PCB TO: ISL850AEVALZ LABEL, TO RENAME BOARD INTERSIL LABEL-RENAME BOARD 6 AN70.0 October, 0

7 ISL850AEVALZ Board Layout Application Note 70 ISL850AEVALZ FIGURE. TOP COMPONENTS FIGURE. TOP LAYER ETCH 7 AN70.0 October, 0

8 Application Note 70 ISL850AEVALZ Board Layout (Continued) FIGURE. ND LAYER ETCH FIGURE. RD LAYER ETCH 8 AN70.0 October, 0

9 Application Note 70 ISL850AEVALZ Board Layout (Continued) FIGURE 5. BOTTOM LAYER COMPONENTS (MIRRORED) FIGURE 6. BOTTOM LAYER ETCH (MIRRORED) Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see 9 AN70.0 October, 0

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