Wide Input Voltage Range, - Exar

1 Date: /20/06 SP7653 wide Input Voltage Range, .3 MHz, Buck Regulator Copyright 2006 Sipex Corporation1 Date: 2/17/06 SP7653 wide Input Voltage Range, , Buck Regulator Copyright 2006 Sipex CorporationSP7653 FEATURES to 20V Step Down Achieved Using Dual Input Output Voltage down to 3A Output Capability Built in Low RDSON Power Switches (40 m1 typical) Highly Integrated Design, Minimal Components Fixed Frequency Operation UVLO Detects Both VCC and VIN Over Temperature Protection Short Circuit Protection with Auto-Restart wide BW Amp Allows Type II or III Compensation Programmable Soft Start Fast Transient Response High Efficiency.

2 Greater than 95% Possible Asynchronous Start-Up into a Pre-Charged Output Small 7mm x 4mm DFN Package Patent #6,922,041 wide Input Voltage Range, , Buck RegulatorThe SP7653 is a synchronous step-down switching regulator optimized for high efficiency. The part is designed to beespecially attractive for dual supply, 12V to 20V distributed power systems stepped down with 5V used to power thecontroller. This lower VCC Voltage minimizes power dissipation in the part and is used to drive the top switch. The SP7653is designed to provide a fully integrated buck regulator solution using a fixed frequency, PWM Voltage modearchitecture. Protection features include Under Voltage Lock Out (UVLO), thermal shutdown and output short circuitprotection.

3 The SP7653 is available in the space saving DFN APPLICATION CIRCUITNow Available in Lead Free PackagingDESCRIPTIONP owerBloxTM123456789101112131415161718192 0212223242526 BOTTOM VIEWH eatsink Pad 1 Connect to LxHeatsink pad 2 Connect to GNDH eatsink pad 3 Connect to VINPGNDPGNDGNDVFBCOMPUVINGNDSSVINLXLXLXL XVCCGNDGNDGNDBSTNCLXLXLXDFN PACKAGE 7mm x 4mmSP7653 PGNDVINVINVIN CBST1uFR3200k1,1%L1 , Irate= ,1%GNDC347uFALL RESISTORS & CAPACITORS ARE SIZE0603 UNLESS OTHERWISE :CERAMICX5RC522 Bottom-Side Layout should havethree Contacts which areisolated from one another: QT-Drain Contact, QB-Drain Contact andController-GND ,1%VOUTGND2R4100k1,1% ,C5 ,1% , 1%CF1100pFFs= ,1%1234567891011121314151617181920212 223242526 BOTTOM VIEWH eatsink Pad 1 Connect to LxHeatsink Pad 2 Connect to GNDH eatsink Pad 3 Connect to VINPGNDPGNDGNDVFBCOMPNCLXLXLXLXVCCBSTLXL XLXDFN PACKAGE 7mm x 4mm SP7653 PGNDSSGNDGNDGNDUVINVINVINVINVINGND2 Date: /20/06 SP7653 wide Input Voltage Range.

4 3 MHz, Buck Regulator Copyright 2006 Sipex Corporation2 Date: 2/17/06 SP7653 wide Input Voltage Range, , Buck Regulator Copyright 2006 Sipex CorporationELECTRICAL SPECIFICATIONSU nless otherwise specified: -40 C < TAMB < 85 C, -40 C< Tj< 125 C, < VCC < , 3V< Vin< 28V, Boost=LX + 5V,LX = GND = , UVIN = , CVCC = 1 F, CCOMP = F, CSS = 50nF, Typical measured at VCC = zdenotes the specifications which apply over the full temperature range, unless otherwise to to 20 VAll other to VCC+ -65 C to 150 CPower Limited via OTPESD HBMT hermal Resistance 5 C/WABSOLUTE MAXIMUM )gnihctiwsoN( )gnihctiws(tnerruCylppuS8Am oN(tnerruCylppuStsooB) )gnihctiws( siseretsyHNIVU002003004 VmtnerruCtupnINIVU1A.

5 GifnoCniaGX2 VBFV;CCC 52=T,V5= ecnatcudnocsnarTreifilpmArorrE6V/AmniaGr eifilpmArorrE06 BddaoLoNtnerruCkniSPMOC051A , , 52=AT, /VmThese are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of thespecifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect : /20/06 SP7653 wide Input Voltage Range, .3 MHz, Buck Regulator Copyright 2006 Sipex Corporation2 Date: 2/17/06 SP7653 wide Input Voltage Range, , Buck Regulator Copyright 2006 Sipex CorporationELECTRICAL SPECIFICATIONSU nless otherwise specified.

6 -40 C < TAMB < 85 C, -40 C< Tj< 125 C, < VCC < , 3V< Vin< 28V, Boost=LX + 5V,LX = GND = , UVIN = , CVCC = 1 F, CCOMP = F, CSS = 50nF, Typical measured at VCC = zdenotes the specifications which apply over the full temperature range, unless otherwise to to 20 VAll other to VCC+ -65 C to 150 CPower Limited via OTPESD HBMT hermal Resistance 5 C/WABSOLUTE MAXIMUM )gnihctiwsoN( )gnihctiws(tnerruCylppuS8Am oN(tnerruCylppuStsooB) )gnihctiws( siseretsyHNIVU002003004 VmtnerruCtupnINIVU1A ,.gifnoCniaGX2 VBFV;CCC 52=T,V5= ecnatcudnocsnarTreifilpmArorrE6V/AmniaGr eifilpmArorrE06 BddaoLoNtnerruCkniSPMOC051A , , 52=AT, /VmThese are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of thespecifications below is not implied.

7 Exposure to absolute maximum rating conditions for extended periods of time may affect : 2/17/06 SP7653 wide Input Voltage Range, , Buck Regulator Copyright 2006 Sipex CorporationELECTRICAL SPECIFICATIONSU nless otherwise specified: -40 C < TAMB < 85 C, -40 C< Tj< 125 C, < VCC < , 3V< Vin< 28V, Boost = LX + 5V,LX = GND = , UVIN = , CVCC = 1 F, CCOMP = F, CSS = 50nF, Typical measured at VCC = zdenotes the specifications which apply over the full temperature range, unless otherwise , ,C 52= /VmhtdiWesluPmuminiMHG09081sn oitaRytuDelballortnoCmumixaM2979%oitaRyt uDmumixaMerofebtsujderusaeMsnigebgnislup oitaRytuDmumixaM001% TRATSTFOS:SREMIT:tnerruCegrahCSS01A :tnerruCegrahcsiDSS1Am ,tneserPtluaFlamrehT& VderusaeMFER-) ( siseretsyHlamrehT01C EGATSREWOP:TUPTUOR hctiwSediShgiHNOSD04 mVCCI;V5=TUOA3=TBMAC 52=RhctiwSediswoLsuonorhcnySNOSD04 mVCCI;V5=TUOA3=TBMAC 52=tnerruCtuptuOmumixaM3A Date: /20/06 SP7653 wide Input Voltage Range.

8 3 MHz, Buck Regulator Copyright 2006 Sipex Corporation4 Date: 2/17/06 SP7653 wide Input Voltage Range, , Buck Regulator Copyright 2006 Sipex CorporationGeneral OverviewThe SP7653 is a fixed frequency, Voltage mode,synchronous PWM regulator optimized for highefficiency. The part has been designed to beespecially attractive for high Input voltages to heart of the SP7653 is a wide bandwidthtransconductance amplifier designed to accom-modate Type II and Type III compensationschemes. A precision reference, present onthe positive terminal of the error amplifier,permits the programming of the output voltagedown to via the VFBpin.

9 The output of theerror amplifier, COMP, compared to a ramp is responsible for trailingedge PWM control. This Voltage ramp, andPWM control logic are governed by the internaloscillator that accurately sets the PWM fre-quency to OF OPERATIONThe SP7653 contains two unique control fea-tures that are very powerful in distributed appli-cations. First, asynchronous driver control isenabled during startup, to prohibit the low sideswitch from pulling down the output until thehigh side switch has attempted to turn on. Sec-ond, a 100% duty cycle timeout ensures that thelow side switch is periodically enhanced duringextended periods at 100% duty cycle. This guar-antees the synchronized refreshing of the Boostcapacitor during very large duty cycle SP7653 also contains a number of valuableprotection features.

10 Programmable VINUVLO allows the user to set the exact value at which theconversion Voltage can safely begin down con-version, and an internal VCCUVLO which en-sures that the controller itself has enough volt-age to operate properly. Other protection fea-PIN DESCRIPTIONPin #Pin NameDescription1-3 PGNDG round connection for the synchronous rectifier4,8,19-21 GNDG round Pin. The control circuitry of the IC and lower power driver arereferenced to this pin. Return separately from other ground traces to the (-)terminal of Voltage and Short Circuit Detection pin. It is the inverting Input ofthe Error Amplifier and serves as the output Voltage feedback point for theBuck Converter.