SEMTECH SC2677B

SC2677B Dual Synchronous Voltage Mode Controller with Current Sharing Circuitry POWER MANAGEMENT Features Description The SC2677B is a versatile 2 phase, synchronous, voltage ‹ 300kHz to 1MHz externally programmable mode PWM controller that can be used in two distinct ways. frequency operation First, the SC2677B is ideal for applications where point of ‹ Soft Start and Enable function use output power exceeds any single input power budget. ‹ Power Good output provided Alternatively, the SC2677B can be configured as a dual ‹ Cycle-by-cycle peak current limit switcher. The SC2677B features a precise temperature ‹ Latch off for over current protection compensated voltage reference, cycle-by-cycle peak cur- ‹ Phase-shifted switchers minimize ripple rent limit, under voltage lockout over current protection, ‹ High efficiency operation, >90% and internal level-shifted high-side gate drive circuitry. ‹ Programmable output(s) as low as 0.5V ‹ Industrial temperature range In current sharing configuration, the SC2677B can pro- ‹ TSSOP-24 package duce a single output voltage from two separate input volt- ‹ TSSOP-24 EDP package age sources (which can be different in voltage levels) while ‹ Bias voltage as low as 4.5V maintaining current sharing between the two channels. ‹ Adjustable phase shift between channels Current sharing is programmable to allow each input sup- ply to be loaded differently per application requirements. Two Phase, Current Sharing Controller ‹ Flexible, same or separate V IN In dual switcher configuration, two feedback paths are pro- ‹ Programmable current sharing vided for independent control of the separate outputs. The ‹ Thermal distribution via multi-phase output device will provide a regulated output from flexibly config- ured inputs, such as 3.3V, 5V, 12V etc. The phasing be- Applications tween the two switchers is adjustable to minimize the in- ‹ Graphics cards put and output ripple. ‹ Peripheral add-in card ‹ Dual-Phase power supply ‹ Power supplies requiring two outputs Typical Application Schematic D2 CS1- R51 CS1+ C63 D1 C6 R50 L1 M1 1 2 Vout1 C4 M3 R5 C19 C23 R8 PWRGD ENABLE CS1+ CS1- C28 R13 C26 C25 R10 R14 Vin U1 SC2677B R19 C33 R21 R20 CS2+ CS2- C36 CS2- R49 C39 C38 CS2+ C62 R18 R48 L2 1 2 Vout2 M5 C43 M7 C57 D3 C59 D4 Dual Independent outputs Revision: Dec. 04, 2009 1 www.semtech.com 1 24 CS 2+ CS 1 + 2 23 CS 2- CS 1- 3 22 VR EF GN D 4 21 FR E Q PW R GD 5 20 VC C SS/EN A 6 19 +IN 2 PH ASIN G 7 18 -IN 2 -IN1 8 17 CO MP2 CO M P 1 9 16 BS T 2 BS T 1 10 15 DH 2 DH 1 11 14 DL2 DL1 12 13 PG N D BST C SC2677B Dual Synchronous Voltage Mode Controller with Current Sharing Circuitry POWER MANAGEMENT Typical Application Schematic D2 CS1- Vin3 R51 CS1+ C63 D1 C6 R50 L1 M1 VP1 1 2 Vin1 Vout C4 M3 C19 R5 C23 R8 PWRGD ENABLE CS1+ CS1- C28 R13 C26 C25 R10 R14 U1 SC2677B R19 C33 R21 CS2+ CS2- C35 C36 VOUT C37 VOUT R26 R22 Vin3 R24 C38 C39 VP2 VP1 CS2- R49 CS2+ D C62 R48 L2 VP2 1 2 Vin2 M5 C43 C59 M7 C57 D3 D4 Vin3 Dual Input, Single output, Current share Mode D2 CS1- R51 CS1+ C63 D1 C6 R50 L1 M1 VP1 1 2 Vout C4 M3 C19 R5 C23 R8 PWRGD ENABLE CS1+ CS1- C28 R13 C26 C25 R10 R14 Vin U1 SC2677B R19 C33 R21 CS2+ CS2- C35 C36 VOUT C37 VOUT R26 R22 R24 C38 C39 VP2 VP1 CS2- R49 CS2+ D C62 R48 L2 VP2 1 2 M5 C43 C59 M7 C57 D3 D4 Single Input/output, Current share Mode 2 www.semtech.com 1 24 CS 2 + CS 1 + 2 23 CS 2 - CS 1 - 3 22 1 24 CS2+ CS1+ VR E F GN D 2 23 4 21 CS2- CS1- FR E Q PW R G D 3 22 5 20 VRE F GN D VC C SS/EN A 4 21 6 19 FREQ PW RG D +IN 2 PH AS IN G 5 20 7 18 VCC SS /E NA -IN1 -IN2 6 19 +IN2 PHA S ING 8 17 CO M P 2 CO M P 1 7 18 -IN2 -IN1 9 16 BS T 2 BS T 1 8 17 CO MP2 CO MP1 10 15 DH2 DH1 9 16 BST2 BS T1 11 14 DL 2 DL 1 10 15 DH2 DH1 12 13 P G N D BST C 11 14 DL2 DL1 12 13 PG ND BS TC SC2677B POWER MANAGEMENT Absolute Maximum Rating Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. PPr PrPl a a a ar r r ra a a am m m me e e et t t te e e er r Sl SSs Sl y y y ym m m mb b b bo o o ol LLs LsLs iiiim m m miiiit t t ts UUs Us Un n n niiiit t t ts Parameter Symbol Limits Units VtV o GND -V 0.3 to 15 CC IN PGND to GND ±V 1 BST1, BST2 to GND -V 0.3 to 30 BSTC to GND -V 0.3 to 20 -IN1, +/-IN2 to GND 7V COMP1, COMP2 to GND 7V (6) DH1, DH2 to GND -V 0.3 to 30 DL1, DL2 to GND -V 0.3 to BSTC + 0.3 (1) -) 3 peak (50nS V CS1+, CS1-, CS2+, CS2- 7V PWRGD to GND V+V 0.3 CC PHASING 7V SS/ENA to GND -V 0.3 to 7 Thermal Resistance Junction to Case θ TSSOP-24 17 °C/W JC TSSOP-24 EDP 5.5 Thermal Resistance Junction to Ambient θ TSSOP-24 90 °C/W JA TSSOP-24 EDP 32 OT perating Ambient Temperature Range -C 40 to 85 ° A OT perating Junction Temperature Range -C 40 to 125 ° J ST torage Temperature Range -C 65 to +150 ° STG LT ead Temperature (Soldering) 10 sec 3C 00 ° LEAD Electrical Characteristics Unless Specified: V = 4.75 to 5.25V, GND = PGND = 0V, FB = V , T = 25°C, V = V = 12V CC O J BSTC BST Pr P PPs Pr a a a a ar r r r ra a a a am m m m me e e e et t t t te e e e er r r Cs C CCn Cs o o o o on n n n nd d d d diiiiit t t t tiiiiio o o o on n n n ns s M M Mn MnMp iiiiin n T TTp TpTx y y y y yp p M MMx MxMs a a a a ax x U UUs Us Un n n n niiiiit t t t ts s OV utput Voltage = V 00 .49505 .500V .50 OUT FB o V = V -40 to 125C200 .4908 .500V .50 OUT FB, SV upply Voltage 45 .5 1V CC SV upply Current =0 5.0 1A m CC UV VLO R4 amp up Threshold 2V .8 CC UV VLO Hysteresis 1V 00 m CC Reference 0V .5 RV eference Load Regulation s2 ource 10uA ~ 100uA 0% . REF RV eference Line Regulation 5