SC2443 Dual-Phase Single or Two Output Synchronous Step-Down Controller POWER MANAGEMENT Description Features The SC2443 is a high-frequency dual synchronous step-down u Wide input voltage range: 4.7V to 16V switching power supply controller. It provides out-of-phase u 0.5V feedback voltage for low-voltage outputs high-current output gate drives to all N-channel MOSFET power u Programmable frequency up to 1 MHz per phase stages. The SC2443 operates in synchronous continuous-con- u 2-Phase synchronous continuous conduction mode for duction mode. Both phases are capable of maintaining regula- high efficiency step-down converters tion with sourcing or sinking load currents, making the SC2443 u Out-of-phase operation for low input current ripples suitable for generating both VDDQ and the tracking VTT for u Output source and sink currents DDR applications. u Fixed frequency peak current-mode control u 75mV/-110mV maximum current sense voltage The SC2443 employs fixed frequency peak current-mode con - u Inductor DCR current-sensing for low-cost applications trol for the ease of frequency compensation and fast transient u Dual outputs or 2-phase single output operation response. u Excellent current sharing between individual phases u Individual soft-start, overload shutdown and enable The dual-phase step-down controllers of the SC2443 can be u External reference input for DDR applications used to produce two individually controlled and regulated out- u External synchronization puts or a single output with shared current in each phase. The u Industrial temperature range Step-down controllers operate from an input of at least 4.7V u 4mm X 4mm X1mm 24-lead MLPQ package and are capable of regulating outputs as low as 0.5V Applications Individual soft-start and overload shutdown timer is included in each step-down controller. The SC2443 implements hiccup u Telecommunication power supplies overload protection. In single output current share configura - u DDR memory power supplies tion, the master timer controls the soft-start and overload shut- u Graphic power supplies down functions of both controllers. u Servers and base stations Typical Application Circuit VIN VIN VOUT1 VP1 VIN VIN VOUT1 VP1 VP1 VOUT1 VP1 VOUT1 U1 IN1- U1 IN1- 1 18 1 18 IN1- IN1- GDL1 IN1- IN1- GDL1 2 17 2 17 COMP1 PVCC COMP1 PVCC 3 16 VIN 3 16 VIN SYNC PGND SYNC PGND SC2443 SC2443 4 15 4 15 AGND GDL2 AGND GDL2 5 14 REF GDH2 5 14 VOUT2 REF GDH2 6 13 IN2- REFIN BST2 6 13 REFIN BST2 VIN VIN IN2- Dual Independent Outputs Single Output With Current Sharing Aug. 2008 1 7 24 COMP2 ROSC 8 23 IN2- CS1- 9 22 CS2- CS1+ 10 21 CS2+ SS1/EN1 11 20 SS2/EN2 BST1 12 19 AVCC GDH1 7 24 COMP2 ROSC 8 23 IN2- CS1- 9 22 CS2- CS1+ 10 21 CS2+ SS1/EN1 11 20 SS2/EN2 BST1 12 19 AVCC GDH1GDH1 AVCC BST1 SS2/EN2 SS1/EN1 CS2+ CS1+ CS2- CS1- IN2- ROSC COMP2 SC2443 Pin Configuration Ordering Information Top View Device Package (1,2) SC2443MLTRT 24-lead 4mm X 4mm X mm MLPQ SC2443EVB Evaluation Board 24 19 Notes: ( ) Available in tape and reel only. A reel contains 3,000 devices. (2) Available in lead-free package only. Device is WEEE and RoHS IN1- 1 18 GDL1 compliant. COMP1 PVCC SYNC PGND GDL2 AGND GDH2 REF REF 6 13 BST2 IN 7 12 (24-lead 4mm X 4mm X mm MLPQ ) = 29C/W JA Marking Information Marking for the 4 X 4mm MLPQ-24 package: 2