Data Sheet No. PD94713 IR3637SPBF 1% ACCURATE SYNCHRONOUS PWM CONTROLLER FEATURES DESCRIPTION 0.8V Reference Voltage The IR3637 controller IC is designed to provide a simple Operates with a single 5V Supply Voltage synchronous Buck regulator for on-board DC to DC ap- Internal 400kHz Oscillator plications in a small 8-pin SOIC. The output voltage can Soft-Start Function be precisely regulated using the internal 0.8V reference Fixed Frequency Voltage Mode voltage for low voltage applications. Short Circuit Protection The IR3637 operates at a fixed internal 400kHz switch- ing frequency to reduce the component size. APPLICATIONS The device features under-voltage lockout for both input supplies, an external programmable soft-start function Computer Peripheral Voltage Regulator as well as output under-voltage detection that latches Memory Power supplies off the device when an output short is detected. Graphics Card Low cost on-board DC to DC TYPICAL APPLICATION 12V 5V C1 C2 C3 Vc Vcc HDrv Q1 L1 D1 SS/SD Vout C4 Q2 C6 IR3637 LDrv Comp R3 C5 Fb Gnd R2 R1 Figure 1 - Typical application of IR3637. ORDERING INFORMATION PKG PACKAGE PIN PARTS PARTS T & R DESIG DESCRIPTION COUNT PER TUBE PER REEL Oriantation S IR3637SPBF 8 95 ------ Fig A S IR3637STRPBF 8 ------- 2500 Rev. 1.1 www.irf.com 1 06/16/05IR3637SPBF ABSOLUTE MAXIMUM RATINGS Vcc Supply Voltage ................................................ 16V Vc Supply Voltage .................................................. 25V Storage Temperature Range ..................................... -65C To 150C Operating Junction Temperature Range ..................... 0C To 125C ESD Classification ................................................. HMB Class 2 (2KV) JEDEC Standard Moisture Sensitivity Level ........................................ JEDEC Level 1 260C Caution: Stresses above those listed in Absolute Maximum Rating may cause permanent damage to the device. These are stress ratings only and function of the device at these or any other conditions beyond those indicated in the operational sections of the specifica- tions is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability PACKAGE INFORMATION Recommended Operating Conditions Parameter Min Max Units Vcc 4.5 5.5 V Fb 1 8 SS/SD Vc 8 14 V Vcc 2 7 Comp LDrv 3 6 Vc Gnd 4 5 HDrv JA=154C/W JC=41.2C/W ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply over Vcc=5V, Vc=12V and 0C<Tj<125C. PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS Feedback Voltage Fb Voltage VFB V 0.792 0.808 0.800 25C<Tj<75C V 0.789 0.811 0C<Tj<125C 0.800 Fb Voltage Line Regulation LREG 4.5<Vcc<5.5 % 0.1 UVLO UVLO Threshold - Vcc UVLO Vcc Supply Ramping Up V 4.0 4.4 4.2 UVLO Hysteresis - Vcc V 0.25 UVLO Threshold - Vc UVLO Vc Supply Ramping Up V 3.1 3.5 3.3 UVLO Hysteresis - Vc V 0.2 UVLO Threshold - Fb UVLO Fb Fb Ramping Down V 0.3 0.5 0.4 Supply Current Vcc Dynamic Supply Current Dyn Icc Freq=400kHz, CL=1500pF mA 4 16 8 Vc Dynamic Supply Current Dyn Ic Freq=400kHz, CL=1500pF mA 6 20 15 Vcc Static Supply Current ICCQ SS=0V mA 1 6 3.3 Vc Static Supply Current ICQ SS=0V mA 0.5 4.7 1 Soft-Start Section Charge Current SSIB SS=0V A -15 -35 -25 Shutdown Threshold SD Note1 V 0.4 Note1: Guaranteed by design. Not production tested. Rev.1.1 www.irf.com 2 06/16/05