Data Sheet No. PD94173 revD IRU3037/IRU3037A & (PbF) 8-PIN SYNCHRONOUS PWM CONTROLLER FEATURES DESCRIPTION Synchronous Controller in 8-Pin Package The IRU3037 controller IC is designed to provide a low Operating with single 5V or 12V supply voltage cost synchronous Buck regulator for on-board DC to DC Internal 200KHz Oscillator converter applications. With the migration of todays ASIC (400KHz for IRU3037A) products requiring low supply voltages such as 1.8V and Soft-Start Function lower, together with currents in excess of 3A, traditional Fixed Frequency Voltage Mode linear regulators are simply too lossy to be used when 500mA Peak Output Drive Capability input supply is 5V or even in some cases with 3.3V Protects the output when control FET is shorted input supply. The IRU3037 together with dual N-channel SOIC 8-Lead also available LEAD-FREE MOSFETs such as IRF7313, provide a low cost solution for such applications. This device features an internal APPLICATIONS 200KHz oscillator (400KHz for version), under-volt- DDR memory source sink Vtt application age lockout for both Vcc and Vc supplies, an external Low cost on-board DC to DC such as 5V to 3.3V, programmable soft-start function as well as output un- 2.5V or 1.8V der-voltage detection that latches off the device when an Graphic Card output short is detected. Hard Disk Drive TYPICAL APPLICATION 5V 12V L1 1uH C3 C4 C1 C2 1uF 1uF 10TPB100M, 47uF 100uF, 55m Vcc Vc Q1 HDrv 1/2 of IRF7313 L2 1.5V/5A SS/SD U1 D05022P-562, 5.6uH, 5.3A C8 IRU3037 Q2 0.1uF C7 LDrv 1/2 of IRF7313 2x 6TPC150M, 150uF, 40m Comp R3 C9 Fb 249, 1% 2200pF Gnd R5 R4 1.24K, 1% 24k Figure 1 - Typical application of IRU3037 or IRU3037A. PACKAGE ORDER INFORMATION TA (C) DEVICE LEADFREE DEVICE PACKAGE FREQUENCY 0 To 70 IRU3037CF IRU3037CFPbF 8-Pin Plastic TSSOP (F) 200KHz 0 To 70 IRU3037CS IRU3037CSPbF 8-Pin Plastic SOIC NB (S) 200KHz 0 To 70 IRU3037ACF IRU3037ACFPbF 8-Pin Plastic TSSOP (F) 400KHz 0 To 70 IRU3037ACS IRU3037ACSPbF 8-Pin Plastic SOIC NB (S) 400KHz www.irf.com 1IRU3037/IRU3037A & (PbF) ABSOLUTE MAXIMUM RATINGS Vcc Supply Voltage .................................................. 25V Vc Supply Voltage ...................................................... 30V (not rated for inductive load) Storage Temperature Range ...................................... -65C To 150C Operating Junction Temperature Range ..................... 0C To 125C CAUTION: Stresses above those listed inAbsolute Maximum Rating may cause permanent damage to the device. PACKAGE INFORMATION 8-PIN PLASTIC TSSOP (F) 8-PIN PLASTIC SOIC (S) Fb 1 8 SS/SD Fb 1 8 SS/SD 7 Vcc 2 7 Comp Vcc 2 Comp LDrv 3 6 Vc LDrv 3 6 Vc 4 5 HDrv Gnd Gnd 4 5 HDrv JA=160C/W JA=124C/W (Also available LEAD-FREE) ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply over Vcc=5V, Vc=12V and TA=0 to 70C. Typical values refer to TA=25C. Low duty cycle pulse testing is used which keeps junction and case temperatures equal to the ambient temperature. PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS Reference Voltage Fb Voltage VFB IRU3037 1.225 1.250 1.275 IRU3037A 0.784 0.800 0.816 V Fb Voltage Line Regulation LREG 5<Vcc<12 0.2 0.35 % UVLO UVLO Threshold - Vcc UVLO Vcc Supply Ramping Up 4.0 4.2 4.4 V UVLO Hysteresis - Vcc 0.25 V UVLO Threshold - Vc UVLO Vc Supply Ramping Up 3.1 3.3 3.5 V UVLO Hysteresis - Vc 0.2 V UVLO Threshold - Fb UVLO Fb Fb Ramping Down (IRU3037) 0.4 0.6 0.8 V (IRU3037A) 0.3 0.4 0.5 UVLO Hysteresis - Fb 0.1 V Supply Current Vcc Dynamic Supply Current Dyn Icc Freq=200KHz, CL=1500pF 2 5 8 mA Vc Dynamic Supply Current Dyn Ic Freq=200KHz, CL=1500pF 2 7 10 mA Vcc Static Supply Current ICCQ SS=0V 1 3.3 6 mA Vc Static Supply Current ICQ SS=0V 0.5 1 4.5 mA Soft-Start Section Charge Current SSIB SS=0V -10 -20 -30 A www.irf.com 2