IRU3033CSTR

Data Sheet No. PD94147revA IRU3033(PbF) 8-PIN PWM SWITCHER AND LINEAR CONTROLLER IC FEATURES DESCRIPTION LDO Controller allows the use of a low cost pass transistor for the I/O supply 8-Pin SOIC combines switching and linear controller Internal pre-regulator eliminates cross talk between switching and linear regulators Automatic shut down of the linear regulator when connected to the Vcc2 detect pin On-Board MOSFET Driver Fastest transient response of any controller method (0 to 100% Duty Cycle in 100ns) 1% Internal Voltage Reference Internal Under-Voltage Lockout protects MOSFET during start-up APPLICATIONS Dual supply low voltage processor applications, such as: P55C, CYRIX M2, POWER PC and AMD K6 Simple 5V to 3.3V switcher for Pentium with AGP or Pentium II applications The IRU3033 IC combines a switching controller and a linear regulator controller all in a compact 8-pin surface mount package, providing a total solution for dual supply processor applications such as an Intel P55C, AMD K6, as well as Cyrix 6X86L and the M2 processors. Typically in these applications a dual supply regulator converts 5V to 3.3V for I/O supply and a jumper programmable supply of 1.25V to 3.5V for Core supply. The linear regulator controller portion in the IRU3033 is a programmable controller allowing flexibility for the I/O regulator and has a minimum of 50mA drive current capability designed to provide ample current for an external pass transistor. The IC uses an internal regulator generated from the 12V supply to power the controller as well as the 12V supply to drive the power MOSFET, allowing a low cost N-channel MOSFET switch to be used. The IC also includes an error comparator for fast transient response, a precise voltage reference for setting the output voltage as well as a direct drive of the MOSFET for the minimum part count. TYPICAL APPLICATION Q1 5V R10 C1 R6 C6 R9 12V D2 C8 5V V12 Drv2 VFB2 IRU3033 Drv1 I/O R7 CPU R8 Gnd Vcc2 Det V12(SW) VFB1 VHYST L2 C3 R3 Core C5 R4 L1 C7 Q2 C2 D1 R5 Figure 1 - Typical application of IRU3033 in a flexible mother board designed for Intel P55, P54, AMD K5, K6 as well as Cyrix M1 and M2 applications. Notes: P54C, P55C, Pentium II are trademarks of Intel Corp. K5 & K6 are trademarks of AMD Corp. Cyrix 6X86L, M1, M2 are trademarks of Cyrix Corp. Power PC is trademark of IBM Corp. PACKAGE ORDER INFORMATION Basic Part (Non-Lead Free) TA (°C) 0 To 70 Leadfree Part 8-PIN PLASTIC SOIC (S) IRU3033CS TA (°C) 0 To 70 www.irf.com 8-PIN PLASTIC SOIC (S) IRU3033CSPbF 1 IRU3033(PbF) ABSOLUTE MAXIMUM RATINGS V12,V12(SW) Supply Voltages ....................................... 20V Fb Pin Voltages ........................................................ -0.3V To 5V Storage Temperature Range ...................................... -65°C To 150°C Operating Junction Temperature ................................ 0°C To 150°C PACKAGE INFORMATION 8-PIN PLASTIC SOIC (S) TOP VIEW Drv1 1 8 V12 V12(SW) 2 7 Drv2 VFB1 3 6 VFB2 VHYST 4 5 Gnd θJA =160 C/W ELECTRICAL SPECIFICATIONS Unless otherwise specified, the following specification applies over V12=V12(SW)=12V and TA=0 to 70°C. Low duty cycle pulse testing is used which keeps junction and case temperatures equal to the ambient temperature. PARAMETER Linear Controller Section Fb Voltage Initial Accuracy Fb Voltage Total Variation Fb Voltage Line Regulation Fb Input Bias Current Maximum Drive Current V12 Supply Current Switching Controller Section Fb Voltage Initial Accuracy Fb Voltage Total Variation Fb Voltage Line Regulation Fb Input Bias Current Min On Time SYM VFB2 TEST CONDITION MIN TYP MAX UNITS TJ=25 C, Drv2=VFB2, CL=100µF Drv2=VFB2, CL=100µF 10