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 The IRU3033 IC combines a switching controller and a transistor for the I/O supply linear regulator controller all in a compact 8-pin surface 8-Pin SOIC combines switching and linear mount package, providing a total solution for dual sup- controller ply processor applications such as an Intel P55C, AMD Internal pre-regulator eliminates cross talk K6, as well as Cyrix 6X86L and the M2 proces- between switching and linear regulators sors. Typically in these applications a dual supply regu- Automatic shut down of the linear regulator when lator converts 5V to 3.3V for I/O supply and a jumper connected to the Vcc2 detect pin programmable supply of 1.25V to 3.5V for Core supply. On-Board MOSFET Driver The linear regulator controller portion in the IRU3033 is a Fastest transient response of any controller programmable controller allowing flexibility for the I/O method (0 to 100% Duty Cycle in 100ns) regulator and has a minimum of 50mA drive current ca- 1% Internal Voltage Reference pability designed to provide ample current for an exter- Internal Under-Voltage Lockout protects MOSFET nal pass transistor. The IC uses an internal regulator during start-up generated from the 12V supply to power the controller as well as the 12V supply to drive the power MOSFET, APPLICATIONS allowing a low cost N-channel MOSFET switch to be Dual supply low voltage processor applications, used. The IC also includes an error comparator for fast such as: P55C, CYRIX M2, POWER PC transient response, a precise voltage reference for set- and AMD K6 ting the output voltage as well as a direct drive of the Simple 5V to 3.3V switcher for Pentium with AGP MOSFET for the minimum part count. or Pentium II applications TYPICAL APPLICATION Q1 5V R10 R6 C1 C6 I/O R9 12V D2 R7 5V C8 V12 Drv2 VFB2 CPU R8 IRU3033 Gnd Vcc2 Det Drv1 V12(SW) VFB1 VHYST L2 C3 Core R3 C5 L1 R4 C7 Q2 D1 R5 C2 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) Leadfree Part TA (C) 8-PIN PLASTIC SOIC (S) TA (C) 8-PIN PLASTIC SOIC (S) 0 To 70 IRU3033CS 0 To 70 IRU3033CSPbF www.irf.com 1IRU3033(PbF) ABSOLUTE MAXIMUM RATINGS V12,V12(SW) Supply Voltages ....................................... 20V Fb Pin Voltages ........................................................ -0.3V To 5V Storage Temperature Range ...................................... -65C To 150C Operating Junction Temperature ................................ 0C To 150C PACKAGE INFORMATION 8-PIN PLASTIC SOIC (S) TOP VIEW 1 8 Drv1 V12 V12(SW) 2 7 Drv2 VFB1 3 6 VFB2 4 5 VHYST Gnd JA =160 C/W ELECTRICAL SPECIFICATIONS Unless otherwise specified, the following specification applies over V12=V12(SW)=12V and TA=0 to 70C. 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 Linear Controller Section VFB2 Fb Voltage Initial Accuracy TJ=25 C, Drv2=VFB2, CL=100F 1.237 1.250 1.262 V Fb Voltage Total Variation Drv2=VFB2, CL=100F 1.225 1.250 1.275 V Fb Voltage Line Regulation 10<V12<14V, Drv2=VFB2, CL=100F 0.2 % Fb Input Bias Current IFB2 VFB2=1.25V -1 +1 A Maximum Drive Current IDRV(max) VFB2=1V, VFB1=1.5V 50 mA V12 Supply Current I12 VFB2=1V, VFB1=1.5V, IDRV2=0 5 mA Switching Controller Section Fb Voltage Initial Accuracy VFB1 TJ=25 C 1.237 1.250 1.262 V Fb Voltage Total Variation 1.225 1.250 1.275 V Fb Voltage Line Regulation 0.2 % Fb Input Bias Current IFB1 VFB1=1.25V -1 +1 A Min On Time VFB1 is sq wave with 300ns on 800 ns time and 2s off time Min Off Time VFB1 is sq wave with 300ns off 800 ns time and 2s on time VHYST Pin Output-HI ISOURCE=500A, VFB1=1.5V 11 V VHYST Pin Output-LO ISINK=500A, VFB1=1V 1 V Supply Current I12(SW) VFB1=1V, VFB2=1.5V 10 mA Maximum Duty Cycle DMAX VFB1=1V 100 % Minimum Duty Cycle DMIN VFB1=1.5V 0 % Gate Drive Rise/Fall Time VGATE Load=IRL3303 70 ns www.irf.com 2