Triple Linear Regulator Controllers General Description The is a triple linear regulator controller designed for motherboard application. The regulators are intended to regulate the computer system AGP (X/X) power, the.v clock power, and the.8v power for North/South Bridge core voltage and/or cache memory circuits. All controllers can drive NPN or NMOSFET pass transistor. A special scheme employing driver voltage could be higher than V DD when driving NMOSFET through the V power. The future a small SOP8 package for saving board area. It also builds in current limiting and thermal shutdown protection function. Ordering Information Note : Richtek products are : Package Type S : SOP8 Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) RoHS compliant and compatible with the current requirements of IPC/JEDEC JSTD00. Suitable for use in SnPb or Pbfree soldering processes. Features Integrated Three Linear Controllers in a SOP8 Package Driving NPN or NMOSFET Sourcing ( > 00mA) and Sinking ( > ma) Driver TriState Output Driver Low Internal 0.8V Reference Adjustable Output Voltage Setting High Output Stability V DDQ./ Automatic Changing for AGP Wide V to 8V Input Voltage Range Current Limiting and Thermal Protection RoHS Compliant and 00% Lead (Pb)Free Applications Mother Boards Power Supply Graphic Cards Pin Configurations DRI (TOP VIEW) 8 SOP8 DRI DRI Function Block Diagram OC Thermal Limit OC DRI OC DRI 0.8V.V Reference
Typical Application Circuit V V DDQ. / C 000uF V Q PHDN0LT K C 0nF DRI 8 DRI D N8 R8 #TYPEDET Q SD80 V O R.8V C R Q SD80 R R C V O.V Q = if >.V #TYPEDET = 0V to Q =.V #TYPEDET = Open to Q = Figure. Triple LDOs with Q for M/B Application V K V 8 DRI 0 V TTPG C8 0.0 R9 Q MMBT90 V DDQ. / Q PHDN0LT C 000uF R.K.99K C 0nF D N8 R8 DRI #TYPEDET V TTESL Q SD80 R R C R K C V TT 8.K Figure. Dual LDOs with V TTPG for VRM 8. Application
V O C 000uF V C 0. V Q PHDN0LT K R R8 K R9.K.V DRI 8 DRI Q PHD0LT R R.8V C Q PHD0LT R R V O V O.V C Figure. Triple LDOs Driving MOS Application Functional Pin Description Pin Name DRI DRI Pin Function Power Supply Input Regulator Driver Output Regulator Feedback Noninverting Input Power Ground Regulator Driver Output Regulator Feedback Noninverting Input Regulator Driver Output Regulator Feedback Noninverting Input
Absolute Maximum Ratings Input Voltage V DD 8V Feedback // 0. to 8V Driver DRI//DRI 0. to V Power Dissipation, P D @ T A = C SOP8 0.W Package Thermal Resistance SOP8, θ JA 0 C/W Operating Junction Temperature Range 0 C to C Storage Temperature Range C to 0 C Electrical Characteristics (V DD = V, CIN = F, TA = C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Supply Current I DD No Load 0.8 ma Feedback Reference Voltage V REF No Load 0.8 0.8 0.8 V Line Regulation V LINE V DD = to V 0 mv Source 00mA, DRI//DRI =.V 0 Load Regulation V LOAD Sink ma, DRI//DRI =.V 0 mv Driving Capability I O Sourcing, DRI//DRI =.V 00 Sink DRI//DRI =.V ma Driver Current Limiting I CL Sourcing, DRI//DRI =.V 00 00 Sink DRI//DRI =.V 0 0 ma Driver TriState Threshold V TS Sweep // to Driver Output Off.0..0 V Thermal Limit 0 C Power On Reset Voltage POR. V
Typical Operating Characteristics Reference (V) 0.8 0.8 0.80 Reference vs Temperature Sourcing(mA) 00 0 00 Driver Sourcing vs Drop Out 0 C C 8 C 0.9 0 0.8 0 0 0 0 0 0 Temperature ( C) 0 0 V DD V DRI,, (V). Supply Current vs Temperature 0 Driver Sinking vs V OUT. 8 C 0 IQ(mA) 0.8 C 0 C Sinking (ma) 0 0 C C 0. 0 8 C 0. 8 V DD (V) 0 0 V OUT (V). TriSate Vth vs Temperature 00 Short Current vs Temperature 0 Vth(V)...0 Short Current (ma) 00 0 0.8 0 0 0 0 0 0 Temperature ( C) 00 0 0 0 0 0 00 0 Temperature ( C)
Application Information Capacitors Selection A 0.μF minimum capacitor is recommended between V DD and ground to increase stability. The linear controllers use dominant pole compensation integrated into the error amplifier and are sensitive to output capacitor selection. When driving external pass transistor, normally a minimum 0μF capacitor must be placed at output for stability and good transient response. When using internal pass transistor, just need 0μF capacitor for stable. Pass Transistor Selection The are designed specifically to driver external NPN or NMOSFET pass transistor for up to A output current. The driver could deliver more 00mA when driving NPN transistor and sinking for a pull up resistor load when driving a NMOSFET. Typically pass transistor with NPN hfe > 0 at Imax or NMOSFET Rdson 00mΩ are suitable in most application. Layout Considerations There are two critical layout considerations. One is the divider resistors should be located to as possible to avoid inducing any noise. The second is C OUT should be put at near the pass transistor to avoid oscillation. V DD D D D As close as to Figure R C OUT V IN V OUT Output Voltage Setting The develop a 0.8V reference voltage, especially suit for low voltage application. As shown in Figure, the output voltage could be easy set by & R resistor. The divided resistor must keep below kω for quick response and stability. Tristate Operation A special Tristate design is empolyed in the for AGP X/X power supply. Typical application shown the detail circuit. In AGP X SELECT = open, will be pulled up over.v through R 8 to trip the Tristate threshold. R 8 has to meet the following relationship: R 8 < 0. (V.) x R, R if 0.8 =.. When in AGP X SELECT =, V DDQ will work in normal.v setting.
Outline Dimension A H M J B F I C D Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A.80.00 0.89 0.9 B.80.988 0.0 0. C.. 0.0 0.09 D 0.0 0.08 0.0 0.00 F.9. 0.0 0.0 H 0.0 0. 0.00 0.00 I 0.00 0. 0.00 0.00 J.9. 0.8 0. M 0.00.0 0.0 0.00 8Lead SOP Plastic Package Richtek Technology Corporation Headquarter F, No. 0, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (88)89 Fax: (88) Richtek Technology Corporation Taipei Office (Marketing) F, No. 9, Minchiuan Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (88)899 Fax: (88)8 Email: marketing@richtek.com Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.