RT9174GS

RT9174 Triple Linear Regulator Controllers General Description Features The RT9174 is a triple linear regulator controller designed for motherboard application. z Integrated Three Linear Controllers in a SOP-8 Package z Driving NPN or NMOSFET Sourcing ( > 100mA) and Sinking ( > 5mA) Driver Tri-State Output Driver Low Internal 0.8V Reference Adjustable Output Voltage Setting High Output Stability VDDQ 1.5/3.3V Automatic Changing for AGP Wide 3V to 8V Input Voltage Range Current Limiting and Thermal Protection RoHS Compliant and 100% Lead (Pb)-Free The regulators are intended to regulate the computer system AGP (2X/4X) power, the 2.5V clock power, and the 1.8V 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 VDD when driving z z z z z z NMOSFET through the 12V power. z The RT9174 future a small SOP-8 package for saving board area. It also builds in current limiting and thermal shutdown z z protection function. Applications Ordering Information z RT9174 z Package Type S : SOP-8 Mother Boards Power Supply Graphic Cards Pin Configurations Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) (TOP VIEW) VDD Note : Richtek products are : ` 8 DRI 3 DRI 1 2 7 FB3 FB1 3 6 DRI 2 GND 4 5 FB2 RoHS compliant and compatible with the current requireSOP-8 ments of IPC/JEDEC J-STD-020. ` Suitable for use in SnPb or Pb-free soldering processes. Function Block Diagram OC Thermal Limit VDD + DRI1 DRI2 - OC + + FB2 OC + + FB1 - DRI3 + GND 0.8V 1.3V FB3 Reference DS9174-08 April 2011 www.richtek.com 1 RT9174 Typical Application Circuit 5V C1 1uF 12V C1 1uF 3.3V R1 5K 3.3V 1 2 3 VDDQ 1.5 / 3.3V 4 C6 2SD1802 5 FB2 GND Q2 6 DRI2 FB1 R4 250 10nF + 1N4148 R1 1K 3.3V R5 200 RT9174 D1 C2 1000uF R6 424 R7 200 VO2 1.8V VO3 2.5V C3 470uF + R1 1K FB3 DRI1 2SD1802 7 + Q1 PHD45N03LT 8 DRI3 VDD Q3 C3 470uF #TYPEDET R8 1K VDDQ = 3.3V if FB1>1.3V #TYPEDET = 0V to VDDQ = 1.5V #TYPEDET = Open to VDDQ = 3.3V Figure 1. Triple LDOs with VDDQ for M/B Application R9 1K 5V VTTPG C1 1uF 12V C1 1uF R1 5K 3.3V 1K 1 2 Q1 PHD45N03LT 3 VDDQ 1.5 / 3.3V C6 4 VDD DRI3 DRI1 FB3 FB1 DRI2 GND FB2 + D1 1N4148 R3 4.99K 3.3V R8 1K Q3 MMBT3904 8 7 3.3V Q2 6 2SD1802 5 R4 250 10nF C2 1000uF C8 0.01uF RT9174 R11 374 R5 200 #TYPEDET VTTESL VTT + R2 4.3K R10 C3 R6 3K 470uF C7 1uF R12 8.2K Figure 2. Dual LDOs with VTTPG for VRM 8.5 Application www.richtek.com 2 DS9174-08 April 2011 RT9174 12V R9 1.2K C5 0.1uF R8 3K 3.3V 7.5V Q3 PHD4503LT C1 1uF R1 5K 1 5V 2 Q1 PHD45N03LT 3 VO1 3.3V 4 DRI3 DRI1 FB3 FB1 DRI2 GND FB2 + RT9174 C2 1000uF C4 470uF 7 6 5 Q2 PHD4503LT R4 250 R5 200 VO2 1.8V + R2 624 VDD R7 200 8 VO3 2.5V + R6 424 C3 470uF R3 200 Figure 3. Triple LDOs Driving MOS Application Functional Pin Description Pin Name Pin Function VDD Power Supply Input DRI1 Regulator 1 Driver Output FB1 Regulator 1 Feedback Non-inverting Input GND Power Ground DRI2 Regulator 2 Driver Output FB2 Regulator 2 Feedback Non-inverting Input DRI3 Regulator 3 Driver Output FB3 Regulator 3 Feedback Non-inverting Input DS9174-08 April 2011 www.richtek.com 3 RT9174 Absolute Maximum Ratings z z z z z z z Input Voltage VDD ---------------------------------------------------------------------------------------------------- 8V Feedback FB1/FB2/FB3 ------------------------------------------------------------------------------------------- −0.3 to 8V Driver DRI1/DRI2/DRI3 ---------------------------------------------------------------------------------------------- −0.3 to 12V Power Dissipation, PD @ TA = 25°C SOP-8 ------------------------------------------------------------------------------------------------------------------ 0.625W Package Thermal Resistance SOP-8, θJA ------------------------------------------------------------------------------------------------------------ 160° C/W Operating Junction Temperature Range ------------------------------------------------------------------------- −40° C to 125° C Storage Temperature Range --------------------------------------------------------------------------------------- −65° C to 150° C Electrical Characteristics (VDD = 5V, CIN = 1F, TA = 25° C, unless otherwise specified) Parameter Min Typ Max Unit No Load -- 0.8 2 mA Feedback Reference Voltage VREF No Load 0.78 0.8 0.82 V Line Regulation VLINE VDD = 4 to 7V -- 2 10 mV Load Regulation Source 100mA, DRI1/DRI2/DRI3 = 2.5V VLOAD -- 5 10 Sink 5mA, DRI1/DRI2/DRI3 = 2.5V -- 10 15 100 -- -- Sink DRI1/DRI2/DRI3 = 2.5V 5 - -- Sourcing, DRI1/DRI2/DRI3 = 2.5V -- 300 700 Sink DRI1/DRI2/DRI3 = 2.5V -- 40 150 1.0 1.35 2.0 V -- 150 -- °C -- 2.4 -- V Supply Current Driving Capability Driver Current Limiting Driver Tri-State Threshold Symbol IDD Sourcing, DRI1/DRI2/DRI3 = 2.5V IO ICL VTS Thermal Limit Power On Reset Voltage www.richtek.com 4 Test Conditions POR Sweep FB1/FB2/FB3 to Driver Output Off mV mA mA DS9174-08 April 2011 RT9174 Typical Operating Characteristics Driver Sourcing vs Drop Out Reference vs Temperature 300 0.82 VDD = 5V VDD = 5V -20°C 0.81 Sourcing(mA) Reference (V) 250 0.80 25°C 200 85°C 150 100 0.79 50 0 0.78 -50 -10 30 70 110 0 150 1 2 3 4 5 VDD - VDRI1,2,3 (V) Temperature (°C) Driver Sinking vs VOUT Supply Current vs Temperature 50 1.4 VDD = 5V 85°C 40 Sinking (mA) IQ(mA) 1.2 25°C 1 -20°C 0.8 30 -20°C 25°C 20 85°C 0.6 10 0.4 3 4 5 6 7 0 8 1 2 VDD (V) 3 4 5 VOUT (V) Tri-Sate Vth vs Temperature Short Current vs Temperature 400 1.6 VDD = 5V VDD = 5V 350 Short Current (mA) Vth(V) 1.4 1.2 1.0 300 250 200 150 100 0.8 -50 -10 30 70 Temperature (°C) DS9174-08 April 2011 110 150 -50 -20 10 40 70 100 130 Temperature (°C) www.richtek.com 5 RT9174 Application Information Capacitors Selection Layout Considerations A 0.1μF minimum capacitor is recommended between VDD 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 470μF capacitor must be placed at output for stability and good transient response. When using internal pass transistor, just need 10μF capacitor for stable. There are two critical layout considerations. One is the divider resistors should be located to RT9174 as possible to avoid inducing any noise. The second is COUT should be put at near the pass transistor to avoid oscillation. VDD 1uF The RT9174 are designed specifically to driver external NPN or NMOSFET pass transistor for up to 5A output current. The driver could deliver more 100mA when driving NPN transistor and sinking for a pull up resistor load when driving a NMOSFET. VOUT FB1 FB2 FB3 R1 + Pass Transistor Selection VDD VIN DR11 RT9174 DR12 DR13 COUT R2 As close as to RT9174 Figure 4 Typically pass transistor with NPN hfe > 50 at Imax or NMOSFET Rds-on 100mΩ are suitable in most application. Output Voltage Setting The RT9174 develop a 0.8V reference voltage, especially suit for low voltage application. As shown in Figure 4, the output voltage could be easy set by R1 & R2 resistor. The divided resistor must keep below 1kΩ for quick response and stability. Tri-state Operation A special Tri-state design is empolyed in the RT9174 for AGP 2X/4X power supply. Typical application shown the detail circuit. In AGP 2X SELECT = open, FB1 will be pulled up over 1.3V through R8 to trip the Tri-state threshold. R8 has to meet the following relationship: R8 < 0.75 (V33 - 1.3) x R2, R3 + R2 if × 0.8 = 1.5 . R3 When in AGP 4X SELECT = GND, VDDQ will work in normal 1.5V setting. www.richtek.com 6 DS9174-08 April 2011 RT9174 Outline Dimension H A M J B F C I D Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 4.801 5.004 0.189 0.197 B 3.810 3.988 0.150 0.157 C 1.346 1.753 0.053 0.069 D 0.330 0.508 0.013 0.020 F 1.194 1.346 0.047 0.053 H 0.170 0.254 0.007 0.010 I 0.050 0.254 0.002 0.010 J 5.791 6.200 0.228 0.244 M 0.400 1.270 0.016 0.050 8-Lead SOP Plastic Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 5F, No. 95, Minchiuan Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)86672399 Fax: (8862)86672377 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. DS9174-08 April 2011 www.richtek.com 7