RT9174 Preliminary 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 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 ~ 8V Input Voltage Range Current Limiting and Thermal Protection z 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 empoly driver voltage could be higher than VDD when driving NMOSFET through the 12V power. The RT9174 future a small SOP-8 package for saving board area. It also builds in current limiting and thermal shutdown protection function. Ordering Information z z z z z z z z Applications z z Mother Boards Power Supply Graphic Cards Pin Configurations RT9174C S Part Number Package type S : SOP-8 RT9174CS (Plastic SOP-8) Operating temperature range C: Commercial standard Pin Configurations TOP VIEW VDD 1 8 DRI3 DRI1 2 7 FB3 FB1 3 6 DRI2 5 FB2 GND 4 Function Block Diagram OC + Thermal Limit VDD _ + + DRI1 DRI2 _ OC FB2 _ OC + + _ FB1 DRI3 _ _ + GND 0.8V 1.3V FB3 Reference DS9174-00 April 2001 www.richtek.com 1 RT9174 Preliminary Pin Description Pin Name Pin Function VDD Power Supply Input DRI1 Regulator 1 Driver Output FB1 Regulator 1 Feedback Non-inverting Input GND 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 Typical Application Circuit 5V C1 1µF 12V C5 0.1µF 3.3V R1 5K 1 3.3V 2 Q1 PHD45N03LT V DDQ 1.5/ 3.3V C2 + 1000µF R2 4.3K R3 4.99K C6 10nF VDD DRI3 DRI1 FB3 7 3 FB1 DRI2 6 4 GND FB2 5 D1 R6 424 Q2 2SD1802 RT9174 R4 250 R5 200 1N4148 3.3V Q3 2SD1802 8 + V O2 1.8V C3 470µF R7 200 + V O3 2.5V C4 470µF #TYPEDET R8 1K VDDQ = 3.3V if FB1 >1.3V #TYPEDET = 0V →VDDQ = 1.5V #TYPEDET = Open →VDDQ = 3.3V Fig 1. Triple LDOs with VDDQ for M/B Application www.richtek.com 2 DS9174-00 April 2001 RT9174 Preliminary 5V C1 1µF 12V R10 Q3 MMBT3904 1K C5 0.1µF R1 5K 1 3.3V 2 Q1 PHD45N03LT 4 1.5/ 3.3V DRI3 DRI1 FB3 C6 10nF R2 4.3K GND 7 DRI2 6 FB2 5 2SD1802 V TT R4 113 + R5 200 R11 374 1N4148 3.3V 3.3V Q2 RT9174 D1 R3 4.99K C8 0.01µF 8 VDD 3 FB1 VDDQ + R9 1K V TTPG C3 470µF R6 3K C7 1µF R12 8.2K #TYPEDET R8 1K VTTSEL Q4 2N7002 VDDQ = 3.3V if FB1 >1.3V #TYPEDET = 0V →VDDQ = 1.5V #TYPEDET = Open →VDDQ = 3.3V VTTSEL = 0V →VTT = 1.25V VTTSEL = 5V →VTT = 1.5V Fig 2. Dual LDOs with VTTPG for VRM8.5 Application 12V R9 1.2K C5 0.1µF 7.5V R1 5K 3.3V C1 1µF R8 3K Q3 PHD45N03LT V O3 1 5V 2 Q1 PHD45N03LT V O1 3.3V R2 624 C2 + 1000µF R3 200 VDD DRI3 DRI1 FB3 8 R6 424 + 7 3 FB1 DRI2 6 Q2 4 GND FB2 5 PHD45N03LT V O2 RT9174 R4 250 R5 200 R7 200 2.5V C4 470µF 1.8V + C3 470µF Fig 3. Triple LDOs Driving MOS Application DS9174-00 April 2001 www.richtek.com 3 RT9174 Preliminary Absolute Maximum Ratings z z z z z z z Input Voltage VDD Feedback FB1/FB2/FB3 Driver DRI1/DRI2/DRI3 Power Dissipation, PD @ TA = 25°C SOP-8 Package Thermal Resistance SOP-8, θJA Operating Junction Temperature Range Storage Temperature Range 8V -0.3 ~ 8V -0.3 ~ 12V 0.625W 160°C/W -40°C ~ 125°C 65°C ~ 150°C Electrical Characteristics (VDD = 5V, CIN = 1µF, TA = 25°C, unless otherwise specified) Parameter Supply Current Symbol IDD Feedback Reference Voltage VREF Line Regulation ∆VLINE Load Regulation ∆VLOAD Driving Capability Driver Current Limiting Driver Tri-State Threshold www.richtek.com 4 Typ Max Units ICL VTS POR Min 0.8 2 mA 0.8 0.82 V VDD = 4V~7V 2 10 mV Source 100mA, DRI1/DRI2/DRI3 = 2.5V 5 10 Sink 5mA, DRI1/DRI2/DRI3 = 2.5V 10 15 No Load No Load Sourcing, DRI1/DRI2/DRI3 = 2.5V IO Thermal Limit Power On Reset Voltage Test Conditions Sink DRI1/DRI2/DRI3 = 2.5V 0.78 100 mA 5 Sourcing, DRI1/DRI2/DRI3 = 2.5V 300 700 Sink DRI1/DRI2/DRI3 = 2.5V 40 150 1.35 2.0 Sweep FB1/FB2/FB3 to Driver Output Off 1.0 mV mA V 150 °C 2.4 V DS9174-00 April 2001 RT9174 Preliminary Typical Operating Charateristics Driver Sourcing vs Drop Out Reference vs Tempature 0.82 300 VDD = 5V 250 -20°C 25°C 200 85°C 0.81 Sourcing(mA) Reference (Volt) VDD = 5V 0.80 150 100 0.79 50 0 0.78 -50 -10 30 70 110 0 150 1 Temperature (° C) 2 3 4 5 VDD - VDRI1,2,3 (Volt) Driver Sinking vs VOUT Supply Current vs Temperature 1.4 50 VDD = 5V 85°C 1.2 Sinking (mA) IQ(mA) 40 25°C 1 -20°C 0.8 -20°C 25°C 85°C 30 20 0.6 10 0.4 3 4 5 6 7 0 8 1 2 VDD (Volt) 3 4 5 VOUT (Volt) Tri-Sate Vth vs Temperature Short Current vs Temperature 1.6 400 VDD = 5V VDD = 5V 350 Short Current (mA) Vth(Volt) 1.4 1.2 1.0 300 250 200 150 0.8 100 -50 -10 DS9174-00 April 2001 30 70 Temperature( ° C) 110 150 -50 -20 10 40 70 Temperature (° C) 100 130 www.richtek.com 5 RT9174 Preliminary Applications 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. V IN DRI1 VDD RT9174 DRI2 DRI3 V DD 1µF Pass Transistor Selection FB1 FB2 FB3 V OUT R1 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. + COUT R2 As close as to RT9174 Fig 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 Fig. 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) ×R2, if R3 + R2 × 0.8 = 1.5 . R3 When in AGP 4X SELECT = GND, VDDQ will work in normal 1.5V setting. www.richtek.com 6 DS9174-00 April 2001 RT9174 Preliminary Package Information H A M J B F C D I Dimensions In Millimeters Symbol Dimensions In Inches 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 0.178 0.254 0.007 0.010 I 0.102 0.254 0.004 0.010 J 5.791 6.198 0.228 0.244 M 0.406 1.270 0.016 0.050 8-Lead SOP Plastic Package DS9174-00 April 2001 www.richtek.com 7 RT9174 Preliminary RICHTEK TECHNOLOGY CORP. RICHTEK TECHNOLOGY CORP. Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)89191466 Fax: (8862)89191465 Email: [email protected] www.richtek.com 8 DS9174-00 April 2001