RT9206 Preliminary High Efficiency, Synchronous Buck with Dual Linear Controllers General Description Features The RT9206 is a low cost, combo power controller, which integrates a synchronous step down voltage mode PWM and 2 linear controllers. RT9206 directly drive external N-channel MOSFET makes it easy to implement a high efficiency and cost attractive power solution. Voltage mode control loop and constant operation frequency with external compensation network provide better stability in wide operation range. Adjustable operation frequency up to 600kHz can minimize the inductor value and PCB board space. It is particularly suitable in wide input voltage range (from 5V to 28V) and multi output applications. z z z z z z z z z Wide input range (5V to 28V) 0.8V internal reference High efficiency Synchronous Buck topology Integrate 2 linear controllers Low cost N channel MOSFET design Duty Cycle from 0% to 90%. Adjustable switching frequency from 200kHz to 600kHz, Default 200KHz Sense OCP by low side MOSFET RDS(ON) Power good signal output Applications Linear controller features in flexible linear power design, delivered power can be simply decided by external NMOSFET’s selection. Output voltage level is chosen via external resistor divider, 0.8V internal reference can satisfied most of the chip’s requirement. Under voltage lock-out provide cost effective protection of output. z z z z z RT9206 provides complete safety protection function: soft start, over current protection, over voltage and under voltage protection. Set current limit by choosing different MOSFET and works in HICCUP mode as over current occurs. Synchronous Buck control mode provides excellent over voltage protection by turning on low side MOSFET to prevent any damage of end device from abnormal voltage stress as over voltage condition occurs. LCD Monitor Desk Note IEEE1394 Client Desktop IA Broadband Pin Configurations TOP VIEW LDRV1 VIN LDRV2 LFB2 COMP FB1 PG SS/EN Ordering Information 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 SOP-16 RT9206 Package Type S : SOP-16 Operating Temperature Range C : Commercial Standard DS9206-01 June 2003 1 LFB1 BST UG PHS VINT LG GND RT RT9206 Preliminary Typical Application Circuit R1 C1 1uF VOUT1 Q1 3.3V C4 1uF C6 10uF VOUT3 2.5V C5 1uF R4 11K 5.6K D1 LDRV1 BSH108 LDRV2 11K 10uF R11 3.3K C14 3.3nF R12 51K 0 UG LFB2 PHS COMP VINT FB LG C13 PG GND 68pF SS/EN 0 0.1uF C8 4.7uF L1 15uH Q4 R5 RT R8 3K R9 560 R12 C14 C13 VIN = 9V 68K 2.7nF 68pF VIN = 12V 51K 3.3nF 68pF VIN = 19V 33K 5.6nF 56pF Function Block Diagram LDO2 LDRV1 0.8V LFB1 5.8V Reg VINT LDRV2 Thermal Protection LDO1 LFB2 COMP 0.8V + GM - FB SS +PWM CP - RAMP Generator 0.6V + UV - 1V + OVP - 0.72V + PG Soft Start SS/EN Driver Control Logic OSC PG 8uA 2 VIN 12V Si9925DY Q3 0.1uF R10 51K C3 100uF C9 VIN RT9206CSBST R3 C7 R2 LDRV1 BSH108 Q2 C2 1uF 10 BST UG PHS VINT LG GND RT C10 1000uF VOUT1 C11 1uF Preliminary RT9206 Pin Description Pin NO. Pin Name 1 LDRV1 2 VIN 3 LDRV2 4 LFB2 5 COMP 6 FB 7 PG Pin Function LDO1 driver. Connect to the gate of exteran N-channel MOSFET pass transistor to form a positive linear regulator Input supply voltage. LDO2 driver. Connect to the gate of exteran N-channel MOSFET pass transistor to form a positive linear regulator LDO2 feedback input. The feedback setpoint is 0.8V. Connect to a resistive divider between the positive linear regulator's output and GND to adjust the output voltage. Switching regulator compensation pin. Switching regulator feedback input. The feedback setpoint is 0.8V. Connect to a resistive divider between the switching regulator output and GND to adjust the output voltage. Open drain power good indicator. PG is low when switching regulator output voltage is lower than 10% of its regulation voltage. Connect a pull high resistor between PG and switching regulator output for pull high logic level voltage. 8 SS/EN 9 RT Soft start input with 6uA soucing currnet and IC enable control. Operational frequency setting. Connect a resistor between RT and GND to set operational frequency. The operational frequency will nominally run at 200KHz when open. The formula between resistor setting and operational frequency are as follows: RT = 10 GND 11 LG 12 Vint 62 × 10 8 Fosc − 200 × 10 3 Ground Low side gate driver. Drives low side N-channel MOSFET with a voltage swing between Vint and GND Internal 5.8V regulator output. The low side gate driver and control circuit and external boostrap diode are powered by this voltage. Decouple this pin to power ground with a 1uF or greater ceramic capacitor close to the Vint pin. 13 PHS 14 UG 15 BST 16 LFB1 Inductor connection with (-) terminal boostrap flying capacitor connection. High side gate driver. Drives high side N-channel MOSFET with a voltage swing between BST and PHS High side floating driver supply with (+) terminal boostrap flying capacitor connection. Voltage swing is from a diode drop below Vint to VIN+Vint LDO1 feedback input. The feed back setpoint is 0.8V. Connect to a resistive divider between the positive linear regulator's output and GND to adjust the output voltage. 3 RT9206 Preliminary Absolute Maximum Ratings z z z z z z z z z z Input Supply Voltage (VIN) ------------------------------------------------------------------------------------------ – 0.3 to 30V PHS ---------------------------------------------------------------------------------------------------------------------- – 0.6V to 30V PHS (PHS Transient Time Interval < 50ns) -------------------------------------------------------------------- – 5V BST to PHS ------------------------------------------------------------------------------------------------------------ – 0.3V to 7V LDRI1, LDRI2 ---------------------------------------------------------------------------------------------------------- – 0.3V to 30V Power Good Voltage ------------------------------------------------------------------------------------------------- – 0.3V to 7V The other pins --------------------------------------------------------------------------------------------------------- – 0.3V to 7V Operation Temperature Range ------------------------------------------------------------------------------------ – 20°C to 85°C Junction Temperature Range -------------------------------------------------------------------------------------- 0°C to 125°C Storage Temperature Range -------------------------------------------------------------------------------------- – 65°C to 150°C Electrical Characteristics (VIN = 12V, FADJ left floating, TA = 25°C, Unless Otherwise specification) Parameter Symbol Test Condition Min Typ Max Units 5 -- 28 V 200 -- 600 mV System Supply Input Operation voltage Range VIN (Note 1) Power On Reset Hysteresis Supply Current ICC VCC=30V, VSS=VINT -- 1.3 4 mA Shut Down Current ICC VCC=30V, VSS<0.4V -- 1 3.5 mA Power Good under Threshold VFB 87 -- 92 % PG Fault Condition VPG 5 -- -- mA Soft start Current ISS 4 8 12 µA Normal Operation Voltage VSS -- VINT -- V Shut down Voltage VSS 0.4 0.7 -- V Free Run Frequency FOSC 160 200 240 kHz Operation Frequency Setting FOSC -30 -- +30 % Ramp Amplitude -- 1.9 -- V Maximum Duty Cycle 85 90 -- % 0.784 0.8 0.816 V Soft Start PWM Section Oscillator By setting RT (Note 2) Reference Voltage Feedback Voltage VFB1 Internal Voltage VINT VIN=8V, IINT=10mA 5.5 6 6.5 V Internal Voltage Source Current IINT VIN=12V 20 -- -- mA To be continued 4 RT9206 Preliminary Parameter Symbol Test Condition Min Typ Max Units GM -- 1.6 -- mS Compensation Source Current 45 90 140 µA Compensation Sink Current 45 90 140 µA Upper Driver Source Impendence -- 5 8 Ω Upper Driver Sink Impendence -- 5 8 Ω Lower Driver Source Impendence -- 3 5 Ω Lower Driver Sink Impendence -- 1.5 3 Ω -270 -300 -330 mV Error Amplifier Gate Driver Protection Over Current Threshold Over Voltage Protection VFB1 0.9 1 1.1 V Under Voltage Protection VFB1 0.54 0.6 0.66 V Feedback Voltage FB2 / FB3 0.784 0.8 0.816 V Output Current DRV2/DRV3 10 -- -- mA 0.54 0.6 0.66 V -- 170 -- °C Linear Controller Section Error Amplifier Protection Under Voltage Protection FB2 / FB3 Over Temperature Protection Note 1: VCC-VOUT2 or VCC-VOUT3 must be higher than 4V to keep linear controller operation Note 2: RT = 62 x10 8 FOSC − 200 x10 3 5 RT9206 Preliminary Typical Operating Characteristics Power On Power On f = 200kHz VOUT1 = 5V IOUT1 = 2A VOUT2 = 2.5V IOUT2 = 1A VOUT3 = 2.5 V IOUT3 = 0.5A VOUT3 = 1.8 V IOUT3 = 0.5A VIN VIN VOUT1 VOUT1 VOUT2 VOUT2 VOUT3 VOUT3 PG PG VIN = 12V VIN VOUT1 f = 200kHz f = 200kHz VOUT1 = 3.3V IOUT1 = 2A VOUT2 = 3.3V IOUT2 = 1A VIN = 28V Time (40ms/Div) Time (40ms/Div) Power Off Power Off VIN VOUT1 = 5V IOUT1 = 2A VOUT2 = 3.3V IOUT2 = 1A VOUT3 = 2.5 V IOUT3 = 0.5A f = 200kHz VOUT1 VOUT2 VOUT1 = 3.3V IOUT1 = 2A VOUT2 = 2.5V IOUT2 = 1A VOUT3 = 1.8 V IOUT3 = 0.5A VOUT2 VOUT3 VOUT3 PG PG VIN = 12V VIN = 28V Time (100ms/Div) Time (100ms/Div) Bootstrap Wave Form Bootstrap Wave Form VIN = 28V BST VIN = 12V BST PHS PHS UG UG LG LG Time (2µs/Div) Time (4µs/Div) 6 RT9206 Preliminary Dynamic Loading VOUT1 Dynamic Loading 12V VVININ==12V VIN = 12V VOUT1 1V/Div 1V/Div UG UG 10V/Div 10V/Div IOUT1 IOUT1 2A/Div 2A/Div Time (10µs/Div) Time (10µs/Div) Short Hiccup Soft Start vs. Temperature 6.1 VIN = 12V VOUT1 = 5V f = 200kHz 6.05 VOUT1 VIN = 12V f = 200kHz VSS (V) 6 UG LG 5.95 5.9 5.85 IOUT1 (5A/Div) 5.8 -50 -25 0 Time (40ms/Div) Oscillator Frequency vs. Temperature 75 100 125 150 Reference Voltage vs. Temperature 0.82 VIN = 12V f = 200kHz 0.815 VIN = 12V f = 200kHz 0.81 224 223 Vref (V) Frequency (kHz) A 225 50 Temperature ( ° C) 227 226 25 222 221 220 0.805 0.8 0.795 219 0.79 218 217 0.785 -50 -25 0 25 50 75 100 125 150 -50 Temperature ( ° C) -25 0 25 50 75 Temperature ( ° C) 7 100 125 150 RT9206 Preliminary Quiescent Current vs. Input Voltage POR(Rising/Falling) vs. Temperature 5 1150 VIN = 12V 4.75 Quiescent Current ( µ A) f = 200kHz 4.5 4.25 POR (V) 4 3.75 3.5 3.25 3 2.75 1140 1135 1130 1125 1120 2.5 2.25 1115 2 -50 -25 0 25 50 75 100 125 0 150 Fosc vs. RT 800 700 VIN = 12V 600 500 400 300 200 100 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Vin (V) Temperature ( ° C) Operation Frequency (kHz) A VSS = 0V 1145 5 10 15 20 25 30 35 40 45 50 55 60 65 70 RT (k Ω ) 8 RT9206 Preliminary Outline Dimension H A M B J F C I D Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 9.804 10.008 0.386 0.394 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 16-Lead SOP Plastic Package 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] 9