Application Note Roland van Roy & Sophia Tong AN034–July 2015 Richtek Wide Input Voltage Range DC/DC Power Solutions for Industrial, Automotive and LED lighting applications AN034 © 2015 Richtek Technology Corporation 1 Application Note Table of Contents Introduction ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------3 Power Conversion IC Portfolio Overview ----------------------------------------------------------------------------------------------------------------------------------------------4 1.4V~6V VIN, up to 4A, Buck converters/LDOs --------------------------------------------------------------------------------------------------------------------------------------5 4V~18V VIN, up to 6A Buck converters-------------------------------------------------------------------------------------------------------------------------------------------------6 3V~24V VIN, up to 8A Buck converters-------------------------------------------------------------------------------------------------------------------------------------------------7 3.5V~36V VIN, up to 0.6A Buck converters/ low quiescent LDOs --------------------------------------------------------------------------------------------------------------8 4.5V~36V VIN, up to 5A Buck converters ----------------------------------------------------------------------------------------------------------------------------------------------9 4.5V~80V VIN, up to 230mA. High voltage LDOs -----------------------------------------------------------------------------------------------------------------------------------10 4.5V~29V VIN, Boost controller -----------------------------------------------------------------------------------------------------------------------------------------------------------11 4.5V~50V VIN, Constant Current LED Driver Converters -------------------------------------------------------------------------------------------------------------------------12 4.5V~150V VIN, Constant Current LED Driver Controllers------------------------------------------------------------------------------------------------------------------------13 Power Switch and DDR termination regulator ---------------------------------------------------------------------------------------------------------------------------------------14 AN034 © 2015 Richtek Technology Corporation 2 Application Note Introduction Richtek provides comprehensive power conversion solutions for input voltages ranging from 1.4V up to 80V, suitable for a wide range of applications in the industrial, automotive, and professional lighting field. The selected product range in this brochure highlights Richtek linear and switching converters, from low quiescent LDOs to highly efficient step-up and step down converters and controllers, LED lighting drivers, Power Switches and DDR terminators. Many parts come with extra features such as PGOOD signaling and programmable Soft-Start. Richtek Buck converters use robust control architectures like ACOT ™ which is compensation free and simple to use. The listed parts have thermally enhanced packages, allowing higher ambient temperature operation. Richtek also offers both 3T parts (qualified over the full -40C ~ 85C industrial temperature range) and Automotive AEC-Q100 qualified parts. All parts can be used with ceramic input and output capacitors which extends operation life time. These features make the Richtek parts extremely suitable for demanding applications fields such as: Industrial AN034 eMetering Embedded Computing Industrial control systems Portable equipment Instrumentation Surveillance Cameras Automotive Infotainment USB power Communications Networking Servers Data storage © 2015 Richtek Technology Corporation Professional LED Lighting Car lighting Street Lighting Display lighting Lighting controls 3 Application Note Power conversion IC Portfolio for Industrial, Automotive and LED lighting applications AN034 © 2015 Richtek Technology Corporation 4 Application Note Step down converters and LDOs 1.4V~6V VIN, up to 4A, Buck converters/LDOs, Ideal for Li-ion battery powered applications, 5V input power rails and intermediate power conversions. P/N Description RT2657BQ IOUT 0.6A RT5712A 2A 1.4V ~ 6V LDOs/Buck up to 4A VIN converters IOUT VIN 2.7V~5.5V 2.7V~5.5V VOUT 0.6V~5.5V 0.6V~3.4V fSW Buck converter 3A 2.95V~6V VREF: 0.827V Package AEC-Q100 Compliance Built-in Soft-Start 1.5A Current limit peak 1MHz RON 100mΩ HS / 70mΩ LS 1.2ms fixed Soft-Start CMCOT topology: good transient response, stable with MLCC Hiccup or Latch off UVP WDFN-6L-2x2 300kHz~2MHz RON 45mΩ HS / 45mΩ LS Power Good Adjustable Soft-Start WQFN-16L-3x3 RON 50mΩ HS / 40mΩ LS CMCOT topology: good transient response, stable with MLCC 2.25MHz Synchronous RT8079 Key Features WDFN-8L 3x3 RT8086B 3.5A 2.8V~5.5V 0.6V~3.3V 1.2MHz Power Good Built-in Soft-Start Hiccup UVP UQFN-12L-2x2 (FC) RT8074 4A 2.7V~5.5V 0.8V~5V 200kHz~2MHz Built-in Soft-Start PSOP-8 P/N Description IOUT VIN VOUT VDropout Key Features Package 1A 2.2V~6V 1.2V~VIN 200mV@1A AEC-Q100 Compliance Low Quiescent 1.5µA in Shutdown Mode PSOP-8 RT2517C 1A 2.2V~6V 1.2V~VIN 150mV@1A 3T Grade Low Quiescent 0.1µA in Shutdown Mode VDFN-8AL-3x3 RT2518 1A 1.4V~6V 0.5V~VIN 200mV@1A 3T Grade EN control WDFN-8L-3x3 2A 1.4V~6V 0.5V~VIN 400mV@2A 3T Grade EN control PSOP-8 RT2517B LDO LDO with EN RT2515H AN034 © 2015 Richtek Technology Corporation 5 Application Note 4V~18V VIN, up to 6A Buck converters, ideal for applications powered from 5V~12V power rails, intermediate power conversions, etc. P/N RT8297B Description Current Mode Synchronous Buck converter IOUT 1.5A 4V ~ 18V Buck 1.5A ~ 6A VIN converters IOUT VIN 4V~17V VOUT 0.8V~12V fSW 800kHz Key Features Power Good Package WDFN-8L-2x2 RT6232/33/A/B A:PSM B:PWM RT7275/76 75:PWM 76:PSM RT7231/32 31:PWM 2A/3A 500kHz 3A 700kHz WDFN-8L-2x3 ACOT™ topology for ultra-fast transient response and MLCC COUT stable Adjustable Soft-Start Power Good Force PWM or PSM (enhanced light load efficiency) ACOT™ Synchronous Buck converter 4.5V~18V 0.765V~8V 4A 650kHz 5.5A 650kHz 32:PSM RT6206B PSM RT2859A/B A:PSM B:PWM RT2855A/B A:PSM B:PWM 3A ACOT™ Synchronous 650kHz 4.5V~18V Buck converter 0.765V~7V 4A 650kHz Current Mode RT2856 AN034 Synchronous Buck converter 6A 4.5V~18V VREF: 0.8V 200kHz~1.6MHz © 2015 Richtek Technology Corporation WDFN-10L-3x3 PTSSOP-14 WDFN-10L-3x3 PTSSOP-14 WDFN-10L-3x3 PSOP-8 3T Grade ACOT™ topology for ultra-fast transient response and MLCC COUT stable WDFN-16L-3x3 Adjustable Soft-Start Power Good Hiccup or Latch off UVP WDFN-16L-3x3 3T Grade RON 26mΩ HS / 19mΩ LS Adjustable Soft-Start Power Good VREF:0.8V ±1% over -40C ~ 85C WQFN-14AL-3.5x3.5 6 Application Note 3V~24V VIN, up to 8A Buck converters, ideal for applications powered from 12V system power rails requiring extra input voltage de-rating P/N RT7262/63/64 Description Current Mode Synchronous Buck converter RT8299 RT6220 RT7238 ACOT™ Synchronous Buck converter ACOT™ Synchronous Buck converterwith 3.3V/5V LDO IOUT 3V ~ 24V Buck up to 8A VIN converters IOUT VIN VOUT fSW Key Features 2A/3A/4A 4.5V~21V 0.808V~15V 500kHz Synchronized external clock from 300kHz~2MHz Adjustable Soft-Start Low LS RON ideal for low VOUT 3A 3V~24V 0.8V~15V 500kHz Power Good and very wide VIN range Package WDFN-14L-4x3 PSOP-8 WDFN-10L-3x3 PSOP-8 ACOT™ topology for ultra-fast transient response and 6A 4.5V~23V 0.6V~5V 500kHz MLCC COUT stable RON 31mΩ HS / 20mΩ LS UQFN-16L-3x3(FC) Power Good 8A 8V~23V 0.9V~5V Adj. 3.35V fixed 5.0V fixed 500kHz ACOT™ topology for ultra-fast transient response and MLCC COUT stable RON 27mΩ HS / 10mΩ LS UQFN-10L-3x3(FC) With fixed 70mA 3.3V/5V LDO Also see: Application note ‘’Buck converter selection criteria’’ Application note "Comparing Buck converter topologies–Current mode, CMCOT™ and ACOT™" AN034 © 2015 Richtek Technology Corporation 7 Application Note 3.5V~36V VIN, up to 0.6A Buck converters/ low quiescent LDOs, ideal for applications from 24V rails, for powering low power MCUs in e-metering, lighting controls, sensors, etc. P/N RT6208 Description Buck converter RT6200 P/N RT9058 RT2560Q IOUT LDOs/Buck 0.1A~0.6A VIN converters IOUT VIN VOUT 0.1A 4.5V~36V Adj.VOUT VREF = 0.8V 0.6A 4.5V~36V 0.8V~15V± 2% Description LDO 3.5V ~ 36V IOUT 100mA VIN fSW Hysteretic mode operation using Boundary conduction mode 2.5V,3.3V,5V,12V fixed Synchronous Adjustable current limit 25µA IQ Very high efficiency at low load Asynchronous with internal 0.3Ω HS MOSFET 1.2MHz VOUT 3.5V~36V Key Features VDropout Key Features AEC-Q100 Grade (RT2560Q) 550mV@10mA 2µA ultra low IQ Package SOT-23-6 PSOP-8(w/PG) SOT-23-8(w/PG) SOT-23-6 Package SOT-23-3 SOT-89 PSOP-8 Application note “How to power small MCU’s from industrial supply rails” 4.5V ~ 36V VIN 5 CIN (open = automatic start) 3 SW VIN RT6208GE EN FB 4 ISET R1 (peak current setting) 6 VOUT 3.3V/100mA L1 R2 C1 COUT 1 SW VIN ISET R3 GND 2 6 5 4 2 3 FB GND EN SOT-23-6 36V low power buck delivering high efficiency from light load to full load conditions. AN034 © 2015 Richtek Technology Corporation 8 Application Note 4.5V~36V VIN, up to 5A Buck converters, ideal for applications from 24V power rails, such as USB supply, displays, medium power MCUs, Instrumentation, etc. 4.5V ~ 36V VIN P/N Description RT7272A/B 3A (PWM/PSM) RT2872 RT2875A/B (latch UV/hiccup UV) IOUT VOUT 4.5V~36V 3A Current Mode Buck converter VIN 3A 4.5V~36V RT8289 5A 5.5V~32V RT8279 peak 5.5V~36V RT2805A 5A peak fSW 0.8V~30V 4.5V~36V Key Features Adjustable current limit: 2.5A~5.5A 500kHz Integrated 150/80mΩ HS/LS MOSFET Package PSOP-8 300kHz~1MHz AEC-Q100 Grade 3 105/80mΩ HS/LS MOSFET Ext.compensation PSOP-8 0.6V~24V 300kHz~2.1MHz PTSSOP-14 1.222V~26V 500kHz 0.8V~30V 5.5V~36V 3A ~ 5A IOUT Buck converters 1.222V~26V VIN 4.5V ~ 36V 3 7 (frequency setting) 3T Grade Asynchronous with integrated 110mΩ HS MOSFET Internal compensation & Soft-Start SW R4 ROSC Internal compensation & Soft-Start RT2872GSP 2 VIN BOOT CIN EN Asynchronous with integrated 100mΩ HS MOSFET 500kHz 8 EN RT 3T Grade 95/70mΩ HS/LS MOSFET Ext.compensation Adjustable current limit:1.5A~6A GND 4, 9 (pad) PSOP-8 C11 VOUT (3A max) L1 1 R1 FB 5 COMP PSOP-8 6 COUT R2 C7 R3 36V / 3A buck converter for automotive applications. AN034 © 2015 Richtek Technology Corporation 9 Application Note 4.5V~80V VIN, up to 230mA. High voltage LDOs, ideal for applications from highly fluctuating power rails (±60/±80V) such as automotive battery powered applications, for powering sensors, low power MCUs, etc. 4.5V ~ 80V LDOs VIN P/N Description IOUT 20mA ~ 230mA VIN VOUT IOUT VDropout Key Features Package RT2571 50mA 4.5V~60V 2.5V,3.3V,5V Fixed 1.25-60V Adj. 250mV@50mA 30µA low IQ -60V reverse protection PSOP-8, PMSOP-8, SOT-223 RT9074 100mA 4.5V~60V 2.5V,3.3V,5V Fixed 1.25-60V Adj. 300mV@100mA 30µA low IQ -60V reverse protection PSOP-8, PMSOP-8, SOT-223 RT9068 230mA 4.5V~60V 2.5V,3.3V,5V fixed 1.25V~60V Adj. 230mV@50mA 30µA low IQ -60V reverse protection PSOP-8, PMSOP-8, SOT-223 RT9072A/B 20mA 4.5V~80V 1.25V~60V Adj. 180mV@20mA LDO VIN 4.5V ~ 60V CIN 180nF Shut Down RT9068-xx VIN VOUT VOUT 2.5V/3.3V/5V VIN 4.5V ~ 60V CIN 180nF COUT 1μF SENSE SHDN VOUT SENSE NC NC GND GND 8 2 3 7 GND 9 4 6 5 VIN GND GND SHDN Shut Down 23µA low IQ SOT-23-5, WDFN-8L 3x3 -80V reverse protection RT9068 VIN VOUT SENSE SHDN VOUT 1.25V ~ 60V CCOMP R1 COUT 1μF FB GND PMSOP-8 R2 VOUT SENSE FB NC 8 2 3 4 GND 7 9 6 5 VIN GND GND SHDN PMSOP-8 1 VIN 2 3 GND VOUT (TAB) SOT-223 8 VOUT SENSE 2 NC NC 3 GND GND 6 GND 5 SHDN 9 4 VIN 7 PSOP-8 RT9068 high voltage LDO in fixed and adjustable versions. AN034 © 2015 Richtek Technology Corporation VOUT SENSE 2 FB 3 NC 4 GND 8 VIN 7 GND 6 GND 5 SHDN 9 PSOP-8 10 Application Note Step up controller for high power Boost applications 4.5V~29V VIN, Boost controller, ideal for applications in high boost power, such as 24V to 48V conversion, large display backlighting, thermal printers, battery pack charging, etc. P/N RT8525 Description Boost controller 4.5V ~ 29V Boost IOUT VIN controller limited by ext. MOSFET IOUT VIN Limited by ext.MOSFET VOUT 4.5V~29V Limited by MOSFET VIN 4.5V ~ 29V Key Features Programmable Soft-Start Time Programmable Boost SW Frequency Fault signaling pin 50K-600kHz L1 Package SOP-14 D1 VOUT RIN CIN VIN DRV RT8525GS CIN1 ISW VDC VREF Rp1 R4 COUT Q1 RSLP RSW1 RSW2 CREF PWMI R14 RFB1 Rp2 FB Fault FAULT EN COMP EN CC2 fSW RC1 CC1 Rt CSS RFB2 ROVP1 OOVP FSW SS AGND PGND ROVP2 VDC VIN COMP SS FSW AGND PWMI 14 2 13 3 12 4 11 5 10 6 9 7 8 DRV PGND EN ISW OOVP FB FAULT SOP-14 RT8525 Boost controller application for high output powers AN034 © 2015 Richtek Technology Corporation 11 Application Note LED Drivers 4.5V~50V VIN, Constant Current Buck converters, ideal for medium power industrial LED lighting applications. 4.5V ~ 50V VIN P/N RT8471 RT8474/A (A:OVP for hot swap function) AN034 Description Hysteretic control, high brightness LED driver 50V high voltage LED driver IOUT 1/1.2A 2A VIN 7V~36V 4.5V~50V LED drivers Key Features Simple application: no COUT needed Analog or digital dimming control Ultra-fast response Colour control for single string Analog or digital dimming control Low RON © 2015 Richtek Technology Corporation up to 2A Where to use, (application examples) LED strips, signage, < 15W MR-16 ≤ 4WSingle string buck with color control via LED shunt dimming LED strips, signage, LED engines, POUT< 30W RT8474A with special open string protection is ideal Package TSOT-23-5 PMSOP-8 PSOP-8 PSOP-8 for hot-swap LED string 12 Application Note 4.5V~150V VIN, Constant Current Buck / Boost / Buck-Boost controllers, ideal for industrial/automotive LED lighting applications, such as high power LED string applications, street lighting, display backlight. P/N Description IOUT RT8477A Buck / Boost controller RT8475/ RT8494 LED Driver Controller for Buck, Boost or Buck-Boost Topology RT8485 LED Driver controller for Buck/Boost/Buck-Boost topologies VIN Limited by external MOSFET ext. MOSFET limited LED drivers 4.5V ~ 150V VIN VLED Key Features Where to use Package 4.5V~50V up to 50V low component count Analog or PWM Dimming control Wide input / output range with medium power: LED modules, down-light, emergency lighting Buck ≤ 60W, Boost ≤ 40W 4.5V~36V (IC VIN) up to 90V Programmable FSW 100kHzto 1MHz Analog or Digital to Analog Dimming control Industrial Display Backlight AEC-Q100 Compliance (RT8494) SOP-14, WQFN-16L 3x3 up to 150V Programmable switching frequency Analog, Digital or Digital to Analog Dimming control Street lighting High power, high LED string application Buck ≤ 100W, Boost ≤ 80W SOP-14 4.5V~36V (IC VIN) PSOP-8 VIN2 Up to 150V ISP 3 CIN2 VIN 4.5V ~ 50V CIN VIN1 4.5V ~ 36V ISP 2 R1 C1 ISN 3 Ext. Sync RT8477AGSP D1 5 CTL Analog Dimming 4 VC C5 COUT Digital Dimming L1 C2 R3 CIN1 R2 1 VCC 11 VCC DRV 7 8 CREG SENS 6 GND C3 9 (pad) Analg Dimming VCC R12 C4 R5 ISP 2 ISN 3 VC 4 GND 8 CREG 7 DRV 6 SENS 5 CTL 9 RVC 9 7 6 D1 SYNC DCTL ACTL 8 SS CVC COUT RT8485 5 VC Q1 RSENSE ISN 4 CSS L1 DRV 14 GATE 6 SENS M1 OVP 10 RSET 1 GBIAS 13 GND 12 RSW CB RSW AN034 RSET ISW ISP ISN VC ACTL DCTL 14 2 13 3 12 4 11 5 10 6 9 7 8 GATE GBIAS GND VCC OVP SYNC SS SOP-14 SOP-8 (Exposed Pad) 50V high current Buck LED driver LEDs 150V High power Buck LED Driver © 2015 Richtek Technology Corporation 13 Application Note Power Switch and DDR termination regulator P/N RT2528 Description Power Switch with adj.ILIM IOUT 0.5A~2.5A VIN 2.5V~5.5V Key Features AEC-Q100 Grade 3 Adjustable current limit: 0.5A~2.5A via an ext. resistance 120mΩ P-MOSFET Built-in Soft-Start Low supply current:120µA Package PSOP-8 Reverse input-out voltage RT2526Q DDR Termination regulator DDRII/III:2A VIN:3.1V~3.6V VLDOIN:1.2V~1.8V 3T Grade S3, S5 off modes MLCC stable PSOP-8 Remote sense Richtek Technology Corporation st 14F, No. 8, Tai Yuen 1 Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: 886-3-5526789 Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries. AN034 © 2015 Richtek Technology Corporation 14