RT9971 7 CH Power Management IC General Description Features The RT9971 is a complete power supply solution for digital still cameras and other hand held devices. The RT9971 is a multi-channel power management IC including two stepup DC/DC converters, two step-down DC/DC converters, one selectable step-up/step-down DC/DC converter, one inverting DC/DC converter and one WLED driver. l The RT9971 is designed to fulfill the applications for DSC just as follows : l l l l l l l CH1 is a synchronous step-up output for motor or DSC system I/O power CH2 is a selectable synchronous step-up/step-down output for motor or DSC system I/O power CH3 and CH4 are synchronous step-down outputs for DSP core and memory power supply l l l l l l l CH5 is a high voltage step-up output for CCD bias power supply CH6 is an inverting output for negative CCD bias power supply One Synchronous Step-Up or Step-Down Selectable Convertor Support 2AA or Li-ion Battery Applications Preset On/Off Sequence 5 CHs with Internal Compensation All Power Switches Integrated Up to 95% Efficiency 100% (max) Duty Cycle for Step-Down Converter Adjustable Output Voltage LED PWM Dimming Control LED Open Protection Transformerless Inverting Converter for CCD Fixed 1MHz Switching Frequency at CH1 to CH7 RTC_LDO/SW1 Selectable by CN Pin 40-Lead WQFN Package RoHS Compliant and Halogen Free Applications Digital Still Camera PDA Portable Device l l CH7 is a high voltage step-up output for driving WLED l For the CH2, the step-up or step-down converter, operation mode can be selected by the SEL pin. Among all CHs, there are 5 CHs with the built-in internal compensation. The RT9971 also provides a transformerless inverting Ordering Information RT9971 Package Type QW : WQFN-40L 5x5 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) converter for supplying the CCD power. For the synchronous step-up and step down converters, the efficiency can be up to 95%. The IC provides load disconnection for CH 1 and CH 5. The IC has selectable RTC_LDO/SW1 that can be determined by the CN pin. The RT9971 is able to support Li-ion and 2AA battery applications. The RT9971 provides WLED open protection, current limit, thermal shutdown protection, over voltage and under voltage protection to achieve complete protection. The RT9971 is available in WQFN-40L 5x5 package. DS9971-01 April 2011 Note : Richtek products are : } RoHS compliant and compatible with the current require- } Suitable for use in SnPb or Pb-free soldering processes. ments of IPC/JEDEC J-STD-020. www.richtek.com 1 RT9971 Pin Configurations EN134 LX2 LX1 EN2 COMP1 FB1 OK VOUT1 FB2 COMP2 (TOP VIEW) 40 39 38 37 36 35 34 33 32 31 PVDD1 LX6 PVDD6 CP CN PNEG FB6 1 30 2 29 3 28 4 27 5 6 26 GND 25 7 FB4 8 EN6 9 LX4 10 24 41 23 22 21 PVDD2 VDDM CFB7 GND LX7 LX5 VOUT7 FB3 EN7 LX3 PVDD4 EN5 SW5O SW5I FB5 VREF SEL RTC_R RTC_PWR PVDD3 11 12 13 14 15 16 17 18 19 20 WQFN-40L 5x5 www.richtek.com 2 DS9971-01 April 2011 RT9971 Typical Application Circuit For 2AA 3V3 L1 2.2µH VBAT VOUT_SW1 3.3V C1 10µF R19 50k 1 C27 10µF x 2 37 C2 4.7pF R1 470k R2 150k C3 R3 560pF 39k C4 10µF VOUT_CH2 5V 3V3 L3 4.7µH VOUT_CH3 2.5V C9 10µF R7 768k 34 FB2 33 COMP2 20 PVDD3 C10 22pF C25 1µF R11 1000k R12 90.9k VBAT L6 10µH VOUT_CH6 -7V D4 C18 10µF/16V x 2 C17 1nF FB6 7 R14 11.3k VREF 16 C19 0.1µF L7 10µH VBAT C26 1µF LX7 23 FB3 C16 10µF/25V 15V C15 1nF 21 LX3 R8 360k 26 WLED D5 D1 VOUT7 24 C20 1µF/16V D2 CFB7 28 3V3 VOUT_CH4 1.8V C11 10uF C12 10µF VOUT_CH5 15V R13 63.4k C7 R6 560pF 39k R5 88.7k C8 10uF LX6 2 PVDD2 C6 4.7pF R4 470k FB5 15 PVDD6 3 31 LX2 30 C14 10µF/25V SW5O 13 SW5I 14 RT9971 38 COMP1 L2 2.2µH VBAT D3 FB1 36 OK 35 VOUT1 C5 10µFx2 LX5 25 PVDD1 C24 1µF L5 10µH 29 VDDM C22 10µF VOUT_CH1 3V3 Q1 40 LX1 VBAT C23 1µF L4 4.7µH 11 PVDD4 RTC_R C13 33pF R9 470k RTC_PWR 8 39 32 12 9 R10 374k ON OFF FB4 EN2 EN134 EN5 EN6 17 SEL 22 EN7 VBAT 18 10 LX4 CP 19 R15 10 R16 10k RTC 3.25V 4 CN 5 PNEG 6 GND RTC Reset C28 0.1µF C29 1µF 27, Exposed Pad (41) Note : (1) SEL = High, CH2 is Step -Up, CN Connect to CAP (2) VBAT = 1.8V to 3.2V Timing Diagram Power On Sequence : CH1 Step -Up 3.3V→ CH3 Step -Down 2.5V→ CH4 Step -Down 1.8V→ (CH2 Step -Up 5V and SW1 3.3V) Power Off Sequence : (CH2 Step -Up 5V and SW1 3.3V) → CH4 Step -Down 1.8V→ CH3 Step -Down 2.5V→ CH1 Step -Up 3.3V VDDM EN2, EN134 VOUT_CH1 3.3V VOUT_CH3 2.5V VOUT_CH4 1.8V VOUT_SW1 3.3V VOUT_CH2 5V DS9971-01 April 2011 User define 3.5ms 3.5ms 3.5ms 3.5ms 3.5ms IC shutdown Wait until FB3 < 0.1V Wait until FB4 < 0.1V Wait until VOUT1 < 0.4V Depends on loading www.richtek.com 3 RT9971 For Li-ion VBAT C23 1µF L1 2.2µH VBAT 40 LX1 LX5 25 1 PVDD1 C1 10µF x 2 R1 470k 37 R2 88.7k R3 39k RTC 3.25V 36 OK 35 VOUT1 C21 0.22F VBAT or 5V 30 VOUT_CH2 3.3V C4 10µF C5 10µF L2 4.7µH VBAT 33 COMP2 20 PVDD3 L3 4.7µH VOUT_CH3 2.5V C9 10µF 34 FB2 C7 R6 2200pF 15k R5 150k C8 10µF PVDD2 23 FB3 R12 90.9k VBAT L6 10µH D4 R13 63.4k FB6 7 R14 11.3k VREF 16 C17 1nF VOUT_CH6 -7V C18 10µF/16V x 2 C19 0.1µF L7 10µH VBAT C26 1µF 26 WLED D5 D1 VOUT7 24 D2 C20 1µF/16V CFB7 28 11 VBAT L4 4.7µH PVDD4 10 LX4 C13 33pF R9 470k R10 374k C25 1µF VOUT_CH5 15V R11 1000k LX6 2 LX7 R8 360k VOUT_CH4 1.8V C11 10µF C12 10µF PVDD6 3 21 LX3 C10 22pF R7 768k RT9971 C16 10uF/25V 15V C15 1nF FB5 15 31 LX2 C6 10pF R4 470k C14 10µF/25V FB1 38 COMP1 VBAT D3 SW5O 13 SW5I 14 C2 4.7pF C3 560pF C24 1µF L5 10µH 29 VDDM C22 10µF VOUT_CH1 5V VBAT ON 8 39 32 12 9 17 22 OFF RTC_R RTC_PWR 19 CP FB4 EN2 EN134 EN5 EN6 SEL EN7 18 CN PNEG GND RTC Reset R15 10 R16 10k RTC 3.25V 4 5 R18 10k VBAT 6 27, Exposed Pad (41) Note : (1) SEL = Low, CH2 is Step -Down, CN Pull High (2) VBAT = 2.7V to 4.2V Timing Diagram Power On Sequence : CH1 Step -Up 5V→CH3 Step -Down 2.5V→ CH4 Step -Down 1.8V→ CH2 Step -Down 3.3V Power Off Sequence : CH2 Step -Down 3.3V→ CH4 Step -Down 1.8V→CH3 Step -Down 2.5V→CH1 Step -Up 5V VDDM EN2, EN134 V OUT_CH1 5V V OUT_CH3 2.5V V OUT_CH4 1.8V V OUT_CH2 3.3V www.richtek.com 4 User define 3.5ms 3.5ms 3.5ms 3.5ms IC shutdown Wait until FB3 < 0.1V Wait until FB4 < 0.1V Wait until FB2 < 0.1V DS9971-01 April 2011 RT9971 Table 1. Recommended Components for the Typical Application Circuit Channel CH3 Formula VOUT_CH3 = (1+R7/R8) x 0.8 VOUT_CH3 (V) 2.5 1.8 1.5 1.3 1.2 1 L3 (µH) 4.7 4.7 4.7 4.7 4.7 4.7 R7 (kΩ) 768 470 330 237 187 23.2 R8 (kΩ) 360 374 374 374 374 93.1 C10 (pF) 22 33 47 68 82 47 C9 (µF) 10 10 10 10 10 10 Channel CH4 Application VOUT_CH4 = (1+R9/R10) x 0.8 V OUT_CH4 (V) 2.5 1.8 1.5 1.3 1.2 1 L4 (µH) 4.7 4.7 4.7 4.7 4.7 4.7 R9 (kΩ) 768 470 330 237 187 23.2 R10 (kΩ) 360 374 374 374 374 93.1 C13 (pF) 22 33 47 68 82 47 C12 (µF) 10 10 10 10 10 10 Channel CH5 Formula VOUT_CH5 = (1+R11/R12) x 1.25 VOUT_CH5 (V) 12 13 14 15 15.5 16 L5 (µH) 10 10 10 10 10 10 R11 (kΩ) 820 820 953 1000 820 886 R12 (kΩ) 95.3 86.6 93.1 90.9 71.5 75 C15 (pF) 1000 1000 1000 1000 1000 1000 C16 (µF) 10/16V 10/16V 10/25V 10/25V 10/25V 10/25V Channel Formula CH6 V OUT_CH6 = (R13/R14) x (-1.25) * R13+R14 <90k VOUT_CH6 (V) -6 -6.3 -7 -7.5 -8 L6 (µH) 10 10 10 10 10 R13 (kΩ) 57.6 69.8 63.4 68 68 R14 (kΩ) 12 13.7 11.3 11.3 10.5 C17 (pF) 1000 1000 1000 1000 1000 C18 (µF) 10 x 2pcs. 10 x 2pcs. 10 x 2pcs. 10 x 2pcs. 10 x 2pcs. DS9971-01 April 2011 www.richtek.com 5 RT9971 Functional Pin Description Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27, 41 (Exposed Pad) 28 29 Pin Name PVDD1 LX6 PVDD6 CP CN PNEG FB6 FB4 EN6 LX4 PVDD4 EN5 SW5O SW5I FB5 VREF SEL RTC_R RTC_PWR PVDD3 LX3 EN7 FB3 VOUT7 LX5 LX7 GND CFB7 VDDM 30 PVDD2 31 32 33 34 LX2 EN134 COMP2 FB2 35 VOUT1 36 OK 37 38 39 40 FB1 COMP1 EN2 LX1 www.richtek.com 6 Pin Function Power Output of CH1. Switch Node of CH6. High impedance in shutdown mode. Power Input of CH6. Charge Pump External Driver. Charge Pump External Driver. Negative Output of Charge Pump. Feedback Input of CH6. High impedance in shutdown mode. Feedback Input of CH4. High impedance in shutdown mode. Enable Control Input of CH6. Switch Node of CH4. High impedance in shutdown mode. Power Input of CH4. Enable Control Input of CH5. Output of CH5 Load Disconnect. Input of CH5 Load Disconnect. Feedback Input of CH5. High impedance in shutdown mode. 1.25V Reference Output. Li-ion or 2AA Select. Logic state can not be changed during operation. RTC_Reset Output. Power Input of RTC_Reset. Power Input of CH3. Switch Node of CH3. High impedance in shutdown mode. Enable Control Input of CH7. Feedback Input of CH3. High impedance in shutdown mode. Sense Input for CH7 Output Voltage. Switch Node of CH5. High impedance in shutdown mode. Switch Node of CH7. High impedance in shutdown mode. Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum thermal dissipation. Feedback Input of CH7. IC Analog Power Input. Power Input of CH2 step-down converter, or power output of CH2 step-up converter. Switch Node of CH2. High impedance in shutdown mode. Enable Control Input of CH1, CH3 and CH4. Compensation of CH2. Pull to GND in shutdown mode. Feedback input of CH2. High impedance in shutdown mode. CN is set to low or floating : Sense Pin for CH1 Output Voltage. High impedance in shutdown. CN is set to High: Output pin of RTC_LDO. CN is set to low or floating : External Switch Control. High impedance in shutdown. CN is set to High : Power input pin of RTC_LDO. Feedback Input of CH1. High impedance in shutdown mode. Compensation of CH1. Pull to GND in shutdown mode. Enable Control Input of CH2. Switch Node of CH1. High impedance in shutdown mode. DS9971-01 April 2011 RT9971 Function Block Diagram VDDM LX5 PVDD1 CH5 C-Mode Step-Up PWM CH1 C-Mode Step-Up LX1 + FB5 1.25V REF SW5 SW5I SW5O 0.8V REF PVDD6 CH6 C-Mode Inverting PVDD2 CH2 C-Mode Step-Up or Step-Down LX6 FB6 + - LX7 COMP2 FB2 0.8V REF PVDD3 + VDDM 0.25V REF Enable Mode Sequence 1.25V REF CH3 C-Mode Step-Down EN2 EN134 EN5 EN6 SEL LX3 + FB3 0.8V REF CP CN PNEG OK VOUT1 LX2 + CH7 C-Mode Step-Up PWM VOUT7 EN7 CFB7 VREF COMP1 FB1 + Negative Charge Pump SW1 PVDD4 CH4 C-Mode Step-Down RTC LDO LX4 + RTC_PWR RTC_R RTC Reset FB4 0.8V REF GND Timing Diagram CH5 and CH6 Timing Diagram EN5 10ms SW5I Depends on loading SW5O (to CCD +) Depends on loading EN6 V OUT_CH6 (to CCD -) DS9971-01 April 2011 10ms Depends on loading www.richtek.com 7 RT9971 Absolute Maximum Ratings (Note 1) Supply Voltage, VDDM ------------------------------------------------------------------------------ −0.3V to 7V Power Switch : LX1, LX2, LX3, LX4 ---------------------------------------------------------------------------------- −0.3V to 6.5V LX5, LX7, SW5I, SW5O, VOUT7 ---------------------------------------------------------------- −0.3V to 21V LX6 ----------------------------------------------------------------------------------------------------- (PVDD6 − 14V) to (PVDD6 + 0.3V) l The Other Pins -------------------------------------------------------------------------------------- −0.3V to 6.5V l Power Dissipation, PD @ TA = 25°C WQFN 40L 5x5 -------------------------------------------------------------------------------------- 2.778W l Package Thermal Resistance (Note 2) WQFN 40L 5x5, θJA --------------------------------------------------------------------------------- 36°C/W WQFN 40L 5x5, θJC -------------------------------------------------------------------------------- 7°C/W l Junction Temperature ------------------------------------------------------------------------------ 150°C l Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------- 260°C l Storage Temperature Range ---------------------------------------------------------------------- −65°C to 150°C l ESD Susceptibility (Note 3) HBM (Human Body Mode) ------------------------------------------------------------------------ 2kV MM (Machine Mode) ------------------------------------------------------------------------------- 200V l l Recommended Operating Conditions l l (Note 4) Junction Temperature Range --------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range --------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (VDDM = 3.3V, TA = 25°C, unless otherwise specified) Parameter Supply Voltage VDDM Operating Voltage VDDM Startup Voltage VDDM Over Voltage Protection Supply Current Shutdown Supply Current into VDDM CH1 (Syn-Step-Up) : Supply Current into VDDM CH2 (Syn-Step-Up or Syn-Step-Down) : Supply Current into VDDM CH3 (Syn-Step-Down) : Supply Current into VDDM CH4 (Syn-Step-Down) : Supply Current into VDDM CH5 (Asyn-Step-Up) : Supply Current into VDDM CH6 (Inverting) + Charge pump : Supply Current into VDDM CH7 (WLED): Supply Current into VDDM Symbol Test Condition VDDM VST Min Typ Max Unit 2.7 1.5 6 --6.25 5.5 -6.5 V V V IOFF All EN = 0, CN = 3.3V -- 5 10 µA IQ1 Non Switching, EN134 = 3.3V -- -- 800 µA IQ2 Non Switching, EN2 = 3.3V -- -- 800 µA IQ3 Non Switching, EN134 = 3.3V -- -- 800 µA IQ4 Non Switching, EN134 = 3.3V -- -- 800 µA IQ5 Non Switching, EN5 = 3.3V -- -- 800 µA IQ6 Non Switching, EN6 = 3.3V PVDD6 = 3.3V -- -- 800 µA IQ7 Non Switching, EN7 = 3.3V -- -- 800 µA To be continued www.richtek.com 8 DS9971-01 April 2011 RT9971 Parameter Oscillator CH1,2,3,4, 5, 6, 7 Operating Frequency Symbol Test Condition fOSC Min Typ Max Unit 900 1000 1100 kHz CH1 Maximum Duty Cycle (Step-Up) VFB1 = 0.7V 80 83 86 % CH2 Maximum Duty Cycle (Step-Up) CH2 Maximum Duty Cycle (Step-Down) VFB2 = 0.7V VFB2 = 0.7V 80 -- 83 -- 86 100 % % CH3 Maximum Duty Cycle (Step-Down) VFB3 = 0.7V -- -- 100 % CH4 Maximum Duty Cycle (Step-Down) VFB4 = 0.7V -- -- 100 % CH5 Maximum Duty Cycle (Step-Up) VFB5 = 1.15V 91 94 97 % CH6 Maximum Duty Cycle (Inverting) VFB6 = 0.1V 91 94 97 % CH7 Maximum Duty Cycle (WLED) Feedback Regulation Voltage Feedback Regulation Voltage @ FB1, FB2, FB3, FB4 VFB7 = 0.15V 91 94 97 % 0.788 0.8 0.812 V 1.237 1.25 1.263 V -15 0 15 mV OK = 1V 0.237 50 0.25 -- 0.263 -- V µA 0µA < IREF < 200µA 1.237 -- 1.25 -- 1.263 10 V mV 3.4 0.1 4.1 3.6 0.3 4.5 3.8 0.5 4.9 V V V ------ 150 150 3 150 150 ------ -------- 1.5 3 200 200 1.5 200 200 -------- -- 1.5 -- A Feedback Regulation Voltage @ FB5 Feedback Regulation Voltage @ FB6 (Inverting) Feedback Regulation Voltage @ CFB7 OK Sink Current Reference VREF Output Voltage VREF Load Regulation Negative Charge Pump PVDD6 Low Threshold to Start Pump PVDD6 Hysteresis Gap to Stop Pump (PVDD6 − PNEG) Clamped Voltage Power Switch CH1 On Resistance of MOSFET VREF PVDD6 = 3.3V RDS(ON) P-MOSFET, PVDD1 = 3.3V N-MOSFET, PVDD1 = 3.3V CH1 Current Limitation (Step-Up) CH2 On Resistance of MOSFET RDS(ON) P-MOSFET, PVDD2 = 3.3V N-MOSFET, PVDD2 = 3.3V CH2 Current Limitation (Step-Down) CH2 Current Limitation (Step-Up) CH3 On Resistance of MOSFET R DS(ON) P-MOSFET, PVDD3 = 3.3V N-MOSFET, PVDD3 = 3.3V CH3 Current Limitation (Step-Down) CH4 On Resistance of MOSFET R DS(ON) P-MOSFET, PVDD4 = 3.3V N-MOSFET, PVDD4 = 3.3V CH4 Current Limitation (Step-Down) mΩ A mΩ A A mΩ A mΩ CH5 Load Disconnect MOSFET P-MOSFET, SW5I = 3.3V -- 0.5 -- Ω CH5 On Resistance of MOSFET N-MOSFET -- 0.5 -- Ω CH5 Current Limitation N-MOSFET -- 1.2 -- A To be continued DS9971-01 April 2011 www.richtek.com 9 RT9971 Parameter Symbol Test Condition Min Typ Max Unit CH6 On Resistance of MOSFET P-MOSFET, PVDD6 = 3.3V -- 0.5 -- Ω CH6 Current Limitation P-MOSFET -- 1.5 -- A CH7 On Resistance of MOSFET N-MOSFET -- 1 -- Ω CH7 Current Limitation N-MOSFET -- 0.8 -- A 6 6.25 6.5 V Under Voltage Protection of VOUT1 -- 1.75 -- V Over Voltage Protection of SW5I 18 -- 21 V Over Voltage Protection of VOUT7 12 -- 16 V 0.35 0.4 0.45 V Under Voltage Protection of FB2 (Step-Down) -- 0.4 -- V Under Voltage Protection of FB3 -- 0.4 -- V Under Voltage Protection of FB4 -- 0.4 -- V Under Voltage Protection of FB5 -- 0.8 -- V Under Voltage Protection of FB6 -- 0.4 -- V Protection Fault Delay -- 100 -- ms EN134, EN2, EN5, EN6, EN7 Input High Level Threshold 1.3 -- -- V EN134, EN2, EN5, EN6, EN7 Input Low Level Threshold -- -- 0.4 V EN134, EN2, EN5, EN6, EN7 Sink Current -- 2 6 µA SEL Input High Level Threshold 1.3 -- -- V SEL Input Low Level Threshold -- -- 0.4 V -- 2 6 µA 125 160 -- °C -- 20 -- °C 1.57 1.6 1.63 V -- 16 -- mV -- 2 4 µA 35 55 75 ms 4 -- -- mA Protection Over Voltage Protection of PVDD1 and PVDD2 CH5 Load Disconnect UVP of SW5O Control SEL Sink Current SEL = 3.3V Thermal Protection Thermal Shutdown TSD Thermal Shutdown Hysteresis ΔTSD RTC Reset RTC_PWR Reset Threshold Hysteresis Standby Current RTC_PWR = 3V RTC_R Rising Delay Time RTC_R Sink Capability RTC_R = 0.5V, RTC_PWR = 1.5V To be continued www.richtek.com 10 DS9971-01 April 2011 RT9971 Parameter RTC LDO, CN = High Input Voltage Range Symbol Test Condition VIN Standby Current Min Typ Max Unit -- -- 5.5 V VIN = 4.2V -- 5 8 µA Output Voltage Maximum Output Current VOUT IOUT = 0mA VIN = 4.2V -60 3.25 -- 3.3 -- V mA Dropout Voltage VDROP IOUT = 20mA -- -- 200 mV Note 1. Stresses listed as the above “ Absolute Maximum Ratings” may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. θJA is measured in the natural convection at TA = 25°C on a high effective four layers thermal conductivity test board of JEDEC 51-7 thermal measurement standard. The case point of θJC is on the exposed pad for the WQFN package. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. DS9971-01 April 2011 www.richtek.com 11 RT9971 Typical Operating Characteristics CH1 Step-Up Efficiency vs. Output Current 100 90 90 80 80 VBAT VBAT VBAT VBAT VBAT VBAT 70 60 50 40 = = = = = = 3V 2.7V 2.5V 2.2V 2V 1.8V Efficiency (%) Efficiency (%) CH1 Step-Up Efficiency vs. Output Current 100 30 20 VBAT VBAT VBAT VBAT VBAT VBAT 70 60 50 40 30 VDDM = 5V, VOUT_CH1 = 5V, L1 = 2.2µH, C1 = 10µFx2 10 0 0 10 100 1000 10 100 Output Current (mA) CH2 Step-Down Efficiency vs. Output Current 100 100 90 90 VBAT VBAT VBAT VBAT VBAT VBAT 70 60 50 = = = = = = 80 3.4V 3V 2.7V 2.5V 2.2V 1.8V Efficiency (%) 80 1000 Output Current (mA) CH2 Step-Up Efficiency vs. Output Current Efficiency (%) 4.5V 4.2V 3.9V 3.6V 3.3V 3V 20 VDDM = 3V, VOUT_CH1 = 3.3V, L1 = 2.2µH, C1 = 10µFx2 10 40 30 20 VBAT VBAT VBAT VBAT VBAT VBAT 70 60 50 40 = = = = = = 3.4V 3.6V 3.9V 4.2V 4.5V 5V 30 20 VDDM = 3V, VOUT_CH2 = 5V, L2 = 2.2µH, C5 = 10µFx2 10 VDDM = 5V, VOUT_CH2 = 3.3V, L2 = 4.7µH, C5 = 10µF 10 0 0 10 100 1000 10 100 Output Current (mA) 1000 Output Current (mA) CH3 Step-Down Efficiency vs. Output Current CH4 Step-Down Efficiency vs. Output Current 100 100 90 90 80 80 VBAT VBAT VBAT VBAT VBAT VBAT VBAT 70 60 50 40 = = = = = = = 2.7V 3V 3.3V 3.6V 3.9V 4.2V 4.5V Efficiency (%) Efficiency (%) = = = = = = 30 70 VBAT VBAT VBAT VBAT VBAT VBAT 60 50 40 = = = = = = 1.8V 2.5V 3V 3.3V 3.6V 4.5V 30 20 20 VDDM = 5V, VOUT_CH3 = 2.5V, L3 = 4.7µH, C9 = 10µF 10 0 10 100 Output Current (mA) www.richtek.com 12 1000 VDDM = 3V, VOUT_CH4 = 1V, L4 = 4.7µH, C12 = 10µF 10 0 10 100 1000 Output Current (mA) DS9971-01 April 2011 RT9971 CH5 Step-Up Efficiency vs. Output Current 90 90 VBAT VBAT VBAT VBAT VBAT 70 60 50 = = = = = Inverting Efficiency (%) 100 80 Efficiency (%) CH6 Inverting Efficiency vs. Output Current 100 4.5V 4.2V 3.9V 3.6V 3.4V 40 30 20 VDDM = 5V, VOUT_CH5 = 16V, L5 = 10µH, C16 = 10µF 10 80 VBAT VBAT VBAT VBAT VBAT 70 60 50 = = = = = 3.4V 3.6V 3.9V 4.2V 4.5V 40 30 20 VDDM = 5V, VOUT_CH6 = -8V, L6 = 10µH, C18 = 10µFx2 10 0 0 1 10 100 1 10 Output Current (mA) 100 Output Current (mA) CH7 Efficiency vs. Input Voltage CH1 Step-Up Output Voltage vs. Output Current 5.080 100 90 5.075 Output Voltage (V) Efficiency (%) 80 70 60 50 40 30 20 VBAT = 3V 5.070 VBAT = 4.5V 5.065 5.060 5.055 10 VDDM = 5V VDDM = 5V, L7 = 10µH, C20 = 1µF, IOUT = 25mA 5.050 0 3.4 3.5 3.6 3.7 3.8 3.9 4 0 4.1 4.2 4.3 4.4 4.5 100 200 300 400 500 600 Output Current (mA) Input Voltage (V) CH1 Step-Up Output Voltage vs. Output Current CH2 Step-Down Output Voltage vs. Output Current 3.35 3.340 3.335 3.31 VBAT = 1.8V 3.29 VBAT = 4.5V 3.27 Output Voltage (V) Output Voltage (V) 3.33 3.330 3.325 3.320 VBAT = 4.5V VBAT = 5V 3.315 3.310 3.305 VDDM = 3V 3.25 VDDM = 5V 3.300 0 100 200 300 400 Output Current (mA) DS9971-01 April 2011 500 600 0 100 200 300 400 500 600 Output Current (mA) www.richtek.com 13 RT9971 CH2 Step-Up Output Voltage vs. Output Current CH3 Step-Down Output Voltage vs. Output Current 5.07 2.520 2.515 5.05 VBAT = 3.4V 5.04 Output Voltage (V) Output Voltage (V) 5.06 5.03 2.510 VBAT = 3V 2.505 VBAT = 4.5V 2.500 2.495 VDDM = 3V VDDM = 5V 5.02 2.490 0 100 200 300 400 500 600 0 100 Output Current (mA) 200 300 400 500 600 Output Current (mA) CH4 Step-Down Output Voltage vs. Output Current CH5 Step-Up Output Voltage vs. Output Current 1.015 16.3 1.013 16.2 1.009 1.007 1.005 1.003 VBAT = 3V VBAT = 1.8V VBAT = 4.5V 1.001 0.999 Output Voltage (V) Output Voltage (V) 1.011 16.1 16.0 VBAT = 4.5V VBAT = 3.4V VBAT = 2.7V 15.9 15.8 0.997 VDDM = 3V 0.995 VDDM = 5V 15.7 0 100 200 300 400 500 0 600 Output Current (mA) 20 40 60 80 100 Output Current (mA) CH6 Inverting Output Voltage vs. Output Current Power On Inverting Output Voltage (V) -8 -8.05 VOUT_CH1 (5V/Div) VOUT_CH2 (5V/Div) -8.1 -8.15 VBAT = 4.5V VBAT = 3.4V VBAT = 2.7V -8.2 VOUT_CH3 (2V/Div) VOUT_CH4 (1V/Div) -8.25 VDDM = 5V VDDM = 5V, VBAT = 3.7V, SEL = Low -8.3 0 20 40 60 80 100 Time (5ms/Div) Output Current (mA) www.richtek.com 14 DS9971-01 April 2011 RT9971 Power Off CH1 Output Voltage Ripple VOUT_CH1 (5V/Div) VOUT_CH2 (5V/Div) LX1 (2V/Div) VOUT_CH3 (2V/Div) VOUT_CH1_ac (20mV/Div) VOUT_CH4 (1V/Div) VDDM = 5V, VBAT = 3.7V, VOUT_CH1 = 5V, IOUT = 400mA, L1 = 2.2μH, C1 = 10μFx2 VDDM = 5V, VBAT = 3.7V, SEL = Low Time (1ms/Div) Time (1μs/Div) CH2 Output Voltage Ripple CH3 Output Voltage Ripple LX2 (2V/Div) LX3 (2V/Div) VOUT_CH2_ac (10mV/Div) VOUT_CH3_ac (10mV/Div) VDDM = 5V, VBAT = 3.7V, VOUT_CH3 = 2.5V, IOUT = 300mA, L3 = 4.7μH, C9 = 10μF VDDM = 5V, VBAT = 3.7V, VOUT_CH2 = 3.3V, IOUT = 400mA, L2 = 4.7μH, C5 = 10μF Time (1μs/Div) Time (1μs/Div) CH5 Output Voltage Ripple CH6 Output Voltage Ripple LX6 (10V/Div) LX5 (10V/Div) VOUT_CH6_ac (10mV/Div) VOUT_CH5_ac (10mV/Div) VDDM = 5V, VBAT = 3.7V, VOUT_CH5 = 16V, IOUT = 30mA, L5 = 10μH, C16 = 10μF Time (1μs/Div) DS9971-01 April 2011 VDDM = 5V, VBAT = 3.7V, VOUT_CH6 = -8V, IOUT = 50mA, L6 = 10μH, C18 = 10μFx2 Time (1μs/Div) www.richtek.com 15 RT9971 CH2 Load Transient Response CH1 Load Transient Response IOUT (200mA/Div) IOUT (200mA/Div) V OUT_CH1_ac (100mV/Div) V OUT_CH2_ac (100mV/Div) VDDM = 5V, VBAT = 3.7V, VOUT_CH2 = 3.3V, IOUT = 0 to 300mA, L2 = 4.7μH, C5 = 10μF VDDM = 3V, VBAT = 1.8V, VOUT_CH1 = 3.3V, IOUT = 50mA to 250mA, L1 = 2.2μH, C1 = 10μFx2 Time (1ms/Div) Time (1ms/Div) CH3 Load Transient Response CH4 Load Transient Response IOUT (200mA/Div) IOUT (200mA/Div) V OUT_CH3_ac (50mV/Div) V OUT_CH4_ac (50mV/Div) VDDM = 3V, VBAT = 1.8V, VOUT_CH4 = 1V, IOUT = 100mA to 300mA, L4 = 4.7μH, C12 = 10μF VDDM = 5V, VBAT = 3V, VOUT_CH3 = 2.5V, IOUT = 100mA to 300mA, L3 = 2.2μH, C9 = 10μF Time (1ms/Div) Time (1ms/Div) CH5 Load Transient Response CH6 Load Transient Response IOUT (20mA/Div) IOUT (20mA/Div) V OUT_CH5_ac (50mV/Div) V OUT_CH6_ac (50mV/Div) VDDM = 5V, VBAT = 3.7V, VOUT_CH5 = 16V, IOUT = 10mA to 30mA, L5 = 10μH, C16 = 10μF Time (1ms/Div) www.richtek.com 16 VDDM = 5V, VBAT = 3.7V, VOUT_CH6 = -8V, IOUT = 15mA to 50mA, L6 = 10μH, C18 = 10μFx2 Time (1ms/Div) DS9971-01 April 2011 RT9971 Application information The RT9971 includes the following seven DC/DC converter CHs to build a multiple-output power-supply system. The output voltage can be set by the following equation : CH1 : Step-up synchronous current mode DC/DC converter with internal power MOSFETs. The output voltage could be load disconnected by a switch controller and an external P-MOSFET. Where VFB1 is 0.8V typically. CH2 : Selectable step-up or step-down synchronous current mode DC/DC converter with internal power MOSFETs. CH3 : Step-down synchronous current mode DC/DC converter with internal power MOSFETs and internal compensation network. CH4 : Step-down synchronous current mode DC/DC converter with internal power MOSFETs and internal compensation network. CH5 : Step-up asynchronous current mode DC/DC converter with internal power MOSFET and internal compensation network. The output voltage could be load disconnected by an internal P-MOSFET. CH6 : Inverting current mode DC/DC converter with internal power P-MOSFET and internal compensation network. CH7 : Current mode WLED driver with internal power N-MOSFET and internal compensation network. This CH also provides open LED protection. SW1 : Load disconnect controller. SW5 : Load disconnect switch for CH5 CH1 to CH7 operate in PWM mode with 1MHz constant frequency under moderate to heavy loading. RTC_LDO : Low quiescent current, high output voltage accuracy LDO for Real Time Clock. VOUT_CH1 = (1+R1/R2) x VFB1 SW1 SW1 is an open drain controller to drive an external P-MOSFET and then functions as a load disconnect switch for CH1. This switch features soft-start, Power On/ Off Sequence and under voltage protection functions. OK is an open drain control pin. Once CH1, CH3, and CH4's soft-start are finished, SW1 will be turned on. The OK pin is slowly pulled low and controlled with soft-start to suppress the inrush current. VOUT1 is used for SW1 softstart and under voltage protection. CH2 : Synchronous Step-Up or Step-Down Selectable DC/DC Converter The CH2 is a synchronous step-up or step-down selectable converter for motor or DSC system I/O power. Mode setting The CH2 of the RT9971 features flexible Step-up or Stepdown topology setting for either 1 x Li-ion or 2 x AA application by the SEL pin. Please refer to “Electrical Characteristics” for level of Logic-High or Logic-Low. When the CH2 operates as a Step-up converter, the SEL must be set at Logic-High. If the CH2 operates at Step-down mode, the SEL must be set at Logic-Low. In addition, please note that the logic state can not be changed during operation. Table 2. CH2 Mode Setting CH2 Operating Mode SEL Step-up Logic-High Step-down Logic-Low RTC_Reset : Accurate voltage detector for RTC LDO. CH1: Synchronous Step-Up DC/DC Converter The CH1 is a synchronous step-up converter for motor or DSC system I/O power. The converter operates at fixed frequency and PWM Current Mode. The CH1 converter integrates internal MOSFETs, compensation network and synchronous rectifier for up to 95% efficiency. DS9971-01 April 2011 Step-Up : The converter operates at fixed frequency PWM Mode, continuous current mode (CCM), and discontinuous current mode (DCM) with internal MOSFETs, compensation network and synchronous rectifier for up to 95% efficiency. www.richtek.com 17 RT9971 Step-Down : The converter operates at fixed frequency PWM mode and continuous current mode (CCM) with internal MOSFETs, compensation network and synchronous rectifier for up to 95% efficiency. The CH2 step-down converter can be operated at 100% maximum duty cycle to extend the input operating voltage range. While the input voltage is close to the output voltage, the converter enters low dropout mode. converter is inactive until the SW5 soft-start procedure is finished. This feature provides load disconnect function and effectively limits inrush current at start up. The output voltage can be set by the following equation : VOUT_CH5 = (1+R11/R12) x VFB5 Where VFB5 is 1.25V typically. SW5 Where VFB2 is 0.8V typically. SW5 is an internal switch enabled by EN5 and functions as a load disconnection for CH5. This switch features softstart, Powe On Sequence, over voltage (for SW5I) and under voltage (for SW5O) protection functions. CH3 : Synchronous Step-Down DC/DC Converter CH6 : INV DC/DC Converter The converter operates at fixed frequency PWM mode, CCM, integrated internal MOSFETs and compensation network. The CH3 step-down converter can be operated at 100% maximum duty cycle to extend the battery operating voltage range. When the input voltage is close to the output voltage, the converter could enter low dropout mode with low output ripple. This converter integrates an internal P-MOSFET and an external schottky diode to provide CCD negative power supply. The output voltage can be set by the following equation : VOUT_CH2 = (1+R4/R5) x VFB2 The output voltage can be set by the following equation : VOUT_CH6 = (R13/R14) x (-VREF) Where R13 and R14 are the feedback resisters connected to FB6, VREF equals to 1.25V in typical. The output voltage can be set by the following equation : VOUT_CH3 = (1+R7/R8) x VFB3 Where VFB3 is 0.8V typically. CH4 : Synchronous Step-Down DC/DC Converter The converter operates at fixed frequency PWM mode, CCM, integrated internal MOSFETs and compensation network. The CH4 step-down converter can be operated at 100% maximum duty cycle to extend battery operating voltage range. When the input voltage is close to the output voltage, the converter could enter low dropout mode with low output ripple. The output voltage can be set by the following equation : Charge Pumps The charge pump will be enabled while the PVDD6 voltage is lower than 3.6V. This CH provides pump voltage to enhance P-MOSFET gate driving capability. This function is not necessary while battery is Li-ion type. Reference Voltage The RT9971 provides a precise 1.25V reference voltage with souring capability of 100µA. Connect a 0.1µF ceramic capacitor from the VREF pin to GND. Reference voltage is enabled by connecting EN6 to logic high. Furthermore, this reference voltage is internally pulled to GND at shutdown. VOUT_CH4 = (1+R9/R10) x VFB4 Where VFB4 is 0.8V typically. CH5 : Step-Up DC/DC Converter It integrates asynchronous step-up converter with an internal N-MOSFET, internal compensation and an external schottky diode to provide CCD positive power supply. The www.richtek.com 18 CH7 : WLED Driver It is an asynchronous step-up converter with an internal MOSFET, internal compensation and an external schottky diode to drive up to 3 WLED. This CH also features PWM dimming control from EN7 pin and open diode protection. In addition, CH7 will be turned on until the CH4 soft-start is finished. DS9971-01 April 2011 RT9971 The current flows through WLED can be set by the following equation : I (mA) = [250mV/R(Ω)] x Duty (%) R : Current sense resistor from CFB7 to GND. Duty: PWM dimming by EN7 pin. Dimming frequency range is from 30kHz to 100kHz. Hold EN7 low for more than 64µs will turn off CH7. RTC_Reset The RT9971 provides an accurate voltage detector for RTC_LDO voltage detection. It is used to detect whether RTC_LDO output voltage is ready or not. Its power pin is RTC_PWR and output pin is RTC_R. The output pin is an open drain N-MOSFET and the sink capability is above 4mA. Once the RTC_PWR pin reaches 1.6V, it will count for about 55ms, then the RTC_R will go high. RTC_LDO The RT9971 provides a LDO for real time clock. The LDO function has features of low quiescent current (5µA) and high output voltage accuracy since this LDO is running all the time, even when the system is shutdown. In addition, LDO share “OK” and “VOUT1” pin with SW1 and the function is decided by “CN” pin. Following table is used to select LDO or SW1. and CH2 (Note A) will be shutdown. After that, CH4 will be turned off and internally pulled low to wait for the completion of CH4's shutdown. And then, CH3 will be turned off and internally pulled low to wait for CH3's shutdown completion. Then, CH1 will be turned off and internally pulled low (Note B) to wait for CH1's shutdown completion. Finally, the whole IC will be shutdown (if EN2, EN5, EN6 and EN7 already go low). Note A : If CH2 is configured as a step -up, then the CH2 will not be internally pulled low and the completion of shutdown will not be checked. Note B : CH1 is configured as a step -up, so the CH1 will not be internally pulled low and the completion of shutdown will not be checked. Table 4. Power On/Off Sequence Power On Sequence Power Off Sequence CH1 -> CH3 -> CH4 -> (SW1 and CH2) (SW1 and CH2) -> CH4 -> CH3 -> CH1 Thermal Considerations Function CN RTC_LDO Logic-High For continuous operation, do not exceed absolute maximum operation junction temperature. The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junction to ambient. The maximum power dissipation can be calculated by following formula : SW1 Logic-Low PD(MAX) = (TJ(MAX) − TA ) / θJA Table 3. RTC_LDO and SW1 Setting Power On/Off Sequence Where T J(MAX) is the maximum operation junction temperature, TA is the ambient temperature and the θJA is The Power On Sequence is : the junction to ambient thermal resistance. While EN134 goes high, CH1 will be turned on to wait for the completion of CH1's soft-start. After that, CH3 will be turned on to wait for the completion of CH3's soft-start. And then, CH4 will be turned on to wait for the completion of CH4's soft-start. Then,SW1 will be turn on and CH2 is allowed to be turn on by EN2 at any time. Finally, SW1 soft-start will be completed. The Power-Off Sequence is : For recommended operating conditions specification of RT9971, The maximum junction temperature is 125°C. The junction to ambient thermal resistance θJA is layout dependent. For WQFN-40L 5x5 packages, the thermal resistance θJA is 36°C/W on the standard JEDEC 51-7 four layers thermal test board. The maximum power dissipation at TA = 25°C can be calculated by following formula : At first, while EN134 goes low, (SW1 is shutdown and internally pull low, CH2 must be turned off by EN2) SW1 PD(MAX = (125°C −25°C) / (36°C/W ) = 2.778W for WQFN-40L 5x5 packages DS9971-01 April 2011 www.richtek.com 19 RT9971 Layout Considerations Maximum Power Dissipation (W) The maximum power dissipation depends on operating ambient temperature for fixed T J(MAX) and thermal resistance θJA. For RT9971 packages, the Figure 1 of derating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. 3.0 2.8 2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 For the best performance of the RT9971, the following PCB layout guidelines must be strictly followed. Four Layers PCB } Place the input and output capacitors as close as possible to the input and output pins respectively for good filtering. } Keep the main power traces as wide and short as possible. } The switching node area connected to LX and inductor should be minimized for lower EMI. } Place the feedback components as close as possible to the FB pin and keep these components away from the noisy devices. } Place the compensative components as close as possible to the COMP pin and keep these components away from the noisy devices. } Connect the GND and Exposed Pad to a strong ground plane for maximum thermal dissipation and noise protection. WQFN-40L 5x5 0 25 50 75 100 125 Ambient Temperature (°C) Figure 1. Derating Curves for RT9971 Packages Place the feedback and compensation components as close as possible to the FB and COMP pin and keep away from noisy devices. LX should be connected to inductor by wide and short trace, keep sensitive components away from this trace. V OUT_CH2 VOUT_CH1 GND C2 R1 GND VBAT GND C6 R4 C5 C3 C7 R3 R2 C21 R5 R6 C1 4 27 5 26 GND 24 8 23 41 9 21 11 12 13 14 15 16 17 18 19 20 VOUT_CH5 GND R16 R12 PVDD2 VDDM CFB7 GND LX7 LX5 VOUT7 FB3 EN7 LX3 R15 VBAT D1 C23 D5 L7 WLED+ VBAT C20 C26 L5 C24 D3 VBAT GND C14 R8 R7 C10 L3 GND V OUT_CH3 C9 C8 C15 R11 VBAT VBAT GND 22 10 C11 C16 VOUT_CH4 25 7 L4 C12 EN1234 LX2 28 RTC_PWR PVDD3 R9 R10 29 3 GND C13 2 6 D2 C4 30 SEL RTC_R C19 WLED- 40 39 38 37 36 35 34 33 32 31 FB5 VREF C18 L2 1 PVDD4 VOUT_CH6 L6 PVDD1 LX6 D4 PVDD6 C25 VBAT CP CN C17 PNEG R13 FB6 R14 FB4 EN6 LX4 COMP2 LX1 SYS_R C22 EN5 SW5O SW5I Input/Output capacitors must be placed as close as possible to the Input/Output pins. COMP1 FB1 OK VOUT1 FB2 L1 GND Connect the Exposed Pad to a ground plane. Figure 2. PCB Layout Guide www.richtek.com 20 DS9971-01 April 2011 RT9971 Protection type V DDM CH1 Step-Up CH2 Step-Up Table 5. Protection Items Threshold (typical) Refer to Electrical Protection methods spec. VDDM > 6.25V Automatic reset at VDDM < 6V 100ms VDDM power reset Current Limit N-MOSFET current > 3A N-MOSFET off, P-MOSFET off. Automatic reset at next clock 100ms cycle VDDM power reset PVDD1 OVP PVDD1 > 6.25V N-MOSFET off, P-MOSFET off. No-delay VDDM power reset Current Limit N-MOSFET current > 3A N-MOSFET off, P-MOSFET off. Automatic reset at next clock 100ms cycle VDDM power reset PVDD2 OVP PVDD2 > 6.25V N-MOSFET off, P-MOSFET off. No-delay VDDM power reset P-MOSFET current > 1.5A CH3 Current Step-Down Limit P-MOSFET current > 1.5A CH4 Current Step-Down Limit P-MOSFET current > 1.5A CH7 WLED SW 1 N-MOSFET off, P-MOSFET off. Automatic reset at next clock 100ms cycle N-MOSFET off, P-MOSFET off. Automatic reset at next clock 100ms cycle N-MOSFET off, P-MOSFET off. Automatic reset at next clock 100ms cycle VD DM power reset VDDM power reset VDDM power reset Current Limit N-MOSFET current > 1.2A N-MOSFET off. Automatic reset 100ms at next clock cycle VDDM power reset Current Limit P-MOSFET current > 1.5A P-MOSFET off. Automatic reset 100ms at next clock cycle Current Limit N-MOSFET current > 0.8A N-MOSFET off. Automatic reset Not at next clock cycle Applicable OVP VOUT7 > 14V Shutdown CH7 Not Applicable UVP VOUT1 < 1.75V after SW1 soft start end Automatic reset at VOUT1 > 1.75V 100ms OVP SW5I > 18V N-MOSFET off No-delay UVP SW5O < 0.4V after SW5 soft start end Automatic reset at SW5O > 0.4V 100ms Thermal shutdown Temperature > 160°C All channels stop switching VDDM power reset Automatic reset at next clock cycle Reset by toggling EN7 VDDM power reset VDDM power reset VDDM power reset Temperature < 140°C VDDM power reset SW 5 Thermal Reset method OVP CH2 Current Step-Down Limit CH5 Asyn Step-Up CH6 Inverting IC Shutdown Delay time No-delay CH2 UVP Step-Down FB2 < 0.4V after CH2 soft start end N-MOSFET off, P-MOSFET off. 100ms Automatic reset at FB2 > 0.4V CH3 UVP Step-Down CH4 UVP Step-Down FB3 < 0.4V after CH3 soft start end FB4 < 0.4V after CH4 soft start end FB5 < 0.8V after CH5 soft start end N-MOSFET off, P-MOSFET off. 100ms Automatic reset at FB3 > 0.4V N-MOSFET off, P-MOSFET off. 100ms Automatic reset at FB4 > 0.4V N-MOSFET off. No-delay FB6 > 0.4V P-MOSFET off. No-delay CH5 UVP CH6 UVP DS9971-01 April 2011 VDDM reset VDDM reset VDDM reset VDDM reset power power power power www.richtek.com 21 RT9971 Outline Dimension D SEE DETAIL A D2 L 1 E2 E e b 1 1 2 2 DETAIL A Pin #1 ID and Tie Bar Mark Options A A3 A1 Symbol Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated. Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.700 0.800 0.028 0.031 A1 0.000 0.050 0.000 0.002 A3 0.175 0.250 0.007 0.010 b 0.150 0.250 0.006 0.010 D 4.950 5.050 0.195 0.199 D2 3.250 3.500 0.128 0.138 E 4.950 5.050 0.195 0.199 E2 3.250 3.500 0.128 0.138 e L 0.400 0.350 0.016 0.450 0.014 0.018 W-Type 40L QFN 5x5 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: [email protected] 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. www.richtek.com 22 DS9971-01 April 2011