® RT9527 Single Cell Li-Ion Battery Charger with Adjustable Charging Current for Portable Applications General Description Features The RT9527 is a low cost single-cell Li-ion charger for low current charge applications. z z z The RT9527 can be powered up from an AC adapter or USB (Universal Serial Bus) port inputs. The RT9527 enters sleep mode when VIN power is removed. The RT9527 optimizes the charging task by using a control algorithm, which includes pre-charge mode, fast-charge mode and constant voltage mode. The charging task is kept in constant voltage mode to hold the battery in a full charge condition. The charge current is adjustable via an external resistor. The internal thermal feedback circuitry regulates the die temperature to optimize the charge rate for all ambient temperatures. The RT9527 features 28V maximum rating voltages for VIN. Other features include under voltage protection and over voltage protection for the AC adapter supply. z z z z z z z z z z z z Applications The RT9527 is available in a WDFN-8L 2x2 package. z z Ordering Information z RT9527 z Package Type QW : WDFN-8L 2x2 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) Cellular Phones Digital Cameras PDAs and Smart Phone Portable Instruments Marking Information 0S : Product Code Note : 0SW Richtek products are : ` 28V Maximum Rating for AC Adapter Internal Integrated Power FETs Adjustable Charging Current Programmable Safe Charge Timer NTC Thermistor Input Battery Reverse Protection ISET Pin Short Protection Charge Status Indicator AC Adapter Power Good Status Indicator End of Charge Current is 10% of Fast-Charge Current Under Voltage Protection Over Voltage Protection Thermal Feedback Optimized Charge Rate Small Thermally Enhanced 8-Lead WDFN Package RoHS Compliant and Halogen Free W : Date Code RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. ` Suitable for use in SnPb or Pb-free soldering processes. Simplified Application Circuit Input Power VIN RT9527 TIMER BAT PGOOD CHG ISET Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS9527-00 May 2012 Battery Indicator GND is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT9527 Ordering Information Pin Configurations RT9527 VIN PGOOD CHG GND 1 2 3 4 GND (TOP VIEW) Package Type QW : WDFN-8L 2x2 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) 9 8 7 6 5 BAT TS TIMER ISET WDFN-8L 2x2 Note : Richtek products are : ` RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. ` Suitable for use in SnPb or Pb-free soldering processes. Functional Pin Description Pin No. Pin Name Pin Function 1 VIN Supply Voltage Input. VIN can withstand up to 28V input. 2 PGOOD Power Good Status Output. Active-low, open-drain output. 3 CHG Charger Status Output. Active-low, open-drain output. 4, GND 9 (Exposed Pad) Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. 5 ISET Charge Current Setting. 6 TIMER Safe-Charge Timer Setting. 7 TS Temperature Sense Input. The TS pin connects to a battery’s thermistor to determine whether the battery is too hot or too cold for charging operation. If the battery’s temperature is out of range, charging is paused until it re-enters the valid range. 8 BAT Charge Current Output for Battery. Function Block Diagram BAT Switch Well VIN BASE Too Cold VREF VCC Thermal Circuit + - IBIAS + Too Hot Sleep Mode ISET Current Set Block CC/CV/TR Multi Loop Controller TIMER TS - TMIER CHG OVP Logic UVLO Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 PGOOD GND is a registered trademark of Richtek Technology Corporation. DS9527-00 May 2012 RT9527 Operation The RT9527 is a Li-ion charger that can support the input voltage range from 4.4V to 6V. It provides a wide fastcharge current setting ranging from 10mA up to 600mA. CC/CV/TR Multi Loop Controller Change Current Setting Too Hot or Too Cold The charging current is adjustable via an external resistor between the ISET and GND pin. The temperature sense input TS pin can be connected a thermistor to determine whether the battery is too hot or too cold for charging operation. If the battery's temperature is out of range, charging is paused until it re-enters the valid range. UVLO If the input voltage (VIN ) is lower than the threshold voltage VUVLO − ΔVUVLO, the charger will stop charging until VIN is larger than VUVLO. OVP If the input voltage (VIN) is higher than the threshold voltage VOVP, the internal OVP signal will go high and the charger will stop charging until VIN is below VOVP − ΔVOVP. Switch Well The switch well will choose the highest voltage between VIN and BAT to prevent the power switch from damage. There are constant current loop, constant voltage loop and thermal regulation loop to control the charging current. PGOOD The PGOOD is an open-drain output used to indicate the input voltage status. PGOOD will assert low when VIN is in the proper working range. CHG The CHG pin is an open-drain output. CHG will assert low when the charger starts to charge the battery and become high impedance when the termination current is reached. TIMER Sleep Mode When the voltage difference between VIN and BAT is under VOS_L, the charger will enter sleep mode to save the system power consumption. Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS9527-00 May 2012 The charger contains the safety timer. When the charging time is longer than tPCHG in the pre-charge mode or tFCHG in the fast-charge mode, time fault happens. Then, the charger will be turned off and the CHG pin will become high impedance. is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT9527 Absolute Maximum Ratings z z z z z z z z z (Note 1) Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------CHG, PGOOD -------------------------------------------------------------------------------------------------------------Other Pins ------------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C WDFN-8L 2x2 -------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) WDFN-8L 2x2, θJA --------------------------------------------------------------------------------------------------------WDFN-8L 2x2, θJC --------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) ---------------------------------------------------------------------------------------------MM (Machine Model) ----------------------------------------------------------------------------------------------------- Recommended Operating Conditions z z z −0.3V to 28V −0.3V to 28V −0.3V to 6V 0.833W 120°C/W 8.2°C/W 260°C 150°C −65°C to 150°C 2kV 200V (Note 4) Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 4.4V to 6V Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (VIN = 5V, VBAT = 4V, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Supply Input VIN Under Voltage Lockout Threshold VIN Under Voltage Lockout Hysteresis VIN − BAT VOS Rising VUVLO VIN = 0V to 5V 3.1 3.3 3.5 V ΔVUVLO VIN = 5V to 0V -- 240 -- mV VOS_H -- 100 200 mV VIN − BAT VOS Falling VOS_L 10 50 -- mV VIN Standby Current ISTANDBY VBAT = 4.5V -- 1 2 mA BAT Sleep Leakage Current ISLEEP VIN = 0V -- -- 1 μA Battery Voltage Regulation VREG 0°C to 85°C 4.158 4.2 4.242 V Re-Charge Threshold ΔVREGCHG Battery Regulation − Recharge Level 60 100 140 mV -- 0.8 -- Ω mA Voltage Regulation VIN Power FET On-Resistance RDS(ON) IBAT = 450mA Current Regulation VIN Charge Setting Range ICHG 10 -- 600 KCHG_F1 ICHG_F1 = KCHG_F1 / RISET, ICHG_F1 = 10mA to 50mA 510 600 690 KCHG_F2 ICHG_F2 = KCHG_F2 / RISET, ICHG_F2 = 50mA to 600mA 570 Fast-Charge Current Factor Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 AΩ 600 630 is a registered trademark of Richtek Technology Corporation. DS9527-00 May 2012 RT9527 Parameter Pre-Charge Current Factor Symbol Test Conditions Min Typ Max Unit KCHG_P ICHG_P = KCHG_P / RISET 30 60 90 AΩ BAT Pre-Charge Threshold VPRECH V BAT Falling 2.7 2.8 2.9 V BAT Pre-Charge Threshold Hysteresis ΔVPRECH -- 200 -- mV 5 10 15 % Pre-Charge Charge Termination Termination Current Ratio ITERMI V BAT > VPREC, ICHG < ITERMI , CHG = L to H Protection Thermal Regulation TREG -- 125 -- °C Over Voltage Protection VOVP 6.2 6.5 6.8 V Over Voltage Protect Hysteresis ΔVOVP -- 0.2 -- V ISET Pin Short Protection RSHORT 375 500 625 Ω 60 61 62 %V IN -- 2 -- %V IN 29 30 31 %V IN -- 2 -- %V IN 1800 NTC Cold Temperature Fault VCOLD Threshold Voltage Cold Temperature Fault ΔVCOLD Threshold Hysteresis Hot Temperature Fault Threshold VHOT Voltage Rising Threshold Falling Threshold Hot Temperature Fault Threshold ΔVHOT Hysteresis Timer Pre-Charge Fault Time tPCHG CTIMER = 1μF (1 / 8 x tFCHG ) 1440 2160 s Fast-Charge Fault Time tFCHG CTIMER = 1μF 11520 14400 17280 s PGOOD Pull Down Voltage VPGOOD IPGOOD = 5mA -- 200 -- mV CHG Pull Down Voltage VCHG ICHG = 5mA -- 200 -- mV PGOOD Deglitch Time tPGOOD Time measured from the edge V IN = 0V to 5V in 1μs to PGOOD = L -- 2 -- ms -- 50 -- μs tOVP_R -- 2 -- ms tPF -- 25 -- ms tFP -- 25 -- ms Termination Deglitch Time tTERMI -- 25 -- ms Recharge Deglitch Time tRECHG -- 100 -- ms Sleep Deglitch Time tNO-IN -- 25 -- ms Pack Temperature Fault Detection Deglitch Time tTS -- 25 -- ms Other Input Over Voltage Blanking Time tOVP Input Over Voltage Recovery Time Pre-Charge to Fast-Charge Deglitch Time Fast-charge to Pre-Charge Deglitch Time Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS9527-00 May 2012 is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT9527 Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and 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 may affect device reliability. Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is measured at the exposed pad of the package. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 is a registered trademark of Richtek Technology Corporation. DS9527-00 May 2012 RT9527 Typical Application Circuit 1 Adapter or USB RT9527 8 VIN BAT CIN R1 2 R2 3 RT1 RNTC PGOOD CHG TS 7 6 TIMER 4, GND 9 (Exposed Pad) ISET 5 Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS9527-00 May 2012 COUT RT2 RISET CTIMER is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT9527 Typical Operating Characteristics TS Inserted/Removed Charge On/Off Control from VIN V CHG (1V/Div) VIN (5V/Div) V CHG (5V/Div) VBAT (5V/Div) VBAT (2V/Div) IBAT (500mA/Div) VTS (2V/Div) IBAT (500mA/Div) VIN = 5V, VBAT = Real Battery, RISET = 1kΩ VIN = 5V, VBAT = Real Battery, RISET = 1kΩ Time (500ms/Div) Time (25ms/Div) VIN Hot-Plug with NTC/Without Battery VIN Hot-Plug Without NTC/Battery VIN (5V/Div) VPGOOD (5V/Div) VIN (5V/Div) VPGOOD (5V/Div) VBAT (5V/Div) VBAT (5V/Div) VTS (5V/Div) VTS (5V/Div) VIN = 5V Time (100ms/Div) Time (100ms/Div) VIN Hot-Plug with NTC/Battery VIN Over Voltage Protection VIN (5V/Div) VPGOOD (5V/Div) VBAT (5V/Div) VTS (5V/Div) IBAT (500mA/Div) VIN (10V/Div) V CHG (10V/Div) VIN = 5V, VBAT = Real Battery, RISET = 1kΩ Time (100ms/Div) Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 VIN = 5V VBAT (5V/Div) IBAT (500mA/Div) VIN = 5V to 15V, VBAT = Real Battery, RISET = 1kΩ Time (100ms/Div) is a registered trademark of Richtek Technology Corporation. DS9527-00 May 2012 RT9527 OVP Threshold Voltage vs. Temperature ICHG Thermal Regulation vs. Temperature 6.65 I CHG Thermal Regulation (mA)1 700 OVP Voltage (V) 6.60 Rising 6.55 6.50 6.45 6.40 6.35 Falling 6.30 VIN = 5V, VBAT = 3.7V 6.25 600 500 400 300 200 100 VIN = 5V, VBAT = 3.7V, ICHG = 600mA 0 -50 -25 0 25 50 75 100 125 -50 -25 0 Temperature (°C) ICHG Thermal Regulation vs. Temperature 75 100 125 Battery Regulation Voltage vs. Temperature 4.300 4.275 Battery Voltage (V) I CHG Thermal Regulation (mA)1 50 Temperature (°C) 12 9 6 3 4.250 4.225 4.200 4.175 4.150 4.125 VIN = 5V, VBAT = 3.7V, ICHG = 10mA VIN = 5V 0 4.100 -50 -25 0 25 50 75 100 125 0 Temperature (°C) 10 20 30 40 50 60 70 80 90 Temperature (°C) Pre-Charge Current vs. Battery Voltage Fast-Charge Current vs. Battery Voltage 70 800 60 750 Fast-Charge Current (mA)1 Pre-Charge Current (mA) 25 50 40 30 20 10 700 650 600 550 500 450 VIN = 5V, RISET = 1kΩ VIN = 5V, RISET = 1kΩ 0 400 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Battery Voltage (V) Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS9527-00 May 2012 3 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 4.1 Battery Voltage (V) is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT9527 Application Information The RT9527 is a fully integrated low cost single-cell Liion battery charger ideal for portable applications. The internal thermal feedback circuitry regulates the die temperature to optimize the charge rate at all ambient temperatures. The RT9527 features 20V maximum rating voltages for VIN. Other features include under voltage protection and over voltage protection for AC adapter supply, as well as a charging time monitor. Pre-Charge Mode When the output voltage becomes lower than 2.8V, the charging current reduces to 10% of the setting current to protect the battery life time as shown below : Charge State Charging Charging suspended by thermal loop Safety timers expired TS fault Charging done Recharging after termination No valid input power CHG Output Low (for first charger cycle) High impedance Low (for first charger cycle) High impedance PGOOD Indicator ICHG_P = KCHG_P / RISET This open-drain output pin is used to indicate the input voltage status. PGOOD output asserts low when where KCHG_P is the pre-charge current factor. 1. VIN > VUVLO Fast-Charge Mode 2. (VIN − VBAT) > VOS_H When the output voltage becomes higher than 3V, the charging current will be equal to the setting current which is determined by RISET. 3. VIN < VOVP ICHG_F = KCHG_Fx / RISET It can be used to drive an LED or communicate to the host processor. Note that “LOW” indicates the opendrain transistor is turned on and the LED is bright. where KCHG_Fx is the fast-charge current factor. Charge Termination Constant Voltage Mode When the charge current is lower than the charge termination current ratio (10% = ICHG / ICHG_F) for VBAT > 4.1V and the time is larger than the deglitch time (25ms), CHG transits from low to high. CHG will be latched high unless the power is re-toggled. As the output voltage is near 4.2V, the charging current will be reduced to maintain the output voltage. The charger remains active and maintains the output voltage at 4.2V in order to keep the battery in a full charge state. Recharge Mode When the chip is in charge termination mode, the charging current goes down to zero and the battery voltage drops to 4.1V. After a deglitch time of 100ms (typ.), the battery begins recharging. However, when recharge happens, the indicator CHG remains in logic high. CHG Indicator The CHG pin is an open-drain output. CHG will assert low when the charger starts to charge the battery and become high impedance when the charge termination current is reached. The CHG signal is interfaced either with a microprocessor GPIO or an LED for indication. Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 ISET Pin Short Protection After VIN power plugs in, RT9527 will detect that ISET pin is short to ground or not. If RISET is smaller than RSHORT, RT9527 regard that ISET pin is short to ground. Then, RT9527 will disable charge function until VIN power reset. If RISET is larger than RSHORT, RT9527 will charge. If RT9527 begins charge status and ISET pin is short to ground, thermal regulation will work to limit junction temperature around 125°C. is a registered trademark of Richtek Technology Corporation. DS9527-00 May 2012 RT9527 Battery Connect Reverse 2.5RTCRTH RTC − 3.5RTH 7RTHRT2 = 3 (RTH + RT2 ) RT2 = If battery is connected reversely, it causes that the voltage of BAT pin is negative. RT9527 will disable charger function until battery voltage is normal. RT1 Time Fault Temperature Regulation In order to maximize charge rate, the RT9527 features a junction temperature regulation loop. If the power dissipation of the IC results in junction temperature greater than the thermal regulation threshold (125°C), the RT9527 will cut back on the charge current and disconnect the battery in order to maintain thermal regulation at around 125°C. This operation continues until the junction temperature falls below the thermal regulation threshold (125°C) by the hysteresis level. This feature prevents the maximum power dissipation from exceeding typical design conditions. Sleep mode The RT9527 enters sleep mode if both the AC and USB ports are removed from the input. This feature prevents draining the battery during the absence of an input supply. The Fast-Charge Fault Time is set according to the following equations : Fast-Charge Fault Time : tFCHG = 14400 x CTIMER (s) Pre-Charge Fault Time : tPCHG = 1 / 8 x tFCHG (s) where the CTIMER unit is in μF. When time fault happens, the charger cycle will be turned off and the CHG pin will become high impedance. Thermal Considerations For continuous operation, do not exceed absolute maximum junction temperature. The maximum power dissipation depends on the thermal resistance of the IC package, PCB layout, rate of surrounding airflow, and difference between junction and ambient temperature. The maximum power dissipation can be calculated by the following formula : Battery Pack Temperature Monitoring PD(MAX) = (TJ(MAX) − TA) / θJA The RT9527 features an external battery pack temperature monitoring input. The TS input connects to the NTC thermistor in the battery pack to monitor battery temperature and prevent danger over temperature conditions. If at any time the voltage at TS falls outside of the operating range, charging will be suspended. The timers maintain their values but suspend counting. When charging is suspended due to a battery pack temperature fault, the CHG pin remains low and continues to indicate charging. where TJ(MAX) is the maximum junction temperature, TA is the ambient temperature, and θJA is the junction to ambient thermal resistance. VIN Too Cold NTC_fault PD(MAX) = (125°C − 25°C) / (120°C/W) = 0.833W for WDFN-8L 2x2 package RT1 + + Too Hot - TS RNTC Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS9527-00 May 2012 For recommended operating condition specifications, the maximum junction temperature is 125°C. The junction to ambient thermal resistance, θJA, is layout dependent. For WDFN-8L 2x2 package, the thermal resistance, θJA, is 120°C/W on a standard JEDEC 51-7 four-layer thermal test board. The maximum power dissipation at TA = 25°C can be calculated by the following formula : RT2 The maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA. The derating curve in Figure 1 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation. is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT9527 Layout Considerations Maximum Power Dissipation (W)1 0.9 Four-Layer PCB The RT9527 is a fully integrated low cost single cell Li-Ion battery charger ideal for portable applications. Careful PCB layout is necessary. For best performance, place all peripheral components as close to the IC as possible. A short connection is highly recommended. The following guidelines must be strictly followed when designing a PCB layout for the RT9527. 0.8 0.7 0.6 0.5 0.4 0.3 0.2 ` Input and output capacitor should be placed close to IC and connected to ground plane. The trace of input in the PCB should be placed far away from the sensitive devices and shielded by the ground. ` The GND and exposed pad should be connected to a strong ground plane for heat sinking and noise protection. ` The connection of RISET should be isolated from other noisy traces. A short wire is recommended to prevent EMI and noise coupling. 0.1 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 1. Derating Curve of Maximum Power Dissipation Place CIN near the IC to improve performance. Connect the Exposed Pad to a ground plane. VIN GND R2 R1 VIN PGOOD CHG GND 1 2 3 4 COUT GND CIN 9 8 7 6 5 BAT TS TIMER ISET RISET GND GND should be connected to a strong ground plane for heat sinking and noise protection. RT1 RT2 CTIMER The RISET connection copper area should be minimized and kept far away from noise sources. Figure 2. PCB Layout Guide Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 is a registered trademark of Richtek Technology Corporation. DS9527-00 May 2012 RT9527 Operation State Diagram for Charger Function (RT9527) NO Standby State PFET = OFF YES YES VBAT > 3V Charge Termination VBAT = 4.2V ICHG = 0A CHG = H (latch) NO Fast-Charge Mode CHG = L VOVP > VIN > VUVLO Reset Time Counter NO VBAT < VREG - 0.1V NO YES YES Time >Ttermi Pre-CHG State ICHG_P = 0.1 x YES Power Off State PFET = OFF YES ICHG_F CHG = L VIN – VBAT > VOS Time < Tfchg NO Time < Tfchg VBAT ~4.2V NO NO NO Any State VIN > VOVP YES IBAT < Iterm YES Sleep State PFET = OFF Or VIN < VUVLO NO YES YES Power re-plug CV Mode CHG = L FAULT CHG = High impedance PFET = OFF NO NO VBAT < VREG - 0.1V YES YES Charge Termination VBAT = 4.2V ICHG = 0A CHG = H (latch) NO Fast-Charge Mode CHG = H (latch) Reset Time Counter NO YES NO VBAT > 3V Time > Ttermi YES VBAT ~4.2V YES IBAT < Iterm Time < Tpchg NO NO Time < Tpchg YES ICHG_F CHG = L NO YES CV Mode CHG = H (latch) YES Pre-CHG State ICHG_P = 0.1 x VIN – VBAT > VOS NO FAULT CHG = High impedance PFET = OFF Power re-plug YES Sleep State PFET = OFF NO Note1 : If termination happens, CHG will be latched H. (VIN > VOVP or VIN < VUVLO or VIN – VBAT < VOS_L) will release CHG latch H state. But VBAT < VREG - 0.1 can not release CHG latch H state. Note2 : If time out happens, CHG will become high impedance. (VIN > VOVP or VIN < VUVLO or VIN – VBAT < VOS_L) will release time out state Figure 2. Operation State Diagram for Charging Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS9527-00 May 2012 is a registered trademark of Richtek Technology Corporation. www.richtek.com 13 RT9527 Outline Dimension D2 D L E E2 1 e SEE DETAIL A b 2 1 2 1 A A1 A3 DETAIL A Pin #1 ID and Tie Bar Mark Options Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated. Dimensions In Millimeters Dimensions In Inches Symbol 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 0.200 0.300 0.008 0.012 D 1.950 2.050 0.077 0.081 D2 1.000 1.250 0.039 0.049 E 1.950 2.050 0.077 0.081 E2 0.400 0.650 0.016 0.026 e L 0.500 0.300 0.020 0.400 0.012 0.016 W-Type 8L DFN 2x2 Package Richtek Technology Corporation 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)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. www.richtek.com 14 DS9527-00 May 2012