RT9502GQW

RT9502 Linear Single Cell Li-Ion Battery Charger IC with Dual Input Supply General Description Features The RT9502 is a fully integrated low cost single-cell LiIon battery charger IC ideal for portable applications. The RT9502 is capable of being powered up from AC adapter and USB (Universal Serial Bus) port inputs. The RT9502 can automatically detect and select the AC adapter and the USB port as the power source for the charger. The RT9502 enters sleep mode when both supplies are removed. z The RT9502 optimizes the charging task by using a control algorithm including precondition mode, fast charge mode and constant voltage mode. The charging task is terminated as the charge current drops below the preset threshold. The USB charge current can be selected from preset ratings of 100mA and 500mA, while the AC adapter charge current can be programmed up to 1A with an external resister. The internal thermal feedback circuitry regulates the die temperature to optimize the charge rate for all ambient temperatures. The RT9502 features 18V and 7V maximum rating voltages for AC adapter and USB port inputs respectively. The other features are under voltage protection, over voltage protection for AC adapter supply and battery temperature monitoring. z z z z z z z z z z z z Automatic Input Supplies Selection 18V Maximum Rating for AC Adapter Integrated Selectable 100mA and 500mA USB Charge Current Internal Integrated P-MOSFETs AC Adapter Power Good Status Indicator Charge Status Indicator Under Voltage Protection Over Voltage Protection Automatic Recharge Feature Battery Temperature Monitoring Small 10-Lead WDFN Package Thermal Feedback Optimizing Charge Rate RoHS Compliant and 100% Lead (Pb)-Free Applications z z z z z Digital Cameras Cellular Phones Personal Digital Assistants (PDAs) MP3 Players Hand Held PCs Pin Configurations (TOP VIEW) Ordering Information Package Type QW : WDFN-10L 3x3 (W-Type) Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) ACIN 1 USB 2 CHG_S 3 PGOOD 4 GND 5 BATT TS 8 EN 7 ISETU ISETA 10 9 GND 11 9 RT9502 WDFN-10L 3x3 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. DS9502-02 April 2011 Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. www.richtek.com 1 RT9502 Typical Application Circuit Battery Pack AC Adapter 1 ACIN BATT 10 + RT9502 1uF 2 USB USB TS 1uF EN To System 3 To System 4 PGOOD 5, Exposed Pad(11) 9 Chip Shutdown 8 Chip Enable CHG_S GND ISETU ISETA 0.1uF to 10uF H : 500mA L : 100mA 7 6 R SET Pre-Charge Phase Fast Charge Phase Constant Voltage Phase & Re-Charge Phase Standby Phase Programmed Charge Current Battery Voltage Charging Current 4.1V Recharge Threshold 1/10 Programmed Charge Current 2.8V Precharge Threshold Charge Complete Functional Pin Description Pin No. Pin Name Pin Function 1 ACIN AC Adaptor Charge Input Supply. 2 USB USB Charge Input Supply. 3 CHG_S Charge Status Indicator Output (open drain). 4 Power Good Indicator Output (open drain). 5 PGOOD GND Ground. 6 ISETA Wall Adaptor Supply Charge Current Set Point. 7 ISETU USB Supply Charge Current Set Input (active low). 8 Charge Enable Input (active low). 9 EN TS Temperature Sense Input. 10 BATT Battery Charge Current Output. 11 (Exposed Pad) GND www.richtek.com 2 The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. DS9502-02 April 2011 RT9502 Function Block Diagram ACIN USB 2.5V Charge Input Selection SENSE MOSFET USB P-MOSFET OVP Comparator + OVP - ACIN P-MOSFET SENSE MOSFET ISETA BATT GND 2.5V V REF 0.5V Thermal Sense 115 C ACIN/USB V FB 0.25V DRV VCC/USB Precharge Loop Controller 1.5k 7.5k Termination Comparator V REF - 0.25V + 0.9V - Charge Disable Thermal Sense PGOOD Logic Temperature Fault + 1uA 1uA ISETU DS9502-02 April 2011 EN Temperature Sense CHG_S TS www.richtek.com 3 RT9502 Table RT9502 Flow Chart Start-Up Precharge Phase Fast Charge Phase Standby/Fault Recharge Phase UVP / OVP DISABLE ACIN/USB Power Up DISABLE MODE P-MOSFET OFF IBATT =0 YES V EN > 1.4V ? NO V ACIN > 6.5V or (V ACIN < 4.4V and V USB < 4.4V) ? OVP/UVP MODE P-MOSFET OFF IBATT =0 YES NO Start-Up SLEEP V ACIN < V BATT and V USB < V BATT ? SLEEP MODE P-MOSFET OFF IBATT =0 YES NO 1ms Delay V TS > 2.5V or V TS < 0.5V? RECHARGE YES TEMP FAULT/CHG_S HIGH IMPEDANCE NO YES V BATT > 2.8V? NO IBATT = 0.1 Charge Current /CHG_S Pull Down YES IBATT = Charge Current /CHG_S Pull Down YES STANDBY PFET OFF V BATT = 4.2V, IBATT = 0 NO YES V BATT > 4.1 V? NO V BATT ~ 4.2V, IBATT < 0.1 ICHG? www.richtek.com 4 DS9502-02 April 2011 RT9502 Absolute Maximum Ratings z z z z z z z z z z (Note 1) ACIN Input Voltage -------------------------------------------------------------------------------------------------------USB Input Voltage --------------------------------------------------------------------------------------------------------EN Input Voltage ----------------------------------------------------------------------------------------------------------Output Current ------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C WDFN-10L 3x3 ------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) WDFN-10L 3x3, θJA ------------------------------------------------------------------------------------------------------WDFN-10L 3x3, θJC ------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ---------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------ Recommended Operating Conditions z z z −0.3V to 18V −0.3V to 7V −0.3V to 6V 1.2A 0.926W 108°C/W 8.2°C/W 260°C 150°C −65°C to 150°C 2kV 200V (Note 4) ACIN, USB Input Voltage Range --------------------------------------------------------------------------------------- 4.5V to 6V Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (ACIN = USB = 5V, TA = 27°C, Unless Otherwise specification) Parameter Symbol Test Conditions Min Typ Max Units Supply Input ACIN/USB UVP Rising Threshold Voltage ACIN/USB UVP Hysteresis VUV_HIGH -- 4.4 4.5 V VUV_LOW 50 80 120 mV ACIN/USB Standby Current ISTBY VBATT = 4.5V -- 300 500 uA ACIN/USB Shutdown Current ISHDN -- 50 100 uA ACIN/USB UVP Current IUVP -- 150 250 uA BATT Sleep Leakage Current ISLEEP VEN = High VACIN = 4V, V USB = 4V, VBATT = 3V VACIN = 4V, V USB = 4V VBATT = 4.5V -- 2 5 uA 4.158 4.2 4.242 V −1 -- +1 % IBATT = 500mA -- 600 -- mΩ -- 1200 -- mΩ 2.42 2.5 2.55 V 100 -- 1200 mA Voltage Regulation BATT Regulation Voltage VREG IBATT = 60mA Regulation Voltage Accuracy ACIN MOSFET RDS(ON)_ACI N USB MOSFET RDS(ON)_USB IBATT = 500mA Current Regulation ISETA Set Voltage (Fast Charge Phase) Full Charge setting range VISETA VBATT = 3.5V ICHG_ACIN To be continued DS9502-02 April 2011 www.richtek.com 5 RT9502 Parameter ACIN Charge Current accuracy Symbol Min Typ Max Units -- 500 -- mA VPRECH 2.6 2.8 3 V ΔVPRECH 50 100 200 mV ICHG_ACIN Test Conditions V BATT = 3.8V; RISET = 1.5kΩ Precharge BATT Pre-charge Rising Threshold BATT Pre-charge Threshold Hysteresis Pre-Charge Current IPCHG V BATT = 2V 8 10 12 % ΔVRECH_L V REG − VBATT 60 100 150 mV VTERM V BATT = 4.2V 200 250 275 mV ITERM V BATT = 4.2V -- 10 -- % CHG_S Pull Down Voltage VCHG_S TBD; ICHG_S = 5mA -- 65 -- mV PGOOD Pull Down Voltage VPGOOD TBD; IPGOOD = 5mA -- 220 -- mV Logic-High Voltage VIH 1.5 -- -- V Logic-Low Voltage VIL -- -- 0.4 V -- -- 2 uA 1.5 -- Recharge Threshold BATT Re-charge Falling Threshold Hysteresis Charge Termination Detection ISETA Charge Termination Set Voltage Termination Current Ratio (default) Logic Input/Output EN Threshold EN Pin Input Current ISETU Threshold High Voltage Low Voltage ISETU Pin Input Current IEN V EN = 2V VISETU_HIGH VISETU_LOW IISETU V ISETU =2V V -- -- 0.4 V -- -- 2 uA -- -- 100 400 450 500 96 102 108 uA USB Charge Current & Timing ICHG(USB100) USB Charge Current ICHG(USB500) V USB = 5V; VBATT = 3.5V, ISETU = 0V V USB = 5V; VBATT = 3.5V, ISETU = 5V mA Battery Temperature Sense TS Pin Source Current TS Pin Threshold ITS V TS = 1.5V Low Voltage VTS_LOW Falling 0.485 0.5 0.515 V High Voltage VTS_HIGH Rising 2.45 2.5 2.55 V -- 125 -- °C -- 6.5 -- V Protection Thermal Regulation OVP SET www.richtek.com 6 Internal Default DS9502-02 April 2011 RT9502 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 thermal conductivity test board (4 layers, 1S) of JEDEC 51-7 thermal measurement standard. The case point of θJC is on the expose pad for 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. DS9502-02 April 2011 www.richtek.com 7 RT9502 Typical Operating Characteristics ACIN Power On USB Power On VACIN (5V/Div) VUSB (5V/Div) VBATT (2V/Div) VBATT (2V/Div) CHG_S (5V/Div) CHG_S (5V/Div) I CHARGE (0.5A/Div) VBATT = 3.7V I CHARGE (0.5A/Div) VBATT = 3.7V Time (250us/Div) Time (250us/Div) ACIN Power Off USB Power Off VACIN (5V/Div) VUSB (5V/Div) VBATT (2V/Div) VBATT (2V/Div) CHG_S (5V/Div) CHG_S (5V/Div) I CHARGE (0.5A/Div) I CHARGE (0.5A/Div) VBATT = 3.7V VBATT = 3.7V Time (500us/Div) Time (200us/Div) ACIN OVP ACIN OVP VACIN (10V/Div) VACIN (5V/Div) VBATT (5V/Div) VBATT (5V/Div) CHG_S (5V/Div) CHG_S (5V/Div) I CHARGE (0.5A/Div) ACIN = 0V to 10V, VBATT = 3.7V Time (1ms/Div) www.richtek.com 8 I CHARGE (1A/Div) ACIN = 5V to 8V to 5V, VBATT = 3.7V Time (1ms/Div) DS9502-02 April 2011 RT9502 Input Voltage Transition Input Voltage Transition ACIN Power On ACIN Power Off VACIN (5V/Div) VACIN (5V/Div) VUSB (5V/Div) VUSB (5V/Div) CHG_S (5V/Div) CHG_S (5V/Div) I CHARGE (1A/Div) I CHARGE (1A/Div) VBATT = 3.7V VBATT = 3.7V Time (500us/Div) DS9502-02 April 2011 Time (500us/Div) www.richtek.com 9 RT9502 Application Information Automatically Power Source Selection Battery Temperature Monitoring The RT9502 is a battery charger IC which is designed for Li-ion Battery with 4.2V rated voltage. The RT9502 continuously monitors battery temperature by measuring the voltage between the TS and GND pins. The RT9502 has an internal current source to provide the bias for the most common 10kΩ negative-temperature coefficient thermal resistor (NTC) (see Figure 2). The RT9502 compares the voltage on the TS pin against the internal VTS_HIGH and VTS_LOW thresholds to determine if charging is allowed. The RT9502 can be adopted for two input power source, ACIN or USB Input. It will automatically select the input source and operate in different mode as below. ACIN Mode : When the ACIN input voltage (ACIN) is higher than the UVP voltage level (4.4V), the RT9502 will enter ACIN Mode. In the ACIN Mode, ACIN P-MOSFET is turned on and USB P-MOSFET is turned off. USB Mode : When ACIN input voltage is lower than UVP voltage level and USB input voltage is higher than UVP voltage level (4.4V), the RT9502 will operate in the USB Mode. In the USB Mode, ACIN P-MOSFET is turned off and USB P-MOSFET is turned on. Sleep Mode : The RT9502 will enter Sleep Mode when both ACIN and USB input voltage are removed. This feature provides low leakage current from the battery during the absence of input supply. V ACIN > UVP ACIN Mode USB Mode V ACIN < UVP V USB > UVP When the temperature outside the VTS_HIGH and VTS_LOW thresholds is detected, the device will immediately stop the charge. The RT9502 stops charge and keep monitoring the battery temperature when the temperature sense input voltage is back to the threshold between VTS_HIGH and VTS_LOW, the charger will be resumed. Charge is resumed when the temperature returns to the normal range. However the user may modify thresholds by the negative-temperature coefficient thermal resistor or adding two external resistors. (see Figure 3.) The capacitor should be placed close to TS(Pin 9) and connected to the ground plane. The capacitance value (0.1uF to 10uF) should be selected according to the quality of PCB layout. It is recommended to use 10uF if the layout is poor if prevent noise. Sleep Mode V BATT + V ACIN < UVP V USB < UVP A ITS Figure 1. Input Power Source Operation Mode. ACIN Over Voltage Protection NTC Temperature Sense TS Battery The ACIN input voltage is monitored by an internal OVP comparator. The comparator has an accurate reference of 2.5V from the band-gap reference. The OVP threshold is set by the internal resistive. The protection threshold is set to 6.5V. When the input voltage exceeds the threshold, the comparator outputs a logic signal to turn off the power P-MOSFET to prevent the high input voltage from damaging the electronics in the handheld system. When the input over oltage condition is removed (ACIN < 6V), the comparator re-enables the output by running through the soft-start. www.richtek.com 10 0.1uF to 10uF VTS = ITS × RNTC Turn off when VTS ≥ 2.5V or VTS ≤ 0.5V Figure 2. Temperature Sensing Configuration DS9502-02 April 2011 RT9502 Case 2 : USB Mode V BATT + A A low-level signal of ISETU pin sets the charge current at 100mA and a high level signal sets the charge current at 500mA. ITS NTC R T1 TS Temperature Sense When charging from a USB port, the ISETU pin can be used to determine the charge current of 100mA or 500mA. Battery R T2 Pre- Charge Current Setting 0.1uF to 10uF During a charge cycle if the battery voltage is below the VPRECH threshold, the RT9502 applies a pre-charge mode to the battery. This feature revives deeply discharged cells and protects battery life. The RT9502 internal determines the pre-charge rate as 10% of the fast-charge current. RT2 × (RT1 + RNTC ) RT1 + RT2 + RNTC Turn off when VTS ≥ 2.5V or VTS ≤ 0.5V VTS = ITS Figure 3. Temperature Sensing Circuit Battery Voltage Regulation Fast-Charge Current Setting Case 1 : ACIN Mode The RT9502 offers ISETA pin to determine the ACIN charge rate from 100mA to 1.2A. The charge current can be calculated as following equation. Icharge_ac = K SET VSET RSETA The parameter KSET = 300 ; VSET = 2.5V. RSETA is the resistor connected between the ISETA and GND. Charge Status Outputs The open-drain CHG_S and PGOOD outputs indicate various charger operations as shown in the following table. 1200 1000 Charge Current (mA) The RT9502 monitors the battery voltage through the BATT pin. Once the battery voltage level closes to the VREG threshold, the RT9502 voltage enters constant phase and the charging current begins to taper down. When battery voltage is over the VREG threshold, the RT9502 will stop charge and keep to monitor the battery voltage. However, when the battery voltage decreases 100mV below the VREG, it will be recharged to keep the battery voltage. These status pins can be used to drive LEDs or communicate to the host processor. Note that ON indicates the open-drain transistor is turned on and LED is bright. 800 600 CHG_S PGOOD Charge ON ON Charge done OFF ON Charge ON OFF Charge done OFF OFF Charge State 400 200 ACIN 0 0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 (k) RRSETA SETA(kΩ) 9.5 USB Figure 4. ACIN Mode Charge Current Setting DS9502-02 April 2011 www.richtek.com 11 RT9502 In order to maximize the charge rate, the RT9502 features a junction temperature regulation loop. If the power dissipation of the IC results in a junction temperature greater than the thermal regulation threshold (125°C), the RT9502 throttles back on the charge current in order to maintain a junction temperature around the thermal regulation threshold (125°C). The RT9502 monitors the junction temperature, TJ, of the die and disconnects the battery from the input if TJ exceeds 125°C. This operation continues until junction temperature falls below thermal regulation threshold (125°C) by the hysteresis level. This feature prevents the chip from damage. Selecting the Input and Output Capacitors In most applications, the most important is the highfrequency decoupling capacitor on the input of the RT9502. A 1uF ceramic capacitor, placed in close proximity to input pin and GND pin is recommended. In some applications depending on the power supply characteristics and cable length, it may be necessary to add an additional 10uF ceramic capacitor to the input. The RT9502 requires a small output capacitor for loop stability. A 1uF ceramic capacitor placed between the BATT pin and GND is typically sufficient. ` Output capacitor should be placed close to IC and connected to ground plane to reduce noise coupling. ` The TS's capacitor should be placed close to TS (Pin 9) and connected to ground plane. The capacitance (0.1uF to 10uF) base on PCB layout. When PCB has poor layout, the 10uF is recommended to prevent noise. The capacitor should be placed close to IC pin and connected to ground plane. C1 C2 C4 ACIN 1 USB 2 CHG_S 3 PGOOD 4 GND 5 GND 10 BATT 9 TS 8 EN 7 ISETU 9 Temperature Regulation and Thermal Protection ISETA R SETA GND The GND should be connected to a strong ground plane for heat sinking and noise protection. Battery C3 The TS's capacitor should be placed close to TS(Pin 9) and connected to ground plane. The capacitance (0.1uF to 10uF) base on PCB layout. When PCB has poor layout the 10uF is recommended to prevent noise. The connection of R SETA should be isolated from other noisy traces. The short wire is recommended to prevent EMI and noise coupling. Figure 5 Layout Consideration The RT9502 is a fully integrated low cost single-cell LiIon 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 should be strictly followed when designing a PCB layout for the RT9502. ` Input capacitor should be placed close to IC and connected to ground plane. The trace of input in the PCB should be placed far away the sensitive devices or shielded by the ground. ` The GND should be connected to a strong ground plane for heat sinking and noise protection. ` The connection of RSETA should be isolated from other noisy traces. The short wire is recommended to prevent EMI and noise coupling. www.richtek.com 12 DS9502-02 April 2011 RT9502 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. Symbol 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 0.180 0.300 0.007 0.012 D 2.950 3.050 0.116 0.120 D2 2.300 2.650 0.091 0.104 E 2.950 3.050 0.116 0.120 E2 1.500 1.750 0.059 0.069 e L 0.500 0.350 0.020 0.450 0.014 0.018 W-Type 10L DFN 3x3 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: marketing@richtek.com 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. DS9502-02 April 2011 www.richtek.com 13