RT9515 Linear Single Cell Li-Ion Battery Charger IC General Description Features The RT9515 is a fully integrated low cost single-cell LiIon battery charger IC ideal for portable applications. The RT9515 is capable of being powered up from AC adapter. The RT9515 enters sleep mode when AC adapter is removed. z 18V Maximum Rating for AC Adapter z 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 Halogen Free The RT9515 features 18V maximum rating voltages for AC adapter. The other features are under voltage protection, over voltage protection for AC adapter supply and battery temperature monitoring. Ordering Information z z z z z z z z Applications z z z z z Digital Cameras Cellular Phones Personal Data Assistants (PDAs) MP3 Players Handheld PCs Pin Configurations RT9515 (TOP VIEW) Package Type QW : WDFN-10L 3x3 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) Note : ACIN 1 NC 2 CHG_S 3 PGOOD 4 GND 5 BATT TS 8 EN 7 NC ISETA 10 9 GND 11 9 The RT9515 optimizes the charging task by using a control algorithm including preconditioning mode, fast charge mode and constant voltage mode. The charging task is terminated as the charge current drops below the preset threshold. 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. z 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. WDFN-10L 3x3 Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. DS9515-01 April 2011 www.richtek.com 1 RT9515 Typical Application Circuit Battery Pack AC Adapter 1 ACIN BATT 10 + RT9515 1uF To System 3 To System 4 PGOOD 5, Exposed Pad (11) TS CHG_S GND EN ISETA 9 8 Chip Shutdown Chip Enable 0.1uF to 10uF 6 RSET 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 Charge Complete 2.8V Precharge Threshold Functional Pin Description Pin No. Pin Name Pin Function ACIN Wall Adaptor Charge Input Supply. NC No Internal Connection. 3 CHG_S Charge Status Indicator Output (open drain). 4 PGOOD Power Good Indicator Output (open drain). 5 GND Ground. 6 ISETA Wall Adaptor Supply Charge Current Set Point. 8 EN Charge Enable Input (active low). 9 TS Temperature Sense Input. 10 BATT Battery Charge Current Output. 1 2, 7 11 (Exposed Pad) GND www.richtek.com 2 Exposed pad should be soldered to PCB board and connected to GND. DS9515-01 April 2011 RT9515 Function Block Diagram ACIN OVP Comparator 2.5V Charge Input Control GND SENSE FET + OVP - ACIN PFET ISETA BATT VREF 2.5V Precharge Comparator + 0.5V 2.5V 0.25V Recharge Comparator + 2.5V Loop Controller + 0.9V - Recharge VCC PGOOD Tcrmination Comparator 0.25V - Precharge VREF 125 C Charge Done Charge Disable Logic Temperature Fault + 1uA EN DS9515-01 April 2011 Temperature Sense CHG_S TS www.richtek.com 3 RT9515 Operation State Diagram for Charger function (RT9515) UVLO <VIN < OVP & EN = Low & VIN > BATT YES BATT < 4.1V YES BATT > 2.8V YES Fast-CHG State ICHG_F = 500mA @RSET = 1.5kΩ NO NO Power Off State PFET = OFF Pre-CHG State IPCHG NO Any State if VIN < UVLO or VIN > OVP or EN = High or VIN < BATT ICHG < 0.1 x ICHG_F NO = 0.1 x ICHG_F YES Charge Done State ICHG = 0A VTS > 2.5V or VTS < 0.5V www.richtek.com 4 DS9515-01 April 2011 RT9515 Absolute Maximum Ratings z z z z z z z z z (Note 1) ACIN 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 6V 1.2A 1.667W 60°C/W 8.2°C/W 260°C 150°C −65°C to 150°C 2kV 200V (Note 4) ACIN 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 = 5V, TA = 25°C, Unless Otherwise specification) Parameter Symbol Test Conditions Min Typ Max Units -- 3 3.5 V 50 80 120 mV Supply Input ACIN UVLO Threshold Voltage VUVLO Rising ACIN UVLO Hysteresis VUVLO_Hys ACIN Standby Current ISTBY VBATT = 4.5V -- 300 500 uA ACIN Shutdown Current ISHDN VEN = High -- 50 100 uA ACIN Quiescent Current IQ -- 150 250 uA BAT T Sleep Leakage Current ISLEEP -- 2 5 uA 4.168 4.21 4.252 V −1 -- +1 % -- 600 -- mΩ 2.45 2.5 2.55 V 100 -- 1200 mA -- 500 -- mA VACIN = 4V, VUSB = 4V, VBATT = 3V VACIN = 4V, V USB = 4V, VBATT = 4.5V Voltage Regulation BAT T Regulation Voltage VREG IBATT = 60mA Regulation Voltage Accuracy ACIN MOSFET RDS(ON)_ACIN IBATT = 500mA Current Regulation ISETA Set Voltage (Fast Charge Phase) Full Charge Setting Range VISETA ICHG_F ACIN Charge Current accuracy ICHG_F V BATT = 3.5V V BATT = 3.8V, RISE T = 1.5kΩ To be continued DS9515-01 April 2011 www.richtek.com 5 RT9515 Parameter Symbol Test Conditions Min Typ Max Units Precharge BATT Pre-Charge Rising Threshold V PRECH 2.6 2.8 3 V BATT Pre-Charge Threshold Hysteresis ΔV PRE CH 50 100 200 mV Pre-Charge Current I PCHG V BATT = 2V 8 10 12 % ΔV RECH_L V REG − VB ATT 60 100 170 mV V TE RM V BATT = 4.2V 225 250 275 mV I TERM V BATT = 4.2V -- 10 -- % CHG_S Pull Down Voltage V CHG_S TBD, ICHG _S = 5mA -- 65 -- mV PGOOD Pull Down Voltage V PGOOD TBD, IP GOOD = 5mA -- 220 -- mV 1.5 -- -- V -- -- 0.4 V Recharge Threshold BATT Re-Charge Falling Threshold Hysteresis Charge Termination Detection ISETA Charge Termination Set Voltage Termination Current Ratio (default) Logic Input/Output EN T hreshold Logic-High Voltage V IH Logic-Low Voltage V IL EN Pin Input Current I EN V EN = 2V -- -- 2 uA I TS V TS = 1.5V 96 102 108 uA Low Voltage V TS _LOW Falling 0.485 0.5 0.515 V High Voltage V TS _HIGH Rising 2.45 2.5 2.55 V -- 125 -- °C -- 6.5 -- V Battery Temperature Sense TS Pin Source Current TS Pin Threshold Protection Thermal Regulation OVP SET Internal Default 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, 2S2P) 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. www.richtek.com 6 DS9515-01 April 2011 RT9515 Typical Operating Characteristics ACIN Power On ACIN Power Off VBATT = 3.7V VBATT = 3.7V VACIN (5V/Div) VACIN (5V/Div) V CHG_S (2V/Div) V CHG_S (2V/Div) VBATT (5V/Div) VBATT (5V/Div) I CHG_S (1A/Div) I CHG_S (1A/Div) Time (250us/Div) Time (250us/Div) ACIN OVP ACIN OVP VACIN (10V/Div) VACIN (10V/Div) VBATT (5V/Div) VBATT (5V/Div) V CHG_S (5V/Div) V CHG_S (5V/Div) I CHG_S (1A/Div) VACIN = 0V to 10V, VBATT = 3.7V Time (1ms/Div) DS9515-01 April 2011 I CHG_S (1A/Div) VACIN = 5V to 8V to 5V, VBATT = 3.7V Time (1ms/Div) www.richtek.com 7 RT9515 Application Information Automatically Power Source Selection resistor or adding two external resistors. (see Figure 2.) The RT9515 is a battery charger IC which is designed for Li-ion Battery with 4.21V rated voltage. 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 to prevent noise. ACIN Mode : When the ACIN input voltage is higher than the UVP voltage level (3V) and lower than OVP voltage level (6.5V), the RT9515 will turn on ACIN P-MOSFET. Sleep Mode : The RT9515 will enter Sleep Mode when ACIN input voltage are removed. This feature provides low leakage current from the battery during the absence of input supply. V BATT + A ITS NTC ACIN Over Voltage Protection Battery 0.1uF to 10uF VTS = ITS × RNTC Turn off when VTS ≥ 2.5V or VTS ≤ 0.5V Figure 1. Temperature Sensing Configuration V BATT A ITS Battery Temperature Monitoring The RT9515 continuously monitors battery temperature by measuring the voltage between the TS and GND pins. The RT9515 has an internal current source to provide the bias for the most common 10kΩ negative-temperature coefficient thermal resistor (NTC) (see Figure 1). The RT9515 compares the voltage on the TS pin against the internal VTS_HIGH and VTS_LOW thresholds to determine if charging is allowed. When the temperature outside the VTS_HIGH and VTS_LOW thresholds is detected, the device will immediately stop the charge. The RT9515 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 www.richtek.com 8 TS Temperature Sense + 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. NTC TS Temperature Sense R T1 Battery R T2 0.1uF to 10uF RT2 × (RT1 + RNTC ) RT1 + RT2 + RNTC Turn off when VTS ≥ 2.5V or VTS ≤ 0.5V VTS = ITS Figure 2. Temperature Sensing Circuit Fast-Charge Current Setting The RT9515 offers ISETA pin to determine the ACIN charge current from 100mA to 1.2A. The charge current can be calculated as following equation. ICHG_F = K VISETA RSET DS9515-01 April 2011 RT9515 The parameter K = 300 ; VISETA = 2.5V. RSET is the resistor connected between the ISETA and GND. Charge State ACIN 1200 CHG_S PGOOD Charge ON ON Charge done OFF ON Charge Current (mA) 1000 Temperature Regulation and Thermal Protection 800 600 400 200 0 0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 (k) RSET SETA(kΩ) Figure 3. Charge Current Setting In order to maximize the charge rate, the RT9515 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 RT9515 throttles back on the charge current in order to maintain a junction temperature around the thermal regulation threshold (125°C). The RT9515 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 damaging. Pre- Charge Current Setting During a charge cycle if the battery voltage is below the VPRECH threshold, the RT9515 applies a pre-charge mode to the battery. This feature revives deeply discharged cells and protects battery life. The RT9515 internally determines the pre-charge rate as 10% of the fast-charge current. Battery Voltage Regulation The RT9515 monitors the battery voltage through the BATT pin. Once the battery voltage level closes to the VREG threshold, the RT9515 voltage enters constant phase and the charging current begins to taper down. When battery voltage is over the VREG threshold, the RT9515 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. Charge Status Outputs The open-drain CHG_S and PGOOD outputs indicate various charger operations as shown in the following table. 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. DS9515-01 April 2011 Selecting the Input and Output Capacitors In most applications, the most important is the highfrequency decoupling capacitor on the input of the RT9515. 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 RT9515 requires a small output capacitor for loop stability. A 1uF ceramic capacitor placed between the BATT pin and GND is typically sufficient. Thermal Considerations 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 : PD(MAX) = ( TJ(MAX) - TA ) / θJA Where T J(MAX) is the maximum operation junction temperature 125°C, TA is the ambient temperature and the θJA is the junction to ambient thermal resistance. www.richtek.com 9 RT9515 die (125°C) and TA is the ambient temperature. The junction to ambient thermal resistance θJA is layout dependent. For WDFN-10L 3x3 packages, the thermal resistance θJA is 60°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 : ` Connect the GND and Exposed Pad to a strong ground plane for maximum thermal dissipation and noise protection. ` The TS's capacitor should be placed close to TS (Pin 9) and connected to ground plane. If the PCB layout is poor, it is recommended to use a 10uF at C2 to prevent noise. The capacitor should be placed close to IC pin and connected to ground plane. PD(MAX) = (125°C − 25°C) / (60°C/W) = 1.667W for WDFN-10L 3x3 packages The maximum power dissipation depends on operating ambient temperature for fixed T J(MAX) and thermal resistance θJA. For WDFN-10L 3x3 package, the Figure 4 of derating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. Maximum Power Dissipation (W) 1.8 Four Layers PCB 1.6 C1 C3 ACIN 1 NC 2 CHG_S 3 PGOOD 4 GND 5 GND 1.2 9 TS 8 EN 7 NC ISETA Battery C2 The TS's capacitor should be placed close to TS(Pin 9) and connected to ground plane. RSETA GND The GND should be connected to a strong ground plane for heat sinking and noise protection. 1.4 10 BATT 9 For recommended operating conditions specification, where TJ(MAX) is the maximum junction temperature of the The connection of R SET should be isolated from other noisy traces. The short wire is recommended to prevent EMI and noise coupling. WDFN-10L 3x3 1.0 Figure 5. PCB Layout Guide 0.8 0.6 0.4 0.2 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 4. Derating Curves for RT9515 Package Layout Considerations For the best performance of the RT9515, the following PCB layout guidelines must be strictly followed. ` 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 connection of RSETA should be isolated from other noisy traces. The short wire is recommended to prevent EMI and noise coupling. www.richtek.com 10 DS9515-01 April 2011 RT9515 Outline Dimension D2 D L E E2 1 e SEE DETAIL A 2 b A3 Symbol 2 1 DETAIL A Pin #1 ID and Tie Bar Mark Options A A1 1 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 0.180 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: [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. DS9515-01 April 2011 www.richtek.com 11