RT9524GQW

RT9524 Linear Single Cell Li-Ion Battery Charger IC for Portable Applications The RT9524 is a fully integrated single cell Li-ion battery charger IC ideal for portable applications. The RT9524 optimizes the charging task by using a control algorithm including pre-charge mode, fast charge mode and constant voltage mode. the input voltage range of the VIN pin can be as high as 28V. When the input voltage exceeds the OVP threshold, it will turn off the charging MOSFET to avoid overheating of the chip. In RT9524, the maximum charging current can be programmed with an external resistor. For USB application, the user can set the current to 100mA/500mA through the EN/SET pin. For the factory mode, the RT9524 can allow 4.2V/2.3A power pass through to support system operation. It also provides a 50mA LDO to support the power of peripheral circuit. The internal thermal feedback circuit regulates the die temperature to optimize the charge rate for all ambient temperatures. The RT9524 provides protection functions such as under voltage protection, over voltage protection for VIN supply and thermal protection for battery temperature. Features z z z z z z z z z z 28V Maximum Rating for DC Adapter Internal Integrated Power MOSFETs Support 4.2V/2.3A Factory Mode 50mA Low Dropout Voltage Regulator Status Pin Indicator Programmed Charging Current Under Voltage Lockout Over Voltage Protection Thermal Feedback Optimized Charge Rate RoHS Compliant and Halogen Free Applications z Cellular Phones Digital Cameras PDAs and Smart Phones z Protable Instruments z z Pin Configurations (TOP VIEW) VIN ISET GND LDO IEOC The RT9524 is available in a WDFN-10L 3x2 package to achieve optimized solution for PCB space and thermal considerations. 1 2 3 4 5 GND General Description 11 10 9 8 7 6 BATT PGB CHGSB GND EN/SET WDFN-10L 3x2 Ordering Information RT9524 Marking Information Package Type QW : WDFN-10L 3x2 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) A0 : Product Code A0W W : Date Code 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. DS9524-01 April 2011 www.richtek.com 1 RT9524 Typical Application Circuit RT9524 1 VIN Adapter or USB BATT 10 CIN COUT 9 BATT 2 5 RISET + PGB CHGSB 8 ISET LDO 4 EN/SET 6 3, 7, 11(Exposed Pad) GND IEOC RIEOC BATT Functional Pin Description Pin No. Pin Name Pin Function 1 VIN The Input Power Source. 2 ISET Charging Current Setting. 3, 7, GND 11 (Exposed Pad) Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. 4 LDO LDO Output (4.9V). This pin provides 50mA output current. 5 IEOC End-of-Charge Current Setting. The IEOC is from 5% to 5O% Ichg-fast which is programmed by the ISET pin. 6 EN/SET Enable and Operation Mode Setting. 8 CHGSB Indicator Output for Charging Status. 9 PGB Indicator Output for Power Status. 10 BATT Battery Charge Current Output. Function Block Diagram Switch Well BATT CHGSB VIN VREF VDD IBias Base PGB GND Status Sleep Mode IEOC IEOC Set Block CC/CV/TR Multi Loop Controller Current Set Block ISET Current Set Block EN/SET 200k OVP Logic LDO LDO UVLO www.richtek.com 2 DS9524-01 April 2011 RT9524 Absolute Maximum Ratings z z z z z z z (Note 1) Supply Input Voltage, VIN ---------------------------------------------------------------------------------------------Other Pins ----------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C WDFN-10L 3x2 ----------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) WDFN-10L 3x2, θJA -----------------------------------------------------------------------------------------------------WDFN-10L 3x2, θJC ----------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------------------Junction Temperature --------------------------------------------------------------------------------------------------Storage Temperature Range ------------------------------------------------------------------------------------------- Recommended Operating Conditions z z z −0.3V to 28V −0.3V to 6V 1.111W 90°C/W 15°C/W 260°C 150°C −65°C to 150°C (Note 3) Supply Input Voltage, VIN ---------------------------------------------------------------------------------------------- 4.3V to 5.5V Junction Temperature Range ------------------------------------------------------------------------------------------ −40°C to 125°C Ambient Temperature Range ------------------------------------------------------------------------------------------ −20°C to 85°C Electrical Characteristics (VIN = 5V, VBATT = 4V, TA = 25°C, unless otherwise specified) Parameter VIN POR Rising Threshold Voltage VIN POR Threshold Voltage Hysteresis VIN OVP Threshold Voltage VIN OVP Threshold Voltage Hysteresis VIN − VOUT VOS Rising Symbol Test Conditions VPOR VOVP VIN − VOUT VOS Falling Min Typ Max Unit 3.15 3.3 3.45 V -- 200 300 mV 6.7 6.9 7.1 V -- 200 300 mV -- 75 150 mV 18 32 -- mV VIN Standby Current VBATT = 4.5V, EN/SET = High -- 250 300 μA VIN Supply Current VBATT = 4.5V, EN/SET = Low -- 1 2 mA -- 1 10 μA VOUT Sleep Leakage Current VOUT Regulation 4.158 4.2 4.242 V Thermal Regulation -- 125 -- °C OTP -- 155 -- °C OTP Hysteresis -- 20 -- °C PGB/CHGSB Sink Current 20 -- -- mA 2.4 2.5 2.6 V -- 25 -- ms 90 95 100 mA 15 20 25 % -- REOC/KEOC -- % Pre-Charge Threshold Fast-Charge to Pre-Charge Deglitch Time Pre-Charge Current End of Charge Current (EOC) 0°C to 85°C, ILOAD = 0mA VOUT Rising IPRECHG USB100 Mode USB500 Mode or ISET Mode, ratio of fast-charge current To be continued DS9524-01 April 2011 www.richtek.com 3 RT9524 Parameter IEOC Setting Current IEOC Setting KEOC Symbol IEOC IOUT = 1A VIN Power FET RDS(ON) ISET Set Voltage Test Conditions VISET ISET Short Protect Threshold ISET Short Protect Deglitch Time ISET Short Protect Maximum Current As ISET Mode, RISET = 530 VIN Charge Current ICHRG Max Unit 70 Typ 75 80 μA 180 200 220 Ω/% -- 280 512 mV -- 1.5 -- V 320 -- 460 Ω -- 1.5 -- ms -- 2 -- A 0.9 1 1.1 A As USB100 Mode 90 95 100 mA As USB500 Mode 380 395 415 mA -- 200 -- kΩ EN/SET Pull Low Resistor Logic-High VIH 1.4 -- -- Logic-Low VIL -- -- 0.4 3 6 Ω 4.75 4.9 5.05 V 60 120 180 mA 4.116 4.2 4.284 V 2.3 -- -- A Timer to disable chip 1.5 -- -- ms Timer to lock pulse count 1.5 -- -- ms Logic-High Duration 100 -- 700 μs Logic-Low Duration 100 -- 700 μs EN/SET Voltage LDO On-Resistance RDS(ON) LDO Output Voltage LDO Maximum Output Current Factory Mode VOUT Factory Mode Maximum Output Current EN/SET Off Time VLDO EN/SET Lock Time EN/SET Min V 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 four-layer test board of JEDEC 51-7 thermal measurement standard. The measurement case position of θJC is on the exposed pad of the package. Note 3. The device is not guaranteed to function outside its operating conditions. www.richtek.com 4 DS9524-01 April 2011 RT9524 Typical Operating Characteristics VOUT Regulation Voltage vs. Input Voltage VOUT Regulation Voltage vs. Temperature 4.215 VOUT Regulation Voltage (V)1 VOUT Regulation Voltage (V) 4.225 4.220 4.215 4.210 4.205 4.200 4.210 4.205 4.200 4.195 4.190 VIN = 5V 4.185 4.195 4.5 4.94 5.38 5.82 6.26 -50 6.7 -25 0 Input OVP Threshold vs. Temperature 6.82 6.80 6.78 6.76 6.74 6.72 6.70 -25 0 25 50 75 100 125 75 100 20 16 12 8 4 0 1.3 125 1.7 2.1 2.5 2.9 3.3 3.7 4.1 4.5 Battery Voltage (V) Temperature (°C) LDO Voltage vs. Temperature LDO Output Voltage vs. Output Current 4.95 4.95 4.93 4.93 LDO Voltage (V) LDO Output Voltage (V) 50 VOUT Sleep Leakage Current vs. Battery Voltage VOUT Sleep Leakage Current (µA)1 Input OVP Threshold (V) 6.84 -50 25 Temperature (°C) Input Voltage (V) 4.91 4.89 4.91 4.89 4.87 4.87 VIN = 5.5V 4.85 0 20 40 60 Output Current (mA) DS9524-01 April 2011 80 100 VIN = 5.5V, ILDO = 50mA 4.85 -50 -25 0 25 50 75 100 125 Temperature (°C) www.richtek.com 5 RT9524 ISET Mode Charge Current vs. Input Voltage USB 500 Mode Charge Current vs. Input Voltage 900 415 R = 680 750 Charge Current (mA) Charge Current (mA) 825 675 600 525 450 R = 1.2k 405 395 385 375 375 VBATT = 3.8V VBATT = 3.8V 300 365 4.5 4.9 5.3 5.7 6.1 6.5 4.5 4.9 Input Voltage(V) 5.3 5.7 6.1 6.5 Input Voltage (V) USB 100 Mode Charge Current vs. Input Voltage ISET Voltage vs. Input Voltage 100 1.53 ISET Voltage (V) Charge Current (mA) 1.52 95 90 1.51 1.50 1.49 1.48 VBATT = 3.8V 85 RISET = 1.2kΩ, VBATT = 3.8V 1.47 4.5 4.9 5.3 5.7 6.1 6.5 4.2 4.72 5.24 5.76 Input Voltage (V) Input Voltage (V) Power On EN/SET Shut-Down VIN (5V/Div) EN/SEB (1V/Div) PGB (2V/Div) CHGSB (2V/Div) VLDO (2V/Div) CHGS (2V/Div) I CHARGER (500mA/Div) I CHARGER (500mA/Div) www.richtek.com 6 6.8 VIN = 5V VBATT = 3.8V, RISET = 680Ω, EN/SEB = Low Time (10ms/Div) 6.28 Time (1ms/Div) DS9524-01 April 2011 RT9524 Charger Current--USB500 mode to ISET mode Charger Current--USB500 mode to USB100 mode VIN (5V/Div) VBATT (5V/Div) EN/SET (2V/Div) VIN (5V/Div) VBATT (5V/Div) EN/SET (2V/Div) I CHARGER (500mA/Div) I CHARGER (500mA/Div) VIN = 5V, VBATT = 3.8V, RISET = 680Ω VIN = 5V, VBATT = 3.8V, RISET = 80Ω Time (1ms/Div) Time (1ms/Div) LDO Load Transient Response Factory Mode VIN (5V/Div) VBATT (200mV/Div) EN/SET (1V/Div) VLDO_ac (100mV/Div) ILDO (500mA/Div) IOUT (1A/Div) VIN = 5V, VBATT = 3.8V, ILDO = 5mA to 50mA Time (250μs/Div) DS9524-01 April 2011 VIN = 5V, COUT = 44μF, IOUT = 10Ω to 2.3Ω Time (50μs/Div) www.richtek.com 7 RT9524 Application Information Description The RT9524 is a fully integrated low cost single-cell LiIon battery charger IC with a constant current mode (CC mode) or a constant voltage mode (CV mode). The charge current is programmable to USB100, USB500 or ISET mode and the CV mode voltage is fixed at 4.2V. The precharge threshold is fixed at 2.5V. If the battery voltage is below the pre-charge threshold, the RT9524 charges the battery with a trickle current until the battery voltage rises above the pre-charge threshold. The RT9524 is capable of being powered up from AC adapter and USB (Universal Serial Bus) port inputs. Moreover, the RT9524 include a linear regulator (LDO 4.9V, 50mA) for supplying low power external circuitry. ACIN Over Voltage Protection The input voltage is monitored by the internal comparator and the input over voltage protection threshold is set to 6.9V. However, input voltage over 28V will still cause damage to the RT9524. 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 voltage condition is removed, the comparator re-enables the output by running through the soft-start. the number of pulses is locked and sent to the control logic and then the mode changes. The RT9524 needs to be restarted to reset the charge current. Once the EN/ SET input is held high for more than 1.5ms, the RT9524 is disabled. Table 1. Pulse Counting Map for EN/SET Interface Pulses 0 1 2 3 ≥4 Charge Condition USB500 Mode ISET Mode USB100 Mode Factory Mode USB100 Mode MODE Control Charge Current Limit Charge Current Limit Charge Current Limit Enabled Charge Current Limit 50µs 100µs < tHigh < 700µs EN/SET 1.5ms 1.5ms ISET USB500 ICHARGE Figure .1 (a) 50µs 100µs < tHigh < 700µs 1.5ms EN/SET 1.5ms USB500 Charger Enable and mode Setting EN/SET is used to enable or disable the charger as well as to select the charge current limit. Drive the EN pin to low or leave it floating to enable the charger. The EN/SET pin has a 200kΩ internal pull down resistor. So, when left floating, the input is equivalent to logic low. Drive this pin to high to disable the charger. After the EN/SET pin pulls low for 50μs, the RT9524 enters the USB500 mode and wait for the setting current signal. EN/SET can be used to program the charge current during this cycle. The RT9524 will change its charge current by sending different pulse to EN/SET pin. If no signal is sent to EN/SET, the RT9524 will remain in USB500 mode. A correct period of time for high pulse is between 100μs and 700μs and the period of pulse to pulse must be between 100μs and 700μs to be properly read. Once EN/SET is held low for 1.5ms, www.richtek.com 8 USB100 ICHARGE Figure .1 (b) Battery Charge Profile The RT9524 charges a Li-Ion battery with a constant current (CC) or a constant voltage (CV). The constant current is decided by the operation mode of USB100, USB500 or ISET mode. The constant current is set with the external resistor RISET and the constant voltage is fixed at 4.2V. If the battery voltage is below the PreCharge Threshold, the RT9524 charges the battery with a trickle current until the battery voltage rises above the trickle charge threshold. When the battery voltage reaches 4.2V, the charger enters CV mode and regulates the battery voltage at 4.2V to fully charge the battery without the risk of over charging DS9524-01 April 2011 RT9524 Pre-charge Mode Constant Current Mode Constant Voltage Mode Battery Charge Current Programmed Charge Current USB500 and USB100 Mode Recharge Phase The fast-charge current is 95mA in USB100 mode and 395mA in USB500 mode. Note that if the fast-charge current set by external resistor is smaller than that in USB500 mode (395mA), the RT9524 charges the battery in ISET mode. 4.2V Battery Regulation Voltage threshold Battery Voltage Regulation (CV Mode) Battery Full CHG_S pull High Precharge Threshold Time Figure 2 Battery Pre-Charge Current During a charge cycle, if the battery voltage is below the pre-charge threshold, the RT9524 enters the pre-charge mode. This feature revives deeply discharged cells and protects battery. Under USB100 Mode, the pre-charge current is internally set to 95mA. When the RT9524 is under USB500 and ISET Mode, the pre-charge current is 20% of fast-charge current set by external resistor RISET. Battery Fast-Charge Current ISET Mode The RT9524 offers ISET pin to program the charge current. The resistor RISET is connected to ISET and GND. The parameter KISET is specified in the specification table. K ICharge = ISEF ; KISEF = 530 RISET Battery Charge Current (mA) 1400 1200 1000 800 600 400 The battery voltage regulation feedback is through the BATT pin. The RT9524 monitors the battery voltage between BATT and GND pins. When the battery voltage closes in on the battery regulation voltage threshold, the voltage regulation phase begins and the charging current begins to taper down. When the charging current falls below the programmed end-of-charge current threshold, the CHGSB pin goes high to indicate the termination of charge cycle. The end-of-charge current threshold is set by the IEOC pin. The resistor REOC is connected to IEOC and GND. The parameters KEOC and IEOC are specified in the specification table. R IEOC (%) = EOC ; KEOC = 200 KEOC The current threshold of IEOC (%) is defined as the percentage of fast-charge current set by RISET. After the CHGSB pin is pulled high, the RT9524 still monitors the battery voltage. Charge current is resumed when the battery voltage goes to lower than the battery regulation voltage threshold. Factory Mode The RT9524 provides factory mode for supplies up to 2.3A for powering external loads with no battery installed and BATT is regulated to 4.2V. The factory mode allows the user to supply system power with no battery connected. In factory mode, thermal regulation is disabled but thermal protection (155°C) is still active. When using currents greater than 1.5A in factory mode, the user must limit the duty cycle at the maximum current to 20% with a maximum period of 10ms. 200 LDO 0 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 RSET (k∠) (kΩ) 3 The RT9524 integrates one low dropout linear regulator (LDO) that supplies up to 50mA. The LDO is active whenever the input voltage is between POR threshold and Figure 3 DS9524-01 April 2011 www.richtek.com 9 RT9524 OVP threshold. It is not affected by the EN/SET input. Note that the LDO current is independence and not monitored by the charge current limit. Charge Status Outputs (CHGSB and PGB) The open-drain CHGSB and PGB 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. Table 2 Condition CHGSB Input OVP OFF Input UVLO OFF Charge (CC Mode and CV Mode) ON Charge Done (IFULL) OFF PGB OFF OFF ON ON 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 maximum power dissipation from exceeding typical design conditions. Selecting the Input and Output Capacitors In most applications, all that is needed is a high-frequency decoupling capacitor on the input. A 1μF ceramic capacitor, placed in close proximity to input to GND, works well. In some applications depending on the power supply characteristics and cable length, it may be necessary to add an additional 10μF ceramic capacitor to the input. The RT9524 requires a small output capacitor for loop stability. A typical 1μF ceramic capacitor placed between the BATT pin and GND is sufficient. Condition Entering OVP (VIN = 5.5V→10V) Leaving OVP (VIN = 10V→5.5V) Entering SLEEP (VIN = 5.5V→3.6V) Leaving SLEEP (VIN = 3.6V→5.5V) Entering UVLO (VIN = 5.5V→2.5V) Leaving UVLO (VIN = 2.5V→5.5V) PGB Deglitches Time EN/SET is EN/SET is High Low 0 100μs 500μs 450μs 0 32ms 500μs 500μs For continuous operation, do not exceed absolute maximum operation junction temperature. The maximum power dissipation depends on 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 : PD(MAX) = (TJ(MAX) − TA) / θJA 0 0 230μs 230μs Sleep Mode The RT9524 enters sleep mode if the power is removed from the input. This feature prevents draining the battery during the absence of input supply. Temperature Regulation and Thermal Protection In order to maximize charge rate, the RT9524 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 RT9524 limits the charge current in order to maintain a junction temperature around the thermal regulation threshold (125°C). The RT9524 monitors the junction www.richtek.com 10 Thermal Considerations where T J(MAX) is the maximum operation junction temperature, TA is the ambient temperature, and θJA is the junction to ambient thermal resistance. For recommended operating conditions specification of RT9524, the maximum junction temperature is 125°C and TA is the maximum ambient temperature. The junction to ambient thermal resistance, θJA, is layout dependent. For WDFN-10L 3x2 packages, the thermal resistance, θJA , is 90°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 : PD(MAX) = (125°C − 25°C) / (90°C/W) = 1.111W for WDFN-10L 3x2 package The maximum power dissipation depends on operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA. For RT9524 package, the derating curve DS9524-01 April 2011 RT9524 in Figure 4 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation. Four-Layer PCB 1.0 0.8 The connection of resistor should be isolated from other noisy traces. Short wire is recommended to prevent EMI and noise coupling. CIN RISET VIN ISET GND LDO IEOC 1 10 2 9 3 4 5 GND Maximum Power Dissipation (W) 1.2 The capacitor should be placed close to IC pin and connected to ground plane. 11 8 7 6 BATT PGB CHGSB GND EN/SET COUT RIEOC GND The GND should be connected to a strong ground plane for heat sinking and noise protection. 0.6 0.4 Figure 5. PCB Layout Guide 0.2 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 4. Derating Curve for RT9524 Package Layout Consideration The RT9524 is a fully integrated low cost single-cell LiIon battery charger IC 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 RT9524. ` Input capacitor should be placed close to the IC and connected to ground plane. The trace of input in the PCB should be placed far away from 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 RISET and RIEOC should be isolated from other noisy traces. The short wire is recommended to prevent EMI and noise coupling. ` Output capacitor should be placed close to the IC and connected to ground plane to reduce noise coupling. DS9524-01 April 2011 www.richtek.com 11 RT9524 Outline Dimension D2 D L E2 E 1 e A A1 SEE DETAIL A b A3 2 1 2 1 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 2.900 3.100 0.114 0.122 D2 2.450 2.550 0.096 0.100 E 1.900 2.100 0.075 0.083 E2 0.750 0.850 0.030 0.033 e L 0.500 0.250 0.020 0.350 0.010 0.014 W-Type 10L DFN 3x2 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. www.richtek.com 12 DS9524-01 April 2011