XB4908A

XB4908 SERIES One Cell Lithium-ion/Polymer Battery Protection IC GENERAL DESCRIPTION  The XB4908 SERIES product is a high i ntegration solution for lithium-ion/polymer battery protection. XB4908 SERIES contai ns advanced power MOSFET, high-accura cy voltage detection circuits and delay circ uits. XB4908 SERIES is put into an ultra-s mall ESN4 package and only one external component makes it an ideal solution in li mited space of battery pack. XB4908 SERIES has all the protection fu nctions required in the battery application i ncluding overcharging, over-discharging, o vercurrent and load short circuiting protecti on etc. The accurate overcharging detectio n voltage ensures safe and full utilization c harging. The low standby current drains littl e current from the cell while in storage. The device is not only targeted for digital cellular phones, but also for any other Li-Io n and Li-Poly battery-powered information appliances requiring long-term battery life.            APPLICATIONS One-Cell Lithium-ion Battery Pack Lithium-Polymer Battery Pack FEATURES   Integrated Advanced Power MOSFET with Equivalent of 13.5 mΩ RSS(ON) Ultra-small ESN4 Package Only One External Capacitor Required Over-temperature Protection Overcharge Current Protection Two-step Overcurrent Detection -Over-discharge Current -Load Short Circuiting Low Current Consumption -Operation Mode: 3.3µA typ -Power-down Mode: 1.8µA typ Charger Detection Function 0V Battery Charging Function Delay Times are generated inside High-accuracy Voltage Detection RoHS Compliant and Lead (Pb) Free Protection of Charger Reverse Connec -tion Protection of Battery Cell Reverse Con -nection Without external load CHARGER+ R1 1KΩ VDD BAT+ C1 0.1µF BATCHARGER- VM GND Figure 1. Typical Application Circuit -1Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2 XB4908 SERIES ORDERING INFORMATION PART NUMBER OCV [VCU] (V) OCRV [VCL] (V) ODV [VDL] (V) ODRV [VDR] (V) TOP MARK XB4908A 4.30±50mV 4.10±50mV 2.4±100mV 3.0±100mV XB4908AYWT(note) XB4908G 4.425±50mV 4.25±50mV 2.4±100mV 3.0±100mV XB4908GYWT(note) Note: “YW” is manufacture date code, “Y” means the year, “W” means the week. “T” means the times of odering. PIN CONFIGURATION VDD 1 GND 2 4 VM 3 VM TOP View Figure 2. PIN Configuration PIN DESCRIPTION XB4908 SERIES PIN NUMBER PIN NAME 1 VDD Positive power input,connected with battery cell’s positive pole. 2 GND Ground, connect the negative terminal of the battery to this pin. 3,4 VM PIN DESCRIPTION The negative terminal of the battery pack. The internal FET switch connects this terminal to GND Please Connect these pins with mass metal. -2Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2 XB4908 SERIES ABSOLUTE MAXIMUM RATINGS (NOTE: DO NOT EXCEED THESE LIMITS TO PREVENT DAMAGE TO THE DEVICE. EXPOSURE TO ABSOLUTE MAXIMUM RATING CONDITIONS FOR LONG PERIODS MAY AFFECT DEVICE RELIABILITY.) PARAMETER VALUE UNIT VDD input pin voltage -0.3 to 6 V VM input pin voltage -6 to 10 V Operating Ambient Temperature -40 to 85 °C Maximum Junction Temperature 150 °C -55 to 150 °C Lead Temperature ( Soldering, 10 sec) 300 °C Power Dissipation at T=25°C 0.3 W Package Thermal Resistance (Junction to Ambient) θJA 150 °C/W Package Thermal Resistance (Junction to Case) θJC 100 °C/W HBM ESD 2000 V Storage Temperature -3Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2 XB4908 SERIES ELECTRICAL CHARACTERISTICS ˚C unless otherwise specified. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Detection Current Overdischarge Current Detection *I V =3.6V 6.0 9.0 12.0 A Overdischarge Current Recovery *I V =3.6V 15 25 40 μA Overcharge Current Detection *I V =3.6V 4 6 8 A Load Short-Circuiting Detection *I V =3.6V 20 40 60 A V =3.6V VM pin floating 3.3 6 µA V =2.0V VM pin floating 1.8 4 µA Current Consumption Current Consumption in Normal Operation I I Current Consumption in Power Down VM Internal Resistance Internal Resistance between VM and V R V =3.6V VM=1.0V 200 300 400 k Internal Resistance between VM and GND R V =3.6V VM pin floating 15 25 35 k FET on Resistance Equivalent FET on Resistance *R V =3.6V I =1.0A m 13.5 Over Temperature Protection Over Temperature Protection *T 150 ˚C Over Temperature Recovery Degree *T 100 ˚C Detection Delay Time Overcharge Voltage Detection DelayTime t 80 130 180 mS Overdischarge Voltage Detection Delay Time t 20 40 60 mS Overdischarge Current1 Detection Delay Time Load Short-Circuiting Detection Delay Time t *t V =3.6V 5 10 20 mS V =3.6V 180 380 600 µS Note1: *---The parameter is guaranteed by design. -4Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2 XB4908 SERIES FUNCTIONAL BLOCK DIAGRAM GND VDD Voltage divider - + POR Overcharge Current Comp - + - + Overdischarge Voltage Comp OSC Overcharge Voltage Comp Logic Contoller Short circuit Comp + - OTP Over discharge Current Comp Switch Charge Detection + - REF VM VM Figure 3. Functional Block Diagram FUNCTIONAL DESCRIPTION The XB4908 SERIES monitors the volta ge and current of a battery and protects it f rom being damaged due to overcharge volt age, overdischarge voltage, overdischarge curren-t, and short circuit conditions by disc onnec-ting the battery from the load or cha rger. These functions are required in order t o ope-rate the battery cell within specified li mits.The device requires only one external capacitor. The MOSFET is integrated and it -s RSS(ON) is as low as 13.5 mΩ typical. and the state continues for the overcharge detection delay time (tCU) or longer, the XB4 908 SERIES turns the charging control FE T off to stop charging. This condition is call ed the overcharge condition. The overchar ge condition is released in the following two cases: 1. When the battery voltage drops below the overcharge release voltage (VCL), the X B4908 SERIES turns the charging control FET on and returns to the normal condition. 2. When a load is connected and dischar -ging starts, the XB4908 SERIES turns the charging control FET on and returns to the normal condition. The release mechanism i s as follows: the discharging current flows t -hrough an internal parasitic diode of the charging FET immediately after a load is co nnected and discharging starts, and the V M pin voltage increases about 0.7 V (forwa -rd voltage of the diode) from the GND pin voltage momentarily. The XB4908 SERIES detects this voltage and releases the overc Normal Mode If no exception condition is detected, charging and discharging can be carried out freely. This condition is called the normal o -perating mode. Overcharge Condition When the battery voltage becomes higher than the overcharge detection voltage (V CU) during charging under normal condition -5Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2 XB4908 SERIES harge condition. Consequently, in the case that the battery voltage is equal to or lower than the overcharge detection voltage (VC U), the XB4908 SERIES returns to the norm -al condition immediately, but in the case th e battery voltage is higher than the overcha rge detection voltage (VCU),the chip does n ot return to the normal condition until the b attery voltage drops below the overcharge detection voltage (VCU) even if the load is c onnected. In addition, if the VM pin voltage is equal to or lower than the overcurrent 1 detection voltage when a load is connected and discharging starts, the chip does not re turn to the norm-al condition. he IC under the overdischarge and powerdown conditions. The power-down condition is released when a charger is connected and the potenti -al difference between VM and VDD becomes 1.3 V (typ.) or higher (load short-circui -ting detection voltage). At this time, the FE T is still off. When the battery voltage becomes the overdischarge detection voltage(V DL) or higher (see note), the XB4908 SERIE S turns the FET on and changes to the nor -mal condition from the overdischarge cond -ition. Remark If the VM pin voltage is no less than the charger d -etection voltage (VCHA), when the battery under ove -rdischarge condition is connected to a charger, the overdischarge condition is released (the discharging control FET is turned on) as usual, provided that t -he battery voltage reaches the overdischarge relea -se voltage (VDU) or higher. Remark If the battery is charged to a voltage higher than t -he overcharge detection voltage (VCU) and the battery voltage does not drops below the overcharge de -tection voltage (VCU) even when a heavy load, whic h causes an overcurrent, is connected, the overcurr -ent 1 and overcurrent 2 do not work until the batter -y voltage drops below the overcharge detection vol -tage (VCU). Since an actual battery has, however, a -n internal impedance of several dozens of mΩ, and the battery voltage drops immediately after a heavy load which causes an overcurrent is connected, the overcurrent 1 and overcurrent 2 work. Detection of load short-circuiting works regardless of the battery voltage. Overcurrent Condition When the discharging current becomes equal to or higher than a specified value (th -e VM pin voltage is equal to or higher than the overcurrent detection voltage) during di -scharging under normal condition and the state continues for the overcurrent detectio -n delay time or longer, the XB4908 SERIE S turns off the discharging control FET to s top discharging. This condition is called overcurrent condition. (The overcurrent includ es overcurrent, or load short-circuiting.) The VM and GND pins are shorted intern -ally by the RVMS resistor under the overcurr -ent condition. When a load is connected, t -he VM pin voltage equals the VDD voltage due to the load. The overcurrent condition returns to the normal condition when the load is released and the impedance between the B+ and Bpins becomes higher than the automatic re -coverable impedance. When the load is re -moved, the VM pin goes back to the GND potential since the VM pin is shorted the G ND pin with the RVMS resistor. Detecting that the VM pin potential is lower than the overc -urrent detection voltage (VIOV), the IC retur- Overdischarge Condition When the battery voltage drops below th -e overdischarge detection voltage (VDL) du -ring discharging under normal condition and it continues for the overdischarge detect -ion delay time (tDL) or longer, the XB4908 SERIES turns the discharging control FET off and stops discharging. This condition is called overdischarge condition. After the discharging control FET is turned off, the VM pin is pulled up by the RVMD resistor between VM and VDD in XB4908 SERIES. Mean while when VM is bigger than 1.5V (typ.) (the load short-circuiting detection voltage), t -he current of the chip is reduced to the po wer-down current (IPDN). This condition is ca lled power-down condition. The VM and V DD pins are shorted by the RVMD resistor in t -6Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2 XB4908 SERIES Abnormal Charge Current Detection short-circuiting is detected over detection d -elay time for overdischarge current 2 or loa -d short-circuiting, the XB4908 SERIES sto ps discharging. When battery voltage falls below overdischarge detection voltage due to overdischarge current, the XB4908 SER IES stop disscharging by overdischarge cu rrent detection. In this case the recovery of battery voltage is so slow that if battery vol tage after overdischarge voltage detection delay time is still lower than overdischarge detection voltage, the XB4908 SERIES shi -fts to power-down. If the VM pin voltage drops below the charger detection voltage (VCHA) during chargi -ng under the normal condition and it continues for the overcharge detection delay tim -e (tCU) or longer, the XB4908 SERIES turn s the charging control FET off and stops ch -arging. This action is called abnormal char ge current detection. Abnormal charge current detection works when the discharging control FET is on a -nd the VM pin voltage drops below the charger detection voltage (VCHA). When an abnormal charge current flows into a battery i -n the overdischarge condition, the XB4908 SERIES consequently turns the charging c ontrol FET off and stops charging after the battery voltage becomes the overdischarge detection voltage and the overcharge detec tion delay time (tCU) elapses. Abnormal charge current detection is released when the voltage difference between VM pin and GND pin becomes lower than the charger detection voltage (VCHA) by se -parating the charger. Since the 0 V battery charging function has higher priority than th -e abnormal charge current detection functi -on, abnormal charge current may not be d -etected by the product with the 0 V battery charging function while the battery voltage i -s low. 0V Battery Charging Function (1) (2) (3) This function enables the charging of a connected battery whose voltage is 0V by self-discharge. When a charger having 0V battery start charging charger voltage (V0CHA) or higher is connected between B+ and B- pins, the charging control FET gate is fixed to VDD potential. When the voltage between the gate and the source of the charging control FET becomes equal to or higher than the turn-on voltage by the charger voltage, the charging control FET is turned on to start charging. At this time, the discharging control FET is off and the charging current flows through the internal parasitic diode in the discharging control FET. If the battery voltage becomes equal to or higher than the overdischarge release voltage (VDU), the normal condition returns. Note: Load Short-circuiting condition If voltage of VM pin is equal or below sho -rt circuiting protection voltage (VSHORT), the XB4908 SERIES will stop discharging and battery is disconnected from load. The maxi mum delay time to switch current off is tSHOR T. This status is released when voltage of V M pin is higher than short protection voltag -e (VSHORT), such as when disconnecting the load. (1) Some battery providers do not recommend charging of completely discharged batteries. Please refer to battery providers before the selection of 0 V battery charging function. (2) The 0V battery charging function has higher priority than the abnormal charge current detection function. Consequently, a product with the 0 V battery charging function charges a battery and abnormal charge current cannot be detected during the battery voltage is low (at most 1.8 V or lower). (3) When a battery is connected to the IC for the first time, the IC may not enter the normal condit -ion in which discharging is possible. In this case, set the VM pin voltage equal to the GND voltage (short the VM and GND pins or connect a charger) to enter the normal condition. Delay Circuits The detection delay time for overdischarg -e current 2 and load short-circuiting starts when overdischarge current 1 is detected. As soon as overdischarge current 2 or load -7Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2 XB4908 SERIES TYPICAL APPLICATION As shown in Figure 5 , the current path must be kept as short & heavy as possible. C1 is a filter decoupling circuit and should be as close as possible to VCC pin of XB4908 SERIES. CHARGER+ R1 1KΩ VDD BAT+ C1 0.1µF BATCHARGER- VM GND Figure 5 XB4908 SERIES in a Typical Battery Protection Circuit Symbol Typ Value range Unit C1 0.1 0.1~2.2 μF R1 1 0.1~1 KΩ Remark: 1.The above parameters may be changed without notice; 2.The schematic diagram and parameters of the IC are not used as the basis to ensure the operation of the circuit. Please conduct full measurement on the actual application circuit before setting the parameters. Precautions • Pay attention to the operating conditions for input/output voltage and load current so that the power loss in XB4908 SERIES does not exceed the power dissipation of the package. • Do not apply an electrostatic discharge to this XB4908 SERIES that exceeds the performance ratings of the built-in electrostatic protection circuit. -8Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2 XB4908 SERIES R0.15 MAX˜4X 2.8±0.05 1.073±0.025 10°˜2X 8°˜2X R0.15 MAX˜4X R0.15 MAX˜4X 10°˜2X 0.180±0.008 0.946±0.025 2.3±0.05 0.950±0.05 0.250±0.025 0.445±0.025 0.793±0.025 3.70±0.1 0.470±0.05 0.673±0.05˜2X PACKAGE OUTLINE(ESN4) R0.08 0.2 0.08±0.05 8°˜2X 0.436±0.05 -9Suzhou XySemi Electronic Technology Co., Limited. 3°± 3° www.xysemi.com.cn Rev0.2 XB4908 SERIES DISCLAIMER The information described herein is subject to change without notice. Suzhou XySemi Electronic Technology Co., Limited is not responsible for any problems caused by circuits or diagrams described herein whose related industrial properties, patents, or other rights belong to third parties. The application circuit examples explain typical applications of the products, and do not guarantee the success of any specific mass-production design. When the products described herein are regulated products subject to the Wassenaar Arrangement or other arrangements, they may not be exported without authorization from the appropriate governmental authority. Use of the information described herein for other purposes and/or reproduction or copying without express permission of Suzhou XySemi Electronic Technology Co., Limited is strictly prohibited. The products described herein cannot be used as part of any device or equipment affecting the human body, such as exercise equipment ,medical equipment, security systems, gas equipment, or any apparatus installed in airplanes and other vehicles, without prior written permission of Suzhou XySemi Electronic Technology Co., Limited. Although Suzhou XySemi Electronic Technology Co., Limited. exerts the greatest possible effort to ensure high quality and reliability, the failure or malfunction of semiconductor may occur. The use of these products should therefore give thorough consideration to safety design, including redundancy, fire-prevention measure and malfunction prevention, to prevent any accidents, fires, or community damage that may ensue. - 10 Suzhou XySemi Electronic Technology Co., Limited. www.xysemi.com.cn Rev0.2