XB8608A

XB8608A XYSEMI | Alldatasheet

Document overview

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Technical content

REV0.7 One Cell Lithium-ion/Polymer Battery Protection IC GENERAL DESCRIPTION The XB8608A Series product is a high integration solution for lithium- ion/polymer battery protection. XB8608A contains advanced power MOSFET, high-accuracy voltage detection circuits and delay circuits. XB8608A is put into an SOP8 package and only one external component makes it an ideal solution in limited space of battery pack. XB8608A has all the protection functions required in the battery application including overcharging, overdischarging, overcurrent and load short circuiting protection etc. The accurate overcharging detection voltage ensures safe and full utilization charging. The low standby current drains little current from the cell while in storage. The device is not only targeted for digital cellular phones, but also for any other Li-Ion and Li-Poly battery-powered information appliances requiring long- term battery life.

FEATURES

• Protection of Charger Reverse Connection
• Protection of Battery Cell Reverse Connection
• Integrate Advanced Power MOSFET with Equivalent of 19mΩ RSS(ON)
• SOP8 Package
• Only One External Capacitor Required
• Over-temperature Protection
• Overcharge Current Protection
• Two-step Overcurrent Detection: -Overdischarge Current -Load Short Circuiting
• Charger Detection Function
• 0V Battery Charging Function - Delay Times are generated inside
• High-accuracy Voltage Detection
• Low Current Consumption - Operation Mode:3.9μ A typ. - Power-down Mode: 2.2μ A typ.
• RoHS Compliant and Lead (Pb) Free

APPLICATIONS

One-Cell Lithium-ion Battery Pack Lithium-Polymer Battery Pack Figure 1. Typical Application Circuit

REV0.7

ORDERING INFORMATION

[VCU] (V) Overcharge Release Voltage [VCL] (V) Overdischarge Detection Voltage [VDL] (V) Overdischarge Release Voltage [VDR] (V) Overcurrent Detection Current [IOV1] (A) Top Mark XB8608A SOP 8 4.30 4.10 2.40 3.0 9 XB8608AYW(note) Note: “YW” is manufacture date code, “Y” means the year, “W” means the week PIN CONFIGURATION Figure 2. PIN Configuration

4 NC No Connect

6 VDD Power Supply

REV0.7 Maximum Junction Temperature 150 °C Storage Temperature -55 to 150 °C Lead Temperature ( Soldering, 10 sec) 300 °C Power Dissipation at T=25°C 0.625 W Package Thermal Resistance (Junction to Ambient) θJA 250 °C/W Package Thermal Resistance (Junction to Case) θJC 130 °C/W ESD 2000 V

ELECTRICAL CHARACTERISTICS

Typicals and limits appearing in normal type apply for TA = 25oC, unless otherwise specified Parameter Symbol Test Condition Min Typ Max Unit Detection Voltage Overcharge Detection Voltage VCU 4.25 4.30 4.35 V Overcharge Release Voltage VCL 4.05 4.10 4.15 V Overdischarge Detection Voltage VDL 2.3 2.4 2.5 V Overdischarge Release Voltage VDR 2.9 3.0 3.1 V Detection Current Overdischarge Current Detection *IIOV1 VDD=3.6V 6.0 9 12.0 A Overdischarge Current Recovery *IROV1 VDD=3.6V 15 25 40 uA Overcharge Current Detection *ICHOC VDD=3.6V 5 7 9 A Load Short-Circuiting Detection *ISHORT VDD=3.6V 20 40 60 A Current Consumption Current Consumption in Normal Operation IOPE VDD=3.5V VM =0V 3.9 6 μ A Current Consumption in power Down IPDN VDD=2.0V VM pin floating 2.2 3 μ A VM Internal Resistance Internal Resistance between VM and VDD *RVMD VDD=2.0V VM pin floating 200 300 400 kΩ Internal Resistance between VM and GND *RVMS VDD=3.6V VM=1.0V 15 25 35 kΩ FET on Resistance 30 Equivalent FET on Resistance *RSS(ON) VDD=3.6V IVM =1.0A 17 19 23 mΩ

Note:* ---The parameter is guaranteed by design. Figure 3. Functional Block Diagram its RSS(ON) is as low as 19mΩ typical.

REV0.7 Normal operating mode If no exception condition is detected, charging and discharging can be carried out freely. This condition is called the normal operating mode. Overcharge Condition When the battery voltage becomes higher than the overcharge detection voltage (VCU) during charging under normal condition and the state continues for the overcharge detection delay time (tCU) or longer, the XB8608A turns the charging control FET off to stop charging. This condition is called the overcharge condition. The overcharge condition is released in the following two cases: 1, When the battery voltage drops below the overcharge release voltage (VCL), the XB8608A turns the charging control FET on and returns to the normal condition. 2, When a load is connected and discharging starts, the XB8608A turns the charging control FET on and returns to the normal condition. The release mechanism is as follows: the discharging current flows through an internal parasitic diode of the charging FET immediately after a load is connected and discharging starts, and the VM pin voltage increases about 0.7 V (forward voltage of the diode) from the GND pin voltage momentarily. The XB8608A detects this voltage and releases the overcharge condition. Consequently, in the case that the battery voltage is equal to or lower than the overcharge detection voltage (VCU), the XB8608A returns to the normal condition immediately, but in the case the battery voltage is higher than the overcharge detection voltage (VCU),the chip does not return to the normal condition until the battery voltage drops below the overcharge detection voltage (VCU) even if the load is connected. In addition, if the VM pin voltage is equal to or lower than the overcurrent detection voltage when a load is connected and discharging starts, the chip does not return to the normal condition. Remark If the battery is charged to a voltage higher than the overcharge detection voltage (VCU) and the battery voltage does not drops below the overcharge detection voltage (VCU) even when a heavy load, which causes an overcurrent, is connected, the overcurrent do not work until the battery voltage drops below the overcharge detection voltage (VCU). Since an actual battery has, however, an 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 work. Detection of load short-circuiting works regardless of the battery voltage. Overdischarge Condition When the battery voltage drops below the overdischarge detection voltage (VDL) during discharging under normal condition and it continues for the overdischarge detection delay time (tDL) or longer, the XB8608A 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 XB8608A. Meanwhile when VM is bigger than 1.5 V (typ.) (the load short-circuiting detection voltage), the current of the chip is reduced to the power-down current (IPDN). This condition is called power-down condition. The VM and VDD pins are shorted by the RVMD resistor in the IC under the overdischarge and power-down conditions. The power-down condition is released when a charger is connected and the potential difference between VM and VDD becomes 1.3 V (typ.) or higher (load short- circuiting detection voltage). At this time, the FET is still off. When the battery voltage becomes the overdischarge detection voltage (VDL) or higher (see note), the XB8608A turns the FET on and

REV0.7 changes to the normal condition from the overdischarge condition. Remark If the VM pin voltage is no less than the charger detection voltage (VCHA), when the battery under overdischarge condition is connected to a charger, the overdischarge condition is released (the discharging control FET is turned on) as usual, provided that the battery voltage reaches the overdischarge release voltage (VDU) or higher. Overcurrent Condition When the discharging current becomes equal to or higher than a specified value (the VM pin voltage is equal to or higher than the overcurrent detection voltage) during discharging under normal condition and the state continues for the overcurrent detection delay time or longer, the XB8608A turns off the discharging control FET to stop discharging. This condition is called overcurrent condition. (The overcurrent includes overcurrent, or load short- circuiting.) The VM and GND pins are shorted internally by the RVMS resistor under the overcurrent condition. When a load is connected, the 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 B- pins becomes higher than the automatic recoverable impedance. When the load is removed, the VM pin goes back to the GND potential since the VM pin is shorted the GND pin with the RVMS resistor. Detecting that the VM pin potential is lower than the overcurrent detection voltage (VIOV1), the IC returns to the normal condition. Abnormal Charge Current Detection If the VM pin voltage drops below the charger detection voltage (VCHA) during charging under the normal condition and it continues for the overcharge detection delay time (tCU) or longer, the XB8608A turns the charging control FET off and stops charging. This action is called abnormal charge current detection. Abnormal charge current detection works when the discharging control FET is on and the VM pin voltage drops below the charger detection voltage (VCHA). When an abnormal charge current flows into a battery in the overdischarge condition, the XB8608A consequently turns the charging control FET off and stops charging after the battery voltage becomes the overdischarge detection voltage and the overcharge detection 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 separating the charger. Since the

0 V battery charging function has higher

priority than the abnormal charge current detection function, abnormal charge current may not be detected by the product with the 0 V battery charging function while the battery voltage is low. Load Short-circuiting condition If voltage of VM pin is equal or below short circuiting protection voltage (VSHORT), the XB8608A will stop discharging and battery is disconnected from load. The maximum delay time to switch current off is tSHORT. This status is released when voltage of VM pin is higher than short protection voltage (VSHORT), such as when disconnecting the load. Delay Circuits The detection delay time for overdischarge current 2 and load short-circuiting starts when overdischarge current 1 is detected. As soon as overdischarge current 2 or load short-circuiting is detected over detection

Figure 4. Overcurrent delay time voltage (VDU), the normal condition returns. the battery voltage is low (at most 1.8 V or lower).

REV0.7 TIMING CHART 1． Overcharge and overdischarge detection VCU VCU-VHC Battery voltage VDL+VDH VDL ON DISCHARGE OFF ON CHARGE OFF VDD Vov1 VSS VCHA VM Charger connection Load connection tCU tCL Figure5-1 Overcharge and Overdischarge Voltage Detection 2． Overdischarge current detection VCU VCU-VHC VDL+VDH VDL Battery voltage ON DISCHARGE OFF VDD VSHORT Vov2 Vov1 VSS VM Charger connection Load connection tIOV1 tIOV2 tSHORT Figure5-2 Overdischarge Current Detection Remark: (1) Normal condition (2) Overcharge voltage condition (3) Overdischarge voltage condition (4) Overcurrent condition

REV0.7 3． Charger Detection VCU VCU-VHC Battery voltage VDL+VDH VDL ON DISCHARGE OFF Charger connection Load connection VDD VSS VCHA VM (1) (1)(3) tDL Figure5-3 Charger Detection 4． Abnormal Charger Detection VCU VCU-VHC Battery voltage VDL+VDH VDL ON DISCHARGE OFF ON CHARGE OFF VDD VSS VCHA VM Charger connection Load connection tDL tCU Figure5-4 Abnormal Charger Detection Remark: (1) Normal condition (2) Overcharge voltage condition (3) Overdischarge voltage condition (4) Overcurrent condition)

REV0.7 TYPICAL APPLICATION As shown in Figure 6, the bold line is the high density current path which must be kept as short as possible. For thermal management, ensure that these trace widths are adequate. C1 is a decoupling capacitor which should be placed as close as possible to XB8608A. Fig 6 XB8608A in a Typical Battery Protection Circuit Precautions

• Pay attention to the operating conditions for input/output voltage and load current so that the power loss in XB8608A does not exceed the power dissipation of the package.
• Do not apply an electrostatic discharge to this XB8608A that exceeds the performance ratings of the built-in electrostatic protection circuit.

REV0.7 PACKAGE OUTLINE(SOP8)

REV0.7 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 belo ng 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 saf ety design, including redundancy, fire -prevention measure and malfunction prevention, to prevent any accidents, fires, or community damage that may ensue.