LI-ION PROTECTION IC EC9522T Ver2.4 2004 / 05 Features Supply current TYP. 3.5uA Standby current (after detecting over-discharge) TYP. 0.25uA High accuracy detector Over-charge detector(Topt=25ºC) +/- 50mV Threshold Over-charge detector (Topt=0 to 50ºC) +/- 60mV Over-discharge detector +/- 3.0% Low supply current Variety of detector threshold Built in protection circuit Output delay of over charge Output delay of over-discharg Over-charge detector threshold 4.0V to 4.4V step of 0.005V Over-discharge detector threshold 2.0V to 3.0V step of 0.005V Excess current protection 0.04V to 0.32V step of 0.04V Accuracy ±20% Time delay at VDD=4.3V 1.2S note1 VDD=2.4V with built-in capacitor 10mS Small package SOT23-6/6-pin Note1: The result was measured from EC9522T0001 Part Number Examples Part No. EC9522T003 …*note2 Over charge detection voltage 4.30V …. Over charge release voltage 4.10V …. marking Pack type E21- SOT-23-6 …. Note2: New model version and specific characteristics may be order by customer. General Description The EC9522T is protection IC for over-charge/discharge of rechargeable one-cell Lithium-ion(Li+) excess load current, further include a short circuit protector for preventing large external short circuit current. Each of these IC is composed of three voltage detectors, a reference unit, a delay circuit, a short circuit protector, and a logic circuit. When charging voltage crosses the detector threshold from a low value to value higher than VDET1, the output of Cout pin, the output of over-charge detector/VD1, switches to low level, charger’s negative pin level. After detecting over-charge the VD1 can be reset and the output of Cout becomes high when the VDD voltage is coming down to a level lower than “VREL1”, or when a kind of loading is connected to VDD after a charger is disconnected from the battery pack while the VDD level is in between “VDET1” and “VREL1” in the EC9522T. The output of Dout pin, the output of over-discharge detector/VD2, switches to low level after internally fixed delay time passed, when discharging voltage crosses the detector threshold from a high value lower than VDET2. After EC9522T detect the over-discharge voltage, connect a charger Page 1 of 8 LI-ION PROTECTION IC EC9522T Ver2.4 2004 / 05 to the battery pack, and when the battery supply voltage becomes higher than the over-discharge detector threshold, VD2 is released and the voltage of Dout becomes “H” level. An excess load current can be sensed and cut off after internally fixed delay time passed through the built in excess current detector, VD3 with Dout being enabled to low level. Once after detecting excess current, the VD3 is released and Dout level switches to high by detaching a battery pack from a load system. Further, short circuit protector makes Dout level to low immediately with external short circuit current and re-moving external short circuit leads Dout level to high. After detecting over-discharge, supply current will be kept extremely low by halt some internal circuits operation. The output delay of over-charge detectors can be set by connecting external capacitors. Output type of Cout and Dout are CMOS. 6-pin, SOT23-6 is available. BLOCK DIAGRAM Page 2 of 8 LI-ION PROTECTION IC EC9522T Ver2.4 2004 / 05 Pin Configurations PIN DESCRIPTION Pin No. 1 2 3 4 5 6 Symbol Dout VCout Ct VDD Vss Pin description Output of over-discharge detection, CMOS output Pin for charge negative input Output of over-charge detection, CMOS output Pin for external capacitor setting output delay of VD1 Power supply Ground ABSOLUTE MAXIMUM RATINGS Symbol VDD VVct Vcout Vdout PD Topt Tstg Item Supply voltage Input voltage V- pin Ct pin Output voltage Cout pin Dout pin Power dissipation Operating temperature range Storage temperature range Ratings -0.3 to 20 Vss=0V Unit V VDD-20 to VDD+0.3 Vss-0.3 toVDD+0.3 V V VDD-20 to VDD+0.3 Vss-0.3 toVDD+0.3 150 -40 to85 -55 to 125 V V mW ºC ºC Absolute Maximum ratings are threshold limit values that must not be exceeded ever for an instant under any conditions. Moreover, such values for any two items must not be reached simultaneously. Operation above these absolute maximum ratings may cause degradation or permanent damage to the device. These are stress ratings only and do not necessarily imply functional operation below these limits. Page 3 of 8 LI-ION PROTECTION IC EC9522T Ver2.4 2004 / 05 ELECTRICAL CHARACTERISTIC Temp=25ºC Symbol VDD1 VDET1 VREL1 Item Operating input voltage Over-charge threshold Release voltage for over-charge detection tVDET1 Output delay of over charge Conditions Voltage defined as VDD-Vss MIN. 1.5 TYP. MAX. 10 Unit V Detect rising edge of supply 003 voltage 25ºC 4.250 4.300 4.350 V 0~50ºC 4.240 4.300 4.360 V -- 003 4.05 4.10 4.15 V 0.8 1.2 1.5 S *Note VDD=3.6V to 4.3V 001, 002, Detect falling edge 003,005 of supply voltage 004 2.425 2.500 2.575 V 2.813 2.900 2.987 V VDD=3.6V to 2.4V 7 10 13 ms 001~4 0.1 0.12 0.14 V 005 0.12 0.14 0.16 V VDET2 Over-discharge threshold tVDET2 Output delay of over-discharge VDET3 Excess current threshold tVDET3 Output delay of excess current VDD=3.0V 9 13 17 ms Vshort Short protection voltage VDD=3.0V VDD1.2 VDD0.9 VDD0.6 V 300 400 us 100 150 kOhm 0.35 0.5 V tshort Rshort Output delay of short protection Reset resistance for excess current protection Vol1 Nch ON voltage of Cout Voh1 Pch ON voltage of Cout Vol2 Nch ON voltage of Dout Voh2 Pch ON voltage of Dout IDD Istandby Supply current Standby current Detect rising edge of “V-“ pin voltage VDD=3.0V VDD=3.6V, V-=1.0V Iol=50uA, VDD=4.4V Iol=-50uA, VDD=3.9V Iol=50uA, VDD=2.4V Iol=-50uA, VDD=3.9V VDD=3.9V, V-=0V VDD=2.0V 50 3.4 3.7 0.2 3.4 V 0.5 3.7 3.0 0.25 V V 5.0 0.4 uA uA *Note: Considering of variation in process parameters, we compensate for this characteristic related to temperature by laser-trim, however, this specification is guaranteed by design, not production tested. Page 4 of 8 LI-ION PROTECTION IC EC9522T Ver2.4 2004 / 05 OPERATION VD1/Over-Charge Detector The VD1 monitors VDD pin voltage. When the VDD voltage crosses over charge detector threshold VDET1 from a low value to a value higher than the VDET1, the VD1 can sense a over-charging and an external charge control Nch-MOS-FET turns to “OFF” with Cout pin being at “L” level. There can be two cases to reset the VD1 making the Cout pin level to “H” again after detecting over-charge. Resetting the VD1 can make charging system allowable to resumption of charging process. The first case is in such conditions that a time when the VDD voltage is coming down to a level lower than “VREL1”. While in the second case, connecting a kind of loading to VDD after disconnecting a charger from the battery pack can make the VD1 resetting when the VDD level is in between “VDET1” and “VREL1”. After detecting over-charge with the VDD voltage of higher than VDET1, connecting system load to the battery pack makes load current allowable through parasitic diode of external charge control FET. The Cout level would be high when the VDD level is coming down to a level below the VDET1 by continuous drawing of load current. An output delay time for over-charge detection can be set by external capacitor C3 connecting between the Vss pin and Ct pin. The external capacitor can make a delay time from a moment detecting over-charge to a time output a signal which enables charge control FET turn off. When the VDD level is going up to a higher level than VDET1 if the VDD voltage would be back to a level lower than the VDET1 within a time period of the output delay time, VD1 would not output a signal for turning off the charge control FET. A level shifter incorporated in a buffer driver for the Cout pin makes the “L” level of Cout pin to the V- pin voltage and the “H” level of Cout pin is set to VDD voltage with CMOS buffer VD2/Over-Discharge Detector The VD2 is monitoring a VDD pin voltage. When the VDD voltage crosses the over-discharge detector threshold VDET2 from a high value to a value lower than the VDET2, the VD2 can sense an over-discharging and the external discharge control Nch MOSFT turns to “OFF” with the Dout pin being at “L” level. To reset the VD2 with the Dout pin level being “H” again after detecting over-discharge it is necessary to connect a charger to the battery pack for EC9522T. When the VDD voltage stays under over-discharge detector threshold VDET2 charge current can flow through parasitic diode of external discharge control MOSFET, then after the VDD voltage comes up to a value larger than VDET2, Dout becomes “H” and discharging process would be able to advance through ON state MOSFET for discharge control. Connecting a charger to the battery pack makes the Dout level being “H” instantaneously when the VDD voltage is higher than VDET2. Besides, for EC9522T, when a cell voltage reaches equal or more than over-discharge released voltage, or VDET2, over-discharge condition can be also released. Page 5 of 8 LI-ION PROTECTION IC EC9522T Ver2.4 2004 / 05 An output delay time for the over-discharge detection is fixed internally, tVDET2 =10ms typ. At VDD=2.4V. When the VDD level is going down to a lower level than VDET2 if the VDD voltage would be back to a level higher than the VDET2 within a time period of the output delay time, VD2 would not output a signal for turning off the discharge control FET. After detection of an over-discharge by VD2, supply current would be reduced to typ. 0.3uA at VDD=2.0V and into standby, only the charger detector is operating. The output type of Dout pin is CMOS having “H” level of VDD and “L” level of Vss. VD3/Excess Current Detector, Short Circuit Protector Both of the excess current detector and short circuit protector can work when both control FETs are in “ON” state. When the V- pin voltage is going up to a value between the short protection voltage Vshort/VDD and excess current threshold VDET3, the excess current detector operates and further soaring of V- pin voltage higher than Vshort makes the short circuit protector enabled. This leads the external discharge control Nch MOSFET turn off with the Dout pin being at “L” level. An output delay time for the excess current detector is internally fixed, 13ms typ. At VDD=3.0V. Aquick recovery of V- pin level from a value between Vshort and VDET3 within the delay time keeps the discharge control FET staying “H” state. When the short circuit protector is enabled, the Dout would be low and its delay time would be 5us typ. The V- pin has a built-in pulled down resistor, typ. 100kOhm with connecting to the Vss pin. After an excess current or short circuit protection is detected, removing a cause of excess current or external short circuit makes an external discharge control FET to an “ON” state automatically with the V- pin level being down to the Vss level through pulled down resistor built-in internally. If VDD voltage would be higher than VDET2 at a time when the excess current is detected the EC9522T does not enter a standby mode, or otherwise in case of lower VDD voltage than VDET2 would lead the EC9522T into a standby. After detecting short circuit the EC9522T will not enter a standby mode. Page 6 of 8 LI-ION PROTECTION IC EC9522T Ver2.4 2004 / 05 Application Circuits Application Hints R1 and C1 will stabilize a supply voltage to the EC9522T. A recommended R1 value is less than 1kOhm. A larger value of R1 leads higher detection voltage, makes some errors, because of shoot through current flowed in the EC9522T. R1 and R2 may cause power consumption over rating of power dissipation of the EC9522T and a total of “R1+R2” should be more than 1kOhm. Page 7 of 8 LI-ION PROTECTION IC EC9522T Ver2.4 2004 / 05 Package Dimension (Unit: mm) SOT-23-6 Taping Specification (Unit: mm) SOT-23-6 E-CMOS CORPORATION IC DATASHEET ADDRESS: No.1, Creation RD. 2nd, science-based industrial park, Hsin-Chu 300, Taiwan, R.O.C. website: http://www.ecmos.com.tw E-mail : [email protected] TEL: 886-3-5783622 FAX:886-3-5783630 Page 8 of 8