RT9541OCE

Preliminary RT9541 Li-Ion Battery Protector General Description The RT9541 Series are protection ICs for overcharge/discharge of rechargeable one-cell Lithium-ion (Li+) batteries by CMOS process. The RT9541 Series can detect over-charge/discharge of Li+ one-cell and excess load current and charge current, further include a short circuit protector for preventing large external short circuit current. Each of these ICs is composed of four voltage detectors, a reference unit, a hysteresis circuit, and a bidirectional short circuit protector. Package of SOT26 is available. Features Low supply current − Supply current: TYP. 2.0µA − Standby current (after detecting overdischarge): Less than 0.2µA High accuracy detector threshold − Over-charge detector: ±25mV − Over-discharge detector: ±2.5% Built-in protection circuit − Excess current trip/Short circuit protector in both charging and discharging direction Output delay of over-charge adjustable with an external capacitor: 75mS at 0.01µF Ultra small package: SOT26 Ordering Information RT9541 Package type E : SOT-26 Type I ER : SOT-26 Type II Operating temperature range C: Commercial standard See Table 1 Applications Over-charge / Over-discharge Protection for Li+ One-cell Pack High Precision Protectors for Cellular Phones or Instruments Using Li+ One-cell Battery Pin Configurations Part Number RT9541 CE Pin Configurations TOP VIEW 6 5 4 Typical Application Circuit R1 100Ω C1 0.1µF CT C3 0.01µF VDD + (Plastic SOT-26) 1 2 3 1. 2. 3. 4. 5. 6. COUT CT VSS DOUT VDD V- RT9541 VCOUT RT9541 CER (Plastic SOT-26) 6 5 4 TOP VIEW 1. 2. 3. 4. 5. 6. DOUT VCOUT CT VDD VSS VSS DOUT 1 2 3 C2 0.1µF R2 1KΩ DS9541-05 August 2001 www.richtek-ic.com.tw 1 RT9541 Absolute Maximum Ratings Allowable Battery Voltage Input Voltage (V) Input Voltage (CT) Output Voltage (COUT) Output Voltage (DOUT) Power Dissipation, PD @ TA = 25°C SOT-26 Package Thermal Resistance SOT-26, θJA Operating Temperature Range Storage Temperature Range Preliminary -0.3V ~ 7V VDD-14V to VDD +0.3V VSS-0.3V to VDD +0.3V VDD-14V to VDD +0.3V VSS-0.3V to VDD +0.3V 0.25W 250°C/W -20°C ~ +85°C -65°C ~ +150°C Electrical Characteristics Parameter Operating Input Voltage Charger Voltage Minimum Operating Voltage for 0V Charging Accuracy of Over-charge Threshold Voltage Over-charge Threshold Hysteresis Output Delay Time of Over-charge TOCHG Accuracy of Over-discharge Threshold Voltage Output Delay Time of Overdischarge Excess Current Threshold Voltage During Discharge Output Delay of Discharge Excess Current Excess Current Threshold Voltage During Charge Output Delay of Charge Excess Current Short Detection Voltage During Discharge Output Delay of Discharge Short Circuit Reset Resistance for Excess Current Protection Supply Current Standby Current www.richtek-ic.com.tw Symbol VDD VCHG Test Conditions Voltage defined as VDD-VSS Voltage defined as VDD-VVoltage defined as VDD-VVDD-VSS = 0V Min 1 ---25 0.1 Typ ----0.15 60 -15 0.17 20 -0.17 20 Max 6 14 1 25 0.2 80 2.5 20 0.19 25 -0.15 25 Units V V V mV V mS % mS V mS V mS V µS kΩ µA µA ∆VOCHG Detect rising edge of supply voltage C3 = 0.01µF, VDD = 3.6V ~ 4.3V Detect falling edge of supply voltage VDD = 3.6V ~ 2.4V Detect rising edge of “V-“ pin voltage VDD = 3.0V Detect falling edge of “V-“ pin voltage 30 -2.5 10 0.15 15 -0.19 15 ∆VODISCHG TODISCHG VDD = 3.0V TSHORT RSHORT IDD ISTANDBY VDD = 3.0V VDD = 3.6V, V- = 1.0V VDD = 3.9V, V- = 0V VDD = 2.0V VDD-1.1 VDD-0.8 VDD-0.5 -25 --5 50 2.0 0.1 50 75 5.0 0.5 DS9541-05 August 2001 2 Preliminary Table 1 Part Number RT9541ACE (R) RT9541BCE (R) RT9541CCE (R) RT9541DCE (R) RT9541ECE (R) RT9541FCE (R) RT9541GCE (R) RT9541HCE (R) RT9541ICE (R) RT9541JCE (R) Over Over Excess Charge Discharge Current 4.25V 4.25V 4.25V 4.25V 4.25V 4.25V 4.30V 4.30V 4.30V 4.30V 2.3V 2.4V 2.5V 2.6V 2.7V 2.8V 2.3V 2.4V 2.5V 2.6V 170mV 170mV 170mV 170mV 170mV 170mV 170mV 170mV 170mV 170mV Part Number RT9541KCE (R) RT9541LCE (R) RT9541MCE (R) RT9541NCE (R) RT9541OCE (R) RT9541PCE (R) RT9541QCE (R) RT9541RCE (R) RT9541SCE (R) RT9541TCE (R) RT9541 Over Over Excess Charge Discharge Current 4.30V 4.30V 4.35V 4.35V 4.35V 4.35V 4.35V 4.35V 4.35V 4.25V 2.7V 2.8V 2.3V 2.4V 2.5V 2.6V 2.7V 2.8V 2.9V 2.9V 170mV 170mV 170mV 170mV 170mV 170mV 170mV 170mV 170mV 170mV Function Block Diagram VDD CT Level Shift + _ VD4 _ Delay + _ + VD1 VD2 VD3 VSS Pin Description Pin Number RT9541- CE RT9541- CER 1 2 3 4 5 6 3 4 6 1 5 2 Pin Name COUT CT VSS DOUT VDD VPin Function Output of Over-charge Detection, CMOS Output Pin for External Capacitor Setting Output Delay of VD1 Ground Output of Over-discharge Detection, CMOS Output Power Supply, through a Resistor (R1) Pin for Charger Negative Input, through a Resistor (R2) DS9541-05 August 2001 _ + Short Circuit Detector DOUT COUT V- www.richtek-ic.com.tw 3 RT9541 Applications Information (1) Operation Description Preliminary Refering to the “Function Block Diagram”, when charging voltage crosses the detector threshold from a low value to a value higher than VDET1, the output of COUT pin, the output of over-charge detector/VD1, swiches to low level,..charger’s negative pin level. After detecting over-charge the VD1 can be reset and the output of COUT pin becomes “H” when the VDD voltage is coming down to a level lower than “VDET1 – VHYS1”, or when a charger is disconnected from the battery pack. The output of DOUT pin, the output of over-discharge detector/VD2, switches to “L” after internally fixed delay time passed, when discharging voltage crosses the detector threshold from a high value to a value lower than VDET2. An excess load current can be sensed and cut off after internally fixed delay time passsed 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 “H” by detaching a battery pack from a load system. Futher, short circuit protector makes DOUT level to “L” immediately with external short circuit current and removing external short circuit leads DOUT level to “H”. The short circuit protection function in charging direction was also provided. When COUT high and the “V-“ pin voltage 5V lower than VSS pin, the RT9541 will turn low COUT with a fixed delay. The COUT will go high after the short circuit condition was removed. After detecting over-discharge, supply current will be kept extremely low by halting some internal circuits operation. The output delay of over-charge detectors can be set by connecting an external capacitor. Output type of COUT and DOUT are CMOS. (2) Component Selection Guide: Referring to “Typical Application Circuit”, R1 and C1 will stabilize a supply voltage to the RT9541. A recommended R1 value is less than 1kΩ. A larger value of R1 leads higher detection voltage, makes some errors, because of shoot through current flowed in the RT9541. R2 and C2 will stabilize a V- pin voltage. The resetting from over-discharge with connecting charger possibly be disabled by larger value of R2. Recommended value is less than 1kΩ. And recommended C2 value is less than 1µF. R1 and R2 can operate as a current limiter against The excess charging current is also monitored, and the charging path will be cut off (by turn low COUT) after excess charging current was detected lasting a internally fixed delay time. The charging path will be re-started (by turn high COUT) after another internally fixed delay. If the excess charging current is still there, the same process will be repeated and cause the charging path toggling on and off with a 12.5% on duty. Such a protection function reduces the average charging current to 12.5% of original value when excess charging current detected. setting cell reverse direction or for applying excess charging voltage to the RT9541. While smaller R1 and R2 may cause an over power dissipation rating of the RT9541 and a total of “R1+R2” should be more than 1kΩ. www.richtek-ic.com.tw DS9541-05 August 2001 4 Preliminary Timing Diagram RT9541- CE/CER RT9541 DS9541-05 August 2001 www.richtek-ic.com.tw 5 RT9541 Package Information Preliminary D C B b A e A1 L H Symbol A A1 B b C D e H L Dimensions In Millimeters Min 0.889 -1.397 0.356 2.591 2.692 0.838 0.102 0.356 Max 1.295 0.152 1.803 0.559 2.997 3.099 1.041 0.254 0.610 Dimensions In Inches Min 0.035 -0.055 0.014 0.102 0.106 0.033 0.004 0.014 Max 0.051 0.006 0.071 0.022 0.118 0.122 0.041 0.010 0.024 www.richtek-ic.com.tw DS9541-05 August 2001 6 Preliminary RT9541 DS9541-05 August 2001 www.richtek-ic.com.tw 7 RT9541 Preliminary RICHTEK TECHNOLOGY CORP. Headquarter 6F, No. 35, Hsintai Road, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5510047 Fax: (8863)5537749 RICHTEK TECHNOLOGY CORP. Taipei Office (Marketing) 8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek-ic.com.tw www.richtek-ic.com.tw DS9541-05 August 2001 8