TS2207A/B
Li-Ion Battery Protector
Pin assignment 1. DOUT 2. V3. COUT 4. CEXT 5. VDD 6. VSS
Ideal for One-Cell Rechargeable Li-Ion Battery
General Description
The TS2207A/B series are protection ICs design to safe guard one-cell Lithium-ion battery pack against over charge/discharge, over current and short circuit. The TS2207A/B series use advanced high voltage CMOS process to provide high accuracy voltage detection and low current consumption. The TS2207A/B series incorporate a reference unit and three voltage detectors. During charging process, when the cell voltage(VDD) is charged to a value higher than the over-charge threshold voltage (VC1), the over charge detector (COM1) will switch the output pin (COUT) to a low level within a delay time (tC1), and thus turning off the MOSFET connected to the charging path. The COUT pin may change to high level again when the VDD voltage falls below “VC1-VHYS”, or when VDD falls below VC1 while the charger is disconnected from the battery pack. During the discharging process, when the VDD voltage drops to a value lower than the over-discharge threshold voltage (VD1), the over-discharge detector (COM2) will switch DOUT to low level within a delay time (tD1), and thus turning off the MOSFET connecting the discharging path. In the mean time, the TS2207A/B series will enter a low current standby mode. Once into standby mode, the system can only be released from standby mode right after the battery pack is connected to a charger. The conditions of over current and short circuit protection are both determined by the voltage at the V- pin. As the voltage of V- pin reaches a higher value than VOC, which indicates an undesirable large current is flowing through the path, DOUT will be switched to a low level and the path is cutoff after internally pre-set delay time (tOC) elapses. In the case of short circuit, i.e. V- rises above VSHORT, the path will also be cutoff but with almost no delay time. Once the over current or factors contributing to short circuit is removed, the built-in resistor at the V- pin, typically 100kΩ, will pull V- down to VSS and bringing the IC back to normal operation. Together with the application circuit, the TS2207A/B will function as a consummate protector, which promotes safe usage and the sustainability of Li-ion battery packs.
Features
Low current consumption Supply current 3uA (typ) and standby current 0.6uA High withstand voltage up to 22V (VDD ~ V-) High accuracy voltage detection Over charge detector: ± 50mV Over discharge detector: ± 3.2% Over current and short circuit protection Small package of SOT-26
Ordering Information
Part No.
TS2207ACX6 TS2207BCX6 Note: Marking BXX, XX is wafer and assembly lot code (A~Z & 1~9)
Threshold Voltage
4.30V ~ 4.40V 4.23V ~ 4.33V
Reel
Black White
Pin Description
No.
1 2 3 4 5 6
Symbol
DOUT VCOUT CEXT
Description
Output of over discharge detection Pin for charger negative input Output of over charge detection Pin for external capacitor Setting COM1 delay time Power supply Ground
Applications
Over-charge and over-discharge protection for Li-ion cell pack High precision protectors for cell-phones and other gadget using on board Li-ion cell battery
VDD VSS
TS2207A/B series
1-6
2003/12 rev. B
Block Diagram
Typical Application
TS2207A/B series
2-6
2003/12 rev. B
Absolute Maximum Rating
Supply Voltage Input Voltage V- pin VCT pin COUT pin DOUT pin VDD VVCext VCOUT VDOUT PD TOPT TSTG -0.3 to 12 VDD-22 to VDD +0.3 VSS -0.3 to VDD +0.3 VDD-22 to VDD +0.3 VSS -0.3 to VDD +0.3 150 -40 to +85 -50 to +120 V V V V V mW
o o
Output Voltage Power Dissipation Operating Temperature Range Storage Temperature Range
C C
Note: Absolute Maximum ratings are threshold limit values that must not be exceeded even for an instant under any conditions. Operation above these absolute maximum ratings may cause degradation or permanent damage to the device. These are stress ratings only and do not necessarily functional operation below these limits.
Electrical Characteristics (Ta = 25 oC, unless otherwise specified.)
Parameter Operating input voltage Conditions Voltage defined as VDD-VSS Detect rising Over-charge threshold voltage edge of supply voltage Over-charge threshold hysteresis range Over-charge delay time Over-discharge threshold voltage Over-discharge delay time Over current detection voltage Over current detection delay time Short circuit detection voltage Short circuit detection delay time Reset resistance for excess current protection Nch ON voltage of COUT Pch ON voltage of COUT Nch ON voltage of COUT Pch ON voltage of COUT Supply current Standby current C3= 0.01µF, VDD = 3.6V to 4.4V Detect falling edge of supply voltage VDD= 3.6V to 2.4V Detect rising edge of “V-” pin voltage VDD= 3.0V VDD= 3.0V VDD= 3.0V VDD= 3.6V,V-=1.0V IOL = 50µA, VDD= 4.4V IOH = -50µA, VDD= 3.9V IOH = 50µA, VDD= 2.4V IOH= -50µA, VDD= 3.9V VDD= 3.9V,V-= 0V VDD= 2.0V TS2207B VHYS tC1 VD1 tD1 VOC tOC Vshort tshort Rshort VOL1 VOH1 VOL2 VOH2 IDD Istandby TS2207A VC1 4.23 0.15 40 2.42 4 0.17 6 VDD-1.2 -50 -3.4 -3.4 --4.28 0.20 75 2.500 10 0.20 13 VDD-0.9 5 100 0.3 3.8 0.2 3.7 3 -4.33 0.25 145 2.58 20 0.23 35 VDD-0.6 50 150 0.5 -0.5 -7 0.6 V ms V ms V ms V µS KΩ V V V V µA µA Symbol VDD1 Min 1.5 4.30 Typ -4.35 Max 10 4.40 V Unit V
TS2207A/B series
3-6
2003/12 rev. B
Operation Description
COM1 (Over-Charge Detector)
COM1 is the monitor of the voltage at the VDD pin. COM1 senses an over charging condition and if this condition continues longer than the delay time (tC1), When the voltage at VDD exceeds the over charge detector threshold VC1. the COUT pin goes to a “L” level thus turns off the external charge control N-ch MOSFET. An internal level shifter is incorporated in the buffer driver at the COUT pin to drive the “L” level of COUT equal to the V- pin voltage. By the way, the “H” level of COUT is set equal to VDD. The delay time (tC1) of over-charging is decided by the external capacitor C3 connected between the Vss and Cext pin, -6 it can be estimated as tC1 = [C3 x (VDD-0.7)] / (0.48 x 10 ). However, if the over-charge condition is not long enough to cover the time delay window, COUT will not go “L” and the charging process continues.
Required Conditions to Reset COM1 from Over Charging
After the MOSFET, the charge control is turns off, COM1 can be reset under two conditions. As resetting COM1 means COUT returns to “H” again and the charging path is reconnected to restart of charging process. One of the condition to reset COM1 is when VDD falls to lower than “VC1 - VHYS” as a result of battery cell internal discharge. Disconnecting the battery pack from the charger can also reset COM1 even when VDD is still within the hysteresis window (VC1 - VHYS ≤VDD < VC1). After the battery pack is disconnected from the charger, connecting a system load to the battery pack allows current to flow through the parasitic diode of external charge control MOSFET. This discharging current will bring VDD down a little over some time and once VDD drops below VC1, COUT will become “H”.
COM2 (Over-Discharge Detector)
COM2 monitors the cell voltage at the VDD pin. When VDD drops below the over-discharge threshold VD2 during the discharging process, COM1 senses an over-charging condition and after delay time (tD1), the DOUT pin goes to a “L” level and thus turning off the external discharge control N-ch MOSFET. As soon as this happens, the V- pin will be pulled “H” by an internal PMOS and TS2207A/B series will be enter a standby mode. Connecting the battery pack to a charger is a necessary condition for TS2207A/B series to recover from standby mode. With the charger connected, the charge current can flow through the parasitic diode of the external discharge control N-ch MOSFET while VDD is still lower than the over-discharge threshold. Once VDD is charged up to a value higher than VD1, the DOUT pin goes “H”. This leads to the “ON” state of both the charge and discharge control MOSFETs, and the charge process proceeds on as long as the charger is connected. Connecting a charger to the battery pack when VDD voltage is already higher then VD1 will make DOUT instantaneously “H”.
COM3 (Over Current Detector, Short Circuit Protector)
The over current detector and short circuit protector can work when both the charge and discharge control N-ch MOSFETs are “ON”. Under normal operation, the V- pin voltage will be either slightly higher or lower than Vss (dependent on the impedance of the two MOSFETs). However, when the V- pin voltage rises to a value between the short protection voltage Vshort and over current threshold VOC, the TS2207A/B series detect an excess current condition. As a result, the external discharge control N-ch MOSFET goes “OFF” with the DOUT pin being at “L”. An output delay time for the over current detection is internally fixed. A quick recovery of V- from a value between Vshort and VOC to the normal value within the delay time keeps the discharge control FET staying at the “ON” state. Short circuit may as well be explained as a “serious” over current condition. When the V- pin voltage rises to a value not only higher than VOC but also higher than Vshort, the short circuit protector will shut the discharge MOSFET down immediately to protect battery pack from being damaged or exploding. The V- pin has a built-in pull down resistor. Thus once the cause of over current or short circuit is removed, the V- pin will be pulled down to the ground level through the internal resistor. Therefore, with V- lower than the over current and short circuit protection threshold, DOUT will be turned back on and the TS2207A/B series can continue normal charge or discharge operation. When over current or short circuit occurs, the TS2207A/B series will not enter a standby mode.
TS2207A/B series
4-6
2003/12 rev. B
Timing Diagram
TS2207A/B series
5-6
2003/12 rev. B
SOT-26 Mechanical Drawing
SOT-26 DIMENSION DIM A B C D E F H L MILLIMETERS MIN MAX 2.70 3.00 0.25 0.50 1.90(typ) 0.95(typ) 1.50 1.05 2.60 1.70 1.35 3.00 INCHES MIN MAX 0.106 0.118 0.010 0.020 0.075(typ) 0.037(typ) 0.059 0.041 0.102 0.067 0.053 0.118
0.60(typ)
0.024(typ)
TS2207A/B series
6-6
2003/12 rev. B
