ETC EC9522T003

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
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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.
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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.
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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.
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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.
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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.
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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
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