Datasheet

UNISONIC TECHNOLOGIES CO., LTD
UB261
Preliminary
CMOS IC
1-CELL LITHIUM-ION/POLYMER
BATTERY PROTECTION IC

DESCRIPTION
The UTC UB261 is a series of lithium-ion/lithium-polymer
rechargeable battery protection ICs incorporating high accuracy
voltage detection circuits and delay circuits.
The UTC UB261 is suitable for protection of single cell lithium-ion /
lithium polymer battery packs from overcharge, over discharge and
over current.
The ultra-small package and less required external components
make it ideal to integrate the UTC UB261 into the limited space of
battery pack.
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6
5
4
1
2
3
SOT-26
FEATURES
Wide Supply Voltage Range: VDD=1.5V~8.0V
Ultra-Low Quiescent Current: IOPE=3.0μA (VDD=3.5V)
Ultra-Low Power-Down Current: IPDN=0.2μA (VDD=1.5V)
Overcharge Detection Voltage: VCU=3.9V~4.4V
Overcharge Release Voltage: VCL=3.8V~4.4V
Over Discharge Release Voltage: VDL=2.0V~3.0V
Over Discharge Release Voltage: VDU=2.0V~3.4V
Over Current 1 Detection Voltage: VIOV1=0.05V~0.30V
Over Current 2 Detection Voltage: VIOV2=0.5V (Fixed)
Short Circuit Detection Voltage: VSHORT=1.2V (Fixed)
Charger Detection Voltage: VCHA=-0.7V (Fixed)
Delay Times are Generated by an Internal Circuit. (External Capacitors are Unnecessary.)
ORDERING INFORMATION
Note:
Ordering Number
UB261G-xx-AG6-R
xx: Output Voltage, refer to Marking Information.
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Copyright © 2014 Unisonic Technologies Co., Ltd
Package
SOT-26
Packing
Tape Reel
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Preliminary
CMOS IC
MARKING INFORMATION
PACKAGE
VOLTAGE CODE (Note)
SOT-26
XX
MARKING
Note: Refer to Serial Code List

SERIAL CODE LIST
Model
Code
UB261
AA
AB
AC
AD
AE
AF
AG
AH
AI
Overcharge
Detection
Voltage
[VCU](V)
4.325
4.325
4.300
4.280
4.280
4.275
4.250
4.200
4.100

PIN CONFIGURATION

PIN DESCRIPTION
PIN NO.
1
2
3
4
5
6
PIN NAME
DO
VM
CO
DP
VDD
VSS
Overcharge
Release
Voltage
[VCL](V)
4.075
4.075
4.200
4.180
4.080
4.075
4.150
4.100
3.850
Over discharge
Detection
Voltage
[VDL](V)
2.50
2.50
2.40
2.50
2.30
2.50
2.40
2.80
2.50
Over discharge
Release
Voltage
[VDU](V)
2.90
2.90
3.00
3.00
2.40
2.90
3.00
2.90
2.90
Over Current
Detection
Voltage
[VIOV1](V)
0.150
0.100
0.200
0.150
0.100
0.150
0.100
0.150
0.150
DESCRIPTION
For discharge control: FET gate connection pin
For current sense and charger detection input pin
For charge control: FET gate connection pin
Test pin for delay time measurement
Positive power input
Negative power input
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UB261

Preliminary
CMOS IC
BLOCK DIAGRAM
0V Battery Charge
Inhibition Detector
VDD
VM
Oscillator
Short circuit Detector
Charger Detector
Divider
Over current 2 Detector
Overdischarge
Detector
Control
Logic
VM
Overcharge
Detector
Over current 1 Detector
From Oscillator
VSS
DP
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Preliminary
CMOS IC
ABSOLUTE MAXIMUM RATING (VSS=0V, TA=25°С unless otherwise specified)
PARAMETER
SYMBOL
RATINGS
UNIT
Input Voltage Between VDD and VSS (Note 2)
VDD
VSS-0.3 ~ VSS+12
V
CO Output Pin Voltage
VCO
VDD-12 ~ VDD+0.3
V
DO Output Pin Voltage
VDO
VSS-0.3 ~ VDD+0.3
V
VM Input Pin Voltage
VM
VDD-14 ~ VDD+0.3
V
Ambient Operating Temperature
TOPR
-40 ~ +85
°С
Storage Temperature
TSTG
-55 ~ +125
°С
Notes: 1. Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
2. Pulse (μsec) noise exceeding the above input voltage (VSS+12V) may cause damage to the IC.

ELECTRICAL CHARACTERISTICS (VSS=0V, TA=25°С unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDITIONS
CURRENT CONSUMPTION
Supply Current
IOPE VDD=3.5V, VM=0V
Power-Down Current
IPDN VDD=VM=1.5V
OPERATING VOLTAGE
Operating Voltage Between VDD-pin and
VDS1
VSS-pin
Operating Voltage Between VDD-pin and
VDS2
VM-pin
DETECTION VOLTAGE
Overcharge Detection Voltage
VCU
Overcharge Release Voltage
VCL
Overdischarge Detection Voltage
VDL
Overdischarge Release Voltage
VDU
Over Current 1 Detection Voltage
VIOV1 VDD=3.5V
Over Current 2 Detection Voltage
VIOV2 VDD=3.5V
Load Short Circuit Detection Voltage
VSHORT
Charger Detection Voltage
VCHA VDU≠VDL
0V BATTERY CHARGE VOLTAGE
0V Battery Charge Inhibition Battery
V0INH
Voltage
INTERNAL RESISTANCE
Resistance between VM-pin and
RVMD VDD=1.8V, VM=0V
VDD-pin
Resistance between VM-pin and
RVMS VDD=3.5V, VM=1.0V
VSS-pin
OUTPUT RESISTANCE
CO-pin Resistance “H”
RCOH VCO=3.0V, VDD=3.5V, VM=0V
CO-pin Resistance “L”
RCOL VCO=0.5V, VDD=4.5V, VM=0V
DO-pin Resistance “H”
RDOH VDO=3.0V, VDD=3.5V, VM=0V
DO-pin Resistance “L”
RDOL VDO=0.5V, VDD=VM=1.8V
DELAY TIME
Overcharge Detection Delay Time
tCU
Overdischarge Detection Delay Time
tDL
Over Current 1 Detection Delay Time
tIOV1 VDD=3.5V
Over Current 2 Detection Delay Time
tIOV2 VDD=3.5V
Short Circuit Detection Delay Time
tSHORT
UNISONIC TECHNOLOGIES CO., LTD
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MIN
TYP
MAX
UNIT
3.0
0.2
8.0
0.5
μA
μA
1.5
8
V
1.5
10
V
VCU+0.050
VCL+0.050
VDL+0.100
VDU+0.100
VIOV1+0.03
0.65
1.7
-0.2
V
V
V
V
V
V
V
V
0.9
1.8
V
100
300
900
kΩ
10
30
70
kΩ
5
5
5
5
10
10
10
10
kΩ
kΩ
kΩ
kΩ
1.2
150
9
2.2
300
1.5
190
12
3.2
380
s
ms
ms
ms
µs
VCU-0.050 VCU
VCL-0.050 VCL
VDL-0.100 VDL
VDU-0.100 VDU
VIOV1-0.03 VIOV1
0.35
0.50
0.5
1.2
-1.6
-0.7
0.9
110
6
1
120
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Preliminary
CMOS IC
OPERATION
1. Normal Condition
The UTC UB261 series monitors the voltage of the battery connected between VDD pin and VSS pin and the
voltage difference between VM pin and VSS pin to control charging and discharging. When the battery voltage is in
the range from the overdischarge detection voltage (VDL) to the overcharge detection voltage (VCU), and the VM pin
voltage is in the range from the charger detection voltage (VCHA) to the overcurrent 1 detection voltage (VIOV1), the IC
turns both the charging and discharging control FETs on. This condition is called the normal condition, and in this
condition charging and discharging can be carried out freely.
Note: When a battery is connected to the IC for the first time, discharging may not be enabled. In this case, short
the VM pin and VSS pin or connect the charger to restore the normal condition.
2. Overcurrent Condition
When a battery in the normal status is in the status where the voltage of the VM pin is equal to or higher than the
overcurrent detection voltage because the discharge current is higher than the specified value and the status lasts
for the overcurrent detection delay time, the discharge control FET is turned off and discharging is stopped. This
status is called the overcurrent status. In the overcurrent status, the VM and VSS pins are shorted by the resistor
between VM and VSS (RVMS) in the IC. However, the voltage of the VM pin is at the VDD potential due to the load as
long as the load is connected. When the load is disconnected, the VM pin returns to the VSS potential. This IC detects
the status when the impedance between the EB+ pin and EB- pin (Refer to the typical application circuit) increases
and is equal to the impedance that enables automatic restoration and the voltage at the VM pin returns to overcurrent
detection voltage 1 (VIOV1) or lower and the overcurrent status is restored to the normal status.
Note: The impedance that enables automatic restoration varies depending on the battery voltage and the set value
of overcurrent 1 detection voltage.
3. Overcharge Condition
When the battery voltage becomes higher than the overcharge detection voltage (VCU) during charging under the
normal condition and the detection continues for the overcharge detection delay time (tCU), the UTC UB261 series
turns the charging control FET off to stop charging. This condition is called the overcharge condition. The overcharge
condition is released by the following two cases:
(1) When the battery voltage falls below the overcharge release voltage (VCL), the UTC UB261 series turns the
charging control FET on and turns to the normal condition.
(2) When a load is connected and discharging starts, the UTC UB261 series turns the charging control FET on
and returns to the normal condition. Just after the load is connected and discharging starts, the discharging current
flows through the parasitic diode in the charging control FET. At this moment the VM pin potential becomes Vf, the
voltage for the parasitic diode, higher than VSS level. When the battery voltage goes under the overcharge detection
voltage (VCU) and provided that the VM pin voltage is higher than the overcurrent 1 detection voltage, the UTC
UB261 series releases the overcharge condition.
Note 1: If the battery is charged to a voltage higher than the overcharge detection voltage (VCU) and the battery
voltage does not fall below the overcharge detection voltage (VCU) even when a heavy load is connected, the
detection of overcurrent 1, overcurrent 2 and load shortcircuiting do not function until the battery voltage falls below
over charge detection voltage (VCU). Since an actual battery has an internal impedance of several dozens of mΩ, the
battery voltage drops immediately after a heavy load that causes overcurrent is connected, and the detection of
overcurrent 1, overcurrent 2 and load short-circuiting function.
Note 2: When a charger is connected after the overcharge detection, the overcharge condition is not released
even if the battery voltage is below the overcharge release voltage (VCL). The overcharge condition is released when
the VM pin voltage goes over the charger detection voltage (VCHA) by removing the charger.
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Preliminary
CMOS IC
OPERATION(Cont.)
4. Overdischarge Condition
When the battery voltage falls below the overdischarge detection voltage (VDL) during discharging under the
normal condition and the detection continues for the overdischarge detection delay time (tDL), the UTC UB261 series
turns the discharging control FET off to stop discharging. This condition is called the overdischarge condition. When
the discharging control FET is turned off, the VM pin voltage is pulled up by the resistor between VM and VDD in the IC
(RVMD). When the voltage difference between the VM and VDD then is 1.2V (typ.) or lower, the current consumption is
reduced to the power-down current consumption (IPDN). This condition is called the power-down condition.
The power-down condition is released when a charger is connected and the voltage difference between the VM
and VDD becomes 1.2V (typ.) or higher. Moreover when the battery voltage becomes the overdischarge detection
voltage (VDL) or higher, the UTC UB261 series turns the discharging FET on and returns to the normal condition.
5. Charger Detection
When a battery in the overdischarge condition is connected to a charger and provided that the VM pin voltage is
lower than the charger detection voltage (VCHA), the UTC UB261 series releases the overdischarge condition and
turns the discharging control FET on when the battery voltage becomes equal to or higher than the overdischarge
detection voltage (VDL) since the charger detection function works. This action is called charger detection.
When a battery in the overdischarge condition is connected to a charger and provided that the VM pin voltage is
not lower than the charger detection voltage (VCHA), the UTC UB261 series releases the overdischarge condition
when the battery voltage reaches the overdischarge detection voltage (VDU) or higher.
6. Abnormal Charge Current Detection
If the VM pin voltage falls below the charger detection voltage (VCHA) during charging under normal condition and it
continues for the overcharge detection delay time (tCU) , the charging control FET turns off and charging stops. This
action is called the abnormal charge current detection.
Abnormal charge current detection works when the DO pin voltage is “H” and the VM pin voltage falls below the
charger detection voltage (VCHA). Consequently, if an abnormal charge current flows to an over-discharged battery,
the UTC UB261 series turns the charging control FET off and stops charging after the battery voltage becomes
higher than the overdischarge detection voltage which make the DO pin voltage “H”, and still after the overcharge
detection delay time (tCU) elapses.
Abnormal charge current detection is released when the voltage difference between VM pin and VSS pin becomes
less than charger detection voltage (VCHA).
7. Delay Circuits
The detection delay times are determined by dividing a clock of the approximately 3.5kHz with the counter.
Note 1: The detection delay time for overcurrent 2 (tIOV2) and load short-circuiting (tSHORT) start when the
overcurrent 1 (VIOV1) is detected. When the overcurrent 2 (VIOV2) or load short-circuiting (VSHORT) is detected over the
detection delay time for each of them (= tIOV2 or tSHORT) after the detection of overcurrent 1 (VIOV1), the UTC UB261
series turns the FET off within tIOV2 or tSHORT of each detection.
Note 2: When the overcurrent is detected and continues for longer than the overdischarge detection delay time (tDL)
without releasing the load, the condition changes to the power-down condition when the battery voltage falls below
the overdischarge detection voltage (VDL). When the battery voltage falls below the overdischarge detection voltage
(VDL) due to the overcurrent, the UTC UB261 series turns the discharging control FET off by the overcurrent
detection. In this case the recovery of the battery voltage is so slow that if the battery voltage after the overdischarge
detection delay time (tDL) is still lower than the over discharge detection voltage (VDL), the UTC UB261 series shifts
to the power-down condition.
8. 0V Battery Charge Inhibiting Function
This function inhibits the recharging when a battery that is short-circuited (0V battery) internally is connected.
When the battery voltage is the 0V battery charge inhibition battery voltage (V0INH) or lower, the charging control FET
gate is fixed to EB- pin voltage to inhibit charging. When the battery voltage is the 0V battery charge inhibition
battery voltage (V0INH) or higher, charging can be performed.
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Preliminary
CMOS IC
TIMING CHART
VM Pin
DO Pin
CO Pin
Battery Voltage
(1) Overcharge Detection, Overdischarge Detection
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Preliminary
CMOS IC
TIMING CHART (Cont.)
VM Pin
DO Pin
CO Pin
Battery Voltage
(2) Discharge Overcurrent Detection
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Preliminary
CMOS IC
TIMING CHART (Cont.)
VM Pin
DO Pin
CO Pin
Battery Voltage
(3) Abnormal Charge Overcurrent Detection
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Preliminary
CMOS IC
TYPICAL APPLICATION CIRCUIT
EB+
R1=100~470Ω
DP
VDD
Battery
UTC UB261
C1=0.1µF
VM
VSS
DO
CO
R2=1kΩ
M1
M2
EB-
Notes: 1. Overdischarge detection voltage must be higher than the threshold voltage of M1 and M2, if not, the M1
may not cut the charging current. If the threshold voltage of M1 equal to or higher than the overdischarge
detection voltage is used, discharging may be stopped before overdischarge is detected.
2. Charger voltage must be higher than the withstanding voltage between the gate and source of M1 and M2,
if not, M1 and M2 may be destroyed.
3. Resistance of R1 can’t be high, the value is about from 100Ω to 470Ω, If R1 has a high resistance, the
voltage between VDD pin and VSS pin may exceed the absolute maximum rating when a charger is
connected in reverse since the current flows from the charger to the IC. Insert a resistor of 100Ω or higher
as R1 for ESD protection.
4. The capacitance of C1 must not be less than 0.022μF, if not, DO pin may oscillate when load
short-circuiting is detected. Be sure to connect a capacitor of 0.022μF or higher to C1, the typical value is
about 0.1μF.
5. The resistance of R2 can not be higher than 2kΩ, if not, the charging current may not be cut when a
high-voltage charger is connected.
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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