ÃÞÝÁ_mm_1451_text01.qxp (page 78)

Protection of Lithium-Ion Batteries (for Double-Protect) MM1451
Protection of Lithium-Ion Batteries (for Double-Protect)
Monolithic IC MM1451
This IC is used for double-protection of lithium-ion batteries with from one to three cells, and has an ultra- compact package. Short-circuits between cells accommodate series connections of one to three cells.
Features
1. Overcharge detection voltage accuracy (0°C to 50°C) 4. Pin I/O current between cells (Vcell=3.8V) 5. Delay time on overcharge voltage detection (Ct=0.22µF) Applications
IC for double-protection of lithium-ion batteries with one to three cells.
Pin Assignment
Protection of Lithium-Ion Batteries (for Double-Protect) MM1451
Block Diagram
Protection of Lithium-Ion Batteries (for Double-Protect) MM1451
Pin Description
Functions
Equivalent circuit diagram
Protection of Lithium-Ion Batteries (for Double-Protect) MM1451
Absolute Maximun Ratings (Ta=25°C)
Operating temparature
Storage temparature
VCC Input voltage
V1 Input voltage *1
V2 Input voltage *1
V3 Input voltage *1
Ct pin voltage *2
VOUT pin voltage
Allowable loss
Note 1 : *1 18V >= V3 >= V2 >= V1 >= -0.3 Note 2 : *2 Do not impress current of 300µA or more on the Ct pin.
Electrical Characteristics 1 (Except where noted otherwise, Ta=25°C, VCEL=V3-V2=V2-V1=V1-GND, VCC=3 VCEL)
Measurement conditions
Min. Typ. Max. Unit
Current consumption 1
Current consumption 2
Pin I/O current between cells
Overcharge detection voltage
Hysterisis voltage
Overcharge detection delay time
Output current
Electrical Characteristics 2 (Except where noted otherwise, Ta=25°C, VCEL=V3-V2=V2-V1=V1-GND, VCC=3 VCEL)
Measurement conditions
Min. Typ. Max. Unit
Current consumption 1
Current consumption 2
Pin I/O current between cells
Overcharge detection voltage
Hysterisis voltage
Overcharge detection delay time
Output current
Output leakage current
Protection of Lithium-Ion Batteries (for Double-Protect) MM1451
Electrical Characteristics 3 (Except where noted otherwise, Ta=25°C, VCEL=V3-V2=V2-V1=V1-GND, VCC=3 VCEL )
Measurement conditions
Min. Typ. Max. Unit
Current consumption 1
Current consumption 2
Current consumption 3
Current consumption 4
Pin I/O current between cells
Overcharge detection voltage
Hysterisis voltage
Overcharge detection delay time
Output current
Output leakage current
Measuring Circuit
Protection of Lithium-Ion Batteries (for Double-Protect) MM1451
Application Circuit
Note 1: Can support 1, 2 or 3 cells by shorting each cell. However, be sure to connect a battery for V3 cell.
V3 cell may not operate correctly when shorted.
Note 2: When connecting batteries, be sure to connect in the following order: GND V3, and VCC Note 3: Output may go ON momentarily when starting up power supply. If this error output during startup becomes a problem, connect the VCC pin last.
Note 4: Operation can not be guaranteed for connections other than the above.
Timing Chart
OUT
(at Ct short)
(at Ct open)
Note: Output goes low simultaneously with overcharge detection at Ct pin short and open.
Protection of Lithium-Ion Batteries (for Double-Protect) MM1451
Characteristics
Detection voltage
Output delay time
Delay time (S)
Output voltage (V)
Input voltage (No delay) (V)
Temperature (°C)
Consumption current
Pin I/O current between cells
Consumption
current (
Pin I/O current
between cells ( -0.3
Cell voltage (V)
Cell voltage (V)

Source: http://www.ast-home.narod.ru/akkum/MM1451.pdf