MITSUMI MM1438

IC for Control of Lithium-ion Betteries Charging MM1438
MITSUMI
IC for Control of Lithium-ion Betteries Charging
Monolithic IC MM1438
Outline
This IC is used to control charging of lithium-ion batteries consisting of a single cell. It is a modification of the
previous MM1332 charging-control IC, with improved charging voltage accuracy and a smaller package.
Features
1. Charging voltage accuracy (Ta=25°C)
2. Charging voltage accuracy (Ta=0 to 50°C)
3. Consumption current (charging on)
4. Consumption current (charging off)
5. Low-voltage detection
6. Leakage current between CEL and CS
±25mV/cell
±30mV/cell
250µA typ.
2µA typ.
2.15V typ.
1µA max.
Package
VSOP-8B
Applications
IC for control of lithium-ion batteries charging.
Pin Assignment
8
1
7
2
6
3
VSOP-8B
5
4
1
GND
2
LV
3
SW2
4
SW1
5
VCC
6
EXT
7
CEL
8
CS
IC for Control of Lithium-ion Betteries Charging MM1438
MITSUMI
Block Diagram
Pin Description
Pin No. Pin name
I/O
1
GND
Input
2
LV
Output
3
SW2
Input
4
SW1
Input
5
VCC
Input
6
EXT
Output
7
CEL
Input
Pin Description
Ground pin
Low voltage detection circuit output pin
ON with NPN-Tr open collector output at low voltage
Low voltage detection circuit ON/OFF control input pin
SW2 = VCC: OFF, SW2 = GND: ON
ON/OFF control input pin for the IC
SW1 = VCC: OFF, SW1 = GND: ON
Power supply input pin
Charging control output pin
Controls external PNP-Tr to control charging.
Battery voltage input pin
Detects battery voltage and controls rated voltage to the prescribed voltage value.
Current detection pin
8
CS
Input
Detects current by drop in external resistor voltage and controls rated current.
Current value can be set at 0.1V/R1 typ.
IC for Control of Lithium-ion Betteries Charging MM1438
MITSUMI
Absolute Maximum Ratings
(Ta=25°C)
Item
Symbol
Ratings
Unit
Storage temperature
TSTG
-40~+125
°C
Operating temperature
TOPR
-20~+70
°C
Power supply voltage
VCC max.
-0.3~+18
V
CFL pin input voltage
VCEL max.
-0.3~+13
V
SW input voltage
VSW
-0.3~VCC+0.3
V
Allowable loss
Pd
300
mW
Recommended Operating Conditions
Item
Symbol
Ratings
Unit
Operating temperature
TOPR
-20~+70
°C
Charging control operating voltage
VOPR
2.5~+17
V
Note: Operating voltage minimum value is during rated current control.
Electrical Characteristics
(Except where noted otherwise, Ta=25°C, VCC=5V, SW3 : A, SW6 : A, SW7 : A)
Item
Symbol
Measurement conditions
Min. Typ.
Consumption current 1
ICC1
VSW1=VSW2=0V (Charge : ON)
250
Consumption current 2
ICC2
VSW1=VSW2=VCC (Charge : OFF)
2
Ta=25°C
4.100 4.125
Output voltage 1
VO1
Output voltage 2
VO2
Ta=0~50°C
4.095 4.125
Current limit
VCL
90
100
Inflow current between
3.0
5.0
ICEL1
CEL-CS during operation
Leak current between CEL-CS
ICEL2
VCC=0V or OPEN
0.01
SW1 input current
ISW1
20
SW1 input voltage L
VL1
Charge : ON
-0.3
SW1 input voltage H
VH1
Charge : OFF
VCC-0.1
Low voltage detection voltage
LV
2.0 2.15
SW2 input current
ISW2
20
SW2 input current L
VL2
Low voltage detection circuit: ON
-0.3
SW2 input current H
VH2
Low voltage detection circuit: OFF
VCC-1.0
Low voltage detection
ILV
output leak current
Low voltage detection
ISINK=1mA
0.2
VLV
output saturation voltage
EXT pin inflow current
IEXT
10
20
EXT pin output voltage
VEXT
For no load
0.3
Note 1: Please insert a capacitor of several µF between power supply and ground when using.
Max. Unit
400
µA
10
µA
4.150 V
4.155 V
110 mV
7.0
µA
1
30
2.0
VCC+0.3
2.3
30
2.0
VCC+0.3
µA
µA
V
V
V
µA
V
V
0.5
µA
0.4
V
VCC-0.3
mA
V
Note 2: Be sure that CS pin potential does not fall below -0.5V.
Note 3: If the IC is damaged and control is no longer possible, its safety can not be guaranteed. Please
protect with something other than this IC.
MITSUMI
Measuring Circuit
IC for Control of Lithium-ion Betteries Charging MM1438
IC for Control of Lithium-ion Betteries Charging MM1438
MITSUMI
Measurement Procedures
(Except where noted otherwise, Ta=25°C, VCC=5V, SW3 : A, SW6 : A, SW7 : A)
Item
Consumption current 1
Consumption current 2
Output voltage
Current limit
Inflow current between
CEL-CS during operation
Leak current between CEL-CS
SW1 input current
SW1 input voltage
Measurement Procedures
V3 = VCC, V4 = 0V. Next, measure A5 current value Icc1 when V3 is changed
from VCC
0V.
V3 = Vd = VCC. Measure A6 current value ICC2 at this time.
V3 = VCC, V4 = 0V. Measure T7 voltage VO at this time.
V3 = Vcc, V4 = 0V. Set V7 voltage 1V lower than T7 (output voltage) potential
and set SW7 to B. Measure T8 voltage VCL at this time.
V3 = VCC, V4 = 0V, SW6: C. V7 = 4.5V, SW7: B. Measure A7 current value
ICEL1 at this time.
V3 = V4 = VCC = 0V, SW6: C. V7 = 4.5V, SW7: B. Measure A7 current value
ICEL2 at this time.
Measure A4 current value ISW1 when V4 = 0V.
V3 = VCC. Charge: ON (VL1) when V4 potential is varied and T7 voltage is the
prescribed output voltage; Charge OFF (VH1) when 0 ~ 0.05V.
V3 = V4 = 0V. Set V7 voltage 1V lower than T7 (output voltage) potential, and
Low voltage detection voltage
SW7: B.
Next gradually lower V7 voltage; V7 voltage is LV when A7 current value is
within ±10µA.
SW2 input current
Measure A3 current value ISW2 when V3 = 0V.
V4 = 0V, V7 = 1V, SW7: B. Low voltage detection circuit: ON (VL2) when V3
SW2 input voltage
voltage is varied and A7 current value is within ±10µA; low voltage detection
circuit: OFF (VH2) otherwise.
Low voltage detection
output leak current
Low voltage detection
output saturation voltage
V3 = VCC, V4 = 0V. Measure A2 current value ILV when V3 is changed from
Vcc 0V.
V3 = V4 = 0V. SW3: B, SW7: B. Measure T2 voltage VLV when V7 voltage is 0V.
EXT pin inflow current
V3 = V4 = 0V. SW6: B, SW7: B, V6 = 4V, V7 = 3V. Measure A6 current value IEXT.
EXT pin output voltage
V3 = V4 = 0V. SW6: C, SW7: B. T6 voltage when V7 = 3V and V7 = 5V is VEXT.
IC for Control of Lithium-ion Betteries Charging MM1438
MITSUMI
Timing Chart
Battery connection and SW1: ON
VCC
0
ON
OFF
SW1
0
ON
Rated voltage mode
OFF
CEL
0
100mV
Charging OFF
Charging ON
Normal charging
CS
0
H
LV
0
Rated current mode
L
CEL
0
Charging OFF
CS
Battery low voltage
(2V or less)
0
LV
L
0
(SW2 : L)
Application Circuit
IC for Control of Lithium-ion Betteries Charging MM1438
MITSUMI
Characteristics
Output voltage vs Power supply voltage
(Ta=25°C)
4.10
0
5
10
15
(VCC=5V)
4.15
Output voltage (V)
Output voltage (V)
4.15
4.05
Output voltage vs Ambient temperature
4.10
4.05
-25
18
Power supply voltage (V)
CS pin voltage vs Power supply voltage
100
95
0
5
10
15
3
2
1
0
15
20
25
LV pin inflow current (mA)
(Ta=25°C,VCC=5V)
EXT pin voltage (V)
4
3
2
1
0
0
5
10
15
20
25
EXT pin inflow current (mA)
0
25
50
75
(Ta=25°C,VCC=5V, at low voltage detection)
150
100
50
0
2
2.1
2.2
2.3
Output voltage (V)
EXT pin voltage vs EXT pin inflow current
5
95
200
CS pin voltage (mV)
LV pin voltage (V)
4
10
100
CS pin voltage vs Output voltage
(Ta=25°C)
5
105
Ambient temperature (°C)
LV pin voltage vs LV pin inflow current
0
75
(VCC=5V)
90
-25
18
Power supply voltage (V)
5
50
110
CS pin voltage (mV)
CS pin voltage (mV)
105
90
25
CS pin voltage vs Ambient temperature
(Ta=25°C)
110
0
Ambient temperature (°C)
30
2.4
2.5