MIC79110
Simple 1.2A Linear Li-ion Battery Charger
General Description
The Micrel MIC79110 is a simple and accurate lithium-ion
battery charger. The part features a built-in pass transistor,
precision programmable current limiting (±5%), and
precision voltage termination (±0.75% over temperature).
The MIC79110 packs full functionality into a small space.
Other features of the MIC79110 include two independent
indicators: a digital end-of-charge signal that is
programmable with a resistor-to-ground and an analog
current output that is proportional to the output current,
allowing for monitoring of the actual charging current.
Additional features include very low dropout (550mV over
the temperature range), thermal shutdown, and reverse
polarity protection. In the event the input voltage to the
charger is disconnected, the MIC79110 also provides
minimal reverse-current and reversed-battery protection.
Available in both fixed 4.2V and adjustable outputs, the
MIC79110 is offered in the leadless 10-pin 3mm × 3mm
DFN with an operating
junction temperature range of
–40˚C
to +125˚C.
Datasheets and support documentation are available on
Micrel’s web site at:
www.micrel.com.
Features
•
Input voltage range: 2.5V to 16V
•
High output voltage accuracy of ±0.75% over –5°C to
+60˚C
•
Current limit ±5% accurate from –5°C
≤ T
J
≤ + 125°C
•
Programmable end-of-charge flag
•
Analog output proportional to output current
•
Adjustable and fixed 4.2V output
•
Low dropout voltage of 550mV at 700mA load, over
temperature
•
1.2A maximum charge current
•
Excellent line and load regulation specifications
•
Reverse-current protection
•
Thermal-shutdown and current-limit protection
•
Tiny 10-pin 3mm
×
3mm DFN package
•
Junction temperature range: –40°C
to +125°C
Applications
•
•
•
•
•
•
Cellular phones and PDAs
Digital cameras and camcorders
MP3 players
Notebook PCs
Portable Meters
Cradle/car chargers, and battery packs
Typical Application
Micrel Inc. • 2180 Fortune Drive •
San
Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
September 24, 2013
Revision 2.1
Micrel, Inc.
MIC79110
Ordering Information
Part Number
MIC79110-4.2YML
MIC79110YML
Marking
(1)
Code
L942
L9AA
Voltage
4.2V
Adjustable
Junction Temperature Range
–40°
to +125°C
–40°
to +125°C
Package
10-Pin 3mm × 3mm DFN
10-Pin 3mm × 3mm DFN
1. Pb-Free “Y” indicator is added to the device mark after logo.
Pin Configuration
Fixed Output
10-Pin 3mm ×
3mm DFN (ML)
Adjustable Output
10-Pin 3mm ×
3mm DFN (ML)
Pin Description
Pin Number
1
2
3
3
4
5, 6
7
Pin Name
SD
RSET
SNS
ADJ
BAT
VIN
ACHG
Pin Function
Shutdown Input. Logic HIGH = Off; Logic LOW = On.
Current limit: Sets constant current limit via an external resistor to ground.
I
RSET
= (0.2V/R
SET
)
×
1000.
(Fixed voltage only): Sense output, connect directly to battery.
(Adjustable
voltage only): Feedback input.
Battery Terminal. Connect to single-cell lithium-ion battery.
Input supply pin.
Analog Charge Indicator Output: Current source who’s output current is equal to 1/1000 of the
BAT pin current.
Digital End-of-Charge Output: N-Channel open-drain output. LOW indicates charging, a current
that is higher than the programmed current set by R
EOC
is charging the battery. When the current
drops to less than the current set by R
EOC
, the output goes high impedance, indicating end-of-
charge.
End-of-Charge Set: Sets end-of-charge
current threshold via an external resistor to ground.
I
EOC
= (0.2V/ R
EOC
)
×
1000.
Ground
8
DEOC
9
10
REOC
GND
September 23, 2013
2
Revision 2.1
Micrel, Inc.
MIC79110
Absolute Maximum Ratings
(2)
Input Supply Voltage (V
IN
) .................................... 0V to 18V
Shutdown Input Voltage (V
SD
) .............................. 0V to 10V
Output Voltage (ADJ) ..................................................... 10V
Power Dissipation ................................... Internally Limited
Junction Temperature ............................... –40°C
to +125°C
Operating Ratings
(3)
Input Supply Voltage ........................................ 2.5V to 16V
Shutdown Input Voltage (V
SD
) ................................ 0V to 7V
Output Voltage (ADJ) .................................................... 9.6V
Junction Temperature Range (T
J
)............. –40°C
to +125°C
3mm × 3mm DFN-10 (θ
JA
) ..................................... 60°C
3mm × 3mm DFN-10 (θ
JC
) ....................................... 2°C
Electrical Characteristics
(4)
T
A
= 25°C with V
IN
= V
OUT
+ 1V; I
LOAD
= 100µA; C
BAT
= 10µF; SD = 0V; R
SET
=
1kΩ.
Bold
values indicate –40ºC < T
J
< +125°C; unless
otherwise specified.
Parameter
Output Voltage Accuracy
ADJ Pin Voltage Accuracy
Line Regulation
Load Regulation
Dropout Voltage
Ground Current
VIN Pin Current
Shutdown Pin Current
Shutdown Input Threshold
Shutdown Hysteresis
Current Limit Accuracy
(6,
7)
(5)
Condition
V
OUT
= 4.2V; I
LOAD
= 50mA; T
J
= –5°C
to +60°C
V
OUT
= 4.2V; I
LOAD
= 50mA; T
J
= –40°C
to +125°C
V
IN
= V
OUT
+ 1V to 16V @ I
LOAD
= 50mA
I
LOAD
= 0.1mA to 1A
I
LOAD
= 100mA, R
SET
= 167Ω
I
LOAD
= 700mA, R
SET
= 167Ω
I
LOAD
= 10mA, R
SET
= 167Ω
I
LOAD
= 700mA, R
SET
= 167Ω
SD = V
IN
SD = 5.2V, V
BAT
= 0
Logic High, regulator off
Logic Low, regulator on
Min.
-0.75
-1.5
0.5955
-0.1
Typ.
Max.
+0.75
+1.5
Units
%
V
%/V
%
mV
mV
mA
mA
µA
µA
V
V
mV
0.6
0.3
160
375
2
24
120
0.1
0.6045
+0.1
250
550
3
35
300
5
0.93
1.05
60
V
OUT
= 0.9
×
V
NOM
; I
OUT
= 1.2A, R
SET
= 167Ω,
T
J
= –40°C
to +85°C
V
OUT
= 0.9
×
V
NOM
; I
OUT
= 0.1A, R
SET
= 2kΩ
-5
-20
0.1
+5
+20
1.2
%
%
A
Current-Limit Setpoint Range
Notes:
(7)
2.
Exceeding the absolute maximum rating may damage the device.
3. The device is not guaranteed to function outside its operating rating.
4. Specification for packaged product only.
5. Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V
differential. For outputs below 2.5V, dropout voltage is the input-to-output voltage differential with the minimum input voltage 2.5V. Minimum input
operating voltage is 2.5V.
6. V
NOM
denotes the nominal output voltage.
7. I
RSET
= (0.2V/R
SET
) × 1000.
September 23, 2013
3
Revision 2.1
Micrel, Inc.
MIC79110
Electrical Characteristics
(4)
(Continued)
T
A
= 25°C with V
IN
= V
OUT
+ 1V; I
LOAD
= 100µA; C
BAT
= 10µF; SD = 0V; R
SET
=
1kΩ.
Bold
values indicate –40ºC < T
J
< +125°C; unless
otherwise specified.
Parameter
Maximum Current Limit
V
BAT
Reverse Current
Condition
R
SET
shorted to ground, V
BAT
= 0.9 × V
NOM
V
IN
= High impedance or ground
35
30
50
40
Min.
1.25
Typ.
1.65
4.2
Max.
2.5
20
65
70
95
100
0.95
190
2.0
55
1150
Units
A
µA
Digital End–of–Charge (DEOC) Output
I
EOC
I
EOC
(8,
9)
R
EOC
= 4kΩ Current Falling
R
EOC
= 4kΩ Current Rising
I
EOC
= 5mA, I
BAT
= 700mA
Logic HIGH = V
IN
= 16V
V
IN
= +5V
R
EOC
shorted to ground
I
BAT
= 50mA
I
BAT
= 1.2A, T
J
= –40°C
to +85°C
50
70
0.74
0.1
150
mA
mA
V
µA
Ω
mA
(8,
9)
D
EOC
Logic–Low Voltage
D
EOC
Leakage Current
D
EOC
On Resistance
R
EOC
Maximum Current Limit
0.5
37
800
1.0
46
950
Analog Charge Indicator (ACHG) Output
I
SOURCE
Notes:
8. Output current I
EOC
when digital end-of-charge output goes high impedance. Currents greater than I
EOC
, the DEOC output is low, currents lower than
I
EOC
, DEOC is high impedance.
9. I
EOC
= (0.2V/R
EOC
) × 1000.
10. I
SOURCE
is the current output from ACHG pin. A resistor to ground from the ACHG pin will program a voltage that is proportional to the output current.
(10)
µA
September 23, 2013
4
Revision 2.1
Micrel, Inc.
MIC79110
Block Diagram
September 23, 2013
5
Revision 2.1
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