![background image](/sites/default/files/pdfhtml_microchip/21704B001.png)
©
2007 Microchip Technology Inc.
DS21704B-page 1
MCP73827
Features
• Linear Charge Management Controller for Single
Lithium-Ion Cells
• High Accuracy Preset Voltage Regulation:
+ 1% (max)
• Two Preset Voltage Regulation Options:
- 4.1V - MCP73827-4.1
- 4.2V - MCP73827-4.2
• Programmable Charge Current
• Automatic Cell Preconditioning of Deeply
Depleted Cells, Minimizing Heat Dissipation Dur-
ing Initial Charge Cycle
• Charge Status Output for LED Drive or Microcon-
troller Interface
• Charge Current Monitor Output
• Automatic Power-Down when Input Power
Removed
• Temperature Range: -20°C to +85°C
• Packaging: 8-Pin MSOP
Applications
• Single Cell Lithium-Ion Battery Chargers
• Personal Data Assistants
• Cellular Telephones
• Hand Held Instruments
• Cradle Chargers
• Digital Cameras
Typical Application Circuit
Description
The MCP73827 is a linear charge management con-
troller for use in space-limited, cost sensitive applica-
tions. The MCP73827 combines high accuracy
constant voltage, controlled current regulation, cell pre-
conditioning, and charge status indication in a space
saving 8-pin MSOP package. The MCP73827 provides
a stand-alone charge management solution.
The MCP73827 charges the battery in three phases:
preconditioning, controlled current, and constant volt-
age. If the battery voltage is below the internal low-volt-
age threshold, the battery is preconditioned with a
foldback current. The preconditioning phase protects
the lithium-ion cell and minimizes heat dissipation.
Following the preconditioning phase, the MCP73827
enters the controlled current phase. The MCP73827
allows for design flexibility with a programmable charge
current set by an external sense resistor. The charge
current is ramped up, based on the cell voltage, from
the foldback current to the peak charge current estab-
lished by the sense resistor. This phase is maintained
until the battery reaches the charge-regulation voltage.
Then, the MCP73827 enters the final phase, constant
voltage. The accuracy of the voltage regulation is better
than +1% over the entire operating temperature range
and supply voltage range. The MCP73827-4.1 is preset
to a regulation voltage of 4.1V, while the
MCP73827-4.2 is preset to 4.2V. The charge status
output, MODE, indicates when the charge cycle has
transitioned to constant voltage mode. The charge
cycle can be terminated by a timer that is started when
the MODE pin goes to a logic High or by monitoring the
charge current monitor output, I
MON
, for a minimum
current.
The MCP73827 operates with an input voltage range
from 4.5V to 5.5V. The MCP73827 is fully specified
over the ambient temperature range of -20°C to +85°C.
Package Type
1
2
5
7
8
MCP73827
6
MODE
332
Ω
4
I
MON
3
+
-
GND
V
DRV
V
SNS
V
IN
V
BAT
SHDN
10 µF
100 k
Ω
100 m
Ω
V
IN
Single
Lithium-Ion
Cell
NDS8434
MA2Q705
500 mA Lithium-Ion Battery Charger
5V
10 µF
MSOP
V
DRV
V
SNS
V
IN
V
BAT
SHDN 1
2
3
4
8
7
MCP73827
5
6
MODE
I
MON
GND
Single Cell Lithium-Ion Charge Management Controller
with Mode Indicator and Charge Current Monitor
![background image](/sites/default/files/pdfhtml_microchip/21704B002.png)
MCP73827
DS21704B-page 2
©
2007 Microchip Technology Inc.
Functional Block Diagram
+
-
MO
D
E
CO
MP
A
R
A
T
O
R
MO
DE
I
MO
N
+
–
CH
A
R
G
E
CURRE
NT
MO
NI
TO
R A
M
P
L
IF
IE
R
138
k
Ω
100
k
Ω
VO
L
T
AG
E C
O
N
T
R
O
L
AM
PLI
F
IE
R
S
HUT
DO
W
N
,
RE
F
E
RE
NCE
G
E
NE
RA
T
O
R
V
RE
F
(
1
.2
V
)
+
–
V
RE
F
V
IN
CHA
RG
E
CURRE
NT
CO
NTRO
L A
M
P
L
IF
IE
R
+
–
V
RE
F
S
HDN
V
BA
T
GN
D
V
DRV
+
–
CHA
RG
E
CURRE
NT
AM
PLI
F
IE
R
V
IN
V
SN
S
1.1
k
Ω
12
k
Ω
50
0
k
Ω
75
k
Ω
75
k
Ω
35
2.
5
k
Ω
(N
O
T
E
1
)
CHA
RG
E
CURRE
NT
F
O
LD
BAC
K AM
PLI
F
IE
R
+
–
37
.5
k
Ω
11
2
.5
k
Ω
V
IN
0.3
V
CL
A
M
P
N
OT
E 1
:
V
a
lu
e =
340
.5
K
Ω
f
o
r MCP738
27-
4.
1
V
a
lu
e
=
35
2.5
K
Ω
fo
r M
C
P
7
3
8
2
7
-4
.2
![background image](/sites/default/files/pdfhtml_microchip/21704B003.png)
©
2007 Microchip Technology Inc.
DS21704B-page 3
MCP73827
1.0
ELECTRICAL
CHARACTERISTICS
1.1
Maximum Ratings*
V
IN
...................................................................... -0.3V to 6.0V
All inputs and outputs w.r.t. GND ................-0.3 to (V
IN
+0.3)V
Current at MODE Pin .............................................. +/-30 mA
Current at V
DRV
.......................................................... +/-1 mA
Maximum Junction Temperature, T
J
.............................. 150°C
Storage temperature .....................................-65°C to +150°C
ESD protection on all pins
..................................................≥
4 kV
*Notice: Stresses above those listed under “Maximum
Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of
the device at those or any other conditions above those
indicated in the operational listings of this specification
is not implied. Exposure to maximum rating conditions
for extended periods may affect device reliability.
PIN FUNCTION TABLE
DC CHARACTERISTICS: MCP73827-4.1, MCP73827-4.2
Pin
Name
Description
1
SHDN
Logic Shutdown
2
GND
Battery Management
0V Reference
3
MODE
Charge Status Output
4
I
MON
Charge Current Monitor
5
V
BAT
Cell Voltage Monitor Input
6
V
DRV
Drive Output
7
V
SNS
Charge Current Sense Input
8
V
IN
Battery Management
Input Supply
Unless otherwise specified, all limits apply for V
IN
= [V
REG
(typ)+1V], R
SENSE
= 500 m
Ω,
T
A
= -20°C to +85°C.
Typical values are at +25°C. Refer to Figure 1-1 for test circuit.
Parameter
Sym
Min
Typ
Max
Units
Conditions
Supply Voltage
V
IN
4.5
—
5.5
V
Supply Current
I
IN
—
—
0.5
250
15
560
µA
Shutdown, V
SHDN
= 0V
Constant Voltage Mode
Voltage Regulation (Constant Voltage Mode)
Regulated Output Voltage
V
REG
4.059
4.158
4.1
4.2
4.141
4.242
V
V
MCP73827-4.1 only
MCP73827-4.2 only
Line Regulation
Δ
V
BAT
-10
—
10
mV
V
IN
= 4.5V to 5.5V,
I
OUT
= 75 mA
Load Regulation
Δ
V
BAT
-1
+0.1
1
mV
I
OUT
=10 mA to 75 mA
Output Reverse Leakage Current
I
LK
—
8
—
µA
V
IN
=Floating, V
BAT
=V
REG
External MOSFET Gate Drive
Gate Drive Current
I
DRV
—
0.08
—
—
1
—
mA
mA
Sink, CV Mode
Source, CV Mode
Gate Drive Minimum Voltage
V
DRV
—
1.6
—
V
Current Regulation (Controlled Current Mode)
Current Sense Gain
A
CS
—
100
—
dB
Δ
(V
SNS
-V
DRV
) /
Δ
V
BAT
Current Limit Threshold
V
CS
40
53
75
mV
(V
IN
-V
SNS
) at I
OUT
Foldback Current Scale Factor
K
—
0.43
—
A/A
Charge Status Indicator - MODE
Threshold Voltage
V
TH
—
V
REG
—
V
Low Output Voltage
V
OL
—
—
400
mV
I
SINK
= 10 mA
Leakage Current
I
LK
—
—
1
µA
I
SINK
=0 mA, V
MODE
=5.5V
Shutdown Input - SHDN
Input High Voltage Level
V
IH
40
—
—
%V
IN
Input Low Voltage Level
V
IL
—
—
25
%V
IN
Input Leakage Current
I
LK
—
—
1
µA
V
SHDN
=0V to 5.5V
Charge Current Monitor - I
MON
Charge Current Monitor Gain
A
IMON
—
26
—
V/V
Δ
V
IMON
/
Δ
(V
IN
-V
SNS
)
![background image](/sites/default/files/pdfhtml_microchip/21704B004.png)
MCP73827
DS21704B-page 4
©
2007 Microchip Technology Inc.
TEMPERATURE SPECIFICATIONS
FIGURE 1-1:
MCP73827 Test Circuit.
Unless otherwise specified, all limits apply for V
IN
= 4.5V-5.5V
Parameters
Symbol
Min
Typ
Max
Units
Conditions
Temperature Ranges
Specified Temperature Range
T
A
-20
—
+85
°C
Operating Temperature Range
T
A
-40
—
+125
°C
Storage Temperature Range
T
A
-65
—
+150
°C
Package Thermal Resistance
Thermal Resistance, 8L-MSOP
θ
JA
—
206
—
°C/W
Single Layer SEMI G42-88
Standard Board, Natural
Convection
GND
V
DRV
V
SNS
V
IN
V
BAT
SHDN
1
2
5
7
8
6
22 µF
22 µF
100 k
Ω
R
SENSE
V
IN
= 5.1V
NDS8434
I
OUT
V
OUT
(MCP73827-4.1)
V
IN
= 5.2V
(MCP73827-4.2)
MCP73827
MODE
3
4
I
MON
100 k
Ω
![background image](/sites/default/files/pdfhtml_microchip/21704B005.png)
©
2007 Microchip Technology Inc.
DS21704B-page 5
MCP73827
2.0
TYPICAL PERFORMANCE CHARACTERISTICS
Note: Unless otherwise indicated, I
OUT
= 10 mA, Constant Voltage Mode, T
A
= 25°C. Refer to Figure 1-1 for test circuit.
FIGURE 2-1:
Output Voltage vs. Output Current
(MCP73827-4.2).
FIGURE 2-2:
Output Voltage vs. Input Voltage
(MCP73827-4.2)
FIGURE 2-3:
Output Voltage vs. Input Voltage
(MCP73827-4.2)
FIGURE 2-4:
Supply Current vs. Output Current.
FIGURE 2-5:
Supply Current vs. Input Voltage.
FIGURE 2-6:
Supply Current vs. Input Voltage.
Note:
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
4.195
4.196
4.197
4.198
4.199
4.200
4.201
4.202
4.203
4.204
4.205
0
200
400
600
800
1000
Output Current (mA)
O
u
tp
u
t Vo
lt
ag
e (
V
)
4.195
4.196
4.197
4.198
4.199
4.200
4.201
4.202
4.203
4.204
4.205
4.5
4.6
4.7
4.8
4.9
5.0
5.1
5.2
5.3
5.4
5.5
Input Voltage (V)
O
u
tp
u
t Vo
lt
ag
e (
V
)
I
OUT
= 1000 mA
4.195
4.196
4.197
4.198
4.199
4.200
4.201
4.202
4.203
4.204
4.205
4.5
4.6
4.7
4.8
4.9
5.0
5.1
5.2
5.3
5.4
5.5
Input Voltage (V)
O
u
tp
u
t Vo
lt
ag
e (
V
)
I
OUT
= 10 mA
200
220
240
260
280
300
0
200
400
600
800
1000
Output Current (mA)
S
uppl
y
Cur
re
nt (
μ
A)
200
220
240
260
280
300
4.5
4.6
4.7
4.8
4.9
5.0
5.1
5.2
5.3
5.4
5.5
Input Voltage (V)
S
uppl
y
Cur
re
nt (
μ
A)
I
OUT
= 1000 mA
200
220
240
260
280
300
4.5
4.6
4.7
4.8
4.9
5.0
5.1
5.2
5.3
5.4
5.5
Input Voltage (V)
S
uppl
y
Cur
re
nt (
μ
A)
I
OUT
= 10 mA
![background image](/sites/default/files/pdfhtml_microchip/21704B006.png)
MCP73827
DS21704B-page 6
©
2007 Microchip Technology Inc.
Note: Unless otherwise indicated, I
OUT
= 10 mA, Constant Voltage Mode, T
A
= 25°C. Refer to Figure 1-1 for test circuit.
FIGURE 2-7:
Output Reverse Leakage Current vs.
Output Voltage.
FIGURE 2-8:
Output Reverse Leakage Current vs.
Output Voltage.
FIGURE 2-9:
Current Limit Foldback.
FIGURE 2-10: Supply Current vs. Temperature.
FIGURE 2-11: Output Voltage vs. Temperature
(MCP73827-4.2).
FIGURE 2-12: Power-Up / Power-Down.
0
2
4
6
8
10
12
2.0
2.5
3.0
3.5
4.0
4.5
Output Voltage (V)
O
u
tp
u
t R
ever
se L
eakag
e C
u
rr
e
n
t (
μ
A)
85
o
C
25
o
C
-20
o
C
V
IN
= Floating
V
SHDN
= V
OUT
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
2.0
2.5
3.0
3.5
4.0
4.5
Output Voltage (V)
O
u
tp
u
t R
ever
se L
eakag
e C
u
rr
e
n
t (
μ
A)
85
o
C
25
o
C
-20
o
C
V
IN
= Floating
V
SHDN
= GND
0.000
0.500
1.000
1.500
2.000
2.500
3.000
3.500
4.000
4.500
0
20
40
60
80
100
120
Output Current (mA)
O
u
tp
u
t Vo
lt
ag
e (
V
)
150
175
200
225
250
275
300
-20
-10
0
10
20
30
40
50
60
70
80
Temperature (
o
C)
S
uppl
y
Cur
re
nt (
μ
A)
4.190
4.192
4.194
4.196
4.198
4.200
4.202
4.204
4.206
-20
-10
0
10
20
30
40
50
60
70
80
Temperature (
o
C)
O
u
tp
u
t Vo
lt
ag
e (
V
)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0
1
2
3
4
5
6
7
8
9
10
Input Voltage (V)
O
u
tp
u
t Vo
lt
ag
e (
V
)
Power Up
Power Down
4
3
2
1
0
![background image](/sites/default/files/pdfhtml_microchip/21704B007.png)
©
2007 Microchip Technology Inc.
DS21704B-page 7
MCP73827
Note: Unless otherwise indicated, I
OUT
= 10 mA, Constant Voltage Mode, T
A
= 25°C. Refer to Figure 1-1 for test circuit.
FIGURE 2-13: Line Transient Response.
FIGURE 2-14: Line Transient Response.
FIGURE 2-15: Load Transient Response.
FIGURE 2-16: Load Transient Response.
![background image](/sites/default/files/pdfhtml_microchip/21704B008.png)
MCP73827
DS21704B-page 8
©
2007 Microchip Technology Inc.
3.0
PIN DESCRIPTION
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
Pin Function Table.
3.1
Logic Shutdown (SHDN)
Input to force charge termination, initiate charge, or ini-
tiate recharge.
3.2
Battery Management 0V Reference
(GND)
Connect to negative terminal of battery.
3.3
Charge Status Output (MODE)
Open-drain drive for connection to an LED for charge
status indication. Alternatively, a pull-up resistor can be
applied for interfacing to a microcontroller. A low
impedance state indicates foldback current limit or con-
trolled current phase. A high impedance indicates con-
stant voltage phase or battery cell disconnected.
3.4
Charge Current Monitor (I
MON
)
Amplified output of the voltage difference between V
IN
and V
SNS
. A host microcontroller can monitor this out-
put with an A/D converter.
3.5
Cell Voltage Monitor Input (V
BAT
)
Voltage sense input. Connect to positive terminal of
battery. Bypass to GND with a minimum of 10 µF to
ensure loop stability when the battery is disconnected.
A precision internal resistor divider regulates the final
voltage on this pin to VREG.
3.6
Drive Output (V
DRV
)
Direct output drive of an external P-channel MOSFET
pass transistor for current and voltage regulation.
3.7
Charge Current Sense Input (V
SNS
)
Charge current is sensed via the voltage developed
across an external precision sense resistor. The sense
resistor must be placed between the supply voltage
(V
IN
) and the source of the external pass transistor. A
50 m
Ω
sense resistor produces a fast charge current of
1 A, typically.
3.8
Battery Management Input Supply
(V
IN
)
A supply voltage of 4.5V to 5.5V is recommended.
Bypass to GND with a minimum of 10 µF.
Pin
Name
Description
1
SHDN
Logic Shutdown
2
GND
Battery Management
0V Reference
3
MODE
Charge Status Output
4
I
MON
Charge Current Monitor
5
V
BAT
Cell Voltage Monitor Input
6
V
DRV
Drive Output
7
V
SNS
Charge Current Sense Input
8
V
IN
Battery Management
Input Supply
![background image](/sites/default/files/pdfhtml_microchip/21704B009.png)
©
2007 Microchip Technology Inc.
DS21704B-page 9
MCP73827
4.0
DEVICE OVERVIEW
The MCP73827 is a linear charge management con-
troller. Refer to the functional block diagram on page 2
and the typical application circuit, Figure 6-1.
4.1
Charge Qualification and
Preconditioning
Upon insertion of a battery or application of an external
supply, the MCP73827 verifies the state of the SHDN
pin. The SHDN pin must be above the logic High level.
If the SHDN pin is above the logic High level, the
MCP73827 initiates a charge cycle. The charge status
output, MODE, is pulled low throughout throughout the
preconditioning and controlled current phases (see
Table 5-1 for charge status outputs). If the cell is below
the preconditioning threshold, 2.4V typically, the
MCP73827 preconditions the cell with a scaled back
current. The preconditioning current is set to approxi-
mately 43% of the fast charge peak current. The pre-
conditioning safely replenishes deeply depleted cells
and minimizes heat dissipation in the external pass
transistor during the initial charge cycle.
4.2
Controlled Current Regulation - Fast
Charge
Preconditioning ends and fast charging begins when
the cell voltage exceeds the preconditioning threshold.
Fast charge utilizes a foldback current scheme based
on the voltage at the V
SNS
input developed by the drop
across an external sense resistor, R
SENSE
, and the out-
put voltage, V
BAT
. Fast charge continues until the cell
voltage reaches the regulation voltage, V
REG
.
4.3
Constant Voltage Regulation
When the cell voltage reaches the regulation voltage,
V
REG
, constant voltage regulation begins. The
MCP73827 monitors the cell voltage at the V
BAT
pin.
This input is tied directly to the positive terminal of the
battery. The MCP73827 is offered in two fixed-voltage
versions for battery packs with either coke or graphite
anodes: 4.1V (MCP73827-4.1) and 4.2V
(MCP73827-4.2).
4.4
Charge Cycle Completion
The charge cycle can be terminated by a host micro-
controller when the output of the charge current moni-
tor, I
MON
, has diminished below approximately 10% of
the peak output voltage level. Alternatively, the transi-
tion of the charge status output, MODE, can be used to
initialize a timer to terminate the charge. The charge is
terminated by pulling the shutdown pin, SHDN, to a
logic Low Level.
![background image](/sites/default/files/pdfhtml_microchip/21704B010.png)
MCP73827
DS21704B-page 10
©
2007 Microchip Technology Inc.
5.0
DETAILED DESCRIPTION
Refer to the typical application circuit, Figure 6-1.
5.1
Analog Circuitry
5.1.1
CHARGE CURRENT MONITOR (I
MON
)
The I
MON
pin provides an output voltage that is propor-
tional to the battery charging current. It is an amplified
version of the sense resistor voltage drop that the cur-
rent loop uses to control the external P-channel pass
transistor. This voltage signal can be applied to the
input of an A/D Converter and used by a host microcon-
troller to display information about the state of the bat-
tery or charge current profile.
5.1.2
CELL VOLTAGE MONITORED INPUT
(V
BAT
)
The MCP73827 monitors the cell voltage at the V
BAT
pin. This input is tied directly to the positive terminal of
the battery. The MCP73827 is offered in two fixed-volt-
age versions for single cells with either coke or graphite
anodes: 4.1V (MCP73827-4.1) and 4.2V
(MCP73827-4.2).
5.1.3
GATE DRIVE OUTPUT (V
DRV
)
The MCP73827 controls the gate drive to an external
P-channel MOSFET, Q1. The P-channel MOSFET is
controlled in the linear region, regulating current and
voltage supplied to the cell. The drive output is auto-
matically turned off when the input supply falls below
the voltage sensed on the V
BAT
input.
5.1.4
CURRENT SENSE INPUT (V
SNS
)
Fast charge current regulation is maintained by the
voltage drop developed across an external sense resis-
tor, R
SENSE
, applied to the V
SNS
input pin. The follow-
ing formula calculates the value for R
SENSE
:
Where:
V
CS
is the current limit threshold
I
OUT
is the desired peak fast charge current in
amps. The preconditioning current is scaled to
approximately 43% of I
PEAK
.
5.1.5
SUPPLY VOLTAGE (V
IN
)
The V
IN
input is the input supply to the MCP73827. The
MCP73827 automatically enters a power-down mode if
the voltage on the V
IN
input falls below the voltage on
the V
BAT
pin. This feature prevents draining the battery
pack when the V
IN
supply is not present.
5.2
Digital Circuitry
5.2.1
SHUTDOWN INPUT (SHDN)
The shutdown input pin, SHDN, can be used to termi-
nate a charge anytime during the charge cycle, initiate
a charge cycle, or initiate a recharge cycle.
Applying a logic High input signal to the SHDN pin, or
tying it to the input source, enables the device. Apply-
ing a logic Low input signal disables the device and ter-
minates a charge cycle. In shutdown mode, the
device’s supply current is reduced to 0.5 µA, typically.
5.2.2
CHARGE STATUS OUTPUT (MODE)
A charge status output, MODE, provides information on
the state of charge. The open drain output can be used
to illuminate an external LED. Optionally, a pull-up
resistor can be used on the output for communication
with a microcontroller. Table 5-1 summarizes the state
of the charge status output during a charge cycle.
TABLE 5-1:
Charge Status Output.
R
SENSE
V
CS
I
OUT
------------
=
Charge Cycle State
Mode
Qualification
OFF
Preconditioning
ON
Controlled Current Fast Charge
ON
Constant Voltage
OFF
Disabled - Sleep mode
OFF
Battery Disconnected
OFF