Semiconductor Components Industries, LLC, 2005
June, 2005 - Rev. 0
1
Publication Order Number:
NCP1835B/D
NCP1835B
Integrated Li-Ion Charger
NCP1835B is an integrated linear charger specifically designed to
charge 1-cell Li-Ion batteries with a constant current, constant
voltage (CCCV) profile.
Its low input voltage capability, adjustable charge current, ability
to maintain regulation without a battery, and its onboard thermal
foldback make it versatile enough to charge from a variety of wall
adapters. The NCP1835B can charge from a standard wall adapter or
from the USB port. It has been optimized to charge low capacity
batteries such as those found in wireless headsets and flash
memory-based MP3 players. It's recommended charge current rate
is 30-300 mA.
Features
Integrated Voltage and Current Regulation
No External MOSFET, Sense Resistor or Blocking Diode Required
Charge Current Thermal Foldback
Integrated Pre-charge Current for Conditioning a Deeply
Discharged Battery
Integrated End-of-Charge (EOC) Detection
1% Voltage Regulation
4.2 V Regulated Output Voltage
Regulation Maintained without a Battery Present
Programmable Full Charge Current
Open-Drain Charger Status and Fault Alert Flags
2.8 V Output for AC Present Indication and Powering Charging
Subsystems
Minimum Input Voltage of 2.4 V Allows Use of Current Limited
Adapters
Automatically Recharging if Battery Voltage Drops after Charging
Cycle is Completed
Low Profile 3x3 mm DFN Package
Pb-Free Package is Available
Typical Applications
Wireless Headsets
MP3 Players
USB Appliances
Battery Operated Devices
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1835B = Device Code
A
= Assembly Location
L
= Wafer Lot
Y
= Year
W
= Work Week
1
1
1835B
ALYW
DFN 3x3
MN SUFFIX
CASE 485C
MARKING
DIAGRAM
PIN CONNECTIONS
(Top View)
V
CC
BAT
FAULT
CFLG
GND
VSNS
ISEL
EN
TIMER
V2P8
1
2
3
4
5
10
9
8
7
6
DFN 3x3
Device
Package
Shipping
ORDERING INFORMATION
NCP1835BMNR2
DFN-10
3000 Units/Reel
For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specification
Brochure, BRD8011/D.
NCP1835BMNR2G
DFN-10
(Pb-Free)
3000 Units/Reel
NCP1835B
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2
FAULT
V
CC
CFLG
V2P8
EN
VSNS
BAT
GND
ISEL TIMER
NCP1835B
V
in
1.6 M
R
ISEL
4.7
m
F
C
in
GND
15 nF
C
T
Microprocessor
4.7
m
F
C
out
Figure 1. Typical 50 mA Application Circuit
V
in
0.1
m
F
C
2p8
PIN FUNCTION DESCRIPTION
Pin
Symbol
Description
1
V
CC
Input Supply Voltage. Provides power to the charger. This pin should be bypassed with at least a 4.7
m
F ceramic
capacitor to ground.
2
FAULT
An open-drain output indicating fault status. This pin is pulled LOW under any fault conditions. A FAULT condition
resets the counter.
3
CFLG
An open-drain output indicating charging or end-of-charge states. The CFLG pin is pulled LOW when the
charger is charging a battery. It is forced open when the charge current drops to I
EOC
. This high impedance mode
will be latched until a recharge cycle or a new charge cycle starts.
4
TIMER
Connecting a timing capacitor, C
TIME
between this pin and ground to set end-of-charge timeout timer.
TIMEOUT = 14*C
TIME
/1.0 nF (minute). The total charge for CC and CV mode is limited to the length of
TIMEOUT. Trickle Charge has a time limit of 1/8 of the TIMEOUT period.
5
GND
Ground pin of the IC. For thermal consideration, it is recommended to solder the exposed metal pad on the
backside of the package to ground.
6
EN
Enable logic input. Connect the EN pin to LOW to disable the charger or leave it floating to enable the charger.
7
V2P8
2.8 V reference voltage output. This pin outputs a 2.8 V voltage source when an adapter is present. The
maximum loading for this pin is 2.0 mA.
8
ISEL
The full charge current (I
FCHG
) can be set by connecting a resistor, R
ISEL
, from the ISEL pin to ground.
For best accuracy, a resistor with 1% tolerance is recommended.
9
VSNS
Battery voltage sense pin. Connect this as close as possible to the battery input connection.
10
BAT
Charge current output. A minimum 4.7
m
F capacitor is needed for stability when the battery is not attached.
NCP1835B
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3
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Supply Voltage
V
CC
7.0
V
Status Flag Output Pins
V
FAULT
, V
CFLG
7.0
V
Voltage Range for Other Pins
V
io
5.5
V
Current Out from BAT Pin
I
O
1.2
A
Thermal Characteristics
Thermal Resistance, Junction-to-Air (Note 3)
Power Dissipation, T
A
= 25
C (Note 3)
R
q
JA
P
D
68.5
1.09
C/W
W
Moisture Sensitivity (Note 4)
MSL
Level 1
Operating Ambient Temperature
T
A
-20 to 70
C
Storage Temperature
T
stg
-55 to 125
C
ESD
Human Body Model
Machine Model
HBM
MM
2000
200
V
V
Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit values
(not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied, damage
may occur and reliability may be affected.
1. This device series contains ESD protection and is tested per the following standards:
Human Body Model (HBM) per JEDEC standard: JESD22-A114.
Machine Model (MM) per JEDEC standard: JESD22-A115.
2. Latchup Current Maximum Rating: 150 mA per JEDEC standard: JESD78.
3. Measure on 1 inch sq. of 1 oz. copper area. R
q
JA
is highly dependent on the PCB heatsink area. For example, R
q
JA
can be 38
C/W on 1 inch
sq. of 1 oz. copper area on 4 layer PCB that has 1 single signal layer with the additional 3 solid ground or power planes. The maximum package
power dissipation limit must not be exceeded:
PD
+
TJ(max)
*
TA
R
q
JA
with R
q
JA
= 68.5
C/W, T
J(max)
= 100
C, P
D
= 1.09 W.
4. Moisture Sensitivity Level per IPC/JEDEC standard: J-STD-020A.
NCP1835B
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4
ELECTRICAL CHARACTERISTICS
(Typical values are tested at V
CC
= 5.0 V and room temperature, maximum and minimum values
are guaranteed over 0
C to 70
C with a supply voltage in the range of 4.3 V to 6.5 V, unless otherwise noted.)
Characteristic
Symbol
Min
Typ
Max
Unit
V
CC
SUPPLY
Operating Supply Range
V
CC
2.8
-
6.5
V
Rising V
CC
Threshold
V
RISE
3.0
3.4
3.95
V
Falling V
CC
Lockout Threshold
V
FALL
2.0
2.4
2.8
V
Quiescent V
CC
Pin Supply Current
Shutdown (EN = Low)
Normal Operation (EN = High)
I
VCC
I
VCC
-
-
30
600
-
-
m
A
m
A
Battery Drain Current
Manual Shutdown (V
CC
= 5.0 V, VSNS = 4.0 V, EN = Low)
I
BMS
-
-
3.0
m
A
CHARGING PERFORMANCE
Regulated Output Voltage in Constant Voltage (CV) Mode, I
CHG
= 10 mA
V
REG
4.158
4.200
4.242
V
Dropout Voltage (V
BAT
= 3.7 V, I
CHG
= 0.1 A)
-
-
80
120
mV
Pre-Charge Threshold Voltage
V
PC
2.52
2.8
3.08
V
Pre-Charge Current (R
ISEL
= 2.7 M
W
, V
BAT
= 2.0 V)
I
PC
1.0
20
30
mA
Pre-Charge Current (R
ISEL
= 270 k
W
, V
BAT
= 2.0 V)
I
PC
30
50
65
mA
Recommended Full Charge Current
I
FCHG
30
-
300
mA
Full-Charge Current in Constant Current (CC) Mode (R
ISEL
= 2.7 M
W
, V
BAT
= 3.7 V)
I
FCHG
30
45
58
mA
Full-Charge Current in Constant Current (CC) Mode (R
ISEL
= 270 k
W
, V
BAT
= 3.7 V)
I
FCHG
280
310
360
mA
End-of-Charge Threshold (R
ISEL
= 2.7 M
W
, V
BAT
= V
REG
)
I
EOC
1.0
4.0
11
mA
End-of-Charge Threshold (R
ISEL
= 270 k
W
, V
BAT
= V
REG
)
I
EOC
26
34
42
mA
Recharge Voltage Threshold
V
RECH
3.80
4.03
4.155
V
Thermal Foldback Limit (Junction Temperature) (Note 5)
T
LIM
-
100
-
C
OSCILLATOR
Oscillation Period (C
TIME
= 15 nF)
T
OSC
2.4
3.0
3.6
ms
STATUS FLAGS
CFLG Pin Recommended Maximum Operating Voltage
V
CFLG
-
-
6.5
V
FAULT Pin Recommended Maximum Operating Voltage
V
FAULT
-
-
6.5
V
CFLG Pin Sink Current (V
CFLG
= 0.8 V)
I
CFLG
5.0
-
-
mA
FAULT Pin Sink Current (V
FAULT
= 0.8 V)
I
FAULT
5.0
-
-
mA
5. Guaranteed by design. Not tested in production.
NCP1835B
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5
TYPICAL OPERATING CHARACTERISTICS
4.5
5.0
5.5
6.0
6.5
V
CC
, INPUT VOLTAGE (V)
V
2P8
, V2P8 VOL
T
AGE (V)
3.00
2.95
2.90
2.85
2.80
2.75
2.70
0
0.06
0.12
0.18
0.24
0.3
I
CHG
, CHARGE CURRENT (A)
V
RE
G
, REGULA
TED OUTPUT VOL
T
AGE (V)
4.30
4.25
4.20
4.15
4.10
4.05
4.00
Figure 2. Regulated Output Voltage vs. Charge
Current
Figure 3. Regulated Output Voltage (floating) vs.
Input Voltage
Figure 4. Regulated Output Voltage vs.
Temperature
Figure 5. ISEL Voltage vs. Input Voltage
Figure 6. V2P8 Voltage vs. Input Voltage
4.5
5
5.5
6
6.5
V
CC
, INPUT VOLTAGE (V)
V
RE
G
, REGULA
TED OUTPUT VOL
T
AGE (V)
4.30
4.25
4.20
4.15
4.10
4.05
4.00
-50
-25
0
25
50
75
T
A
, AMBIENT TEMPERATURE (
C)
V
RE
G
, REGULA
TED OUTPUT VOL
T
AGE (V)
4.30
4.25
4.20
4.15
4.10
4.05
4.00
V
CC
= 5 V
V
BAT
floating
100
125
V
CC
= 5 V
4.5
5.0
5.5
6.0
6.5
V
CC
, INPUT VOLTAGE (V)
V
I
SEL
, ISEL VOL
T
AGE (V)
0.78
0.76
0.74
0.72
0.70
0.80
V
BAT
= 3.7 V
V
BAT
floating
R
ISEL
= 270 k
I
V2P8
= 0
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