HX1001
HX6001
Standalone Linear Li-Ion Battery Charger
with Thermal Regulation
Features
Description
Programmable Charge Current up to
The HX6001 is a complete constant-current/
700mA
constant-voltage linear charger for single cell
No MOSFET, Sense Resistor or Blocking
lithium-ion batteries. Its package and low
Diode Required
external component count make the HX6001
Constant-Current/Constant-Voltage
ideally
Operation with Thermal Regulation
Furthermore,
to
designed
Maximize Charge Rate
suited
to
for
the
portable
HX6001
work
within
applications.
is
specifically
USB
power
specifications.
Charges Single Cell Li-Ion Batteries
Directly from USB Port
No external sense resistor is needed, and no
Preset 4.2V Charge Voltage with 1%
blocking diode is required due to the internal
Accuracy
MOSFET architecture. The charge voltage is
Automatic Recharge
2.9V Trickle Charge Threshold
Available in 5-Lead SOT-23 Package
fixed at 4.2V, and the charge current can be
programmed externally with a single resistor.
The HX6001 automatically terminates the
charge cycle when the charge current drops to
1/10th the programmed value after the final float
Applications
voltage is reached.
Charger for Li-Ion Coin Cell Batteries
The HX6001 converters are available in the
Portable MP3 Players, Wireless Headsets
industry standard SOT-23-5L power packages
Bluetooth Applications
(or upon request).
Multifunction Wristwatches
Order Information
HX6001- ① ②:
SYMBOL
①
②
DESCRIPTION
Denotes Output Voltage:
N: 4.2V
Denotes Package Type:
E: SOT-23-5L
w w w. h x s e m i . c o m
1
HX6001
Typical Application Circuit
DC+
4
VCC
BAT
VOUT
Battery
3
4.5V ~ 6.5V
1
CIN
10µF
R1 300Ω
CHRG PROG
GND
2
5
RSET
COUT
10µF
* IBAT = (VPROG/RSET) • 900.
* When charging in constant-current mode, the VPROG is usually 1V.
Pin Assignment and Description
PIN
NAME
DESCRIPTION
1
CHRG
Open-Drain Charge Status Output
2
GND
Ground
3
BAT
Charge Current Output
4
VCC
Positive Input Supply Voltage
5
PROG
Charge Current Program
Absolute Maximum Ratings (Note 1)
Input Supply Voltage (VCC) ........................................................................................... -0.3V ~ 7V
PROG.............................................................................................................. -0.3V ~ VCC + 0.3V
BAT, CHRG.................................................................................................................... -0.3V ~ 7V
BAT Pin Current ..................................................................................................................... 800mA
Maximum Junction Temperature............................................................................................. +150℃
Operating Ambient Temperature Range (Note 2)......................................................-40℃ ~ +85℃
Storage Temperature Range …………………………………………….................. -65℃ ~ +125℃
Lead Temperature (Soldering, 10 sec)................................................................................... +265℃
Note 1: Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device.
Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability.
Note 2: The HX6001 is guaranteed to meet performance specifications from 0℃ to 70℃. Specifications over the –40℃ to
85℃ operating temperature range are assured by design, characterization and correlation with statistical process
controls.
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2
HX6001
Electrical Characteristics
Operating Conditions: TA=25℃, VCC=5V, unless otherwise specified.
SYMBOL
PARAMETER
VCC
Input Supply Voltage
VOVLO
IQ
OVLO Threshold
Input Supply Current
CONDITIONS
MIN
TYP
MAX
UNITS
4.5
5.0
6.5
V
VIN Rising
6.8
V
Standby Mode (Charge Terminated)
48
μA
Shutdown Mode (RPROG
Connected, VCC < VBAT)
80
μA
Not
Battery Voltage Regulation Constant-Current Charge
VFLOAT
IBAT
Regulated
Output
(Float) Voltage
BAT Pin Current
0℃≤ TA ≤85℃
4.16
V
90
mA
RPROG = 2k, Current Mode
450
mA
-7
μA
±13
μA
Standby Mode, VBAT = 4.2V
(RPROG
Not
Sleep Mode, VCC = 0V
PROG Pin Voltage
4.24
RPROG = 10k, Current Mode
Shutdown Mode
Connected)
VPROG
4.2
RPROG = 2k, Current Mode
0.95
±0.2
±2
μA
1
1.05
V
Trickle Charge
ITRIKL
Trickle
Current
VTRIKL
ITERM
Charge
RPROG = 2k
45
mA
Trickle
Charge
Threshold Voltage
RPROG = 10k, VBAT Rising
2.9
V
C/10
Termination
Current Threshold
RPROG = 2k
45
mA
250
mV
VRECHRG Comparator (Battery Recharge Threshold)
ΔVRECHRG
Recharge
Battery
Threshold Voltage
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VFLOAT - VRECHRG
3
HX6001
Pin Functions
CHRG (Pin 1): Open-Drain Charge Status Output. When the battery is being charged, the CHRG pin is
pulled low by an internal N-channel MOSFET. When the charge cycle is completed or reverse battery
lockout / No AC is detected, CHRG is forced high impedance.
GND (Pin 2): Ground.
BAT (Pin 3): Charge Current Output. It should be bypassed with at least a 1μF capacitor. It Provides
charge current to the battery and regulates the final float voltage to 4.2V. An internal precision resistor
divider from this pin sets the float voltage which is disconnected in shutdown mode.
VCC (Pin 4): Positive Input Supply Voltage. It provides power to the charger. VCC can range from 4.5V
to 6.5V and should be bypassed with at least a 1μF capacitor.
PROG (Pin 5): Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge
current is programmed by connecting a 1% resistor, RPROG, to ground. When charging in
constant-current mode, this pin servos to 1V. In all modes, the voltage on this pin can be used to
measure the charge current using the following formula: IBAT = (VPROG/RSET) • 900.
The PROG pin can also be used to shut down the charger. Disconnecting the program resistor from
ground, the charger enters shutdown mode. Reconnecting RPROG to ground will return the charger to
normal operation.
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4
HX6001
Block Diagram
Application Information
The HX6001 is a single cell lithium-ion battery charger using a constant-current/constant-voltage
algorithm with programmable current. Charge current can be programmed to 700mA (using a good
thermal PCB layout) with a final float voltage accuracy of ±1%. The HX6001 includes an internal
P-channel power MOSFET and thermal regulation circuitry. No blocking diode or external current sense
resistor is required; thus, the basic charger circuit requires only less external components. Furthermore,
the HX6001 is capable of operating from a USB power source.
Normal Charge Cycle
A charge cycle begins when the voltage at the VCC pin rises above 4.5V and a 1% program resistor is
connected from the PROG pin to ground or when a battery is connected to the charger output.
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5
HX6001
If the BAT pin is less than 2.9V, the charger enters trickle charge mode. In this mode, the HX6001
supplies approximately 1/10 the programmed charge current to bring the battery voltage up to a safe
level for full current charging. When the BAT pin voltage rises above 2.9V, the charger goes into the fast
charge constant-current mode, where the programmed charge current is supplied to the battery. When
the BAT pin approaches the final float voltage (4.2V), the HX6001 enters constant-voltage mode and
the charge current begins to decrease. The charge cycle ends when the charge current drops to 1/10 of
the programmed value.
Charge Termination
A charge cycle is terminated when the charge current falls to 1/10th the programmed value after the
final float voltage is reached. This condition is detected by using an internal filtered comparator to
monitor the PROG pin.
When charging, transient loads on the BAT pin can cause the PROG pin to fall below 100mV for short
periods of time before the DC charge current has dropped to 1/10th the programmed value. Once the
average charge current drops below 1/10th the programmed value, the HX6001 terminates the charge
cycle and ceases to provide any current through the BAT pin. In this state, all loads on the BAT pin must
be supplied by the battery.
The HX6001 constantly monitors the BAT pin voltage in standby mode. If this voltage drops below the
recharge threshold (VRECHRG), another charge cycle begins and current is once again supplied to the
battery. To manually restart a charge cycle in standby mode, the input voltage must be removed and
reapplied, or the charger must be shut down and restarted using the PROG pin.
Shutdown Mode
The HX6001 can be shut down by floating PROG pin. In shutdown mode, the battery drain current is
reduced to 13μA and the supply current to about 80μA. A new charge cycle can be initiated by
reconnecting the program resistor. Removing the input power supply will put the charger into sleep
mode.
Automatic Recharge
Once the charge cycle terminates, the HX6001 continuously monitors the BAT pin voltage using a
comparator. When the battery voltage falls 250mV below 4.2V(which corresponds to approximately
80% to 90% battery capacity), a charge cycle will restart. This ensures that the battery is kept at or near
a fully charged condition and eliminates the need for periodic charge cycle initiations. The CHRG output
enters a strong pull down state during recharge cycles.
Programming Charge Current
The charge current is programmed using a single resistor RPROG from PROG pin to ground. The battery
charge current is 900 times the current out of the PROG pin. The RPROG and the charge current can be
calculated as following equation:
RPROG=1V/IBAT • 900, IBAT=1V/ RPROG • 900.
The charge current out of the BAT pin can be determined at any time by monitoring the PROG pin
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6
HX6001
voltage and using the following equation:
IBAT= RPROG/ RPROG • 900.
Thermal Limiting
An internal thermal feedback loop reduces the programmed charge current if the die temperature
attempts to rise above a preset value of approximately 120℃. This feature protects the HX6001 from
excessive temperature and allows the user to push the limits of the power handling capability of a given
circuit board without risk of damaging the HX6001. The charge current can be set according to typical
(not worst-case) ambient temperature with the assurance that the charger will automatically reduce the
current in worst-case conditions. Thin SOT power considerations are discussed further in the
Applications Information section.
VCC Bypass Capacitor
Many types of capacitors can be used for input bypassing, however, caution must be exercised when
using multilayer ceramic capacitors. Because of the self-resonant and high Q characteristics of some
types of ceramic capacitors, high voltage transients can be generated under some start-up conditions,
such as connecting the charger input to a live power source. Adding a 1.5W resistor in series with an
X5R ceramic capacitor will minimize start-up voltage transients.
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7
HX6001
Packaging Information
SOT-23-5L Package Outline Dimension
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
1.050
1.250
0.041
0.049
A1
0.000
0.100
0.000
0.004
A2
1.050
1.150
0.041
0.045
b
0.300
0.500
0.012
0.020
c
0.100
0.200
0.004
0.008
D
2.820
3.020
0.111
0.119
E
1.500
1.700
0.059
0.067
E1
2.650
2.950
0.104
0.116
e
0.950(BSC)
0.037(BSC)
e1
1.800
2.000
0.071
0.079
L
0.300
0.600
0.012
0.024
Subject changes without notice.
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Information furnished by Hexin Semiconductor is believed to be accurate and reliable. However, no responsibility is assumed for its use.