LX2205
®
TM
1A Li-Ion Battery Charger with Power Source Management
P RODUCTION D ATA S HEET
KEY FEATURES
DESCRIPTION
two logically selectable levels (100mA
and 500mA). When powered by a USB
input, the battery is charged with the
excess USB current that is not
consumed by the system load. If the
load exceeds the USB current limit, the
battery will discharge to assist the USB
power source to power the load. The
controller can logically suspend the
USB power to allow the system to
operate from the battery without
loading the USB.
When a wall adapter is applied, it
takes precedent over the USB power
input and disables the USB input to
prevent current flow from the adapter to
the USB port.
Single Cell Li-Ion Battery Charger
Power Source Management
Up to 1A Charging Current
Integrated Power MOSFET
USB Current Compliance
25µA Quiescent Current in
Discharge Mode
Taper Current Termination
o
o
o
o
APPLICATIONS
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
Patents Pending.
Protection features:
USB Reverse Current Blocking
Unsafe Battery Temp Lockout
Internal IC Temperature Limiter
USB Current Limiter
WWW . Microsemi .C OM
The LX2205 is a complete single
cell Lithium Ion or Lithium Polymer
battery charger and power source
manager. In addition to battery
charging, power flow control is
provided from up to three sources: a
wall adapter, a standard USB power
plug or the battery.
The battery charge current and
termination current are independently
adjustable.
The controller also
includes status indicators which show
when the controller is powered by an
external adapter in addition to charge
in progress, and charge completed.
The USB input is current limited at
Navigation Devices
Portable USB Devices
Multi-Media Player
PDA Phones
Digital Cameras
PRODUCT HIGHLIGHT
DC OK
Wall Adapter
MDC
USB Power
USB
Suspend
SUSP
High/Low
UCL
CMP
SYS
LX2205
System Load
BAT
CHG
SHDN
Shutdown
Adapter Present
Charge/
Discharge
DONE
GND
CCP
CTP
CUS TFB
Li-Ion
Thermistor
LX2205
PACKAGE ORDER INFO
TA (°C)
LQ
Plastic MLP 4 x 4mm 16 pin
RoHS Compliant / Pb-free
-40 to 85
LX2205ILQ
Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX2205ILQ-TR)
Copyright © 2007
Rev. 1.0a, 2007-03-02
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
LX2205
®
TM
1A Li-Ion Battery Charger with Power Source Management
P RODUCTION D ATA S HEET
CHG
DC OK
16
15
14
13
CMP
1
12
CTP
BAT
2
11
CCP
SYS
3
10
GND
USB
4
9
CUS
7
8
UCL
to
MDC
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect
ground. Currents are positive into, negative out of specified terminal.
6
SUSP
5
SHDN
Connect Bottom
Pad to GND
LQ PACKAGE
(Top View)
THERMAL DATA
LQ
WWW . Microsemi .C OM
Supply Voltages (MDC, SYS, USB) ................................................................ -0.3V to 7V
Battery Voltage (BAT) ..................................................................................... -0.3V to 6V
All Other Pins .............................................................................................-0.3V to VSUPPLY
USB Current .............................................................................................................600mA
BAT Discharge Current ................................................................................................1.6A
Operating Ambient Temperature Range (TA) ..............................................-45°C to 125°C
Maximum Operating Junction Temperature (TJ) ....................................................... 150°C
Storage Temperature Range.........................................................................-65°C to 150°C
Lead Temperature (Soldering 10 seconds)................................................................. 300°C
Package Peak Temp. for Solder Reflow (40 seconds maximum exposure) ... 260°C (+0 -5)
DONE
PACKAGE PIN OUT
TFB
ABSOLUTE MAXIMUM RATINGS
RoHS / Pb-free 100% Matte Tin Pin Finish
Plastic 4 x 4mm 16-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
28°C/W*
Junction Temperature Calculation: TJ = TA + (PD x θJA).
*The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the
above assume no ambient airflow. See layout guidelines section for important details.
FUNCTIONAL PIN DESCRIPTION
Pin
BAT
2
Battery Connection - This pin is wired to the positive terminal of a single cell lithium ion/polymer battery.
CCP
11
Charge Current Programming Pin - A resistor (RCCP) is connected between this pin and GND. The constant
charging current is determined by the following relationship: RCCP = 50.648 x ICCL-1.0855
with RCCP in kΩ and ICCP in amps.
CHG
14
Charge Indicator - This pin is a logic low level when the battery is being charged, provided VSYS is ≥ 4.4V. It is
capable of driving the series combination of an LED and resistor that is powered from the SYS pin.
CMP
1
Compensation – Connect a 0.1µF capacitor from CMP to SYS.
CTP
12
Charge Termination Programming Pin – A resistor (RCTP) is connected between this pin and GND. The
-1.0876
charge termination taper current is determined by the following relationship: RCTP =0.7354 x ITERM
with RCTP in kΩ and ITERM in amps.
CUS
9
USB Current Limit Programming Pin – A resistor (RCUS) is connected between this pin and GND. The high
level USB charge current is determined by the following relationship: IUSB = 1050 / RCUS.
DC OK
13
Main DC Present – A low level on this logic output indicates that the Main DC power source (typically the wall
adapter) is applied.
DONE
15
Done Indicator - This pin is a logic low level when the battery charge cycle is complete. It is capable of driving
the series combination of an LED and resistor that is powered from the SYS pin.
GND
10
Common Ground – Used as chip ground and as a reference for the battery return.
Copyright © 2007
Rev. 1.0a, 2007-03-02
Description
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
LX2205
Name
LX2205
®
TM
1A Li-Ion Battery Charger with Power Source Management
P RODUCTION D ATA S HEET
FUNCTIONAL PIN DESCRIPTION (CONTINUED)
Pin
Description
MDC
5
Main DC Input – This input is a voltage monitoring input (and not a high current input). Its purpose is to
determine the presence of the main DC input to provide lockout for the USB power input.
SHDN
6
Shutdown – Pulling this pin high will disable the entire device including the battery discharge path and place
the device in a low power sleep mode. This pin has an internal pull-down.
SUSP
7
Suspend (USB) – Pulling this pin high will prevent current from being drawn from the USB input pin. The rest
of the chip functions are unaffected. This pin has an internal pull-down.
SYS
3
System Power Node – This pin provides power to user system. SYS voltage provided will range from the
battery voltage to the wall adapter and/or USB voltage.
TFB
16
Temperature Feedback – Charging is suspended when the TFB pin falls below 29% (typ) of VSYS or rises
above 74% (typ) of VSYS. CHG and DONE pins remain in their prior state during a TFB event. Connecting the
TFB pin to GND disables the TFB function.
USB
4
USB Power Input – USB compliant input.
UCL
8
USB Current Limit – A high logic level will select the high USB current level determined by the programming of
the CUS pin. A low logic level will select a level that is 20% of the high USB current level. This pin has an
internal pull-down.
WWW . Microsemi .C OM
Name
LX2205
Copyright © 2007
Rev. 1.0a, 2007-03-02
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
LX2205
®
TM
1A Li-Ion Battery Charger with Power Source Management
P RODUCTION D ATA S HEET
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, the following specifications apply over the operating temperature -40ºC ≤ TA ≤ 85 ºC and the following test
conditions: VMDC = VUSB = 5V, VSYS =Open, VSUSP = VSHDN = Low, VUCL = High, VBAT = 3.9V, RCCP = 49.9k, RCUS = 2.26k, RCTP = 20k
`
Symbol
Min
LX2205
Typ Max
Units
MAIN CIRCUITRY
Input Voltage
VSUPPLY
Under Voltage Charging Lockout
VSYS(UVLO)
SYS UVLO Hysteresis
USB UVLO
USB Input Supply Current
Battery Drain Current
USB or SYS
4.35
Rising input; VBAT = 3.2V
3.55
Guaranteed by design
VUSB(UVLO)
SYS Input Supply Current
`
Test Conditions
ISYS
IUSB
IBAT
Rising input; VBAT = 3.2V
3.7
6
V
3.95
V
140
4.25
mV
4.30
4.34
V
VBAT = VCVL; (battery charged), VSYS = 5.0V
1.5
2.5
mA
SHDN = High (Shutdown Mode), VSYS = 5.0V
25
µA
VBAT = VCVL; (battery charged), , VMDC = 0V
2
mA
SUSP = High (Suspend Mode), , VMDC = 0V
SHDN = High (Shutdown Mode), , VMDC = 0V
25
µA
25
µA
VMDC = 0V, VUSB = 0V
-1.5
-6
µA
VBAT = VCVL; (battery charged)
0.5
10
µA
VMDC=0V; SUSP = High (Suspend Mode)
25
50
µA
SHDN = High (Shutdown Mode)
0.5
10
µA
VUSB = 0V; VMDC = 0V; Discharge with no load
25
50
µA
4.2
4.24
V
WWW . Microsemi .C OM
Parameter
BATTERY CHARGER
Constant Voltage Charge Voltage
VCVL
CTP Bias Voltage
VCTP
CCP Bias Voltage
VCCP
ICCL
Max Battery Charge Current
IBAT
Conditioning Current
ICOND
Conditioning Current Threshold
Voltage
4.16
IBAT > 100mA
VSYS = 5.0V
0.85
1.30
V
1.25
V
0.98
1.10
A
VMDC=0V
465
mA
VMDC=0V; ISYS = 200mA (out of pin)
261
mA
VMDC=0V; UCL = Low
92
mA
VBAT =2.5V, as a % of ICCL
2.5
5
7.5
%
VCCT
2.55
2.7
2.9
V
Charge Termination Current
IBAT
40
50
60
mA
Top Off Charge Droop Threshold
VDRP
96
97
98
%
Expressed as a % of VCVL
LX2205
Copyright © 2007
Rev. 1.0a, 2007-03-02
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 4
LX2205
®
TM
1A Li-Ion Battery Charger with Power Source Management
P RODUCTION D ATA S HEET
ELECTRICAL CHARACTERISTICS (CONTINUED)
Unless otherwise specified, the following specifications apply over the operating temperature -40ºC ≤ TA ≤ 85 ºC and the following test
conditions: VMDC = VUSB = 5V, VSYS =Open, VSUSP = VSHDN = Low, VUCL = High, VBAT = 3.9V, RCCP = 49.9k, RCUS = 2.26k, RCTP = 20k
`
`
Units
VMDC = 0V, UCL = Low
85
93
100
mA
USB High Current Limit
IUSB
VMDC = 0V
425
463
500
mA
Reverse Leakage Current
ILEAK
VUSB = 0V
2
10
µA
CUS Bias Voltage
VCUS
2.5
V
LOGIC
CHG , DONE Logic High Output
VOH
VSYS = 5.0V, IOH = -25uA
CHG , DONE Logic Low Output
VOL
VSYS = 5.0V, IOL = 5mA
Input Logic : UCL, SUSP, SHDN
VLOG(IN)
Input Logic Current : UCL, SUSP,
SHDN
ILOG(IN)
VLOG(OUT)
Logic Hi,
4.0
4.5
V
0.4
1.2
Logic Lo
0.4
Logic Hi, VLOG = 2V
0
2
4
Logic Lo, VLOG = 0V
-2
0
2
Logic Hi, 10K to 3.3V
3.2
Logic Lo, ILOG = 100µA
0.4
V
V
µA
V
THERMAL DIE PROTECTION
TCTL
140
°C
BI-DIRECTIONAL PASS ELEMENT CONTROL
IBAT = -1A
275
mΩ
Charging Threshold
RDS(ON)
VCHG
VSYS – VBAT
40
mV
Discharging Threshold
VDCH
VBAT – VSYS
40
mV
Charge–To–Discharge or Discharge–To–Charge
2.5
µs
Charging headroom
VSYS – VBAT, IBAT = 5mA
80
mV
Discharging headroom
VBAT – VSYS, IBAT = -20mA
80
mV
Pass Element Switch Mode Delay
tsw
MDC INPUT
VMDC
DC OK Voltage Threshold
Hysteresis
Rising
4.0
4.15
VMDC(HYS)
35
IMDC
15
MDC Input current
`
LX2205
Typ Max
IUSB
Discharge Switch On Resistance
`
Min
USB Low Current Limit
Battery Charger Thermal Limiter
`
Test Conditions
USB CURRENT LIMIT
Output Logic : DC OK
`
Symbol
WWW . Microsemi .C OM
Parameter
4.3
V
mV
35
µA
BATTERY TEMPERATURE MONITOR
VTFB(COLD)
Hot Temp Fault Threshold
VTFB(HOT)
TFB Disable Voltage Threshold
VTFB(DIS)
Copyright © 2007
Rev. 1.0a, 2007-03-02
Rising Threshold ; as % of VSYS
73
75
77
%
Falling Threshold; as % of VSYS
71
73
75
%
Falling Threshold; as % of VSYS
27
28.5
30
%
Rising Threshold; as % of VSYS
28
29.5
31
%
70
100
150
mV
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
LX2205
Cold Temp Fault Threshold
Page 5
LX2205
®
TM
1A Li-Ion Battery Charger with Power Source Management
P RODUCTION D ATA S HEET
CHARGER CONTROL FLOW DIAGRAM
YES
WWW . Microsemi .C OM
SHDN
A TMP FAULT CAUSES THE CHARGER TO
SUSPEND CHARGING. ONCE THE FAULT CLEARS,
CHARGING RESUMES AT THE SAME POINT.
RETURN TO START IF
VSYS > VBAT, UVLO, SUSP, OR SHDN CHANGE
STATE.
START
SWITCH OFF
VOLTAGE
MONITORING
MODE (STATE).
NO
VSYS > VBAT
NO
DISCHARGE
MODE
YES
VBAT60%
NO
CONDITION
CHARGE
MODE
YES
CONSTANT CURRENT
CHARGE MODE
TEMP < 140
IUCL DETERMINED BY THE
STATE OF UCL.
CONSTANT VOLTAGE
CHARGE MODE
TEMP < 140
NO
NO
YES
YES
ISYS< IMAX
REDUCE
CHARGE
CURRENT
YES
YES
ISYS< IMAX
NO
NO
REDUCE
CHARGE
CURRENT
YES
YES
DC OK
DC OK
NO
NO
IUSB< IUCL
NO
NO
YES
YES
NO
LX2205
IUSB< IUCL
NO
VBAT> VCV
IBAT VUSB
VMDC > V DC OK _THRESHOLD
The MDC input is a monitoring input only, it is not a
high current input. When the voltage at SYS exceeds the
UVLO level, (typically 3.7V), the charger portion of the
circuit is activated. The DC OK output is pulled low when
both of the following conditions are true:
1.
2.
The following tables are guidelines for selecting the proper
resistor values:
VMDC > V DC OK _THRESHOLD
VSYS > VBAT
Therefore when using a current limited wall adapter it is
possible to charge the battery and not assert the DC OK
output.
Constant Charge Current (in mA)
RCCP
50
1270k
100
604k
200
294k
300
187k
400
137k
500
107k
600
88.7k
700
75.0k
800
63.4k
900
56.2k
1000
49.9k*
* RCCP minimum value
Termination Current (in mA)
RCTP
5
237k
10
105k
20
51.1k
40
24.9k
60
15.8k
80
11.8k
100
9.09k
120
7.50k
140
6.34k
160
5.49k
180
4.75k
200
4.22k
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
LX2205
PROTECTION FEATURES
Conditioning Current Mode – If the battery terminal
voltage is less than 2.7V, the battery charger will reduce the
charge current to 5% of full scale. This also protects the
appliance from overheating by trying to drive the full
charging current into a short circuited battery.
Under Voltage Lockout – The charger remains inactive
until the under voltage lockout threshold is exceeded at the
SYS pin.
Thermal Control Loop – The power dissipation of the
charger is limited by reducing the charge current with a
control loop to prevent the die temperature from exceeded
approximately 140°C.
Reverse Current Blocking – Current will not flow out of
the USB pin.
Shutdown Mode – If the SHDN pin is logic high, the
charger enters a shutdown mode to prevent draining the
battery.
Battery Temperature Lockout – If an unsafe temperature is
sensed by the TFB input window comparator, battery
charging is suspended.
Copyright © 2007
Rev. 1.0a, 2007-03-02
CHARGE CURRENT PROGRAMMING
The CCP, CTP, and CUS programming pins are used to
program the constant charge current, termination current,
and USB current, respectively. These pins utilize regulated
output voltages that produce a program current across an
external resistor to GND.
WWW . Microsemi .C OM
The power path from the USB input to the SYS pin
consists of a current limiter and a bidirectional switch
(capable of blocking current in either direction). The USB
input is switched off when at least one of the following
conditions exists:
LAYOUT GUIDELINES
It is important when laying out the LX2205 to place
10µF ceramic capacitors as close to the SYS, USB and
VBAT IC terminals as possible to filter switching
transients.
It is important to provide a low thermal impedance path
from the thermal pad on the bottom of the LX2205
package to the ground plane of the circuit board to
maximize heat dissipation.
Generally this is
accomplished by the use of multiple thermal vias.
The compensation capacitor should be placed close to
the CMP pin and connected with a short trace.
Page 11
LX2205
®
TM
1A Li-Ion Battery Charger with Power Source Management
P RODUCTION D ATA S HEET
APPLICATION NOTE
To finish the design it is necessary to create the Thevenin
Voltage and resistance using a voltage divider from the
SYS pin.
The values of R1 and R2 can be calculated as:
R1 =
R2 =
RTH
= 88k
K
R1 × RTH
= 958k
R1 − RTH
WWW . Microsemi .C OM
BATTERY TEMPERATURE MONITOR
The LX2205 has an input to monitor the battery
temperature during battery charging. The SYS voltage
must be used to bias this circuitry. During the occurrence of
a TMP fault, the charge cycle is suspended; however the
status indicators state remains unchanged.
A typical Lithium Ion battery should only be charged
within a temperature range of 0°C to 60°C. For this
calculation example, a Vishay NTHS0402N01N1003J
thermistor was used. This thermistor has the value of
327kΩ at 0°C, 100kΩ at 25°C and 24.9kΩ at 60°C. The
thermistor must be biased with a Thevenin voltage source
and series resistance to achieve the proper TMP thresholds.
A fixed value resistor is added in series with the thermistor
to prevent it from becoming too low impedance at high
temperatures and causing the TMP input to default to off.
Actual standard 1% resistor values are: 953k and
88.7k. The final circuit for this example is:
VSYS
88.7k
TMP
12.4k
953k
RNTC
Using a value of RMIN that is ½ the thermistor high
temperature trip resistance value works well; therefore, for
this example, set the value of RMIN to:
12.4k = R MIN
R
= T =60°C .
2
This has the effect of adding a fixed 12.4k to the
thermistor resistance values so it becomes 339kΩ at 0°C,
112kΩ at 25°C and 37.3kΩ at 60°C.
The TMP voltages with this circuit are:
TEMP (°C)
-20
0
25
60
80
RNTC
971k
327k
100k
24.9k
12.6k
VTMP (% VSYS)
85%
74%
53%
29%
22%
The equations for RTH and VTH are, using Cold
Temperature Fault Threshold average of 74% and the Hot
Temperature Fault Threshold average of 29% of VSYS:
LX2205
0.29 × 0.74 × (RT =0°C − RT =60°C )
VTH
=
VSYS (0.29 × RT =0°C ) − (0.74 × RT =60°C )
= K = 0.916
⎞
⎛ K
RTH = ⎜
− 1⎟ × RT = 0°C = 80.6k
⎝ 0.74 ⎠
Copyright © 2007
Rev. 1.0a, 2007-03-02
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 12
LX2205
1A Li-Ion Battery Charger with Power Source Management
®
TM
P RODUCTION D ATA S HEET
TYPICAL CHARGING CURRENT VS VSYS
1.2
1
1
Charge Current (A)
1.2
0.8
0.6
0.4
WWW . Microsemi .C OM
Charge Current (A)
TYPICAL CHARGING CURRENT VS BATTERY VOLTAGE
0.8
0.6
0.4
V BAT = 3.9V
0.2
0.2
0
0
4.2
3.2
3.4
3.6
3.8
4
4.2
4.6
5
5.4
5.8
SYS Voltage
Battery Voltage
TYPICAL USB CURRENT LIMIT VS USB VOLTAGE
TYPICAL VCVL DISTRIBUTION
500
1500
450
USB Current Limit (mA)
400
Typical Distribution Frequency
USB Low
USB Hi
350
300
250
200
150
100
1250
VSY S = 5V
1000
TA = 25°C
750
500
250
0
4.16 4.17 4.18 4.19 4.20 4.21 4.22 4.23 4.24
50
0
4
4.5
5
5.5
6
VCVL
Input Voltage
CHARGE TO DISCHARGE SWITCHOVER
VSYS
IBAT
LX2205
DC OK
Copyright © 2007
Rev. 1.0a, 2007-03-02
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 13
LX2205
®
TM
1A Li-Ion Battery Charger with Power Source Management
P RODUCTION D ATA S HEET
PACKAGE DIMENSIONS
16-Pin MLPQ Plastic (4x4mm EP / 114x114Cu Exposed Pad)
D
b
E2
L
D2
E
e
A
A1
K
Dim
A
A1
A3
b
D
E
e
D2
E2
K
L
MILLIMETERS
MIN
MAX
0.80
1.00
0
0.05
0.18
0.30
0.23
0.38
4.00 BSC
4.00 BSC
0.65 BSC
2.55
2.80
2.55
2.80
0.20
0.30
0.50
INCHES
MIN
MAX
0.031 0.039
0
0.002
0.007 0.012
0.009 0.015
0.157 BSC
0.157 BSC
0.026 BSC
0.100 0.110
0.100 0.110
0.008
0.012 0.020
Note:
1. Dimensions do not include mold flash or protrusions;
these shall not exceed 0.155mm(.006”) on any side.
Lead dimension shall not include solder coverage.
A3
LX2205
PRODUCTION DATA – Information contained in this document is proprietary to
Microsemi and is current as of publication date. This document may not be modified in
any way without the express written consent of Microsemi. Product processing does not
necessarily include testing of all parameters. Microsemi reserves the right to change the
configuration and performance of the product and to discontinue product at any time.
Copyright © 2007
Rev. 1.0a, 2007-03-02
WWW . Microsemi .C OM
LQ
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 14
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