19-4929; Rev 1; 4/10
30V Li+ Linear Battery Charger
with GSM Test Mode in 3mm x 2mm TDFN
General Description
The MAX8922L linear battery charger safely charges a
single-cell lithium-ion (Li+) battery. Charging rate is
optimized to accommodate the thermal characteristics
of a given application. There is no need to reduce the
maximum charge current at the worst-case charger
power dissipation. Charging is optimized for a single
Li+ cell using a control algorithm that includes low-bat-
tery precharging, voltage and current-limited fast
charging, and top-off charging, while continuously
monitoring for input overvoltage and device die-temper-
ature conditions. The fast-charge current and top-off
current thresholds are programmable by a simple
single-pin serial interface. The charger status and valid
input power are indicated by two open-drain outputs
(CHG and
POK).
The fast-charge current is defaulted to 400mA and pro-
grammable through the single-pin interface (EN/SET).
The MAX8922L also can be programmable to GSM test
mode through the single-pin interface.
The MAX8922L is available in a tiny (3mm x 2mm x
0.8mm) 10-pin TDFN package.
Features
o
Overvoltage-Protected 30V
DC
Rated Input (IN)
o
Input Overvoltage-Protected Safe 4.94V LDO
Output
o
2.3A GSM RF Test Mode
o
No External FET, Blocking Diode, or Sense
Resistor Required
o
Single-Pin Easy Programmable Fast-Charge and
GSM Test Mode (EN/SET)
o
Resistor-Programmable Fast-Charge Current
(SETI)
o
Resistor-Programmable Top-Off Current
Threshold (MIN)
o
Prequalification Charge
o
Power-OK Monitor Output (POK)
o
Charging-Status Output (CHG)
o
Die Temperature Regulation for Optimized
Charge Rate
o
Tiny (3mm x 2mm x 0.8mm) 10-Pin TDFN Package
MAX8922L
Applications
GSM/EDGE/UMTS/CDMA Cell Phones
Digital Cameras
PDAs
Portable Media Players and MP3 Players
Wireless Appliances
Ordering Information
PART
MAX8922LETB+T
PIN-PACKAGE
10 TDFN-EP*
TOP MARK
AWN
+Denotes
a lead(Pb)-free and RoHS-compliant package.
*EP
= Exposed pad.
Note:
This device operates in the -40°C to +85°C extended
operating temperature range.
Pin Configuration
CHG
POK
BAT
Typical Operating Circuit
USB/AC ADAPTER
4.45V TO 30V
IN
BAT
TOP VIEW
10
9
8
7
EN/SET
6
TEST
SETI
R
SETI
LDO
MAX8922L
*EP
1
IN
2
SETI
3
GND
4
LDO
5
MIN
R
MIN
MAX8922L
MIN
SYSTEM SUPPLY
CHG
EN\SET
EP
GND TEST
POK
TDFN
(3mm x 2mm x 0.8mm)
*EP = EXPOSED PAD.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
30V Li+ Linear Battery Charger
with GSM Test Mode in 3mm x 2mm TDFN
MAX8922L
ABSOLUTE MAXIMUM RATINGS
IN to GND ..............................................................-0.3V to +30V
BAT,
CHG, EN/SET, POK,
SETI,
MIN, LDO, TEST to GND ......................................-0.3V to +6V
IN to BAT Continuous Current .......................................1A
RMS
Continuous Power Dissipation (T
A
= +70°C)
10-Pin (3mm x 2mm) TDFN
(derate 14.9mW/°C above +70°C) ..........................1188.7mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature Range ............................-40°C to +150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
IN
= 5V, V
BAT
= 4V, V
EN/SET
= 0V, T
A
= -40°C to +85°C, typical values are at T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
IN
Input Voltage Range
Input Voltage Operating Range
Input Undervoltage Threshold
(UVLO)
Input Overvoltage Threshold
(OVP)
Input Supply Current
IN-to-BAT On-Resistance
IN-to-BAT Comparator Threshold
BAT
BAT Regulation Voltage
Battery Removal Detection
Threshold
I
BAT
= 100mA
V
BAT
rising
Hysteresis
Default fast-charge current, V
BAT
= 3.5V
EN/SET
= one pulse with low > 4ms, R
SETI
= 3kΩ,
one-pulse mode, V
BAT
= 3.5V
EN/SET
= two pulses with low > 4ms, V
BAT
= 3.5V
EN/SET
= three pulses with low > 4ms,
V
BAT
= 3.5V (Note 3)
Soft-Start Time
BAT Precharge Threshold
Precharge Current
BAT Leakage Current
V
IN
= 0V, V
BAT
= 4.2V
Ramp time to fast-charge current
V
BAT
rising, 300mV hysteresis (typ)
365
460
80
T
A
= +25°C
T
A
= -40°C to +85°C
4.179
4.158
4.2
4.2
4.67
0.2
400
500
90
2350
250
2.5
80
1
5
µs
V
mA
µA
435
540
100
mA
4.221
4.242
V
V
(Note 2)
V
IN
rising, 500mV hysteresis (typ)
V
IN
rising, 200mV hysteresis (typ)
I
BAT
= 0mA, charge mode
V
EN/SET
= 5V, standby mode
V
IN
= V
BAT
, shutdown mode
V
IN
= 4.15V, V
BAT
= 4V
V
IN
rising
V
IN
falling
120
0
4.45
3.80
7.2
3.90
7.5
700
250
200
0.35
250
100
500
Ω
mV
28
7
4.00
7.8
1300
440
µA
V
V
V
V
CONDITIONS
MIN
TYP
MAX
UNITS
Charging Current
2
_______________________________________________________________________________________
30V Li+ Linear Battery Charger
with GSM Test Mode in 3mm x 2mm TDFN
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 5V, V
BAT
= 4V, V
EN/SET
= 0V, T
A
= -40°C to +85°C, typical values are at T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
LDO
Minimum LDO Bypass
Capacitance
LDO Regulated Output Voltage
LDO Output-Current Limit
EN/SET
Logic Input Thresholds
Program Lock Time
Shutdown Delay
t
LOW
t
HIGH
Pulldown Resistor
POK, CHG
Logic Output Voltage, Low
Logic Output Current, High
CHG
Default top-off threshold, hysteresis
(typ) = 80mA
Top-Off Threshold
I
BAT
falling,
battery is
charged
EN/SET
= one pulse, R
MIN
=
1.875kΩ, hysteresis (typ) = 130mA
EN/SET
= two pulses, hysteresis
(typ) = 22mA
Detection Delay
THERMAL LOOP
Thermal-Limit Temperature
Thermal-Limit Gain
Junction temperature when the charge current is
reduced, T
J
rising
Reduction of I
BAT
for increase of T
J
, default mode
+105
-28
°C
mA/°C
I
BAT
falls below top-off threshold
60
60
50
2
80
80
60
4
100
100
70
6
ms
mA
I
POK,
= I
CHG
= 5mA
V
POK
= V
CHG
= 5.5V, V
IN
= 0V
T
A
= +25°C
T
A
= +85°C
0.05
0.001
0.01
0.2
1
V
µA
V
IN
= 5V,
EN/SET
from low to high
(Note 4)
(Note 4)
Rising
Falling
0.4
4
4
100
100
2
1400
1400
1.4
V
ms
ms
µs
MΩ
I
LDO
= 10mA, V
IN
= 5V
4.8
1
4.94
100
µF
V
mA
CONDITIONS
MIN
TYP
MAX
UNITS
MAX8922L
Note 1:
Limits are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by design
and characterization.
Note 2:
Guaranteed by undervoltage- and overvoltage-threshold testing. If V
BAT
= 4.2V, V
IN
needs to be > 4.2V + 250mV (typ) to
start normal operation. After the MAX8922L turns on, it can operate until V
BAT
+ 100mV (typ). For complete charging, the
input voltage must be > 4.45V. See the
Input Sources
section.
Note 3:
Used for factory GSM RF calibration. 217Hz, 12.5% current pulse, T
A
= +25°C. Not for continuous charge current.
Note 4:
Not tested. Design guidance only.
_______________________________________________________________________________________
3
30V Li+ Linear Battery Charger
with GSM Test Mode in 3mm x 2mm TDFN
MAX8922L
Typical Operating Characteristics
(V
IN
= 5V, V
EN/SET
= 0V. V
BAT
= 4V, MAX8922L Evaluation Kit. T
A
= +25°C, unless otherwise noted.)
DISABLED SUPPLY CURRENT vs.
SUPPLY VOLTAGE
MAX8922 toc02
MAX8922 toc01
SUPPLY CURRENT vs.
SUPPLY VOLTAGE
1.0
0.9
0.8
SUPPLY CURRENT (mA)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
1
2
3
4
5
6
7
SUPPLY VOLTAGE (V)
1.0
0.9
STANDBY SUPPLY CURRENT (mA)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
CHARGE CURRENT vs.
BATTERY VOLTAGE
500mA SETI MODE
500
CHARGE CURRENT (mA)
400
300
200
90mA PRESET
100
0
400mA PRESET
MAX8922 toc03
600
1
2
3
4
5
6
7
0
1
2
3
4
5
SUPPLY VOLTAGE (V)
BATTERY VOLTAGE (V)
CHARGE CURRENT vs.
SUPPLY VOLTAGE
450
400
CHARGE CURRENT (mA)
350
300
250
200
150
100
50
0
0
3
6
9
12 15 18 21 24 27 30
SUPPLY VOLTAGE (V)
I
BAT
400mA DEFAULT
V
BAT
= 4V
MAX8922 toc04
CHARGE CURRENT WITH ONE
EN/SET PULSE
MAX8922 toc05
CHARGE CURRENT WITH TWO
EN/SET PULSES
MAX8922 toc06
500
5V/div
V
EN/SET
0
500mA
400mA
V
EN/SET
5V/div
0
400mA
100mA/div
0
1ms/div
I
BAT
1ms/div
100mA/div
0
GSM TRANSIENT RESPONSE
MAX8922 toc07
CHARGE CURRENT vs.
INPUT VOLTAGE HEADROOM
700
CHARGE CURRENT (mA)
200mv/div
AC-COUPLED
600
500
400
300
200
100
0
0
50
100
I
FAST-CHARGE
= 677mA
150
200
250
300
MAX8922 toc08
800
NO BATTERY
C
BAT
= 68µF
V
BAT
I
BAT
1A/div
0A
1ms/div
V
IN
- V
BAT
(mV)
4
_______________________________________________________________________________________
30V Li+ Linear Battery Charger
with GSM Test Mode in 3mm x 2mm TDFN
Typical Operating Characteristics (continued)
(V
IN
= 5V, V
EN/SET
= 0V. V
BAT
= 4V, MAX8922L Evaluation Kit. T
A
= +25°C, unless otherwise noted.)
MAX8922L
BAT REGULATION VOLTAGE ACCURACY
vs. AMBIENT TEMPERATURE
MAX8922 toc09
CHARGE CURRENT vs.
AMBIENT TEMPERATURE
MAX8922 toc10
CHARGE CURRENT vs.
AMBIENT TEMPERATURE (1A CHARGE)
900
800
CHARGE CURRENT (mA)
700
600
500
400
300
200
100
0
R
SETI
= 1.5kI
V
IN
= 5V
V
BAT
= 4V
-40
-15
10
35
60
85
MAX8922 toc11
1.0
0.8
V
BAT
REGULATION ACCURACY (%)
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
-40
-15
10
35
60
V
IN
= 5V
NO BATTERY
600
500
CHARGE CURRENT (mA)
400
300
200
100
0
400mA PRESET
V
IN
= 5V
V
BAT
= 4V
-40
-15
10
35
60
1000
85
85
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
Pin Description
PIN
1
NAME
IN
FUNCTION
DC Input Supply. Connect IN to V
IN
> 4V and (V
IN
- V
BAT
)
≥
250mV up to a 7V charging source.
Bypass IN to GND with a 1µF or larger ceramic capacitor.
Charge-Current Program and Fast-Charge Current Monitor. Output current from SETI is 1000µA per
ampere of battery-charging current. Set the charging current by connecting a resistor (R
SETI
in Figure
1) from SETI to GND. I
FAST-CHARGE
= 1500V/R
SETI
.
Connect to GND if pulse 1 mode (external SETI)
is not used.
Ground
4.94V Regulated LDO Output with Input Overvoltage Protection. Bypass LDO to GND with a 1µF or
larger ceramic capacitor. LDO can be used to supply low-voltage-rated USB systems.
Top-Off Current Threshold Programmable Input. I
MIN
= 150V/R
MIN.
Connect to GND if pulse 1 mode
(external SETI) is not used.
Active-Low Enable Input.
EN/SET
is used for programming fast-charge current and GSM test mode. For
detailed descriptions, see the
Charger-Enable and Program Input (
EN
/SET)
section.
Factory Test Input. Connect to GND.
Charging-Status Output.
CHG
is internally pulled low when the charger is in prequalification or fast-
charge mode.
CHG
is high impedance when the charger is in top-off or disabled.
Input Power-OK Monitor.
POK
is an open-drain output that is internally pulled low when V
IN
is greater
than V
UVLO
and lower than V
OVP
and V
IN
> V
BAT
+ 250mV.
POK
is high impedance when V
IN
is less
than V
UVLO
or greater than V
OVP
or V
IN
< V
BAT
+ 100mV.
Battery Connection. The IC delivers charging current and monitors battery voltage using BAT. Bypass
BAT to GND with a 2.2µF or larger ceramic capacitor. BAT is high impedance when the IC is disabled.
Exposed Pad. Connect to the GND plane for increased thermal dissipation.
2
3
4
5
6
7
8
SETI
GND
LDO
MIN
EN/SET
TEST
CHG
9
POK
10
—
BAT
EP
_______________________________________________________________________________________
5
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