View MAX8922L_4556154.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

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-battery precharging, voltage and current-limited fast charging, and top-off charging, while continuously monitoring for input overvoltage and device die-temperature 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 programmable 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 30VDC 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 -40C to +85C 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 RSETI
LDO
MAX8922L
*EP 1 IN 2 SETI 3 GND 4 LDO 5 MIN
RMIN
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 .......................................1ARMS Continuous Power Dissipation (TA = +70C) 10-Pin (3mm x 2mm) TDFN (derate 14.9mW/C above +70C) ..........................1188.7mW Operating Temperature Range ...........................-40C to +85C Junction Temperature Range ............................-40C to +150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C Soldering Temperature (reflow) .......................................+260C
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
(VIN = 5V, VBAT = 4V, VEN/SET = 0V, TA = -40C to +85C, typical values are at TA = +25C, 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 IBAT = 100mA VBAT rising Hysteresis Default fast-charge current, VBAT = 3.5V EN/SET = one pulse with low > 4ms, RSETI = 3k, one-pulse mode, VBAT = 3.5V EN/SET = two pulses with low > 4ms, VBAT = 3.5V EN/SET = three pulses with low > 4ms, VBAT = 3.5V (Note 3) Soft-Start Time BAT Precharge Threshold Precharge Current BAT Leakage Current VIN = 0V, VBAT = 4.2V Ramp time to fast-charge current VBAT rising, 300mV hysteresis (typ) 365 460 80 TA = +25C TA = -40C to +85C 4.179 4.158 4.2 4.2 4.67 0.2 400 500 90 2350 250 2.5 80 1 5 s V mA A 435 540 100 mA 4.221 4.242 V V (Note 2) VIN rising, 500mV hysteresis (typ) VIN rising, 200mV hysteresis (typ) IBAT = 0mA, charge mode VEN/SET = 5V, standby mode VIN = VBAT, shutdown mode VIN = 4.15V, VBAT = 4V VIN rising VIN falling 120 0 4.45 3.80 7.2 3.90 7.5 700 250 200 0.35 250 100 500 mV 28 7 4.00 7.8 1300 440 A 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)
(VIN = 5V, VBAT = 4V, VEN/SET = 0V, TA = -40C to +85C, typical values are at TA = +25C, 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 tLOW tHIGH Pulldown Resistor POK, CHG Logic Output Voltage, Low Logic Output Current, High CHG Default top-off threshold, hysteresis (typ) = 80mA Top-Off Threshold IBAT falling, battery is charged EN/SET = one pulse, RMIN = 1.875k, 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, TJ rising Reduction of IBAT for increase of TJ, default mode +105 -28 C mA/C IBAT falls below top-off threshold 60 60 50 2 80 80 60 4 100 100 70 6 ms mA IPOK, = ICHG = 5mA VPOK = VCHG = 5.5V, VIN = 0V TA = +25C TA = +85C 0.05 0.001 0.01 0.2 1 V A VIN = 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 s M ILDO = 10mA, VIN = 5V 4.8 1 4.94 100 F V mA CONDITIONS MIN TYP MAX UNITS
MAX8922L
Note 1: Limits are 100% production tested at TA = +25C. Limits over the operating temperature range are guaranteed by design and characterization. Note 2: Guaranteed by undervoltage- and overvoltage-threshold testing. If VBAT = 4.2V, VIN needs to be > 4.2V + 250mV (typ) to start normal operation. After the MAX8922L turns on, it can operate until VBAT + 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, TA = +25C. 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
(VIN = 5V, VEN/SET = 0V. VBAT = 4V, MAX8922L Evaluation Kit. TA = +25C, 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) IBAT 400mA DEFAULT VBAT = 4V
MAX8922 toc04
CHARGE CURRENT WITH ONE EN/SET PULSE
MAX8922 toc05
CHARGE CURRENT WITH TWO EN/SET PULSES
MAX8922 toc06
500
5V/div VEN/SET 0 500mA 400mA VEN/SET
5V/div 0
400mA
100mA/div 0 1ms/div IBAT 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 IFAST-CHARGE = 677mA 150 200 250 300
MAX8922 toc08
800
NO BATTERY CBAT = 68F VBAT
IBAT
1A/div 0A 1ms/div
VIN - VBAT (mV)
4
_______________________________________________________________________________________
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN
Typical Operating Characteristics (continued)
(VIN = 5V, VEN/SET = 0V. VBAT = 4V, MAX8922L Evaluation Kit. TA = +25C, 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 RSETI = 1.5kI VIN = 5V VBAT = 4V -40 -15 10 35 60 85
MAX8922 toc11
1.0 0.8 VBAT REGULATION ACCURACY (%) 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1.0 -40 -15 10 35 60 VIN = 5V NO BATTERY
600 500 CHARGE CURRENT (mA) 400 300 200 100 0 400mA PRESET VIN = 5V VBAT = 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 VIN > 4V and (VIN - VBAT) 250mV up to a 7V charging source. Bypass IN to GND with a 1F or larger ceramic capacitor. Charge-Current Program and Fast-Charge Current Monitor. Output current from SETI is 1000A per ampere of battery-charging current. Set the charging current by connecting a resistor (RSETI in Figure 1) from SETI to GND. IFAST-CHARGE = 1500V/RSETI. 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 1F or larger ceramic capacitor. LDO can be used to supply low-voltage-rated USB systems. Top-Off Current Threshold Programmable Input. IMIN = 150V/RMIN. 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 fastcharge 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 VIN is greater than VUVLO and lower than VOVP and VIN > VBAT + 250mV. POK is high impedance when VIN is less than VUVLO or greater than VOVP or VIN < VBAT + 100mV. Battery Connection. The IC delivers charging current and monitors battery voltage using BAT. Bypass BAT to GND with a 2.2F 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
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN MAX8922L
MAX8922
4.45V TO 30V
IN
BAT Li+ LDO
Tj(DIE) CC/CV REGULATOR +105C LDO CONTROL
3.9V
TOP-OFF SWITCH BAT 7.5V
FAST-CHARGE SWITCH
CHARGE AND LOGIC CONTROL
MIN RMIN
SETI
EN/SET
RSETI
BAT
PRECHARGE POK CHG
2.5V
EP TEST
GND
Figure 1. MAX8922L Functional Diagram
6
_______________________________________________________________________________________
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN
Detailed Description
The MAX8922L is designed to charge a single-cell Li+ battery from a DC source voltage between 4.45V and 7V, while VIN can withstand up to 30V. The fast-charge current and top-off current thresholds are programmable with EN/SET, SETI, and MIN.
Soft-Start
To prevent input transients, the rate of change of the charge current is limited when the charger is turned on or changes its current compliance. It takes approximately 250s (typ) (tSOFTSTART) for the charger to go from 0mA to the maximum fast-charge current.
MAX8922L
Charger-Enable and Program Input (EN/SET)
EN/SET is an active-low logic input that enables the charger. Drive EN/SET high longer than 4ms to disable the charger-control circuitry. If EN/SET is left unconnected, an internal 2M pulldown resistor enables 400mA fast-charge current by default. The pulse programming scheme shown in Table 1 and Figure 3 is used to program the charge current and GSM test mode. There are four different fast-charge current states. Default fast-charge current state is 400mA mode. More than three pulses are interpreted to 90mA mode. After programming is locked, the MAX8922L ignores pulses until the IC is disabled/enabled or input power is cycled. Each fast-charge state is locked after a 4ms logic-low is asserted on EN/SET, followed by programming pulses. However, during default mode, if EN/SET does not receive any pulses, the charger stays in default mode unlocked indefinitely.
Thermal-Limit Control
The MAX8922L features a thermal limit that reduces the charge current when the die temperature exceeds +105C. As the temperature increases above +105C, the IC decreases the charge current by 28mA/C.
Charge-Indicator Output (CHG)
CHG is an open-drain output that indicates charger status. CHG goes low during charging in prequalification or fast-charge mode. The CHG internal open-drain MOSFET turns off when the charge current reaches the top-off threshold. The CHG status is latched after the top-off threshold is reached. The latch can be reset as follows: * Disable and re-enable the MAX8922L. * Input power is cycled. * Battery-charge current increases greater than the top-off threshold + hysteresis. When the MAX8922L is used in conjunction with a microprocessor, connect a pullup resistor between CHG and the logic I/O voltage to indicate charge status to the P. Alternatively, CHG can sink 5mA or more for an LED charge indicator.
Debounce Timer
To prevent the MAX8922L from charging the battery momentarily upon IN power-up with EN/SET held low, a 2ms (typ) debounce timer delays the charging loop upon power-up. If EN/SET is logic-low or unconnected (pulled down by an internal pulldown resistor) during IN power-up, the charger starts charging the battery 2ms after VUVLO < VIN < VOVP and VBAT + 250mV < VIN. If EN/SET is logic-high during IN power-up, the charger does not charge the battery.
Table 1. Charge-Current Pulse Settings
CHARGE CURRENT DEFAULT NUMBER OF PULSES + > 4ms LOGIG-LOW One IBAT (mA) 400mA Two Three Four and more FAST-CHARGE CURRENT SETTING SETI, resistor programmable 90mA 2.3A (GSM test) 90mA
_______________________________________________________________________________________
7
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN MAX8922L
CHARGER LOOP DEFAULT IS OFF; IF EN/SET = LOW UPON POK. CHARGER LOOP ACTIVATES AFTER 4ms POR DEBOUNCE ASYNCHRONOUS FROM ANYWHERE tEN/SET = HIGH > 4ms VUVLO < VIN < VOVP AND VIN > VBAT + 250mV
STANDBY MODE CHARGER = OFF POK = LOW CHG = HIGH IMPEDANCE
SHUTDOWN CHARGER = OFF POK = HIGH IMPEDANCE CHG = HIGH IMPEDANCE
EN/SET = LOW
VIN < VUVLO OR VIN > VOVP OR VBAT + 100mV > VIN
ASYNCHRONOUS FROM ANYWHERE VIN < VUVLO OR VIN > VOVP OR VBAT + 100mV > VIN
VBAT < 2.5V
PREQUALIFICATION PRECHARGE CURRENT POK = LOW CHG = LOW
PULSE 3 MODE DOES NOT HAVE PRECHARGE STATE
POK = (VOVP > VIN > VUVLO) AND (VIN - VBAT) > 250mV
VBAT < 2.2V
VBAT > 2.5V
FAST CHARGE (PULSE PROGRAMMABLE) 100% CHARGER CURRENT POK = LOW CHG = LOW
ICHG > ITOP-OFF + HYSTERESIS ICHG < ITOP-OFF
FULL BATTERY VBAT = 4.2V POK = LOW CHG = HIGH IMPEDANCE
FULL BATTERY CONTINUES TO REGULATE VBAT TO 4.2V
Figure 2. Charger State Diagram
Power-OK Indicator (POK)
The MAX8922L contains an open-drain POK output that goes low when VIN is greater than VUVLO and lower than VOVP and VIN exceeds the battery voltage by 250mV. Once charging has started, charging is sustained with
inputs as low as 3.5V, as long as the input voltage remains above the battery voltage by at least 100mV. POK status should be maintained even though the charger is disabled by EN/SET. When VIN > VOVP, POK is high impedance.
8
_______________________________________________________________________________________
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN MAX8922L
DC HIGH IMPEDANCE
POK
PULL LOW
> 4ms 1 EN tHIGH NO TIME LIMIT tSOFTSTART 90mA MODE (2 PULSES + > 4ms LOW) 400mA SETTING (DEFAULT) IFAST GSM TEST MODE (3 PULSES + > 4ms LOW) OFF tLOW SETI MODE (1 PULSE + > 4ms LOW) 2 3 > 4ms
Figure 3. Charge-Current Programming
LDO Output
The LDO is preset to an output voltage of 4.94V and a 100mA current limit (typ). The LDO is powered from IN and has input overvoltage protection. The LDO is on if a valid input is present (VUVLO < VIN < VOVP). Bypass LDO to GND with a 1F or larger ceramic capacitor. The LDO can be used to supply low-voltagerated USB systems.
The voltage at ISET is nominally 1.5V at the selected fast-charge current and decreases with charging current as the cell becomes fully charged or as the thermal-regulation circuitry activates.
Applications Information
Fast-Charge Current Settings In pulse 1 mode, the maximum charging current is programmed by an external resistor connected from SETI to GND (RSETI). Calculate RSETI as follows: RSETI = 1500V/IFAST-CHARGE where I FAST-CHARGE is in amperes and R SETI is in ohms. SETI can be used to monitor the fast-charge current level in the one-pulse mode (RSETI mode). The output current from SETI is 1000A per ampere of charging current. The output voltage at SETI is proportional to the charging current (ICHARGE) when SETI mode is used for the fast-charge current: VSETI = ICHARGE x RSETI/1000
Top-Off Current Settings The top-off charging current is programmed by an external resistor connected from MIN to GND (RMIN) in the one-pulse mode (RSETI mode). Calculate RMIN as follows:
RMIN = 150V/IMIN where IMIN is in amperes and RMIN is in ohms.
Capacitor Selection
Connect a 2.2F ceramic capacitor from BAT to GND for proper stability. Connect a 1F ceramic capacitor from IN to GND. Use a larger input bypass capacitor for high charging currents to reduce supply noise. All capacitors should be X5R dielectric or better. Be aware that some capacitors have large-voltage coefficients, and should be avoided.
_______________________________________________________________________________________
9
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN MAX8922L
AC ADAPTER
IN C1 1F MIN R1 1.87k
BAT C2 2.2F LDO C3 1F VI/O 4.2V Li+ SYSTEM VBUS
MAX8922L
SETI R2 3k POK CHG EN/SET EP GND TEST GPIO GPIO GPIO
Figure 4. AC Adapter Charger Application
Thermal Considerations
The MAX8922L is in a thermally enhanced TDFN package with an exposed pad. Connect the exposed pad of the package to a large copper ground plane to provide a thermal contact between the device and the circuit board. The exposed pad transfers heat away from the device, allowing the IC to charge the battery with maximum current, while minimizing the increase in die temperature.
Recommended PCB Layout and Routing
Place all bypass capacitors for IN and BAT as close as possible to the IC. Connect the battery to BAT as close as possible to the IC to provide accurate battery voltage sensing. Provide a large copper ground plane to allow the exposed pad to sink heat away from the device. Make all high-current traces short and wide to minimize voltage drops. A sample layout is available in the MAX8922L Evaluation Kit to speed designs.
Input Sources
The MAX8922L operates from well-regulated DC sources. The charger input voltage range is 4.45V to 7V. The device survives input voltages up to 30V without damage to the IC. If the input voltage is greater than 7.5V (typ), the IC stops charging. An appropriate power supply must provide at least 4.2V plus the voltage drop across the internal-pass transistor when sourcing the desired peak charging current. VIN(MIN) > 4.2V + IFAST-CHARGE(MAX) x RON where RON is the input-to-BAT resistance. Failure to meet this requirement results in an incomplete charge or increased charge time.
Typical Application Circuits
AC Adapter Charge Figure 4 shows the MAX8922L as a Li+ battery charger with an AC adapter. The MAX8922L detects the presence of an input supply resulting in POK pulled low. Once POK is pulled low, the MAX8922L begins charging the battery when EN/SET is low or unconnected. The system can program the charge current by EN/SET pulses. By monitoring CHG, the system can detect the top-off threshold and terminate the charge through EN/SET. The MAX8922L also provides an overvoltageprotected 4.94V LDO output to a low-voltage-rated USB system input.
10
______________________________________________________________________________________
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN MAX8922L
USB CABLE IN C1 1F MIN R1 1.87k LDO C3 1F VI/O BAT C2 2.2F 4.2V Li+ SYSTEM VBUS
MAX8922L
SETI R2 3k POK CHG EN/SET EP GND TEST GPIO GPIO GPIO
Figure 5. USB-Powered Li+ Battery-Charger Application
USB Charge The universal serial bus (USB) provides a high-speed serial communications port as well as power for the remote device. The MAX8922L can be configured to charge a single Li+ battery at the highest current possible from the host port. Figure 5 shows the MAX8922L as a USB battery charger. The microprocessor enumerates the host to determine its current capability. The system can program the charge current to 90mA, I SETI , or 400mA by EN/SET pulses if the host port is capable. The MAX8922L also provides an overvoltage-protected 4.94V LDO output to a low-voltage-rated USB system input.
GSM Test Mode Figure 6 shows the MAX8922L in a GSM test mode. By sending three pulses to EN/SET, the MAX8922L goes into GSM test mode. GSM PA can pull up to 2.3A for 576s once every 217Hz from the MAX8922L's output. The configuration in Figure 6 is used for system development, testing, and calibrations in the production or design stage.
______________________________________________________________________________________
11
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN MAX8922L
GSM PA
USB CABLE
IN C1 1F MIN R1 1.87k
BAT C2 68F LDO C3 1F VI/O SYSTEM VBUS
MAX8922L
SETI R2 3k POK CHG EN/SET EP GND TEST GPIO GPIO GPIO
Figure 6. GSM Test Mode
Chip Information
PROCESS: BiCMOS
12
______________________________________________________________________________________
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE 10 TDFN-EP PACKAGE CODE T1032N+1 DOCUMENT NO. 21-0429
MAX8922L
______________________________________________________________________________________
TDFN.EPS
13
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN MAX8922L
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.
14
______________________________________________________________________________________
30V Li+ Linear Battery Charger with GSM Test Mode in 3mm x 2mm TDFN
Revision History
REVISION NUMBER 0 1 REVISION DATE 9/09 4/10 Initial release Replaced 1-Wire references with single-pin, updated Absolute Maximum Ratings section, and added soldering temperature DESCRIPTION PAGES CHANGED -- 1, 2
MAX8922L
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15
(c) 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.

▲Up To Search▲

Price & Availability of MAX8922L

	To Download MAX8922L Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .