MAX1811ESA ,USB-Powered Li+ ChargerELECTRICAL CHARACTERISTICS(V = 4.5V, EN = IN, T = 0°C to +85°C, unless otherwise noted.)IN APARAMET ..
MAX1811ESA ,USB-Powered Li+ ChargerApplications Ordering InformationPDAs and PalmtopsPART TEMP RANGE PIN-PACKAGEDigital Still Cameras ..
MAX1811ESA/T ,USB-Powered Li+ ChargerApplications Ordering InformationPDAs and PalmtopsPART TEMP RANGE PIN-PACKAGEDigital Still Cameras ..
MAX1811ESA+ ,USB-Powered Li+ ChargerELECTRICAL CHARACTERISTICS(V = 4.5V, EN = IN, T = 0°C to +85°C, unless otherwise noted.)IN APARAMET ..
MAX1811ESA-T ,USB-Powered Li+ ChargerFeaturesThe MAX1811 is a single-cell lithium-ion (Li+) battery♦ Charges Single-Cell Li+ Batteries D ..
MAX1812EUB ,Dual USB Switch with Fault BlankingApplications Ordering InformationUSB Ports PART TEMP. RANGE PIN-PACKAGEUSB HubsMAX1812EUB -40°C to ..
MAX4674ETE+T ,3V/5V, 4 Ohm, Wideband Quad 2:1 Analog MultiplexerMAX467419-1708; Rev 3; 12/063V/5V, 4Ω, Wideband Quad2:1 Analog Multiplexer
MAX4674EUE ,3V/5V / 4 / Wideband Quad 2:1 Analog Multiplexerfeatures fast turn-on (t ) and turn-offON0.8Ω max(t ) times of 18ns and 6ns, respectively, and is a ..
MAX4674EUE+ ,3V/5V, 4 Ohm, Wideband Quad 2:1 Analog Multiplexerfeatures a low 4Ω max 6Ω max (+3V Supply)on-resistance (R ), 0.4Ω max R matching betweenON ON♦ Guar ..
MAX4674EUE+T ,3V/5V, 4 Ohm, Wideband Quad 2:1 Analog Multiplexerfeatures fast turn-on (t ) and turn-off 0.8Ω maxON(t ) times of 18ns and 6ns, respectively, and is ..
MAX4675EUT+T ,3Ω Single SPST Analog SwitchesApplications_______________Ordering InformationReed Relay ReplacementTEMP. PIN- SOTPARTRANGE PACKAG ..
MAX4678EPE ,2 / Quad / SPST / CMOS Analog SwitchesELECTRICAL CHARACTERISTICS–Dual Supplies(V+ = +5V ±10%, V- = -5V ±10%, V = +2.7V to V+, GND = 0, V ..
MAX1811ESA
USB-Powered Li+ Charger
General DescriptionThe MAX1811 is a single-cell lithium-ion (Li+) battery
charger that can be powered directly from a USB port*
or from an external supply up to 6.5V. It has a 0.5%
overall battery regulation voltage accuracy to allow
maximum utilization of the battery capacity.
The charger uses an internal FET to deliver up to
500mA charging current to the battery. The device can
be configured for either a 4.1V or 4.2V battery, using
the SELV input. The SELI input sets the charge current
to either 100mA or 500mA. An open-drain output (CHG)
indicates charge status.
The MAX1811 has preconditioning that soft-starts a
near-dead battery cell before charging. Other safety
features include continuous monitoring of voltage and
current and initial checking for fault conditions before
charging.
The MAX1811 is available in a small 1.4W thermally
enhanced 8-pin SO package.
________________________ApplicationsPDAs and Palmtops
Digital Still Cameras
MP3 Players
Cell Phones
Two-Way Pagers
Hand-Held Computers
FeaturesCharges Single-Cell Li+ Batteries Directly from
USB Port0.5% Overall Charging AccuracyMinimal External Components Input Diode Not RequiredAutomatic IC Thermal RegulationPreconditions Near-Depleted CellsConvenient Power SO-8 Package (1.4W). Patent # 6,507,172
MAX1811
USB-Powered Li+ Charger
Pin Configuration
Typical Operating Circuit19-2024; Rev 2; 6/03
Ordering Information. Patent # 6,507,172
MAX1811
USB-Powered Li+ Charger
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICSStresses 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.
IN, BATT, SELI, CHG, EN to GND..............................-0.3V to 7V
SELV to GND...............................................-0.3V to (VIN+ 0.3V)
Continuous Power Dissipation (TA= +70°C)
8-Pin SO (derate 17.5mW/°C above +70°C)....................1.4W
Short-Circuit Duration.................................................Continuous
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Maximum Die Temperature..............................................+150°C
Lead Temperature (soldering, 10s).................................+300°C
MAX1811
USB-Powered Li+ ChargerSUPPLY CURRENT
vs. INPUT VOLTAGE (ENABLED)
MAX1811 toc01
VIN (V)
IIN
(mA)
SUPPLY CURRENT vs. INPUT VOLTAGE
(SHUTDOWN)
MAX1811 toc02
VIN (V)
IIN
CHARGE CURRENT
vs. INPUT VOLTAGE HEADROOM
MAX1811 toc03
VIN - VBATT (V)
IBATT
(mA)
Typical Operating Characteristics(CHGunconnected, CBATT= 2.2µF, TA = +25°C, unless otherwise noted.)
ELECTRICAL CHARACTERISTICS(VIN= 4.5V, TA
= -40°C to +85°C, unless otherwise noted.) (Note1)
MAX1811
USB-Powered Li+ Charger
Typical Operating Characteristics (continued)
(CHGunconnected, CBATT= 2.2µF, TA = +25°C, unless otherwise noted.)
MAX1811
USB-Powered Li+ Charger
Pin Description
Figure 1. Functional Diagram
MAX1811
USB-Powered Li+ Charger
Detailed Description
Charger-Control Circuitry
The voltage/current regulator consists of a voltage con-
trol loop, a current control loop, and a thermal control
loop (Figure 1). Use the SELV input to set the battery
regulation voltage to a 4.1V or 4.2V single Li+ cell. The
current and thermal loops are internally compensated
and require no external compensation. The outputs
from all loops drive an internal linear regulator. The
thermal loop modulates the current loop by limiting the
charge current if the die temperature exceeds +125°C.
The MAX1811 is in current mode when the BATT volt-
age is below the regulation set point and in voltage
mode when the BATT voltage is near the regulation set
point. The CHGoutput indicates whether the part is in
current mode (CHG= low) or voltage mode (CHG=
high impedance). Battery voltages less than 2.5V acti-
vate a 43mA preconditioning mode (CHG= high
impedance). Normal charging resumes when the bat-
tery voltage exceeds 2.5V.
System Configuration
The MAX1811 is designed to operate seamlessly with a
universal serial bus (USB) port. In a typical design, the
USB connects to the MAX1811 input, and the MAX1811
drives the load and charges the battery when enabled.
Charge-Current Selection
The MAX1811 charges a single cell Li+ battery in either
100mA or 500mA modes. The MAX1811 expects the
system to poll the USB host to determine if the USB is
capable of providing 100mA or 500mA and regulates
the charging current accordingly (Figure 2). This is to
maintain compatibility with both powered and unpow-
ered USB hosts. A powered USB host is capable of
providing 500mA, and an unpowered USB hub is limit-
ed to only 100mA.
Drive SELI low to set the charge current to the 100mA
mode. Use a 10kΩpulldown resistor to ground on SELI,
if necessary, to ensure that the MAX1811 defaults to
the 100mA mode in the event that no logic signal is
present. Drive SELI high to increase the charge current
to the 500mA mode only if the polled USB port can pro-
vide the required current.
Thermal-Control Circuitry
The thermal loop limits the MAX1811 die temperature to
+125°C by reducing the charging current as neces-
sary. The MAX1811 can operate normally with the ther-
mal loop active. This is not a fault condition and can be
used continuously. The power dissipated by the inter-
nal power FET is determined by (VIN- VBATT) ✕ICHG.
The power dissipation rating for the thermally enhanced
8-pin SO package is 1.4W at +50°C ambient (assuming
a 1in2PC board radiating area), which is the maximum
ambient temperature at which most Li+ battery manu-
facturers allow charging. The 1.4W power dissipation
may never be reached due to the MAX1811’s thermal
regulation loop.
Applications Information
USB Output Voltage
The minimum voltage to a USB-powered device may
be as low as 4.35V when cable and connector drops
are considered (Figure 3). The MAX1811 is optimized
for operation at these low input voltage levels. USB
hubs may also provide as much as 5.5V. At high input
voltages (5.5V) and low cell voltages (2.7V), the
MAX1811’s thermal loop may limit the charge current
until the cell voltage rises.
