The MAX1870A step-up/step-down multichemistry battery charger charges with battery voltages above and below the adapter voltage. This highly integrated charger requires a minimum number of external components. The MAX1870A uses a proprietary step-up/stepdown control scheme that provides efficient charging. Analog inputs control charge current and voltage, and can be programmed by the host or hardwired.The MAX1870A accurately charges two to four lithiumion (Li+) series cells at greater than 4A. A programmable input current limit is included, which avoids overloading the AC adapter when supplying the load and the battery charger simultaneously. This reduces the maximum adapter current, which reduces cost. The MAX1870A provides analog outputs to monitor the current drawn from the AC adapter and charge current. A digital output indicates the presence of an AC adapter. When the adapter is removed, the MAX1870A consumes less than 1µA from the battery.The MAX1870A is available in a 32-pin thin QFN (5mm x 5mm) package and is specified over the -40°C to +85°C extended temperature range. The MAX1870A evaluation kit (MAX1870AEVKIT) is available to help reduce design time.ApplicationsHandheld TerminalsNotebook and Subnotebook Computers

The MAX1874 charges a single-cell Li+ battery from both USB and AC adapter sources. It also includes battery-to-input power switchover, so the system can be powered directly from the power source rather than from the battery.In its simplest application, the MAX1874 needs no external MOSFET or diodes, and accepts input voltages up to 6.5V; however, DC input overvoltage protection up to 18V can be added with a single SOT PFET.On-chip thermal limiting simplifies printed circuit board (PCB) layout and allows optimum charging rate without the thermal limits imposed by worst-case battery and input voltage. When the MAX1874 thermal limit is reached, the charger does not shut down but simply reduces charging current.Ambient or battery temperature can be monitored with an external thermistor. When the temperature is out of range, charging pauses.Other features include an active-low CHG output to indicate when battery current tapers below a predetermined level. DC power-OK (active-low DCOK), USB power-OK (active-low UOK), and power-on (PON) outputs indicate when valid power is present. These outputs drive logic or power-selection MOSFETs to disconnect the charging sources from the load and to protect the MAX1874 from overvoltage.The MAX1874 contains no logic for communication with the USB host. It must receive instructions from a local microcontroller. The MAX1874 is available in a 16-pin 5mm x 5mm thin QFN package and operates over the -40°C to +85°C temperature range.ApplicationsCell PhonesDigital CamerasPDAsWireless Appliances

The low-cost MAX1873R/S/T provides all functions needed to simply and efficiently charge 2-, 3-, or 4-series lithium-ion cells at up to 4A or more. It provides a regulated charging current and voltage with less than ±0.75% total voltage error at the battery terminals. An external P-channel MOSFET operates in a step-down DC-DC configuration to efficiently charge batteries in low-cost designs.The MAX1873R/S/T regulates the battery voltage and charging current using two control loops that work together to transition smoothly between voltage and current regulation. An additional control loop limits current drawn from the input source so that AC adapter size and cost can be minimized. An analog voltage output proportional to charging current is also supplied so that an ADC or microcontroller can monitor charging current.The MAX1873 may also be used as an efficient current-limited source to charge NiCd or NiMH batteries in multichemistry charger designs. The MAX1873R/S/T is available in a space-saving 16-pin QSOP package. Use the evaluation kit (MAX1873EVKIT) to help reduce design time.Applications2-, 3-, or 4-Cell Li+ Battery Pack Chargers6-, 9-, or 10-Cell Li+ Battery Pack ChargersDesktop Cradle ChargersHandheld Instruments (PDAs, Palmtops)Notebook ComputersPortable Desktop Assistants (PDAs)Portable Internet Tablets

The low-cost MAX1873R/S/T provides all functions needed to simply and efficiently charge 2-, 3-, or 4-series lithium-ion cells at up to 4A or more. It provides a regulated charging current and voltage with less than ±0.75% total voltage error at the battery terminals. An external P-channel MOSFET operates in a step-down DC-DC configuration to efficiently charge batteries in low-cost designs.The MAX1873R/S/T regulates the battery voltage and charging current using two control loops that work together to transition smoothly between voltage and current regulation. An additional control loop limits current drawn from the input source so that AC adapter size and cost can be minimized. An analog voltage output proportional to charging current is also supplied so that an ADC or microcontroller can monitor charging current.The MAX1873 may also be used as an efficient current-limited source to charge NiCd or NiMH batteries in multichemistry charger designs. The MAX1873R/S/T is available in a space-saving 16-pin QSOP package. Use the evaluation kit (MAX1873EVKIT) to help reduce design time.Applications2-, 3-, or 4-Cell Li+ Battery Pack Chargers6-, 9-, or 10-Cell Li+ Battery Pack ChargersDesktop Cradle ChargersHandheld Instruments (PDAs, Palmtops)Notebook ComputersPortable Desktop Assistants (PDAs)Portable Internet Tablets

The MAX1925/MAX1926 single-cell lithium-ion (Li+) switch-mode battery chargers use an external PMOS pass element step-down configuration. Charge current is programmable, and an external capacitor sets the maximum charge time.Additional features include automatic input power detection (active-low ACON output), logic-controlled enable, and temperature monitoring with an external thermistor. The MAX1925 disables charging for inputs greater than 6.1V, while the MAX1926 charges for inputs between 4.25V and 12V.The MAX1925/MAX1926 feature two precondition levels to restore near-dead cells. The devices source 4mA to a cell that is below 2V while sourcing C/10 to a cell between 2V and 3V. Full charge current is then applied above 3V. A active-low CHG output drives an LED to indicate charging (LED on) and fault conditions (LED blinking).The MAX1925/MAX1926 are available in a 12-pin 4mm x 4mm thin QFN package and are specified over the extended temperature range (-40°C to +85°C). An evaluation kit is available to speed design.ApplicationsCradle ChargersDigital Still CamerasPDAsSelf-Charging Battery Packs

The MAX14745 is a battery-charge-management solution ideal for low-power wearable applications. The device includes a linear battery charger with a smart power selector and several power-optimized peripherals. The MAX14745 features two ultra-low quiescent current buck regulators and three ultra-low quiescent current low-dropout (LDO) linear regulators, providing up to five regulated voltages, each with an ultra-low quiescent current, allows designers to minimize power consumption and extend battery life in 24/7 operation devices, such as those in the wearable market.The battery charger features a smart power selector that allows operation on a dead battery when connected to a power source. To avoid overloading a power adapter, the input current to the smart power selector is limited based on an I2C register setting. If the charger power source is unable to supply the entire system load, the smart power control circuit supplements the system load with current from the battery. The charger also supports temperature dependent charge currents.The two synchronous, high-efficiency step-down buck regulators feature a variable frequency mode for increased efficiency during light-load operation. The output voltage of these regulators can be programmed through I2C with the default preconfigured. The buck regulators cansupport dynamic voltage scaling to further improve system power consumption.The three configurable LDOs each have a dedicated input pin. Each LDO regulator output voltage can be programmed through I2C with the default preconfigured. The linear regulators can also be configured to operate as power switches that may be used to disconnect the quiescent load of the system peripherals.The MAX14745 features a programmable power controller that allows the device to be configured for applications that require the device be in a true-off, or always-on, state. The controller also provides a delayed reset signal and voltage sequencing.The MAX14745 is available in a 36-bump, 0.4mm pitch, 2.72mm x 2.47mm wafer-level package (WLP).ApplicationsFitness MonitorsRechargeable IoT devicesWearable Electronics

The MAX14745 is a battery-charge-management solution ideal for low-power wearable applications. The device includes a linear battery charger with a smart power selector and several power-optimized peripherals. The MAX14745 features two ultra-low quiescent current buck regulators and three ultra-low quiescent current low-dropout (LDO) linear regulators, providing up to five regulated voltages, each with an ultra-low quiescent current, allows designers to minimize power consumption and extend battery life in 24/7 operation devices, such as those in the wearable market.The battery charger features a smart power selector that allows operation on a dead battery when connected to a power source. To avoid overloading a power adapter, the input current to the smart power selector is limited based on an I2C register setting. If the charger power source is unable to supply the entire system load, the smart power control circuit supplements the system load with current from the battery. The charger also supports temperature dependent charge currents.The two synchronous, high-efficiency step-down buck regulators feature a variable frequency mode for increased efficiency during light-load operation. The output voltage of these regulators can be programmed through I2C with the default preconfigured. The buck regulators cansupport dynamic voltage scaling to further improve system power consumption.The three configurable LDOs each have a dedicated input pin. Each LDO regulator output voltage can be programmed through I2C with the default preconfigured. The linear regulators can also be configured to operate as power switches that may be used to disconnect the quiescent load of the system peripherals.The MAX14745 features a programmable power controller that allows the device to be configured for applications that require the device be in a true-off, or always-on, state. The controller also provides a delayed reset signal and voltage sequencing.The MAX14745 is available in a 36-bump, 0.4mm pitch, 2.72mm x 2.47mm wafer-level package (WLP).ApplicationsFitness MonitorsRechargeable IoT devicesWearable Electronics

The MAX14745 is a battery-charge-management solution ideal for low-power wearable applications. The device includes a linear battery charger with a smart power selector and several power-optimized peripherals. The MAX14745 features two ultra-low quiescent current buck regulators and three ultra-low quiescent current low-dropout (LDO) linear regulators, providing up to five regulated voltages, each with an ultra-low quiescent current, allows designers to minimize power consumption and extend battery life in 24/7 operation devices, such as those in the wearable market.The battery charger features a smart power selector that allows operation on a dead battery when connected to a power source. To avoid overloading a power adapter, the input current to the smart power selector is limited based on an I2C register setting. If the charger power source is unable to supply the entire system load, the smart power control circuit supplements the system load with current from the battery. The charger also supports temperature dependent charge currents.The two synchronous, high-efficiency step-down buck regulators feature a variable frequency mode for increased efficiency during light-load operation. The output voltage of these regulators can be programmed through I2C with the default preconfigured. The buck regulators cansupport dynamic voltage scaling to further improve system power consumption.The three configurable LDOs each have a dedicated input pin. Each LDO regulator output voltage can be programmed through I2C with the default preconfigured. The linear regulators can also be configured to operate as power switches that may be used to disconnect the quiescent load of the system peripherals.The MAX14745 features a programmable power controller that allows the device to be configured for applications that require the device be in a true-off, or always-on, state. The controller also provides a delayed reset signal and voltage sequencing.The MAX14745 is available in a 36-bump, 0.4mm pitch, 2.72mm x 2.47mm wafer-level package (WLP).ApplicationsFitness MonitorsRechargeable IoT devicesWearable Electronics

The MAX14746/MAX14747 are a series of USB charger detectors with an integrated Smart Power Selector™ linear charger solutions that provide a single-chip solution for charging and charger detection.The MAX14746/MAX14747 charger detectors are compliant to USB Battery Charger Detection Rev 1.2* and capable of detecting multiple USB battery-charging methods, including Standard Downstream Ports (SDP), Charging Downstream Ports (CDP), and Dedicated Charger Ports (DCP). The devices also detect common proprietary charge adapters, including those from Apple.The MAX14746/MAX14747 battery chargers feature Smart Power Selector operation, allowing operation with dead or no battery present. The devices limits USB VBUS current based on the detect charger source type. If the charger power source is unable to supply the entire system load, the smart-power control circuit supplements the system load with current from the battery.The devices protect against overvoltage faults up to 28V. This series of USB charger detectors are available with several options, with slight variations in, for example, power-up states. These variations are noted throughout this data sheet.There are five options available with slight variations in, for example, power-up states. The devices are available in a 25-ball, 0.4mm pitch wafer-level package (WLP), and are specified over the -40°C to +85°C extended temperature range.ApplicationsPortable Consumer DevicesPortable Digital CamerasPortable Digital Video CamerasPortable Industrial Devices

The MAX14746/MAX14747 are a series of USB charger detectors with an integrated Smart Power Selector™ linear charger solutions that provide a single-chip solution for charging and charger detection.The MAX14746/MAX14747 charger detectors are compliant to USB Battery Charger Detection Rev 1.2* and capable of detecting multiple USB battery-charging methods, including Standard Downstream Ports (SDP), Charging Downstream Ports (CDP), and Dedicated Charger Ports (DCP). The devices also detect common proprietary charge adapters, including those from Apple.The MAX14746/MAX14747 battery chargers feature Smart Power Selector operation, allowing operation with dead or no battery present. The devices limits USB VBUS current based on the detect charger source type. If the charger power source is unable to supply the entire system load, the smart-power control circuit supplements the system load with current from the battery.The devices protect against overvoltage faults up to 28V. This series of USB charger detectors are available with several options, with slight variations in, for example, power-up states. These variations are noted throughout this data sheet.There are five options available with slight variations in, for example, power-up states. The devices are available in a 25-ball, 0.4mm pitch wafer-level package (WLP), and are specified over the -40°C to +85°C extended temperature range.ApplicationsPortable Consumer DevicesPortable Digital CamerasPortable Digital Video CamerasPortable Industrial Devices