SOT23, Dual-Input, USB/AC Adapter, 1-Cell Li+ Battery Chargers
First Dual-Input, USB/AC-Adapter, Li+ Chargers in a SOT23 Package Require No External FETs or Diodes
DescriptionThe MAX1551 and MAX1555 charge a single-cell lithium-ion (Li+) battery from both USB and AC adapter sources. They operate with no external FETs or diodes, and accept operating input voltages up to 7V.
On-chip thermal limiting simplifies PC board layout and allows optimum charging rate without the thermal limits imposed by worst-case battery and input voltage. When the MAX1551 and MAX1555 thermal limits are reached, the chargers do not shut down, but progressively reduce charging current.
The MAX1551 includes an active-low POK output to indicate when input power is present. If either charging source is active, active-low POK goes low. The MAX1555 instead features a active-low CHG output to indicate charging status.
With USB connected, but without DC power, charge current is set to 100mA (max). This allows charging from both powered and unpowered USB hubs with no port communication required. When DC power is connected, charging current is set at 280mA (typ). No input-blocking diodes are required to prevent battery drain.
The MAX1551 and MAX1555 are available in 5-pin thin SOT23 packages and operate over a -40°C to +85°C range.
- Charge from USB or AC Adapter
- Automatic Switchover when AC Adapter is Plugged In
- On-Chip Thermal Limiting Simplifies Board Design
- Charge Status Indicator
- 5-Pin Thin SOT23 Package
- Cell Phones
- Digital Cameras
- Wireless Appliances
|Part Number||Charging VIN|
|Cell Chemistry||# Lithium Ion Cells|
Technical DocumentsTutorial 4691 Introduction to Hearing Aids and Important Design Considerations
Tutorial 4686 Important Design Considerations for Heart-Rate and Fitness Monitors
App Note 4572 Reverse Battery Charger Protection
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|
- Low Power Consumption
- Delivers USB Compliance and Flexibility
- Simplifies Complex System Designs
- Optimized Feature Set for Supercapacitor Charging
- Reliable Operation in Adverse Environmental Conditions
- Up to 16V Protection
- 13.7V Maximum Input Operating Voltage
- 3.15A Maximum Charging Current
- 3.5V to 23V Input Operating Range, 30VDC Withstand Voltage
- Reverse Leakage Protection
- 50mA to 3.15A Programmable Input Current Limit
- Battery Health + Programmable Safety/Protection
- ModelGauge m5 EZ Algorithm
- Precision Measurement Without Calibration
|Tutorial||4691||Introduction to Hearing Aids and Important Design Considerations|
|Tutorial||4686||Important Design Considerations for Heart-Rate and Fitness Monitors|
|App Note||4572||Reverse Battery Charger Protection|