MAX1555

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


Please check latest availability status for a specific part variant.

Description

The 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.
MAX1551, MAX1555: Typical Operating Circuit MAX1551, MAX1555: Typical Operating Circuit Enlarge+

Key Features

  • 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

Applications/Uses

  • Cell Phones
  • Digital Cameras
  • PDAs
  • Wireless Appliances
Part Number Lithium Ion Cells Protected VIN
(V)
Charging VIN
(V)
Charge Rate Set by Max. ICHG
(A)
Charge Termination Charge Regulation Oper. Temp.
(°C)
Package/Pins Budgetary
Price
max max See Notes
MAX1551  1 7 7 Preset 0.28 External Control Linear -40 to +85
TSOT/5
$0.85 @1k
MAX1555 
TSOT/5
See All Battery Chargers (78)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Technical Documents

Tutorial 4691 Introduction to Hearing Aids and Important Design Considerations
Tutorial 4686 Important Design Considerations for Heart-Rate and Fitness Monitors
Reference Schematic 3241 Charging Batteries Using USB Power

Quality and Environmental Data

Product Reliability Reports: MAX1555.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

Topmark Coding MAX1555
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >

Related Resources


MAX17843
12-Channel, High-Voltage Smart Sensor Data-Acquisition Interface

  • 12-Cell Battery-Voltage Measurement for Lithium-Ion, NiMH, or Super-Cap Cells
  • Two Auxiliary Analog Inputs for NTC Thermistor or Absolute Voltage Measurement
  • Die Temperature Measurement and alert

Type ID Title
Reference Circuit3241Charging Batteries Using USB Power