MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers General Description Features The MAX1551/MAX1555 charge a single-cell lithium-ion Charge from USB or AC Adapter (Li+) battery from both USB and AC adapter sources. Automatic Switchover when AC Adapter is They operate with no external FETs or diodes, and Plugged In accept operating input voltages up to 7V. On-chip thermal limiting simplifies PC board layout and On-Chip Thermal Limiting Simplifies Board allows optimum charging rate without the thermal limits Design imposed by worst-case battery and input voltage. When Charge Status Indicator the MAX1551/MAX1555 thermal limits are reached, the chargers do not shut down, but progressively reduce 5-Pin Thin SOT23 Package charging current. The MAX1551 includes a POK output to indicate when input power is present. If either charging source is active, POK goes low. The MAX1555 instead features a Ordering Information CHG output to indicate charging status. With USB connected, but without DC power, charge cur- PART TEMP RANGE PIN-PACKAGE rent is set to 100mA (max). This allows charging from MAX1551EZK-T -40C to +85C 5 Thin SOT23-5 both powered and unpowered USB hubs with no port MAX1555EZK-T -40C to +85C 5 Thin SOT23-5 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/MAX1555 are available in 5-pin thin SOT23 packages and operate over a -40C to +85C range. Selector Guide PART TOP MARK FEATURES Applications MAX1551EZK ADRT POK Output PDAs MAX1555EZK ADRU CHG Output Wireless Appliances Cell Phones Functional Diagrams Digital Cameras Pin Configuration Typical Operating Circuit TOP VIEW AC ADAPTER DC BAT TO SYSTEM 3.7V TO 7V LOAD Li+ USB 15 BAT CHARGE MAX1551 CONTROL USB GND 2 USB (MAX1555) TO LOGIC RAIL 3.7V TO 6V LOGIC POK POK34 DC CONTROL (CHG) (CHG) MAX1551 THIN SOT23 (MAX1555) GND Pin Configurations appear at end of data sheet. Functional Diagrams continued at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. For pricing, delivery, and ordering information, please contact Maxim Direct 19-2902 Rev 0 7/03 at 1-888-629-4642, or visit Maxims website at www.maxim integrated.com. AVAILABLEMAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers ABSOLUTE MAXIMUM RATINGS DC to GND......................................................................0 to +8V Operating Temperature Range ...........................-40C to +85C DC to BAT.......................................................................0 to +7V Junction Temperature Range ............................-40C to +150C BAT, CHG, POK, USB to GND .................................-0.3V to +7V Storage Temperature Range .............................-65C to +150C Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) .................................+300C A 5-Pin Thin SOT23 (derate 9.1mW/C above +70C)....727mW 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 (V = 5V, V = 0, I = 0, C = 1F, T = 0C to +85C, unless otherwise noted.) DC USB BAT BAT A PARAMETER CONDITIONS MIN TYP MAX UNITS DC DC Voltage Range (Note 1) 3.7 7.0 V DC to BAT Voltage Range 0.1 6.0 V DC Undervoltage Lockout Input rising, 430mV hysteresis, V = 3V (Note 1) 3.75 3.95 4.15 V BAT Threshold DC Supply Current 1.75 3 mA DC to BAT On-Resistance V = 3.7V, V = 3.6V 1 2 DC BAT When charging stops, V = 4V, BAT DC to BAT Dropout Voltage 30 60 90 mV DC falling, 200mV hysteresis USB USB Voltage Range (Note 1) 3.7 6.0 V Input rising, 430mV hysteresis, V = 0, DC USB Undervoltage Threshold 3.75 3.95 4.15 V V = 3V (Note 1) BAT USB Supply Current V = 5V, V = 0 1.65 3 mA USB DC USB to BAT On-Resistance V = 3.7V, V = 3.6V, V = 0 2 4 USB BAT DC When charging stops, V = 4V, BAT USB to BAT Dropout Voltage 30 60 90 mV USB falling, 200mV hysteresis, V = 0 DC BAT BAT Regulation Voltage V or V = 5V 4.158 4.2 4.242 V DC USB DC Charging Current V = 3.3V, V = 0, V = 5V 220 280 340 mA BAT USB DC USB Charging Current V = 3.3V, V = 0, V = 5V 80 90 100 mA BAT DC USB BAT Prequal Threshold V rising, 100mV hysteresis 2.9 3 3.1 V BAT Prequalification Charging Current V = 2.8V 20 40 80 mA BAT BAT Leakage Current V = V = 0, V = 4.2V 5 A DC USB BAT POK, CHG, AND THERMAL LIMIT Charge current where CHG goes high, CHG Threshold 25 50 100 mA I falling, 50mA hysteresis BAT CHG, POK Logic-Low Output I , I = 10mA 150 300 mV CHG POK CHG, POK Leakage Current V , V = 6V, T = +25C 0.001 1 A CHG POK A Charge current reduced by 17mA/C above this Thermal-Limit Temperature +110 C temperature 2 Maxim Integrated