Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - battery management Charge management Li-Ion, Li-Po TSOT 23 5 Surface-mount

AVAILABLE

Functional Diagrams

Pin Configurations appear at end of data sheet.

Functional Diagrams continued at end of data sheet.

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ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

General Description

The MAX1551/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/MAX1555 thermal limits are reached, the

chargers do not shut down, but progressively reduce

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

CHG output to indicate charging status.

With USB connected, but without DC power, charge cur-

rent 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/MAX1555 are available in 5-pin thin SOT23

packages and operate over a -40°C to +85°C range.

Applications

PDAs

Wireless Appliances

Cell Phones

Digital Cameras

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

SOT23 Dual-Input USB/AC Adapter 1-Cell Li+

Battery Chargers

Ordering Information

19-2902; Rev 0; 7/03

PART TEMP RANGE PIN-PACKAGE

MAX1551EZK-T -40°C to +85°C 5 Thin SOT23-5

MAX1555EZK-T -40°C to +85°C 5 Thin SOT23-5

GND

15BATUSB

MAX1551

(MAX1555)

THIN SOT23

TOP VIEW

POK

(CHG)

Pin Configuration

MAX1551

(MAX1555)

USB

BAT

AC ADAPTER

3.7V TO 7V

USB

3.7V TO 6V

TO SYSTEM

LOAD

Li+

GND

TO LOGIC RAIL

CHARGE

CONTROL

POK

(CHG)

LOGIC

CONTROL

Typical Operating Circuit

Selector Guide

PART TOP MARK FEATURES

MAX1551EZK ADRT POK Output

MAX1555EZK ADRU CHG Output

MAX1551/MAX1555

Summary of content (8 pages)

PAGE 1
MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers LE AVAILAB General Description The MAX1551/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.
PAGE 2
MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers ABSOLUTE MAXIMUM RATINGS DC to GND......................................................................0 to +8V DC to BAT .......................................................................0 to +7V BAT, CHG, POK, USB to GND .................................-0.3V to +7V Continuous Power Dissipation (TA = +70°C) 5-Pin Thin SOT23 (derate 9.1mW/°C above +70°C) ....727mW Operating Temperature Range ...........................
PAGE 3
MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers ELECTRICAL CHARACTERISTICS (VDC = 5V, VUSB = 0, IBAT = 0, CBAT = 1µF, TA = -40°C to +85°C, unless otherwise noted.) (Note 2) PARAMETER CONDITIONS MIN MAX UNITS DC DC Voltage Range (Note 1) DC to BAT Voltage Range DC Undervoltage Lockout Threshold Input rising, 430mV hysteresis, VBAT = 3V (Note 1) 3.7 7.0 V 0.1 6.0 V 3.75 4.15 V 3 mA 2 Ω DC Supply Current DC to BAT On-Resistance VDC = 3.7V, VBAT = 3.
PAGE 4
MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers Typical Operating Characteristics (VDC = 5V, VUSB = 0, IBAT = 0, CBAT = 1µF, TA = +25°C, unless otherwise noted.) CHARGE CURRENT vs. DC VOLTAGE HEADROOM 150 100 50 40 20 -20 0.1 0.2 0.3 0.4 150 100 50 VDC = 0, VBAT = 3.8V, VUSB FALLING -50 -50 0.1 0 0.5 0.2 0.3 0.4 0.5 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.
PAGE 5
MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers Pin Description PIN NAME 1 USB USB Port Charger Supply Input. USB draws up to 100mA to charge the battery. Decouple USB with a 1µF ceramic capacitor to GND. 2 GND Ground POK Power-OK Active-Low Open-Drain Charger Status Indicator. POK pulls low when either charger source is present (MAX1551 only). CHG Active-Low Open-Drain Charge Status Indicator. CHG pulls low when the battery is charging.
PAGE 6
MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers Precharge Current not shut down, but progressively reduce charging current by 17mA/°C above a die temperature of +110°C. Solder the MAX1551/MAX1555s’ GND to a large ground plane to help dissipate power and keep the die temperature below the thermal limit. The USB charge current of 100mA is unlikely to induce thermal limiting. The MAX1551/MAX1555 feature a precharge current to protect deeply discharged cells.
PAGE 7
MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.
PAGE 8
MAX1551/MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+ Battery Chargers Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.