Rainbow Electronics MAX1555 - Manual

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
♦ Protected by U.S. Patent #6,507,172
MAX1551/MAX1555
SOT23 Dual-Input USB/AC Adapter 1-Cell Li+
Battery Chargers
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-2902; Rev 0; 7/03
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
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
DC
1 5 BAT USB
MAX1551
(MAX1555)
THIN SOT23
TOP VIEW
2
3 4 POK
(CHG)
Pin Configuration
MAX1551
(MAX1555)
DC
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
*Protected by U.S. Patent #6,507,172.
Selector Guide
PART TOP MARK FEATURES
MAX1551EZK ADRT POK Output
MAX1555EZK ADRU CHG Output