Rainbow Electronics MAX8730 - Manual

MAX8730
Low-Cost Battery Charger
________________________________________________________________ Maxim Integrated Products 1
19-3885; Rev 0; 12/05
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.
EVALUATION KIT
AVAILABLE
General Description
The MAX8730 highly integrated, multichemistry, battery-
charger control IC simplifies construction of accurate
and efficient chargers. The MAX8730 operates at high
switching frequency to minimize external component
size and cost. The MAX8730 uses analog inputs to con-
trol charge current and voltage, and can be pro-
grammed by a microcontroller or hardwired.
The MAX8730 reduces charge current to give priority to
the system load, effectively limiting the adapter current
and reducing the adapter current requirements.
The MAX8730 provides a digital output that indicates
the presence of an AC adapter, and an analog output
that monitors the current drawn from the AC adapter.
Based on the presence and absence of the AC
adapter, the MAX8730 automatically selects the appro-
priate source for supplying power to the system by con-
trolling two external switches. Under system control, the
MAX8730 allows the battery to undergo a relearning
cycle in which the battery is completely discharged
through the system load and then recharged.
An analog output indicates adapter current or battery-
discharge current. The MAX8730 provides a low-quies-
cent-current linear regulator, which may be used when
the adapter is absent, or disabled for reduced current
consumption
The MAX8730 is available in a small, 5mm x 5mm, 28-
pin, thin (0.8mm) QFN package. An evaluation kit is
available to reduce design time. The MAX8730 is
available in a lead-free package.
Applications
Notebook Computers
Tablet PCs
Portable Equipment with Rechargeable Batteries
Features
♦ Small Inductor (3.5µH)
♦ Programmable Charge Current > 4.5A
♦ Automatic Power-Source Selection
♦ Analog Inputs Control Charge Current and
Charge Voltage
♦ Monitor Outputs for
AC Adapter Current
Battery-Discharge Current
AC Adapter Presence
♦ Independent 3.3V 20mA Linear Regulator
♦ Up to 17.6V (max) Battery Voltage
♦ +8V to +28V Input Voltage Range
♦ Reverse Adapter Protection
♦ System Short-Circuit Protection
♦ Cycle-by-Cycle Current Limit
Ordering Information
PART
TEMP
RANGE
PIN-
PACKAGE PKG
CODE
MAX8730ETI+ -40°C to +85°C
28 Thin QFN
(5mm x 5mm)
T2855-5
+Denotes lead-free package.
Pin Configuration appears at end of data sheet.
MAX8730
ADAPTER
INPUT
PDS
SRC
ASNS
ACIN
ACOK
VCTL LDO
CLS
ICTL
MODE
REFON
INPON LDO
RELTH
REF
SWREF
BATT
CSIN
CSIP
DHI
PDL
DHIV
IINP CCV
CCI CCS
CSSP CSSN
GND
REF
HOST
SYSTEM
LOAD
BATTERY
Typical Operating Circuit