Document
19-3885; Rev 0; 12/05
KIT ATION EVALU LE B A IL A AV
Low-Cost Battery Charger
General Description 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
MAX8730
The MAX8730 highly integrated, multichemistry, batterycharger 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 control charge current and voltage, and can be programmed 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 appropriate source for supplying power to the system by controlling two external switches. Under system control, the MAX8730 allows the battery to undergo a relearning Ordering Information cycle in which the battery is completely discharged PINPKG TEMP through the system load and then recharged. PART RANGE PACKAGE CODE An analog output indicates adapter current or batterydischarge current. The MAX8730 provides a low-quies28 Thin QFN MAX8730ETI+ -40°C to +85°C T2855-5 www.DataSheet4U.com (5mm x 5mm) cent-current linear regulator, which may be used when the adapter is absent, or disabled for reduced current +Denotes lead-free package. consumption The MAX8730 is available in a small, 5mm x 5mm, 28pin, thin (0.8mm) QFN package. An evaluation kit is available to reduce design time. The MAX8730 is Typical Operating Circuit available in a lead-free package.
Applications
Notebook Computers Tablet PCs Portable Equipment with Rechargeable Batteries
ADAPTER INPUT
SYSTEM LOAD
CSSP PDS SRC
CSSN DHIV PDL
DHI ASNS
MAX8730
CSIP CSIN BATT SWREF REF
BATTERY
LDO REF
ACIN ACOK VCTL CLS MODE ICTL REFON INPON
HOST
RELTH LDO CCS CCV GND
Pin Configuration appears at end of data sheet.
IINP CCI
________________________________________________________________ Maxim Integrated Products
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Low-Cost Battery Charger MAX8730
ABSOLUTE MAXIMUM RATINGS
CSSP, SRC, A C O K, ASNS, DHIV, BATT, CSIP to GND.......................................................-0.3V to +30V CSIP to CSIN or CSSP to CSSN ...............