ISL88731C Datasheet, PDF (1/25 Pages) Intersil Corporation – SMBus Level 2 Battery Charger

SMBus Level 2 Battery Charger
ISL88731C
The ISL88731C is a highly integrated Lithium-ion
battery charger controller, programmable over the
SMBus system management bus (SMBus). The
ISL88731C is intended to be used in a smart battery
charger (SBC) within a smart battery system (SBS) that
throttles the charge power such that the current from
the AC-adapter is automatically limited. High efficiency
is achieved with a DC/DC synchronous-rectifier buck
converter, equipped with diode emulation for enhanced
light load efficiency and system bus boosting
prevention. The ISL88731C charges one to four
Lithium-ion series cells, and delivers up to 8A charge
current. Integrated MOSFET drivers and bootstrap
diode result in fewer components and smaller
implementation area. Low offset current-sense
amplifiers provide high accuracy with 10mΩ sense
resistors. The ISL88731C provides 0.5% end-of-charge
battery voltage accuracy.
The ISL88731C provides a digital output that indicates
the presence of the AC adapter as well as an analog
output which indicates the adapter current within 4%
accuracy.
The ISL88731C is available in a small 5mmx5mm
28 Ld Thin (0.8mm) QFN package. An evaluation kit is
available to reduce design time. The ISL88731C is
available in Pb-Free packages.
Features
• 0.5% Battery Voltage Accuracy
• 3% Adapter Current Limit Accuracy
• 3% Charge Current Accuracy
• SMBus 2-Wire Serial Interface
• Battery Short Circuit Protection
• Fast Response for Pulse-Charging
• Fast System-Load Transient Response
• Monitor Outputs
- Adapter Current (3% Accuracy)
- AC-Adapter Detection
• 11-Bit Battery Voltage Setting
• 6 Bit Charge Current/Adapter Current Setting
• 8A Maximum Battery Charger Current
• 11A Maximum Adapter Current
• +8V to +26V Adapter Voltage Range
• Pb-Free (RoHS Compliant)
Applications*(see page 24)
• Notebook Computers
• Tablet PCs
• Portable Equipment with Rechargeable Batteries
Related Literature*(see page 24)
• See AN1404 for “ISL88731EVAL2Z Evaluation Board
Setup Procedure”
13.0
3.5
12.5
12.0
11.5
11.0
3.0
2.5
VCHG (V)
2.0
1.5
1.0
10.5
ICHG (A)
0.5
10.0
0
0.0
20 40 60 80 100 120 140 160
CHARGE TIME (MINUTES)
FIGURE 1. TYPICAL CHARGING VOLTAGE AND
CURRENT
100
95
16.8V BATTERY
90
12.6V BATTERY
8.4V BATTERY
85
4.2V BATTERY
80
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
I_OUT (A)
FIGURE 2. EFFICIENCY vs CHARGE CURRENT AND
BATTERY VOLTAGE
March 8, 2010
FN6978.0
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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