ISL88731C_14 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.
Related Literature
• See AN1404 for “ISL88731EVAL2Z and ISL88731CEVAL2Z
Evaluation Boards Setup Procedure”
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
• Notebook Computers
• Tablet PCs
• Portable Equipment with Rechargeable Batteries
13.0
3.5
3.0
12.5
2.5
12.0
VCHG (V)
2.0
11.5
1.5
11.0
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
June 8, 2011
1
FN6978.3
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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