Data Short ISL88732 (Intersil)

DATA SHORT To request the full datasheet, please visit www.intersil.com/products/isl88732 ISL88732 FN7946 SMBus Level 2 Battery Charger with Boost Mode Rev.0.00 September 25, 2012 The ISL88732 is a highly integrated Lithium-ion battery charger Features controller, programmable over the SMBus system management bus (SMBus). The ISL88732 is intended to be used in a smart • Boost Mode to support Intel “Turbo Mode” battery charger (SBC) within a smart battery system (SBS) that • Pin compatible with ISL88731 throttles the charge power such that the current from the AC-adapter is automatically limited. High efficiency is achieved • Over-temp and overcurrent protection with a DC/DC synchronous-rectifier buck converter, equipped • 0.5% battery voltage accuracy with diode emulation for enhanced light load efficiency. The • 4% adapter current limit accuracy ISL88732 charges one to four Lithium-ion series cells, and delivers up to 8A charge current. Integrated MOSFET drivers • 3% charge current accuracy and bootstrap diode result in fewer components and smaller • SMBus 2-wire serial interface implementation area. Low offset current-sense amplifiers • Charge current limited by SMBus DAC OR analog voltage at provide high accuracy with 10m sense resistors. The the CCLIM pin ISL88732 provides 0.5% end-of-charge battery voltage accuracy. • Turbo-boost discharge current limit can be set to 3.3x, 4.85x, 6.37x or 9.31x the charge current limit by SMBus command The ISL88732 is available in a small 5mmx5mm 28 Ld Thin (0.8mm) QFN package. • Monitor outputs - Adapter current (3% accuracy) Boost Mode - Adapter overcurrent ALERT#. Threshold set by resistor If system load current is higher than the adapter current limit, divider ISL88732 will operate in boost mode to draw power from the - AC-adapter detection battery and boost it to adapter voltage. System load current • 11-bit battery voltage setting will be supplied partly from the adapter and partly from the battery. • 6-bit charge current/adapter current setting ISL88732 performs this function by (1) detecting high adapter • 8A maximum battery charger current current, (2) reducing charge current to zero and (3) controlling • 11A maximum adapter current LFET ON time to boost current from the battery and limit • +8V to +22V adapter voltage range current from the adapter. • Pb-free (RoHS compliant) Applications • Notebook computers • Tablet PCs Typical Operating Performance
10 CC = 2.048A, AC = 2.048A, CV = 12.592V, VBAT = 10V 8 6 INPUT CURRENT LIMITED BY REDUCING CHARGE CURRENT INPUT CURRENT 4 (A) 2 NT INPUT CURRENT LIMITED BY BOOSTING CURRENT FROM BATTERY TO SYSTEM LOAD RE 0 DISCHARGE CUR -2 CURRENT LIMIT, INPUT CURRENT SYSTEM LOAD CURRENT -4 NO LONGER IN LIMIT -6 CHARGE CURRENT -8 0 1 2 3 4 5 6 7 8 SYSTEM LOAD CURRENT (A)
FIGURE 1. ISL88732 CURRENT CONTROL IN 4 MODES FN7946 Rev.0.00 Page 1 of 2 September 25, 2012