LTC3558 Linear USB Battery Charger with Buck and Buck-Boost Regulators FEATURES DESCRIPTION Battery Charger The LTC 3558 is a USB battery charger with dual high ef- n Standalone USB Charger ciency switching regulators. The device is ideally suited n Up to 950mA Charge Current Programmable via to power single-cell Li-Ion/Polymer based handheld ap- Single Resistor plications needing multiple supply rails. n HPWR Input Selects 20% or 100% of Programmed Battery charge current is programmed via the PROG pin Charge Current and the HPWR pin with capability up to 950mA of current n NTC Input for Temperature Quali ed Charging at the BAT pin. The CHRG pin allows battery status to be n Internal Timer Termination monitored continuously during the charging process. An n Bad Battery Detection internal timer controls charger termination. Switching Regulators (Buck and Buck-Boost) The part includes monolithic synchronous buck and buck- n Up to 400mA Output Current per Regulator boost regulators that can provide up to 400mA of output n 2.25MHz Constant-Frequency Operation current each and operate at ef ciencies greater than 90% n Power Saving Burst Mode Operation over the entire Li-Ion/Polymer battery range. The buck- n Low Pro le, 20-Lead, 3mm 3mm QFN Package boost regulator can regulate its programmed output voltage at its rated deliverable current over the entire Li-Ion range without drop out, increasing battery runtime. APPLICATIONS The LTC3558 is offered in a low pro le (0.75mm), thermally n SD/Flash-Based MP3 Players enhanced, 20-lead (3mm 3mm) QFN package. n Low Power Handheld Applications , LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION USB Charger Plus Buck Regulator and Buck-Boost Regulator Demo Board USB (4.3V TO 5.5V) V BAT CC + SINGLE 1F PV IN1 Li-lon CELL PV (2.7V TO 4.2V) 1.74k IN2 PROG 10F 1.2V AT 400mA NTC SW1 4.7H LTC3558 10pF 10F 324k CHRG FB1 SWAB2 649k SUSP 2.2H HPWR 3.3V AT 400mA DIGITAL SWCD2 CONTROL V MODE OUT2 121k 22F EN1 324k 33pF EN2 FB2 15k 105k 330pF 10pF EXPOSED GND PAD V C2 3558 TA01 3558f 1LTC3558 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) V (Transient) TOP VIEW CC t < 1ms and Duty Cycle < 1% ....................... 0.3V to 7V V (Static) .................................................. 0.3V to 6V CC 20 19 18 17 16 BAT, CHRG ................................................... 0.3V to 6V 15 EN2 GND 1 14 V BAT 2 PROG, SUSP .................................0.3V to (V + 0.3V) C2 CC 21 FB2 MODE 3 13 HPWR, NTC ................... 0.3V to Max (V , BAT) + 0.3V CC 4 SUSP FB1 12 PROG Pin Current ...............................................1.25mA 5 11 V EN1 OUT2 BAT Pin Current ..........................................................1A 6 7 8 9 10 PV , PV ..................................0.3V to (BAT + 0.3V) IN1 IN2 EN1, EN2, MODE, V .............................. 0.3V to 6V OUT2 UD PACKAGE FB1, SW1 ......................... 0.3V to (PV + 0.3V) or 6V IN1 20-LEAD (3mm 3mm) PLASTIC QFN FB2, V , SWAB2 ............. 0.3V to (PV + 0.3V) or 6V C2 IN2 T = 125C, = 68C/W JMAX JA SWCD2 ............................0.3V to (V + 0.3V) or 6V EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB OUT2 I ...............................................................600mA DC SW1 I , I , I ................................... 750mA DC SWAB2 SWCD2 VOUT2 Junction Temperature (Note 2) ............................. 125C Operating Temperature Range (Note 3).... 40C to 85C Storage Temperature .............................. 65C to 125C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3558EUD PBF LTC3558EUD TRPBF LDCD 40C to 85C 20-Lead (3mm 3mm) Plastic QFN Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: