Datasheet LTC3100 (Analog Devices)

LTC3100 1.5MHz Synchronous Dual Channel DC/DC Converter and 100mA LDO
FEATURES DESCRIPTION
n
Extremely Compact Triple-Rail Solution
The LTC®3100 combines a high efficiency 700mA syn- n
Burst Mode
®
Operation, IQ = 15µA
chronous step-up converter, a 250mA synchronous step- n
1.5MHz Fixed Frequency Operation
down converter and a 100mA LDO regulator. The LTC3100 n Power Good Indicators features a wide input voltage range of 0.65V to 5V. The n
700mA Synchronous Step-Up DC/DC
step-down converter can be powered by the output of 0.65V to 5V VIN Range the step-up converter or from a separate power source 1.5V to 5.25V VOUT Range between 1.8V and 5.5V. The LDO can also be used as a 94% Peak Efficiency sequencing switch on the output of the boost. VIN > VOUT Operation A switching frequency of 1.5MHz minimizes solution foot- Output Disconnect print by allowing the use of tiny, low profile inductors and n
250mA Synchronous Step-Down DC/DC
ceramic capacitors. The switching regulators use current 1.8V to 5.5V VIN Range mode control and are internally compensated, reducing 0.6V to 5.5V VOUT Range external parts count. Each converter automatically transi- n
LDO (VIN Internally Tied to VBST)
tions to Burst Mode operation to maintain high efficiency 0.6V to 5.25V VOUT Range over the full load range. Burst Mode operation can be 200mV Dropout Voltage at 100mA disabled for low noise applications. The integrated LDO n Available in a 16-Lead 3mm × 3mm QFN Package provides a third low noise, low dropout supply. Anti-ringing circuitry reduces EMI by damping the boost
APPLICATIONS
inductor in discontinuous mode. Additional features include shutdown current of under 1µA and overtem- n Bar Code Readers perature shutdown. The LTC3100 is housed in a 16-lead n Medical Instruments 3mm × 3mm 0.75mm QFN package. n Low Power Portable Electronic Devices , 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 Efficiency and Power Loss Two-Cell, Triple Output Converter vs Load Current, VIN = 2.4V
3.3µH 3.3V AT 100mA VBOOST 100 1000 10µF VBATT SWBST V 1.87M INBK VBST 1M 1.6V TO 3.2V ×2 90 VINBST FBBST 80 100 2.2µF 1.07M BOOST_GOOD POWER LOSS (mW) 70 LTC3100 PGBST 3V AT 50mA 60 10 VLDO VLDO 50 102k 2.2µF 40 1 FBLDO EFFICIENCY (%) 25.5k 30 FF EN_BURST MODE BOOST 4.7µH 1.8V AT 200mA 20 0.1 BUCK SWBK VBUCK 10 PL, BOOST BOOST OFF ON RUNBST PL, BUCK 2M 10µF 0 0.01 OFF ON RUNLDO FBBK 0.01 0.1 1 10 100 1000 LDO 1M LOAD CURRENT (mA) 1M OFF ON RUNBK GND PGBK 3100 TA01b BUCK 3100 TA01a BUCK_GOOD 3100fb For more information www.linear.com/LTC3100 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts