PDF《LTC3526L/LTC3526LB》

LTC3526L/LTC3526LB 3526lfc n Medical Instruments n Noise Canceling Headphones n Wireless Mice n Bluetooth Headsets Applications 550mA 1MHz Synchronous Step-Up DC/DC Converters in 2mm * 2mm DFN The LTC? 3526L/LTC3526LB are synchronous, fixed frequency step-up DC/DC converters with output discon- nect.

Synchronous rectification enables high efficiency in the low profile 2mm * 2mm DFN package. Battery life in single AA/AAA powered products is extended further with a 680mV start-up voltage and operation down to 500mV once started. A switching frequency of 1MHz minimizes solution foot- print by allowing the use of tiny, low profile inductors and ceramic capacitors. The current mode PWM design is internally compensated, reducing external parts count. The LTC3526L features Burst Mode operation at light load conditions allowing it to maintain high efficiency over a widerangeofload.TheLTC3526LBfeaturesfixedfrequency operation for low noise applications. Anti-ring circuitry reduces EMI by damping the inductor in discontinuous mode. Additional features include a low shutdown current of under 1?A and thermal shutdown. The LTC3526L/LTC3526LB are housed in a 2mm * 2mm * 0.75mm DFN package. L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Delivers 3.3V at 100mA from a Single Alkaline/ NiMH Cell or 3.3V at 200mA from Two Cells n VIN Start-Up Voltage: 680mV n 1.5V to 5.25V VOUT Range n Up to 94% Efficiency n Output Disconnect n 1MHz Fixed Frequency Operation n VIN >

VOUT Operation n Integrated Soft-Start n Current Mode Control with Internal Compensation n Burst Mode? Operation with 9?A IQ (LTC3526L) n Low Noise PWM Operation (LT3526LB) n Internal Synchronous Rectifier n Logic Controlled Shutdown (IQ <

1?A) n Anti-Ring Control n Low Profile (2mm * 2mm * 0.75mm) DFN-6 Package SW VIN 1.78M 1M 3526l TA01a LTC3526L SHDN VOUT FB VIN 1.6V TO 3.2V VOUT 3.3V 200mA OFF ON 4.7?H 4.7?F 4.7?F GND LOAD CURRENT (mA) 0.01

40 EFFICIENCY (%) POWER LOSS (mW)

50 60

70 80 0.1

1 10

100 1000 3526l TA01b

30 20

10 0

90 100

1 10

100 0.1 0.01

1000 EFFICIENCY POWER LOSS VIN = 2.4V Efficiency and Power Loss vs Load Current Typical Application Features Description LTC3526L/LTC3526LB 3526lfc VIN Voltage. 0.3V to 6V SW Voltage DC. 0.3V to 6V Pulsed 1.230V (LTC3526L Only)

9 18 ?A N-Channel MOSFET Switch Leakage Current VSW = 5V 0.1

5 ?A P-Channel MOSFET Switch Leakage Current VSW = 5V, VOUT = 0V 0.1

10 ?A N-Channel MOSFET Switch On Resistance VOUT = 3.3V 0.4 Ω P-Channel MOSFET Switch On Resistance VOUT = 3.3V 0.6 Ω N-Channel MOSFET Current Limit l

550 750 mA Current Limit Delay to Output (Note 3)

60 ns Maximum Duty Cycle VFB = 1.15V l

87 90 % Minimum Duty Cycle VFB = 1.3V l

0 % Switching Frequency l 0.75

1 1.25 MHz SHDN Pin Input High Voltage 0.8 V SHDN Pin Input Low Voltage 0.3 V Pin Configuration TOP VIEW VOUT FB SHDN SW GND VIN DC PACKAGE 6-LEAD (2mm s 2mm) PLASTIC DFN

7 1

2 3

6 5

4 TJMAX = 125°C, θJA = 102°C/W (NOTE 6) EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PC BOARD Electrical Characteristics Absolute Maximum Ratings LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3526LEDC#PBF LTC3526LEDC#TRPBF LCSS 6-Lead (2mm * 2mm) Plastic DFN C40°C to 85°C LTC3526LBEDC#PBF LTC3526LBEDC#TRPBF LCST 6-Lead (2mm * 2mm) Plastic DFN C40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ Order Information LTC3526L/LTC3526LB 3526lfc Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTC3526LE/LTC3526LBE are guaranteed to meet performance specifications from 0°C to 85°C. Specifications over C40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: Specification is guaranteed by design and not 100% tested in production. Note 4: Current measurements are made when the output is not switching. Note 5: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125°C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may result in device degradation or failure. Note 6: Failure to solder the exposed backside of the package to the PC board ground plane will result in a thermal resistance much higher than 102°C/W. Efficiency vs Load Current and VIN for VOUT = 1.8V (LTC3526L) Efficiency vs Load Current and VIN for VOUT = 3.3V (LTC3526L) Efficiency vs Load Current and VIN for VOUT = 5V (LTC3526L) No-Load Input Current vs VIN (LTC3526L) Maximum Output Current vs VIN Minimum Load Resistance During Start-Up vs VIN LOAD CURRENT (mA) 0.01