LTC3108 (Rev. D) - Analog Devices

1 LTC3108 . Ultralow Voltage Step-Up Converter and Power Manager FEATURES DESCRIPTION. nn Operates from Inputs of 20mV The LTC 3108 is a highly integrated DC/DC converter nn Complete Energy Harvesting Power ideal for harvesting and managing surplus energy from Management System extremely low input voltage sources such as TEGs (ther- nn Selectable V. OUT of , , or 5V moelectric generators), thermopiles and small solar cells. nn LDO: at 3mA The step-up topology operates from input voltages as nn Logic Controlled Output low as 20mV. The LTC3108 is functionally equivalent to nn Reserve Energy Output the LTC3108 -1 except for its unique fixed VOUT options.

2 Nn Power Good Indicator nn Uses Compact Step-Up Transformers Using a small step-up transformer, the LTC3108 provides nn Small 12-Lead (3mm 4mm) DFN or 16-Lead a complete power management solution for wireless sensing and data acquisition. The LDO powers an SSOP Packages external microprocessor, while the main output is pro- APPLICATIONS grammed to one of four fixed voltages to power a wire- less transmitter or sensors. The power good indicator nn Remote Sensors and Radio Power signals that the main output voltage is within regulation. nn Surplus Heat Energy Harvesting A second output can be enabled by the host.

3 A storage nn HVAC Systems capacitor provides power when the input voltage source nn Industrial Wireless Sensing is unavailable. Extremely low quiescent current and high nn Automatic Metering efficiency design ensure the fastest possible charge times nn Building Automation of the output reservoir capacitor. nn Predictive Maintenance The LTC3108 is available in a small, thermally enhanced All registered trademarks and trademarks are the property of their respective owners. 12-lead (3mm 4mm) DFN package and a 16-lead SSOP package. TYPICAL APPLICATION. Wireless Remote Sensor Application Powered From a Peltier Cell VOUT Charge Time 1nF.

4 1:100 5V. C1 VSTORE 1000. +. + + VOUT = THERMOELECTRIC LTC3108 COUT = 470 F. 220 F 330pF GENERATOR. C2 VOUT2 100. PGOOD. PGD P. 20mV TO 500mV SW VLDO. TIME (sec). F SENSORS 10. VS2 VOUT. + RF LINK. 470 F 1. 1:100 Ratio VS1 VOUT2_EN. 1:50 Ratio VAUX GND 3108 TA01a 1:20 Ratio 0. 0 50 100 150 200 250 300 350 400. 1 F. VIN (mV). 3108 TA01b Rev. D. Document Feedback For more information 1. LTC3108 . ABSOLUTE MAXIMUM RATINGS (Note 1). SW to 2V VS1, VS2, VAUX, VOUT, to 6V. C1 to 6V VLDO, to 6V. C2 Voltage (Note 5).. 8V to 8V Operating Junction Temperature Range VOUT2, to 6V (Note 2).

5 40 C to 125 C. 15mA into VAUX Storage Temperature 65 C to 125 C. PIN CONFIGURATION. TOP VIEW. TOP VIEW. GND 1 16 GND. VAUX 1 12 SW. VAUX 2 15 SW. VSTORE 2 11 C2. VSTORE 3 14 C2. VOUT 3 13 10 C1. VOUT 4 13 C1. GND. VOUT2 4 9 VOUT2_EN VOUT2 5 12 VOUT2_EN. VLDO 5 8 VS1 VLDO 6 11 VS1. PGD 6 7 VS2 PGD 7 10 VS2. GND 8 9 GND. DE PACKAGE. 12-LEAD (4mm 3mm) PLASTIC DFN. GN PACKAGE. TJMAX = 125 C, JA = 43 C/W 16-LEAD PLASTIC SSOP NARROW. EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB (NOTE 4). TJMAX = 125 C, JA = 110 C/W. ORDER INFORMATION. LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE.

6 LTC3108 EDE#PBF LTC3108 EDE#TRPBF 3108 12-Lead (4mm 3mm) Plastic DFN 40 C to 125 C. LTC3108 IDE#PBF LTC3108 IDE#TRPBF 3108 12-Lead (4mm 3mm) Plastic DFN 40 C to 125 C. LTC3108 EGN#PBF LTC3108 EGN#TRPBF 3108 16-Lead Plastic SSOP 40 C to 125 C. LTC3108 IGN#PBF LTC3108 IGN#TRPBF 3108 16-Lead Plastic SSOP 40 C to 125 C. Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.

7 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are for TA = 25 C (Note 2). VAUX = 5V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS. Minimum Start-Up Voltage Using 1:100 Transformer Turns Ratio, VAUX = 0V 20 50 mV. No-Load Input current Using 1:100 Transformer Turns Ratio; VIN = 20mV, VOUT2_ 3 mA. EN = 0V; All Outputs Charged and in Regulation Input Voltage Range Using 1:100 Transformer Turns Ratio l VSTARTUP 500 mV. Rev. D. 2 For more information LTC3108 . ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are for TA = 25 C (Note 2).

8 VAUX = 5V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS. Output Voltage VS1 = VS2 = GND l V. VS1 = VAUX, VS2 = GND l V. VS1 = GND, VS2 = VAUX l V. VS1 = VS2 = VAUX l V. VOUT quiescent current VOUT = , VOUT2_EN = 0V A. VAUX quiescent current No Load, All Outputs Charged 6 9 A. LDO Output Voltage Load l V. LDO Load Regulation For 0mA to 2mA Load 1 %. LDO Line Regulation For VAUX from to 5V %. LDO Dropout Voltage ILDO = 2mA 100 200 mV. LDO current Limit VLDO = 0V l 4 11 mA. VOUT current Limit VOUT = 0V l mA. VSTORE current Limit VSTORE = 0V l mA. VAUX Clamp Voltage current into VAUX = 5mA l 5 V.

9 VSTORE Leakage current VSTORE = 5V A. VOUT2 Leakage current VOUT2 = 0V, VOUT2_EN = 0V A. VS1, VS2 Threshold Voltage l V. VS1, VS2 Input current VS1 = VS2 = 5V A. PGOOD Threshold (Rising) Measured Relative to the VOUT Voltage %. PGOOD Threshold (Falling) Measured Relative to the VOUT Voltage 9 %. PGOOD VOL Sink current = 100 A V. PGOOD VOH Source current = 0 V. PGOOD Pull-Up Resistance 1 M . VOUT2_EN Threshold Voltage VOUT2_EN Rising l 1 V. VOUT2_EN Pull-Down Resistance 5 M . VOUT2 Turn-On Time 5 s VOUT2 Turn-Off Time (Note 3) s VOUT2 current Limit VOUT = l A. VOUT2 current Limit Response Time (Note 3) 350 ns VOUT2 P-Channel MOSFET On-Resistance VOUT = (Note 3).

10 N-Channel MOSFET On-Resistance C2 = 5V (Note 3) . Note 1: Stresses beyond those listed under Absolute Maximum Ratings temperature (TJ) is calculated from the ambient temperature (TA) and may cause permanent damage to the device. Exposure to any Absolute power dissipation (PD) according to the formula: TJ = TA + (PD JA C/W), Maximum Rating condition for extended periods may affect device where JA is the package thermal impedance. reliability and lifetime. Note 3: Specification is guaranteed by design and not 100% tested in Note 2: The LTC3108 is tested under pulsed load conditions such that TJ production.