15V, 200mA Synchronous Buck-Boost DC/DC Converter with 1.3μA Quiescent Current
Features and Benefits
- 680nA Input Quiescent Current (Output in Regulation at No Load)
- 1.8V to 5.5V Input Operating Range
- Selectable Output Voltages of 1.8V, 2.5V, 2.8V, 3V, 3.3V, 3.6V, 4.5V, 5V
- Integrated Coulomb Counter Measures Accumulated Battery Discharge
- ±5% Battery Discharge Measurement Accuracy
- Programmable Peak Input Current of 5mA, 10mA, 15mA, 25mA, 50mA, 100mA, 150mA, 250mA
- Up to 50mA of Output Current
- Up to 90% Efficiency
- Programmable Coulomb Counter Prescaler for Wide Range of Battery Sizes
- Programmable Discharge Alarm Threshold
- I2C Interface
- Low Profile (0.75mm) 20-Lead (3mm × 4mm) QFN Package
The LTC3335 is a high efficiency, low quiescent current (680nA) buck-boost DC/DC converter with an integrated precision coulomb counter which monitors accumulated battery discharge in long life battery powered applications. The buck-boost can operate down to 1.8V on its input and provides eight pin-selectable output voltages with up to 50mA of output current.
The coulomb counter stores the accumulated battery discharge in an internal register accessible via an I2C interface. The LTC3335 features a programmable discharge alarm threshold. When the threshold is reached, an interrupt is generated at the IRQ pin.
To accommodate a wide range of battery types and sizes, the peak input current can be selected from as low as 5mA to as high as 250mA and the full-scale coulomb counter has a programmable range of 32,768:1.
The LTC3335 is available in a 3mm × 4mm QFN-20 package.
- Long Lifetime Primary Cell Battery Applications
- Wireless Sensors
- Remote Monitors
- Dust Networks® SmartMesh® Applications
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
The DC2369A demo circuit is a reference design that implements a wireless current sense solution using Analog Device's low power integrated circuits. The only external connection needed is the current to be measured, allowing this circuit to be inserted at any voltage level or isolation level.
The design combines components for current measurement, power management and wireless mesh networking. A micro-power zero-drift op amp (LTC2063) amplifies the voltage across a sense resistor. A 16-bit SAR ADC and precision reference (AD7988 and LT6656) digitize the reading. A SmartMesh IP™ wireless radio module (LTP5901-IPM) runs the application, provides the wireless mesh connectivity and communicates with a central network manager. A switching power supply (LTC3335) counts the cumulative charge drawn from the included battery while also regulating the output voltage for the rest of the application.
The DC2369A can be easily added to the DC9021B SmartMesh IP Starter Kit, or any SmartMesh IP network.
DC2369A Circuit Description - describes theory of operation of the DC2369A circuit
SmartMesh IP Starter Kits - other SmartMesh IP demo boards
SmartMesh IP On-Chip Software Development Kit - Enables users to develop application code to run on a SmartMesh IP Mote
|Software Name||Software Description||Weblink|
|"DC2126A.exe"||Demonstration GUI software that displays temperature and power source data sent wirelessly through the mesh. Runs on the user's Windows PC connected to a SmartMesh IP network manager.||Part of the SmartMesh IP SDK|
|FTDI Driver||USB-to-Serial drivers for communication with a SmartMesh IP manager (e.g. DC9001B SmartMesh IP Evaluation manager)||Download VCP from ftdichip.com|
Demonstration circuit DC2343A is a complete system level solution for a nanopower buck-boost DC/DC with integrated coulomb counter. The DC2343A contains a PIC16F1459 embedded processor for communication to the PC over USB and the LTC3335 via its I2C port. The GUI is capable of reading and writing all the control registers on the LTC3335 as well as displaying and resetting all its alarm registers. The firmware and software for the embedded system and the GUI are available at the LTC3335 solutions page. The DC2343A uses two analog-to-digital converter channels to sample the battery and output voltages. The voltage samples improve the functionality of the GUI, and allow optimal software correction to the measured coulombs. By adding the software correction the first order known errors are compensated for over the operating range and the resultant coulomb count is accurate to within 3%.
Tools & Simulations
Linduino is Analog Devices’ Arduino compatible system for developing and distributing firmware libraries and example code for our integrated circuits.
LTC3335 Companion Parts
Recommended Related Parts
Solutions Bulletins & Brochures (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.