Features and Benefits
- Generates 15V at 20mA, –8V at 50mA from a Li-Ion Cell
- Internal Schottky Diodes
- VIN Range: 2.2V to 16V
- Output Voltages Up to ±34V
- Capacitor-Programmable Soft-Start
- Sequencing: Positive Output Reaches 88% of Final Value Before Negative Output Begins
- Requires Only One Resistor to Set Output Voltage
- Constant Switching Frequency Ensures Low Noise Outputs
- Available in a 10-Lead (3mm × 3mm) DFN Package
The LT3472 dual channel switching regulator generates positive and negative outputs for biasing CCD imagers. The device delivers up to –8V at 50mA and 15V at 20mA from a lithium-ion cell, providing bias for many popular CCD imagers. Switching at 1.1MHz, the LT3472 uses tiny, low profile capacitors and inductors and generates low noise outputs that are easy to filter. Schottky diodes are internal and the output voltages are set with one resistor per channel, reducing external component count. The entire solution is less than 1mm profile and occupies just 50mm2.
Internal sequencing circuitry disables the negative channel until the positive channel has reached 88% of its final value, ensuring that the sum of the two outputs is always positive. Separate soft-start capacitors for each output allow the ramp of each output to be independently controlled.
The LT3472 is available in a low profile (0.75mm) 10-pin 3mm × 3mm DFN package.
- CCD Bias
- TFT LCD Bias
- OLED Bias
- ± Rail Generation for Op Amps
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 (3)
Demonstration circuit SCP-LT3472-EVALZ is a dual output converter featuring the LT3472EDD. The Boost Converter is designed to convert a 2.7V–4.2V input to 15V output at 25mA–45mA load. The Inverting Circuit generates a –8V output at 35mA–65mA from the same input.
Like all boards in the Signal Chain Power series, this board is designed to be easily plugged into other SCP boards to form a complete signal chain power system, enabling fast evaluation of low power signal chains. To evaluate this board, some universal SCP hardware is required, namely:
To properly evaluate SCP series demo boards, you will need the SCP Configurator companion software. SCP Configurator can help you choose the right board and topology for your design.
Note that the Demo Manual does not cover details important to the operation and configuration regarding the LT3472. Please refer to the LT3472 data sheet for a complete description of the part.
Demonstration circuit 760 is a dual, output, 1.1MHz Boost/Inverter in a 3mm x 3mm DFN featuring the LT3472EDD. The demo circuit demonstrates small size and low component count in a Boost Circuit and an Inverting Circuit. The Boost Converter is designed to convert a 2.7V–4.2V input to 15V output at 25mA– 45mA load. The Inverting Circuit generates a –8V output at 35mA–65mA from the same input. Since the maximum VIN of the LT3472EDD is 16V, this demo circuit will work well at higher inputs. The only limitation is the 10V rating of the input capacitor.
The ADALM-SR1 (Analog Devices Active Learning Module, Switching Regulator) board is a companion module for several switching regulator exercises covering buck and boost regulators:
- Boost and Buck converter elements and open-loop operation
- Buck Converters: closed loop operation
- Boost Converters: closed loop operation
The circuits required for these exercises exceed the complexity that can be constructed on a breadboard, so the ADALM-SR1 was designed as a flexible platform for experimenting with power electronics. Onboard current sense amplifiers, adjustable electronic load, and feedback signal injection circuitry eliminate the need for expensive equipment — the only additional equipment required is:
- 5V USB wall adapter
- Basic adjustable power supply for input power (0-12V, 2A)
- ADALM2000 or basic oscilloscope (2 channels with trigger, >10MHz bandwidth)
Features & Benefits
- Companion module for Active Learning labs on buck and boost power converters
- Illustrates important concepts related to buck and boost converters:
- Continuous vs. Discontinuous Conduction Modes
- Open loop operation
- Voltage mode control
- Current mode control
- Independently adjustable parameters: frequency, duty cycle, voltage/current mode
- Onboard current sense amplifiers and adjustable load minimize equipment requirements.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
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.