Features and Benefits
- Quad Step-down Outputs: 1.25A per Channel
- Wide VIN Range: 2.7V to 17V
- Wide VOUT Range: 0.6V to VIN
- 1.25A/2.5A/3.75A/5A IOUT Configurable with One Inductor
- Integrated 300mΩ P-Channel/80mΩ N-Channel MOSFETs Provide Up to 93% Efficiency
- No-Load Burst Mode Operation IQ < 10µA with All Channels Enabled
- Constant Frequency (1MHz/2.25MHz) with ±50% Frequency Synchronization Range
- ±1% Output Voltage Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- Full Dropout Operation (100% Duty Cycle)
- Phase Shift Programmable with External Clock
- 5mm × 5mm × 1.72mm BGA Package
The LTC3644/LTC3644-2 is a quad 1.25A output, high efficiency synchronous monolithic step-down regulator capable of operating from input supplies up to 17V. The switching frequency is internally fixed to 1MHz or 2.25MHz with a ±50% synchronization range. The regulator features ultralow quiescent current and high efficiency over a wide VIN and VOUT range.
The step-down regulator operates from an input voltage range of 2.7V to 17V and provides an adjustable output range from 0.6V to VIN while delivering up to 1.25A of output current per channel. LTC3644/LTC3644-2 can be configured for quad 1.25A outputs, triple 2.5A/1.25A/1.25A outputs, dual 2.5A outputs, or dual 3.75A/1.25A outputs. A user selectable mode input is provided to allow the user to trade off ripple noise for light load efficiency; Burst Mode® operation provides the highest efficiency at light loads, while forced-continuous mode provides the lowest ripple noise. The regulators can be synchronized to an external clock.
- Battery Powered Systems
- Point-of-Load Supplies
- Portable – Handheld Scanners and Cameras
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration circuit 2383A-A features the LTC3644: the wide input and output voltage range, high efficiency and power density, quad 1.25A outputs DC/DC synchronous step-down monolithic regulator. The input voltage range of DC2383A-A is 2.7V to 17V. The default demo board setting of VOUT1, VOUT2, VOUT3, VOUT4 is 1.2V, 3.3V, 2.5V and 1.8V at 1.25A maximum DC output current per channel. There are two assembly versions. The DC2383A-A features LTC3644 which operates at an internally fixed frequency of 1MHz (Typ), while the DC2383A-B features LTC3644-2 which operates at an internally fixed frequency of 2.25MHz (Typ). Peak current limit is internally fixed at 2.2A typical per channel. Each channel comes with independent run pin control and power good indicators. Phase shift selection of either 0 degree or 180 degrees between switch rising edge of channels 1, 2 and channels 3, 4 is also available.
DC2383A-A provides optional onboard 0Ω jumpers to configure the LTC3644 as 4-phase dual 2.5A/2.5A outputs or 4-phase triple 2.5A/1.25A/1.25A outputs. Optional 0Ω jumpers connecting VIN1 to VIN2, VIN3, VIN4 are available for users to operate selected channels of LTC3644 at different input voltages than VIN1.
A user-selectable MODE/SYNC input is provided to allow users to trade off ripple noise for light load efficiency: pulse-skipping mode (PS) or Burst Mode® operation delivers higher efficiency at light load while forced continuous conduction mode (FCM) is preferred for noise sensitive applications. The MODE/SYNC pin can also be used to synchronize the switching frequency to an external clock or set the phase shift between channels 1, 2 and channels 3, 4. Constant frequency, peak current mode control architecture and integrated internal control loop compensation network, allows very fast transient response to line and load changes while maintaining loop stability.
The LTC3644 is available in a thermally enhanced, low profile 36-lead 5mm × 5mm BGA package.
It is recommended to read the data sheet and demo manual of LTC3644 prior to using or making any changes to DC2383A-A.
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:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
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.