Low VIN, High Efficiency, Dual 2A Step-Down DC-DC ConverterMarch 18, 2020 by Paul Shepard
The LTM®4691 from Analog Devices is a complete dual 2A output switching mode dc-dc converter in a tiny 3mm × 4mm × 1.18mm LGA package. Included in the package are the switching controller, power FETs, inductors and all supporting components.
This dc-dc converter is designed for use in telecom, networking and industrial equipment for point-of-load regulation, specifically for FPGAs and ASICs.
Operating over an input voltage range of 2.25V to 3.6V, the LTM4691 supports two outputs with programmable output voltage range from 0.5V to 2.5V set by external resistors. Its high efficiency design delivers up to 2A continuous current on each output. Only bulk input and output capacitors are needed.
The LTM4691 operates in forced continuous mode for low noise pulse-skipping mode or Burst Mode operation for high efficiency at lights loads. The typical buck switching frequency is 2MHz and can be synchronized from 1MHz to 3MHz. Its high switching frequency and a current mode architecture enables a very fast transient response to line and load changes without sacrificing stability.
Other features include precision run thresholds, a PGOOD signal, output overvoltage protection, thermal shutdown and output short-circuit protection. The LTM4691 is Pb-free and RoHS compliant.
Summary of Features and Specifications
- Tiny Surface Mount, Low Profile 3mm × 4mm × 1.18mm LGA Package
- Input Voltage Range: 2.25V to 3.6V
- Dual 2A DC Output Current
- ±1.5% Total Output Voltage Regulation
- Current Mode Control, Fast Transient Response
- External Frequency Synchronization
- 180° Out-of-Phase Operation
- Selectable Pulse-Skipping Mode/Burst Mode® Operation/Forced Continuous Mode
- Power Good Indicator
- Internal Soft-Start
- Internal Compensation
- Overvoltage, Overcurrent and Overtemperature Protection