Step-Down Switching Regulator: LT3995
Linear Technology Corporation announces the LT3995, a 3 A, 60 V step-down switching regulator, requiring only 2.7 µA of quiescent current. The LT3995’s 4.3 to 60 V input voltage range makes it ideal for automotive, commercial vehicle, avionic and industrial applications. Its internal 4.7 A switch can deliver up to 3 A of continuous output current to voltages as low as 1.2 V. The LT3995’s Burst Mode® operation offers ultralow quiescent current, making it well suited for applications such as automotive or industrial systems, which demand always-on operation and optimum battery life.
The unique design of the LT3995 ensures a minimum dropout voltage of only 500mV even when the input voltage drops below the programmed output voltage, suitable for applications subjected to scenarios such as automotive cold-crank. Switching frequency is user-programmable from 200kHz to 2MHz, and synchronizable from 250kHz to 2MHz, enabling the designer to optimize efficiency while avoiding critical noise-sensitive frequency bands. The combination of its 16-lead thermally enhanced MSOP package and high switching frequency keeps external inductors and capacitors small, providing a highly compact, thermally efficient footprint.
The LT3995 utilizes a high efficiency 4.7A, 85mOhm switch, with the boost diode, oscillator, control and logic circuitry integrated into a single die. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mVP-P. Special design techniques and a new high voltage process enable efficiencies up to 90% over a wide input voltage range, while the LT3995’s current mode topology assures fast transient response and excellent loop stability. Other features include a power good flag, soft-start capability and thermal protection.
The LT3995EMSE is packaged in a thermally enhanced MSOP-16, priced starting at $3.55 each for 1,000 piece quantities. The LT3995IMSE is tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and is priced at $3.91 each in 1,000 piece quantities. The LT3995HMSE is tested and guaranteed to operate from a -40°C to 150°C operating junction temperature, priced at $4.16 each in 1,000 piece quantities All versions are available from stock. For more information, visit www.linear.com/product/LT3995.
Summary of Features: LT3995
- Ultralow Quiescent Current: 2.7µA IQ at 12VIN to 3.3VOUT
- Low Ripple Burst Mode® Operation Output Ripple < 15mVP-P
- Wide Input Range: Operation from 4.3V to 60V
- 3A Maximum Output Current
- Excellent Start-Up & Dropout Performance
- Adjustable Switching Frequency: 200kHz to 2MHz
- Synchronizable Between 250kHz to 2MHz
- Accurate Programmable Undervoltage Lockout
- Low Shutdown Current: IQ = 700nA
- Power Good Flag
- Soft-Start Capability
- Thermal Shutdown Protection
- Current Limit Foldback with SS Override
- Saturating Switch Design: 85mOhm on Resistance
- Small, Thermally Enhanced 16-Lead MSOP Package