Analog Devices, which recently acquired Linear Technology Corporation, announces the LT8711, a multitopology current mode PWM controller that can easily be configured as a synchronous buck, boost, SEPIC and ZETA DC/DC converter, or as a nonsynchronous buck-boost converter. This device replaces the output diode with a high efficiency P-channel MOSFET, thereby increasing efficiency and maximum output current up to 10 A, making the LT8711 highly versatile for a wide range of automotive, industrial, solar and general purpose applications.
The LT8711 operates over a 4.5 V to 42 V input voltage range and produces an output voltage that is dependent on the choice of external components. The 15 μA no-load quiescent current with the output voltage in regulation extends operating run time in battery powered systems. Low ripple Burst Mode® operation enables high efficiency at very light loads while maintaining low output voltage ripple. When configured as a synchronous buck, the LT8711 can operate at 100% duty cycle, a useful feature when powered from a battery that is discharging. The LT8711 features innovative EN/FBIN pin circuitry for input voltage regulation to avoid collapsing a high impedance input source such as a solar panel. This pin is also used for adjustable undervoltage lockout. The fixed operating frequency is selectable from 100 kHz to 750 kHz and can be synchronized to an external clock. Additional features include dual chip power supply inputs, a topology selection pin and adjustable soft-start.
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| 400 kHz 5 V to 40 V Input/12 V Output Nonsynchronous Buck Boost. |
The LT8711 is available in 20-lead TSSOP and 3 mm × 4 mm QFN packages. Extended and industrial versions operate over a junction temperature range of –40 °C to 125 °C. Pricing starts at $2.30 each in 1000-piece quantities.
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| Efficiency vs Load Current. |
Summary of Features: LT8711
- Synchronous Buck, Boost, SEPIC and ZETA Topologies
- Nonsynchronous Buck-Boost Topology
- Wide 4.5 V to 42 V Input Voltage Range
- Low Noise Burst Mode Operation
- Low IQ in Burst Mode Operation (15 μA Operating)
- 100% Duty Cycle in Dropout (Buck Mode)
- Input Voltage Regulation Capability
- 2 A Gate Drivers
- Adjustable Soft-Start
- Frequency Programmable from 100 kHz to 750 kHz
- Synchronizable to an External Clock
- 20-Lead TSSOP and 3 mm × 4 mm QFN-20 Packages
