2A, 70V SEPIC/Boost DC/DC Converter with 7μA Quiescent Current

Linear Technology Corporation announces the LT8494, a current mode, fixed frequency SEPIC/boost DC/DC converter with an internal 2 A, 70 V switch. Ultralow quiescent current of only 7 μA makes the device ideal for always-on automotive or other industrial battery powered systems. The LT8494 starts up from an input voltage range of 2.5 V to 32 V and once running it operates from inputs from 1 V to 60 V, making it suitable for applications with input sources ranging from a single-cell Li-Ion to automotive inputs. The LT8494 can be configured as a boost, SEPIC or flyback converter. Its switching frequency can be programmed via a single resistor between 250 kHz and 1.5 MHz, enabling designers to minimize external component sizes. The combination of a thermally enhanced TSSOP-20E or 4 mm × 4 mm QFN package and tiny externals ensures a very compact footprint while minimizing solution cost.

The LT8494’s internal, high efficiency 2 A/70 V switch delivers efficiencies of up to 83% while operating in a SEPIC configuration. A unique design using dual supply pins (V_IN and BIAS) enables the device to operate from the most efficient supply, optimizing efficiency over a wide range of conditions. The LT8494 can operate with input supply voltages up to 60 V for SEPIC topology and up to 32 V, with ride through protection in boost and flyback topologies. Other features include a FMEA tolerant package (TSSOP-20E), power good indicator, programmable softstart and thermal shutdown protection.

Efficiency vs. Load Current.

The LT8494 is available in a thermally enhanced TSSOP-20 package. Pricing starts at $2.85 each for 1,000 piece quantities. Industrial temperature (–40 °C to 125 °C) and high temperature (–40 °C to 150 °C) grades are also available. All versions are available from stock.

Summary of Features: LT8494

• Wide Input Voltage Range of ~1 V to 60 V (2.5 V to 32 V for Start-Up)
• Low Ripple Burst Mode Operation:
  • 7 μA I_Q at 12V_IN to 5.0V_OUT
  • Output Ripple (<10 mV Typ.)
• Dual Supply Pins:
  • Improves Efficiency
  • Reduces Minimum Supply Voltage to ~1 V after Start-Up to Extend Battery Life
• Integrated 2 A/70 V Power Switch
• Power Good Functional for Input Supply Down to 1.3 V
• FMEA Fault Tolerant in TSSOP Package
• Fixed Frequency PWM, SEPIC/Boost/Flyback Topologies
• Programmable Switching Frequency: 250 kHz to 1.5 MHz
• UVLO Programmable on SWEN Pin
• Soft-Start Programmable with One Capacitor
• 20-Lead TSSOP and 4 mm × 4 mm QFN Packages