Analog Devices Inc. LT8494IFE#PBF

Overview

LT8494IFE#PBF from Analog Devices is a monolithic SEPIC/boost/flyback DC/DC controller with integrated 2A/70V NPN power switch, programmable 250kHz–1.5MHz switching frequency, 7µA quiescent current in active Burst Mode, and dual supply pins (VIN/BIAS) enabling operation down to ~1V after startup. It delivers up to 1A output at >12V input in SEPIC topology and targets battery-powered industrial and automotive ECU supplies requiring ultra-low IQ and wide VIN range.

For engineers reviewing the LT8494IFE#PBF datasheet, LT8494IFE#PBF pinout, LT8494IFE#PBF application, or LT8494IFE#PBF equivalent, key selection criteria include its FMEA-fault-tolerant TSSOP package, 1.202V feedback reference with <±22mV tolerance, 92% PG threshold, programmable UVLO via SWEN divider, and guaranteed –40°C to 125°C operation.

Technical Context

The LT8494IFE#PBF implements constant-frequency current-mode control with internal slope compensation, enabling stable operation up to 80% duty cycle in SEPIC/boost topologies. Its dual-supply architecture automatically selects the lower of VIN or BIAS for NPN base drive, reducing minimum operating voltage to ~1V post-startup while maintaining 70V switch rating.

Burst Mode operation reduces quiescent current to <3µA during sleep intervals, delivering single-cycle current pulses to maintain output regulation with <10mV ripple (typ.) using 47µF output capacitance. Frequency foldback below 1V FB ensures controlled start-up by limiting minimum duty cycle.

Key Specifications

Pinout & Package

LT8494IFE#PBF uses a 20-lead plastic TSSOP package with exposed thermal pad (Pin 21) soldered to PCB ground. Pin functions are validated per Linear Technology (Analog Devices) datasheet Rev. FA, with NC pins (4,5,6,9,11,13,15,17,19) unconnected internally and required floating for FMEA compliance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DC/DC controller applications.

Compared with LTC3891EFE#PBF and MAX20098ATPA/VY+, the LT8494IFE#PBF uniquely combines integrated 2A/70V NPN switching, sub-7µA quiescent current, and FMEA-safe TSSOP packaging - making it optimal for ruggedized, battery-backed industrial and automotive power stages where component count and fault resilience are prioritized over peak efficiency or ultra-high frequency.

Availability

LT8494IFE#PBF is available at Aetrix Electronics and suitable for automotive ECU power, portable medical device supply, industrial sensor node, and railway signaling interface applications requiring stable component supply, long-term lifecycle support, and guaranteed –40°C to 125°C operation.

Supply support for LT8494IFE#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision, power, and connectivity applications.

The LT8494 product line delivers highly integrated, fault-resilient DC/DC controllers targeting automotive, industrial, and portable systems where ultra-low quiescent current, wide input range, and robust operation under fault conditions are essential design requirements.

FAQ

What is the maximum input voltage supported by the LT8494IFE#PBF in SEPIC topology?

The LT8494IFE#PBF supports up to 60V input voltage in SEPIC topology, as specified in Absolute Maximum Ratings and confirmed in Applications Information. For boost and flyback configurations, the maximum continuous input is 32V, though it tolerates transient ride-through up to 60V. This 60V rating applies directly to the LT8494IFE#PBF and is validated for the TSSOP package variant.

Does the LT8494IFE#PBF require an external MOSFET or does it integrate the power switch?

The LT8494IFE#PBF integrates a 2A/70V NPN bipolar power switch - no external MOSFET is required. This distinguishes it from controller-only ICs like the LTC3891. The integrated switch enables compact, low-component-count SEPIC/boost designs. All electrical characteristics, including switch VCESAT (340mV at 1.2A) and current limit (2.55A typ.), apply to the LT8494IFE#PBF's internal transistor.

How does the LT8494IFE#PBF achieve ultra-low quiescent current, and what is its value?

The LT8494IFE#PBF achieves 7µA typical quiescent current in active Burst Mode operation and ~0.3µA in shutdown, enabled by deep-sleep circuitry that disables non-essential blocks between current pulses. This is measured per Electrical Characteristics table with VSWEN = 0V and confirmed for the LT8494IFE#PBF temperature grade. The dual-supply architecture further reduces effective IQ by drawing bias from the regulated output when VIN sags.

What package type and thermal performance does the LT8494IFE#PBF use?

The LT8494IFE#PBF uses a 20-lead plastic TSSOP package with exposed thermal pad (Pin 21), achieving θJA = 38°C/W. This package is FMEA fault-tolerant: adjacent pin shorts or opens will not cause output overvoltage. The exposed pad must be soldered to PCB ground for thermal and electrical performance. This package configuration is explicitly listed for LT8494IFE#PBF in the Order Information table.

Can the LT8494IFE#PBF operate with input voltage below 2.5V, and how is this achieved?

Yes, the LT8494IFE#PBF can operate with input voltage as low as ~1V after startup by drawing current from the BIAS pin (connected to VOUT). During startup, VIN must be ≥2.5V to initiate regulation; once running, BIAS sustains operation even if VIN drops to 1.3V (per PG specification) or lower. This behavior is inherent to the LT8494IFE#PBF's dual-supply architecture and is verified in Electrical Characteristics for BIAS ≥2.5V and VIN <2.5V conditions.