Analog Devices Inc. LT8580EMS8E#TRPBF

Overview

LT8580EMS8E#TRPBF from Analog Devices is a PWM DC/DC converter IC with an integrated 1A, 65V NPN power switch, configurable as boost, SEPIC, or inverting topology. It operates from 2.55V to 40V input, delivers up to 12V output at 200mA in typical boost configuration, and features adjustable 200kHz–1.5MHz switching frequency, soft-start, and external synchronization-used in TFT-LCD bias supplies and GPS receivers.

For engineers reviewing the LT8580EMS8E#TRPBF datasheet, LT8580EMS8E#TRPBF pinout, LT8580EMS8E#TRPBF application, or LT8580EMS8E#TRPBF equivalent, key selection criteria include its 65V switch rating, 1.204V positive feedback reference, user-configurable UVLO via SHDN pin, thermal shutdown at ~165°C, and compatibility with both coupled and uncoupled inductors in SEPIC/inverting topologies.

Technical Context

The LT8580EMS8E#TRPBF uses constant-frequency current-mode control with internal slope compensation to ensure stability at duty cycles >50%. Its dual-amplifier FBX architecture supports both noninverting (1.204V reference) and inverting (3mV reference) configurations by reconfiguring the external R_FBX connection-enabling seamless topology change without component substitution.

Switching frequency is set via RT pin resistor (e.g., 56.2kΩ yields 1.5MHz) or synchronized externally via SYNC pin (1.3V high / 0.4V low thresholds). Frequency foldback activates when FBX voltage falls between 300mV–920mV, reducing f_OSC to 1/6 nominal to improve startup control under light load or high-duty-cycle conditions.

Key Specifications

Pinout & Package

LT8580EMS8E#TRPBF is packaged in an 8-lead plastic MSOP (MS8E) with exposed pad (Pin 9 = GND), θ_JA = 35–40°C/W, requiring soldered thermal pad for thermal reliability in continuous 1A operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3780EMS#TRPBF, LT8580EMS8E#TRPBF integrates the 65V/1A switch and simplifies layout but limits max output current; versus LT3580EMS8E#TRPBF, it adds frequency foldback, AEC-Q100 qualification, and extended 65V switch rating-making it the preferred choice for new automotive and high-reliability designs.

Availability

LT8580EMS8E#TRPBF is available at Aetrix Electronics and suitable for TFT-LCD bias supplies, GPS receiver power systems, and DSL modem local supplies requiring stable component supply, automotive-grade reliability, and flexible topology support.

Supply support for LT8580EMS8E#TRPBF 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LT8580EMS8E#TRPBF belongs to the LT® switching regulator product line, designed specifically for high-voltage, multi-topology DC/DC conversion in space-constrained and thermally demanding environments-including automotive infotainment and industrial displays.

FAQ

What is the maximum output voltage achievable with LT8580EMS8E#TRPBF in boost configuration?

The LT8580EMS8E#TRPBF does not impose a fixed maximum output voltage limit in boost mode; instead, practical limits arise from external component ratings and switch stress. With its 65V-rated internal NPN switch and typical 400mV V_CE(SAT), the LT8580EMS8E#TRPBF can safely generate outputs up to ~60V when using appropriately rated diodes, inductors, and output capacitors. Designers must ensure V_SW peak = V_OUT + V_F(DIODE) remains ≤65V.

Can LT8580EMS8E#TRPBF operate in discontinuous conduction mode (DCM)?

Yes, the LT8580EMS8E#TRPBF supports discontinuous conduction mode operation. Its current-mode control architecture and minimum off-time specification (100ns) allow stable DCM operation across all topologies. In SEPIC and inverting configurations, DCM enables reduced output ripple and inherent input-output isolation-particularly beneficial in low-power GPS and VFD bias applications where light-load efficiency matters.

How is the feedback resistor R_FBX calculated for a 15V inverting output using LT8580EMS8E#TRPBF?

For a 15V inverting output, LT8580EMS8E#TRPBF uses the negative feedback reference of 3mV. The datasheet equation is R_FBX = (|V_OUT| + 3mV) / 83.3µA. Substituting V_OUT = –15V gives R_FBX = (15.003V) / 83.3µA ≈ 180.1kΩ. A standard 180kΩ resistor achieves <0.1% error. This calculation assumes typical FBX bias current (83.3µA) and is validated across –40°C to +125°C per Electrical Characteristics table.

Does LT8580EMS8E#TRPBF require an external bootstrap capacitor?

No, the LT8580EMS8E#TRPBF does not require an external bootstrap capacitor. It integrates an NPN transistor switch rather than a high-side MOSFET, eliminating the need for gate-drive bootstrapping. The internal driver directly controls the NPN base with sufficient current to ensure fast turn-on/turn-off at up to 1.5MHz, simplifying layout and reducing component count compared to MOSFET-based controllers.

What is the purpose of the exposed pad (Pin 9) on LT8580EMS8E#TRPBF, and how must it be connected?

The exposed pad (Pin 9) on LT8580EMS8E#TRPBF is electrically and thermally connected to GND. It must be soldered directly to a solid PCB ground plane using multiple thermal vias to achieve the specified θ_JA of 35–40°C/W. Failure to solder the pad results in excessive junction temperature rise-potentially triggering thermal shutdown during 1A switching operation-and degrades EMI performance due to increased ground impedance.