Analog Devices Inc. LT8570IMS8E-1#PBF

Overview

LT8570IMS8E-1#PBF from Analog Devices (formerly Linear Technology) is a 0.25A, 65V monolithic PWM DC/DC converter IC optimized for boost, SEPIC, and inverting topologies in space-constrained industrial and portable power supplies. It features adjustable 200kHz–1.5MHz switching frequency, integrated soft-start, synchronization capability, and user-configurable undervoltage lockout. Its 8-lead MSOP package supports TFT-LCD bias generation and GPS receiver local supplies.

For engineers reviewing the LT8570IMS8E-1#PBF datasheet, LT8570IMS8E-1#PBF pinout, LT8570IMS8E-1#PBF application, or LT8570IMS8E-1#PBF equivalent, key selection criteria include its 0.25A current limit, 2.55V–40V input range, 65V switch rating, SHDN pin hysteresis, and compatibility with dual-inductor inverting configurations requiring low output ripple.

Technical Context

The LT8570IMS8E-1#PBF implements constant-frequency current-mode control with internal slope compensation to prevent subharmonic oscillation above 50% duty cycle. Its dual-feedback architecture (FBX pin supporting ±1.204V/±3mV reference modes) enables seamless reconfiguration between noninverting (boost/SEPIC) and inverting topologies without external component changes.

It integrates frequency foldback during soft-start and low-duty-cycle conditions, reducing minimum on-time impact and improving startup stability. The SHDN pin accepts slowly ramping input signals and provides programmable UVLO via external resistor divider, while the RT pin sets oscillator frequency with ±10% tolerance over temperature.

Key Specifications

Pinout & Package

LT8570IMS8E-1#PBF is housed in an 8-lead plastic MSOP package (MS8E) with exposed pad (Pin 9 = GND), θ_JA = 35°C/W to 40°C/W. The thermally enhanced layout requires soldering the exposed pad directly to the PCB ground plane for optimal thermal performance and EMI reduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3533EMS8E#PBF and LT8330EMSE#PBF, LT8570IMS8E-1#PBF uniquely supports three topologies with one IC, offers programmable frequency and synchronization, and delivers optimal size-efficiency trade-off for <250mA bias supplies in portable and display systems.

Availability

LT8570IMS8E-1#PBF is available at Aetrix Electronics and suitable for TFT-LCD bias supplies, GPS receiver local power, and DSL modem line card supplies requiring stable component supply across extended temperature ranges (–40°C to 125°C).

Supply support for LT8570IMS8E-1#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 acquired Linear Technology in 2017 and maintains its high-performance analog and power management portfolio with rigorous qualification standards for industrial and automotive applications.

The LT8570/LT8570-1 product line was designed specifically for compact, multi-topology DC/DC conversion in display bias, portable RF, and telecom infrastructure where input voltage range, topology flexibility, and thermal performance are critical.

FAQ

What topology configurations does the LT8570IMS8E-1#PBF support?

The LT8570IMS8E-1#PBF supports boost, SEPIC, and inverting topologies through its dual-reference FBX pin architecture. For noninverting operation (boost/SEPIC), FBX connects to VOUT via a resistor referenced to 1.204V; for inverting operation, it references 3mV. This eliminates the need for multiple IC variants or external level-shifting circuitry in multi-rail designs.

How is the switching frequency set on the LT8570IMS8E-1#PBF?

The LT8570IMS8E-1#PBF switching frequency is set either by connecting a resistor from the RT pin to ground (free-running mode, 200kHz–1.5MHz) or by applying a logic-level clock to the SYNC pin. In SYNC mode, the part locks to the external clock if its high/low thresholds (≥1.3V / ≤0.4V) are met, enabling deterministic EMI reduction in synchronized systems.

What is the purpose of the SHDN pin's hysteresis on the LT8570IMS8E-1#PBF?

The SHDN pin on the LT8570IMS8E-1#PBF features 40mV hysteresis between turn-on (1.21V–1.40V) and turn-off (≤0.3V) thresholds to prevent chatter during slow-rising or noisy enable signals. This allows direct connection to microcontroller GPIOs or resistor-divided input rails without additional Schmitt-trigger buffering.

Can the LT8570IMS8E-1#PBF be used in inverting configurations with low output ripple?

Yes-the LT8570IMS8E-1#PBF is explicitly designed for dual-inductor inverting topologies that deliver inherently low output ripple. By placing an output inductor in series with the load, the LT8570IMS8E-1#PBF maintains continuous current delivery during both switch on- and off-times, eliminating abrupt capacitor current steps seen in standard buck-derived inverters.

What is the maximum junction temperature rating for the LT8570IMS8E-1#PBF?

The LT8570IMS8E-1#PBF is rated for operation from –40°C to 125°C junction temperature (I-grade). Its thermal shutdown activates at ~165°C and resets at ~160°C, initiating a full soft-start cycle. The MSOP package's exposed pad must be soldered to a thermal pad on the PCB to achieve the specified θ_JA of 35°C/W–40°C/W.