Analog Devices Inc. LT1161CSW#PBF

Overview

LT1161CSW#PBF from Analog Devices (formerly Linear Technology) is a quad protected high-side N-channel MOSFET driver IC designed for industrial, avionics, and automotive power switching applications. It operates from 8V to 48V supply, provides individual short-circuit protection per channel, features programmable current limit and auto-restart timers, and delivers gate drive voltage up to 14V above V+ to fully enhance standard N-channel MOSFETs.

For engineers reviewing the LT1161CSW#PBF datasheet, LT1161CSW#PBF pinout, LT1161CSW#PBF application, or LT1161CSW#PBF equivalent, key selection considerations include its flowthrough pinout, drain-sense–based current limiting with +0.33%/°C temperature coefficient, 20-lead SOIC-W package, –15V to 60V supply transient tolerance, and independent channel timing capacitor control for restart period tuning.

Technical Context

The LT1161CSW#PBF integrates four independent high-side switch channels, each with a self-contained 750kHz charge pump, supply-referenced drain-sense comparator (65mV nominal threshold), and dedicated timer circuitry. Each channel's gate drive is actively clamped to ~12V above V+, and turn-on/turn-off times are specified at 100–400µs and 75–200µs respectively under 1000pF load.

Input pins feature TTL/CMOS-compatible thresholds (VINH = 2V, VINL = 0.8V), 200mV hysteresis, and internal 75kΩ pull-down resistors; timer pins use a 14µA current source to recharge external CT capacitors to 3V for automatic restart. The device requires Kelvin connection of V+ pins to sense resistor positive terminals for accurate current sensing.

Key Specifications

Pinout & Package

The LT1161CSW#PBF is housed in a 20-lead plastic SOIC-W (SW) package with wide body (0.300-inch), RoHS-compliant lead finish (#PBF), and standard JEDEC SOIC pin spacing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side MOSFET driver applications.

Compared with LT1161CSW#PBF, LT1910CS8#PBF trades channel count and analog flexibility for smaller footprint and lower quiescent current, while TPS2HB35-Q1 replaces hardware-programmable timing with digital configurability and automotive qualification-neither offers identical per-channel analog control and flowthrough routing.

Availability

LT1161CSW#PBF is available at Aetrix Electronics and suitable for industrial motor control, avionics power distribution, and automotive electronic fuse applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for LT1161CSW#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 full technical and manufacturing continuity for legacy Linear products including the LT1161 family.

The LT1161CSW#PBF belongs to Linear's protected high-side driver product line, engineered specifically for harsh-environment power switching where supply transients, thermal stress, and reliability under fault conditions are primary design constraints.

FAQ

What is the maximum supply voltage rating for the LT1161CSW#PBF?

The LT1161CSW#PBF is rated for continuous operation from 8V to 48V, and is 100% tested to survive supply transients from –15V to 60V applied between V+ and GND pins without damage. Exceeding 60V-even briefly-may cause catastrophic failure, so local decoupling and transient suppression are essential in high-voltage environments where the LT1161CSW#PBF is deployed.

How does the LT1161CSW#PBF implement current limiting and fault recovery?

The LT1161CSW#PBF uses a supply-referenced drain-sense comparator with 65mV nominal threshold per channel. When sensed voltage exceeds this level, the gate is turned off within 25–50µs, and the corresponding timer pin is discharged. A user-selected capacitor (CT) then recharges via a 14µA current source to 3V, triggering automatic restart. This cycle repeats until the fault clears-ensuring robust MOSFET protection while maintaining operational awareness in the LT1161CSW#PBF.

Can the LT1161CSW#PBF drive logic-level MOSFETs at low supply voltages?

Yes-the LT1161CSW#PBF supports operation down to 8V supply, but its internal charge pump may not generate sufficient gate voltage to fully enhance standard N-channel MOSFETs below 12V. For reliable low-voltage operation, logic-level MOSFETs with VGS(th) ≤ 2V and VGS(max) ≥ 15V are recommended, enabling full enhancement and safe use across the entire 8–48V range of the LT1161CSW#PBF.

What is the purpose of the dual V+ and GND pins on the LT1161CSW#PBF?

The LT1161CSW#PBF has two V+ pins (11, 20) and two GND pins (1, 10) to support Kelvin sensing: both V+ pins must be connected together externally and tied directly to the positive ends of the drain sense resistors, while both GND pins must also be joined. This configuration eliminates IR drop errors in current sensing and ensures accurate 65mV threshold detection-critical for stable performance of the LT1161CSW#PBF in high-current applications.

Is the LT1161CSW#PBF compatible with opto-isolated inputs?

Yes-the LT1161CSW#PBF inputs accept 0–15V logic levels regardless of V+ status, making them ideal for opto-isolator interfaces. A common configuration uses NEC PS2501-4 or similar quad optocouplers with series resistors (e.g., 100kΩ + 2kΩ network) to ensure input stays within 2–5V range and avoids exceeding absolute maximum ratings. This preserves signal integrity in noisy industrial or automotive environments where the LT1161CSW#PBF is commonly used.