Analog Devices Inc. LTC1159CS-5#TRPBF

Overview

LTC1159CS-5#TRPBF from Analog Devices (formerly Linear Technology) is a synchronous step-down switching regulator controller optimized for 5V fixed-output applications. It operates from 4V to 40V input, delivers up to 2A output current via external MOSFETs, achieves up to 95% efficiency, maintains regulation in Burst Mode down to ~15% load, and features constant off-time current-mode control with adaptive non-overlap gate drives.

For engineers reviewing the LTC1159CS-5#TRPBF datasheet, LTC1159CS-5#TRPBF pinout, LTC1159CS-5#TRPBF application, or LTC1159CS-5#TRPBF equivalent, this device is selected for high-efficiency, wide-input industrial and portable power supplies where low quiescent current (300µA active regulation, 20µA shutdown), precise 5.05V ±1.5% output, and robust short-circuit protection are critical design requirements.

Technical Context

The LTC1159CS-5#TRPBF implements a constant off-time current-mode architecture with internal 1.25V reference and fixed 5V feedback divider connected to SENSE–. It uses P-channel high-side and N-channel low-side external MOSFETs, with level-shifted P-GATE drive referenced to VIN and ground-referenced N-GATE drive.

Operation includes automatic transition between continuous conduction mode and power-saving Burst Mode below ~15% full-load current. The EXTVCC pin enables driver power sourcing from the regulated output voltage, reducing losses at high VIN; adaptive non-overlap circuitry prevents shoot-through by enforcing dead time between P-GATE and N-GATE transitions.

Key Specifications

Pinout & Package

Package: 16-lead plastic SO (Small Outline) - RoHS-compliant, surface-mount, θJA = 110°C/W, rated for –40°C to 85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down controller applications.

Compared with LTC1159CS-5#TRPBF, LTC1149IS-5#PBF trades efficiency for integration simplicity, while LM5116MHX/NOPB offers wider input range and flexibility at the cost of higher component count and absence of true Burst Mode regulation.

Availability

LTC1159CS-5#TRPBF is available at Aetrix Electronics and suitable for industrial power distribution, portable instrumentation, avionics subsystems, and notebook computing applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant manufacturing.

Supply support for LTC1159CS-5#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, Inc. (acquired Linear Technology in 2017) designs precision analog, mixed-signal, and power management ICs for high-reliability industrial, automotive, and aerospace applications.

The LTC1159 series was developed as a high-efficiency synchronous buck controller family targeting portable and wide-input industrial power supplies, emphasizing ultralow quiescent current, robust protection, and seamless Burst Mode transition.

FAQ

What is the output voltage tolerance of the LTC1159CS-5#TRPBF?

The LTC1159CS-5#TRPBF provides a fixed 5V output with guaranteed tolerance of ±1.5% over temperature and line conditions (4.90V to 5.20V at 700mA, VIN = 9V). This tight regulation is achieved via an internal resistive divider connected to the SENSE– pin and a precision 1.25V bandgap reference, eliminating external resistor errors and drift.

How does the LTC1159CS-5#TRPBF achieve high efficiency at light loads?

The LTC1159CS-5#TRPBF achieves high light-load efficiency through automatic Burst Mode™ operation, which reduces switching activity and cuts supply current to just 300µA while maintaining output regulation. This mode activates when load current drops below approximately 15% of maximum, minimizing switching and gate drive losses without compromising stability or transient response.

Can the LTC1159CS-5#TRPBF drive standard-threshold MOSFETs?

Yes-the LTC1159CS-5#TRPBF can drive standard-threshold MOSFETs when the EXTVCC pin is supplied from an external ≥8V source, enabling higher gate drive voltage. With internal VCC only (4.5V), logic-level MOSFETs are required. The datasheet specifies that for VIN > 30V, standard-threshold devices with EXTVCC powered from 12V are recommended to ensure reliable turn-on.

What is the purpose of the CAP pin on the LTC1159CS-5#TRPBF?

The CAP pin on the LTC1159CS-5#TRPBF provides charge compensation for the internal P-gate level-shifting capacitor. A capacitor connected from CAP to VCC stores charge needed during rapid P-GATE transitions, preventing voltage droop that could cause incomplete turn-off of the high-side P-channel MOSFET and resulting shoot-through or inefficiency.

Does the LTC1159CS-5#TRPBF include short-circuit protection?

Yes-the LTC1159CS-5#TRPBF includes robust short-circuit protection via current-mode sensing. When the SENSE+–SENSE– voltage exceeds the high threshold (130–170mV), the controller extends off-time to allow inductor current decay, limiting average short-circuit current to approximately the programmed IMAX. This prevents thermal runaway without requiring external circuitry.