Analog Devices Inc. LTC1159CG-3.3#PBF

Overview

LTC1159CG-3.3#PBF from Analog Devices (formerly Linear Technology) is a fixed-output synchronous step-down switching regulator controller delivering 3.3V at up to 2A, operating from 4V to 40V input, featuring constant off-time current-mode control, Burst Mode™ operation for ultralow quiescent current, and integrated adaptive non-overlap gate drives for external complementary MOSFETs in notebook power supplies and portable instrumentation.

For engineers reviewing the LTC1159CG-3.3#PBF datasheet, LTC1159CG-3.3#PBF pinout, LTC1159CG-3.3#PBF application, or LTC1159CG-3.3#PBF equivalent, this page provides verified package mapping (20-lead SSOP), confirmed pin functions (e.g., P-GATE, N-GATE, SENSE+, SHDN2), exact output regulation specs (3.23–3.43V @ 700mA), thermal limits (0°C to 70°C), and validated alternatives with documented functional differences.

Technical Context

The LTC1159CG-3.3#PBF implements a constant off-time current-mode architecture that maintains stable ripple current in the inductor and delivers excellent line and load transient response. Its internal 4.5V LDO powers control circuitry at startup, while EXTVCC allows driver power to be sourced from the regulated output-enabling up to 95% efficiency at high VIN.

Burst Mode™ activation below ~15% of maximum load reduces standby current to 300µA while regulating, and shutdown current drops to 20µA. The device uses separate SHDN1 (control-only disable) and SHDN2 (master VCC + control shutdown) pins, with precise current-sense thresholds (130–170mV high, 25mV low) set via internal divider tied to SENSE– for fixed 3.3V output.

Key Specifications

Pinout & Package

Package: 20-lead plastic SSOP (G package), 0.65mm pitch, JEDEC MS-013AC compliant, θJA = 135°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC1159CG-3.3#PBF, LTC1149CS-3.3 trades efficiency and low-IQ operation for simplicity and lower cost, while LM5116MH/NOPB extends input range and flexibility at the expense of autonomous light-load management-making LTC1159CG-3.3#PBF optimal for 4–40V battery-powered systems demanding longest runtime.

Availability

LTC1159CG-3.3#PBF is available at Aetrix Electronics and suitable for portable instrumentation, notebook computing, industrial sensor nodes, and avionics subsystems requiring stable component supply with guaranteed commercial-grade temperature performance and long-term lifecycle support.

Supply support for LTC1159CG-3.3#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 product support, datasheet documentation, and application engineering for legacy Linear parts including the LTC series.

The LTC1159CG-3.3#PBF belongs to Linear's high-efficiency synchronous buck controller family, designed specifically for battery-operated and wide-input industrial systems where ultralow shutdown current, Burst Mode regulation, and MOSFET driver integration are essential.

FAQ

What is the exact output voltage tolerance of the LTC1159CG-3.3#PBF over temperature and load?

The LTC1159CG-3.3#PBF delivers 3.23V to 3.43V at 700mA load across 0°C to 70°C, with ±2% initial accuracy and ≤65mV load regulation (5mA–2A). Line regulation is ±40mV from VIN = 9V to 40V. These values are fully specified and tested for the CG grade, ensuring reliable 3.3V rail generation without external trimming.

How does the EXTVCC pin improve efficiency in the LTC1159CG-3.3#PBF?

The EXTVCC pin allows the LTC1159CG-3.3#PBF to power its MOSFET drivers from the regulated 3.3V output instead of the higher VIN rail. This reduces driver switching losses significantly-especially at VIN > 12V-contributing directly to the device's 95% peak efficiency. When EXTVCC is used, VCC is derived from the output via an internal PNP switch with only 250–350mV drop.

Can the LTC1159CG-3.3#PBF operate with 100% duty cycle, and what is the minimum dropout voltage?

Yes, the LTC1159CG-3.3#PBF supports true 100% duty cycle operation, enabling regulation even when VIN approaches VOUT. Its minimum dropout is defined by VIN – VCC, measured at 300–400mV (typical) when VIN = 4V and EXTVCC is open-ensuring stable 3.3V output down to 3.7V input without dropout or reset.

What are the absolute maximum ratings for the SENSE+ and SENSE– pins on the LTC1159CG-3.3#PBF?

The SENSE+ and SENSE– pins on the LTC1159CG-3.3#PBF tolerate –0.3V to 13V differential and common-mode voltage. This wide range accommodates high-side current sensing configurations and protects against inductive kickback during MOSFET switching-critical for robust operation with external RSENSE placed at PGND or high-side locations.

Is the LTC1159CG-3.3#PBF pin-compatible with other variants in the LTC1159 family, such as the LTC1159CG-5?

Yes, all LTC1159CG variants-including LTC1159CG-3.3#PBF and LTC1159CG-5-share identical 20-lead SSOP pinouts and electrical interfaces. Only the internal feedback divider differs: SENSE– is tied to a 3.3V-ratio divider in LTC1159CG-3.3#PBF and a 5V-ratio divider in LTC1159CG-5. No PCB changes are required when swapping between fixed-output versions.