Texas Instruments LM43602DSUR

Overview

LM43602DSUR from Texas Instruments is a 3.5-V to 36-V, 2-A synchronous step-down DC-DC converter in a 16-pin VSON package with wettable flanks. It delivers up to 2 A output current with 27-µA quiescent current in regulation, 500-kHz default switching frequency (adjustable 200 kHz–2.2 MHz), and integrated power-good flag - enabling compact, high-efficiency point-of-load regulation in automotive sub-AM band and industrial power supplies.

For engineers reviewing the LM43602DSUR datasheet, LM43602DSUR pinout, LM43602DSUR application, or LM43602DSUR equivalent, this page provides verified technical context, validated pin functions, confirmed EMI compliance (EN55022 Class B), real-world thermal resistance (R_θJB = 9.6°C/W), and two rigorously cross-checked alternative parts for wide-VIN buck design review.

Technical Context

The LM43602DSUR employs fixed-frequency peak current-mode control with automatic transition to DCM/PFM at light loads, achieving high efficiency across 0–2 A. Its internal compensation eliminates external loop components, while the RT pin enables precise frequency setting via resistor (200 kHz–2.2 MHz) and SYNC supports external clock synchronization within the same range.

It integrates dual N-channel MOSFETs (R_DS(on)-HS = 120 mΩ, R_DS(on)-LS = 65 mΩ), precision enable with 2.2-V threshold and 290-mV hysteresis, soft-start (4.1 ms internal, extendable via SS/TRK), and hiccup-mode short-circuit protection. Thermal shutdown triggers at 160°C with 10°C hysteresis, and PGOOD monitors output within ±13% of FB reference.

Key Specifications

Pinout & Package

The LM43602DSUR is housed in a 16-pin VSON package (4.1 mm × 5.1 mm × 0.9 mm) with wettable flanks for automated optical inspection. Thermal pad (PAD) connects internally to AGND and serves as primary heat dissipation path to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck regulator applications.

Compared with LM43602DSUR, LM43603DSQR offers higher current headroom in identical footprint, while TPS54202HDDCR trades feature depth for lower cost and smaller size - making LM43602DSUR optimal for balanced performance, flexibility, and compliance in wide-VIN industrial and automotive systems.

Availability

LM43602DSUR is available at Aetrix Electronics and suitable for industrial PLC power, automotive sub-AM band electronics, telecom remote radio units, and general-purpose wide-VIN regulation requiring stable component supply and long-term production support.

Supply support for LM43602DSUR 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in power management ICs and broad industrial, automotive, and communications market reach.

The LM43602DSUR belongs to TI's LM436xx family of wide-input synchronous buck regulators, designed specifically for high-efficiency, low-EMI point-of-load conversion in space-constrained and thermally demanding environments.

FAQ

What is the absolute maximum input voltage rating for the LM43602DSUR?

The LM43602DSUR has an absolute maximum input voltage (VIN to PGND) of 42 V, as specified in Section 6.1 of the datasheet. This rating applies under transient conditions with <10-ns pulses; continuous operation must remain within the recommended 3.5 V to 36 V range to ensure reliability and thermal stability. Exceeding 42 V risks permanent damage to the internal high-side MOSFET and control circuitry.

Does the LM43602DSUR require external compensation components?

No, the LM43602DSUR features internal compensation, eliminating the need for external Type II or Type III compensation networks. This simplifies design, reduces BOM count, and improves consistency across production units. The internal loop is optimized for stability with common output capacitor types - ceramic, polymer, tantalum, or aluminum - without additional components.

How does the BIAS pin improve efficiency in the LM43602DSUR?

The BIAS pin allows the LM43602DSUR to power its internal circuitry from the regulated output (when VOUT is 3.3–28 V) instead of VIN, reducing power dissipation in the internal LDO. When tied to VOUT, typical operating quiescent current drops from 27 µA (from VIN) to ~130 µA from BIAS - but overall system efficiency increases because the LDO no longer draws current from the higher input rail.

Can the LM43602DSUR be synchronized to an external clock, and what are the valid frequency and signal requirements?

Yes, the LM43602DSUR supports synchronization via the SYNC pin across 200 kHz to 2.2 MHz. The external clock must meet V_SYNC-HIGH ≥ 2 V and V_SYNC-LOW ≤ 0.4 V, with duty cycle between 10% and 90%, and minimum ON/OFF time of 80 ns. Proper high-speed termination is required to prevent ringing that could cause false triggering or jitter.

What thermal performance can be expected from the LM43602DSUR in its VSON package?

In the VSON-16 package, the LM43602DSUR achieves R_θJB = 9.6°C/W (junction-to-board) on a standard 4-layer JEDEC board - significantly better than the HTSSOP variant (19.9°C/W). With proper thermal pad soldering to a solid ground plane, it sustains 2-A continuous output at ambient temperatures up to 85°C without derating, per thermal characterization data in Section 6.4.