Texas Instruments LM46001PWPR

Overview

LM46001PWPR from Texas Instruments is a 3.5-V to 60-V, 1-A synchronous step-down DC-DC converter in HTSSOP-16 package. It delivers regulated output voltage (1 V to 28 V) with ±1.2% feedback reference accuracy, 24-µA quiescent current in regulation, and integrated high-side/low-side MOSFETs (R_DS(on) = 419 mΩ / 231 mΩ). Used in industrial power supplies and automotive sub-AM band systems for efficient point-of-load conversion.

For engineers reviewing the LM46001PWPR datasheet, LM46001PWPR pinout, LM46001PWPR application, or LM46001PWPR equivalent, key selection criteria include wide input range (3.5–60 V), EN pin precision UVLO (2.0–2.42 V), PGOOD flag with 13% overvoltage/17% undervoltage thresholds, and adjustable switching frequency (200 kHz–2.2 MHz) via RT pin.

Technical Context

The LM46001PWPR uses peak-current-mode control with internal compensation, enabling stable operation with ceramic, polymer, tantalum, or aluminum output capacitors without external loop components. Its DCM and PFM light-load modes maintain high efficiency down to 1 mA load, while hiccup-mode short-circuit protection limits fault energy.

It integrates dual N-channel MOSFETs, a precision 1.016-V feedback reference, soft-start (4.1 ms internal, extendable via SS/TRK), and synchronization capability across 200 kHz–2.2 MHz. Thermal shutdown triggers at 160°C with 10°C hysteresis, and VCC UVLO ensures reliable startup above 3.14 V.

Key Specifications

Pinout & Package

LM46001PWPR is housed in a 16-pin HTSSOP (PWP) package measuring 6.6 mm × 5.1 mm × 1.2 mm with 0.65-mm lead pitch. The exposed thermal pad (Pin 17) must be soldered to PCB ground for thermal performance (R_θJB = 21.7°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM46002PWPR and LM43603PWPR, the LM46001PWPR provides optimal balance of 1-A capability, ultra-low IQ, and BIAS pin flexibility for mid-power industrial and automotive loads - making it ideal where size, efficiency, and thermal constraints are tightly coupled.

Availability

LM46001PWPR is available at Aetrix Electronics and suitable for industrial power supplies, telecommunications systems, and sub-AM band automotive applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for LM46001PWPR 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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for industrial, automotive, and communications markets.

The LM46001PWPR belongs to TI's wide-input-voltage synchronous buck converter family, designed specifically for rugged, high-efficiency DC-DC conversion in space-constrained systems operating from unregulated 12-V, 24-V, and 48-V rails.

FAQ

What is the minimum input voltage required for the LM46001PWPR to start switching?

The LM46001PWPR requires a minimum input voltage of 3.8 V to initiate startup and enter regulation. Below this threshold, the device remains in shutdown mode with only 2.3–5 µA quiescent current. This ensures reliable operation across automotive cold-crank conditions and industrial brownouts while preventing erratic behavior at marginal input levels. The LM46001PWPR resumes normal operation once VIN exceeds 3.8 V.

How does the BIAS pin improve efficiency in the LM46001PWPR?

The BIAS pin on the LM46001PWPR allows connection to VOUT (when 3.3–28 V) or an external 3.3/5 V rail, reducing current drawn from VIN and lowering total power loss. When used, it improves light-load efficiency by up to 3% compared to BIAS-grounded operation. For example, with VOUT = 5 V, routing BIAS to VOUT cuts IQ-SW from 24 µA to ~13 µA. The LM46001PWPR datasheet specifies 85–140 µA IBIAS-NONSW under this configuration.

Can the LM46001PWPR synchronize to an external clock, and what are the valid frequency and duty-cycle ranges?

Yes, the LM46001PWPR supports external clock synchronization via the SYNC pin across 200 kHz–2.2 MHz. Valid logic thresholds are VSYNC-HIGH ≥ 2 V and VSYNC-LOW ≤ 0.4 V, with minimum ON/OFF times of 80 ns each. Duty cycle must stay between 10% and 90% to ensure reliable edge detection. The LM46001PWPR maintains phase alignment and avoids frequency hopping when driven within these limits, enabling deterministic EMI reduction in multi-converter systems.

What is the purpose of the SS/TRK pin on the LM46001PWPR, and how is it configured for tracking?

On the LM46001PWPR, the SS/TRK pin serves dual functions: internal soft-start (4.1 ms when floating) or external voltage tracking. For tracking, connect SS/TRK to the output of a master supply (e.g., another LM46001PWPR or linear regulator) through a resistor divider matching the slave's output ratio. This forces the LM46001PWPR's output to ramp proportionally, ensuring controlled sequencing during power-up/down. The LM46001PWPR's internal soft-start charge current (1.17–2.85 µA) sets ramp rate when capacitor-based timing is used.

Does the LM46001PWPR support operation with ceramic output capacitors, and are there stability requirements?

Yes, the LM46001PWPR is internally compensated and stable with ceramic, polymer, tantalum, and aluminum output capacitors - no external compensation required. Minimum recommended COUT is 10 µF (X5R/X7R), and ESR should be ≤10 mΩ for optimal transient response. The LM46001PWPR's control loop is optimized for 100–220 µF typical values; using <10 µF may cause instability or excessive output ripple. Layout best practices (short PGND paths, Kelvin FB connections) remain essential for ceramic capacitor performance.