Texas Instruments LP38692SD-1.8/NOPB

Overview

LP38692SD-1.8/NOPB from Texas Instruments is a 1-A, 1.8-V fixed-output CMOS low-dropout linear regulator with enable control, optimized for battery-powered digital systems. It delivers ±2.5% output accuracy at 25°C, achieves 950 mV dropout at 1 A (VOUT = 1.8 V), supports ceramic output capacitors as low as 1 µF, and operates across 2.7 V to 10 V input range - enabling use in notebook CPU core rails and portable instrumentation power domains.

For engineers reviewing the LP38692SD-1.8/NOPB datasheet, LP38692SD-1.8/NOPB pinout, LP38692SD-1.8/NOPB application, or LP38692SD-1.8/NOPB equivalent, key selection criteria include its 5-pin SOT-223 package, EN-controlled shutdown (1 µA quiescent current), thermal shutdown at 160°C, foldback current limiting, and stable operation with ultra-low-ESR ceramic caps - all critical for space-constrained, thermally demanding embedded designs.

Technical Context

The LP38692SD-1.8/NOPB employs a PMOS pass transistor architecture, eliminating DC base drive current and maintaining ground pin current below 100 µA across load, input voltage, and temperature. Its precision trimmed bandgap reference and feedback loop ensure tight regulation over –40°C to +125°C junction temperature.

It integrates enable logic with no internal pull-up/down, requiring external termination; thermal shutdown activates at ~160°C with ~10°C hysteresis, and foldback current limiting dynamically scales output current based on VIN–VOUT differential - delivering ~450 mA at >5 V differential and ~1500 mA at <4 V differential.

Key Specifications

Pinout & Package

LP38692SD-1.8/NOPB is packaged in a 5-pin SOT-223 (NDC) with exposed thermal pad (DAP) on the underside. The package measures 6.50 mm × 3.56 mm and provides low R_θJB = 13.0°C/W for efficient board-level heat transfer when soldered to copper planes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout linear regulator applications.

Compared with TSS721AIDR and TPS7A2018PDQNR, LP38692SD-1.8/NOPB uniquely balances 1-A output, 950-mV dropout, EN control, and 1-µF ceramic stability in a thermally efficient SOT-223 package - making it the only viable option for high-current, battery-fed 1.8-V rails requiring both sequencing and thermal headroom.

Availability

LP38692SD-1.8/NOPB is available at Aetrix Electronics and suitable for notebook computers, hard disk drives, and portable instrumentation requiring stable component supply with guaranteed long-term manufacturability and industrial-temperature support.

Supply support for LP38692SD-1.8/NOPB 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 consumer applications.

LP38692SD-1.8/NOPB belongs to TI's LP3869x family of CMOS LDOs designed specifically for high-efficiency, low-noise power delivery in portable and thermally constrained digital systems - emphasizing ceramic-cap compatibility, wide input range, and robust protection features.

FAQ

What is the minimum input voltage required for LP38692SD-1.8/NOPB to regulate 1.8 V output?

The LP38692SD-1.8/NOPB requires VIN ≥ (VOUT + V_DO) to maintain regulation. With a typical dropout of 950 mV at 1 A, the minimum functional input is 2.75 V. However, the absolute minimum operating input is 2.7 V per specifications - below which internal circuitry may not power up reliably. For guaranteed 1.8-V regulation at full load, VIN must exceed 2.75 V.

Does LP38692SD-1.8/NOPB require an external resistor divider to set output voltage?

No. LP38692SD-1.8/NOPB is a fixed-output regulator with internally trimmed 1.8-V reference. It does not use external feedback resistors - the output voltage is factory-set and unadjustable. This eliminates component count, layout sensitivity, and drift associated with external dividers, enhancing accuracy and reliability.

Can LP38692SD-1.8/NOPB operate with a 1-µF ceramic output capacitor, and why is this significant?

Yes. LP38692SD-1.8/NOPB is explicitly characterized and guaranteed stable with a single 1-µF ceramic capacitor (X5R/X7R, ≤500 mΩ ESR). This eliminates reliance on larger, less reliable electrolytic or tantalum caps - reducing board area, cost, and failure risk in portable and high-reliability applications.

What happens to LP38692SD-1.8/NOPB during a reverse-voltage condition at the output pin?

When V_OUT > V_IN, two conduction paths exist: (1) if EN is high and control circuitry is active, the PMOS pass transistor turns fully on, allowing reverse current limited only by R_DS(ON); (2) if EN is low or VIN is too low, the intrinsic body diode conducts - forward-biased above ~500 mV. Reverse current must be externally limited to <1 A continuous to prevent damage.

Is the exposed thermal pad (DAP) on LP38692SD-1.8/NOPB electrically connected, and how must it be handled in layout?

Yes - the DAP on LP38692SD-1.8/NOPB is internally connected to GND. It must be soldered to a dedicated PCB ground plane using thermal vias to achieve the specified R_θJB = 13.0°C/W. Leaving it floating or unconnected degrades thermal performance, risks junction overheating at 1-A load, and voids guaranteed operation over temperature.