Texas Instruments LP38842S-0.8/NOPB

Overview

LP38842S-0.8/NOPB from Texas Instruments is a 1.5A ultra-low-dropout linear regulator with fixed 0.8V output, N-MOS pass transistor architecture, 115mV typical dropout at 1.5A, ±1.5% initial output accuracy, and stable operation with ceramic output capacitors ≥22µF. It powers microcontroller cores and FPGA I/O rails in space-constrained industrial embedded systems.

For engineers reviewing the LP38842S-0.8/NOPB datasheet, LP38842S-0.8/NOPB pinout, LP38842S-0.8/NOPB application, or LP38842S-0.8/NOPB equivalent, this page delivers verified technical context, package-specific thermal behavior, ceramic capacitor stability requirements, shutdown timing (20µs turn-off), and bias rail dependency (4.5–5.5V VBIAS) - all confirmed for the DDPAK/TO-263 (KTT) variant.

Technical Context

The LP38842S-0.8/NOPB uses a dual-rail CMOS architecture: VIN supplies load current while VBIAS (4.5–5.5V) independently drives the N-MOS gate, enabling operation with input voltages as low as ~0.915V (0.8V + 115mV). Its loop stability relies on external ceramic output capacitance ≥22µF and a 0.1µF bias capacitor.

It integrates over-temperature and over-current protection, achieves 30nA shutdown current, maintains 0.1%/A load regulation, and delivers 80dB PSRR at 120Hz on VIN. The device operates across −40°C to +125°C junction temperature and requires no PCB layout changes when replacing other LP38842S-x variants sharing the same KTT package.

Key Specifications

Pinout & Package

LP38842S-0.8/NOPB is housed in a 5-pin DDPAK/TO-263 (KTT) package with exposed thermal pad. The tab is electrically connected to GND and must be soldered to ≥1 in² copper plane for thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-dropout LDO applications.

Compared with TPL7407LDR and TPS7A8300RGRT, the LP38842S-0.8/NOPB uniquely balances 1.5A capability, 0.8V fixed output, dual-rail efficiency, and DDPAK thermal performance-making it optimal for space-constrained, high-reliability 0.8V core regulation where VBIAS availability is assured.

Availability

LP38842S-0.8/NOPB is available at Aetrix Electronics and suitable for ASIC core power supplies, FPGA I/O banks, SMPS post-regulators, and industrial embedded controller designs requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LP38842S-0.8/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 leader specializing in analog, embedded processing, and power management ICs, with decades of expertise in high-reliability linear regulators and power delivery solutions.

The LP38842S-0.8/NOPB belongs to TI's LP3884x ultra-low-dropout LDO family, engineered specifically for high-current, low-voltage digital core and I/O regulation in computing, communications, and industrial systems where ceramic capacitor compatibility and thermal resilience are mandatory.

FAQ

What is the minimum input voltage required for LP38842S-0.8/NOPB to regulate at full 1.5A load?

The LP38842S-0.8/NOPB requires a minimum input-to-output differential of 115mV at 1.5A (typical dropout voltage), meaning VIN must be ≥0.915V when VOUT = 0.8V. This assumes VBIAS is within 4.5–5.5V and thermal limits are observed. At higher temperatures or lower VBIAS, dropout increases slightly-consult Figure 6 in the datasheet for worst-case curves.

Can LP38842S-0.8/NOPB operate without an external VBIAS supply?

No. The LP38842S-0.8/NOPB requires an external 4.5–5.5V VBIAS supply to drive its N-MOS pass transistor gate. It cannot self-bias from VIN. If VBIAS falls below ~4V, under-voltage lockout disables the output. Connecting VIN to BIAS is unsafe and violates absolute maximum ratings-VBIAS must be sourced independently.

What output capacitor is required for stable operation of LP38842S-0.8/NOPB?

LP38842S-0.8/NOPB requires ≥22µF ceramic output capacitance (X7R or X5R dielectric only) placed within 1 cm of the OUT pin and returned to clean analog ground. Tantalum capacitors are not recommended; if used, minimum is 4.7µF but with degraded transient response and higher ESR. Z5U/Y5V ceramics are prohibited due to severe capacitance loss with voltage and temperature.

How does the thermal performance of LP38842S-0.8/NOPB compare between TO-220 and DDPAK packages?

The LP38842S-0.8/NOPB in DDPAK/TO-263 (KTT) achieves θ_J-A = 35°C/W with 1 in² copper, versus 65°C/W for TO-220 without heatsink. This means the DDPAK version dissipates ~1.5× more power at the same ambient temperature. For 1.5A at 0.915V VIN → 0.8V, power dissipation is ~225mW-well within DDPAK's capability at 85°C ambient, eliminating need for external heatsink.

Is LP38842S-0.8/NOPB pin-compatible with other LP38842S-x variants?

Yes. All LP38842S-x/NOPB variants-including LP38842S-1.2/NOPB and LP38842S-1.5/NOPB-share identical DDPAK/TO-263 (KTT) 5-pin pinout, thermal pad layout, and electrical interface. Only the output voltage differs; no PCB redesign is needed when migrating between fixed-output versions in the same package.