Texas Instruments LP2985-33DBVTE4

Overview

LP2985-33DBVTE4 from Texas Instruments is a fixed 3.3V, 150mA low-dropout linear regulator in SOT-23-5 (DBV) package, featuring ±0.5% output accuracy (new chip), 30µVRMS output noise with 10nF bypass capacitor, and 70dB PSRR at 1kHz. It delivers stable power to low-voltage MCUs and RF front-ends in space-constrained industrial and wireless applications.

For engineers reviewing the LP2985-33DBVTE4 datasheet, LP2985-33DBVTE4 pinout, LP2985-33DBVTE4 application, or LP2985-33DBVTE4 equivalent, key selection criteria include dropout voltage at 150mA (180–198mV), shutdown current (1.12µA typ), thermal shutdown threshold (170°C), and compatibility with 2.2µF ceramic output capacitors.

Technical Context

The LP2985-33DBVTE4 employs a CMOS pass transistor architecture with internal bandgap reference and error amplifier, enabling ultra-low dropout and high PSRR. Its integrated soft-start reduces inrush current, while UVLO (2.2–2.4V rising) prevents operation below minimum input voltage.

Functional block includes active-high ON/OFF enable with internal pulldown during disable, BYPASS pin for noise reduction via external capacitor, and full protection suite: overcurrent limiting, thermal shutdown at 170°C, and reverse-current blocking. Operating junction temperature spans –40°C to +125°C.

Key Specifications

Pinout & Package

LP2985-33DBVTE4 is housed in a 5-pin SOT-23 (DBV) package measuring 2.9mm × 2.8mm, optimized for high-density PCB layouts and thermal performance (R_θJA = 178.6°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSS721AIDR and MCP1700T-3302E/MB, LP2985-33DBVTE4 uniquely combines 30µVRMS noise, ±0.5% accuracy, and 1.12µA shutdown in a 5-pin SOT-23 - making it the only choice for noise-critical, thermally demanding, and enable-controlled 3.3V LDO applications.

Availability

LP2985-33DBVTE4 is available at Aetrix Electronics and suitable for washer/dryer control boards, land mobile radio transceivers, active antenna systems (mMIMO), and cordless power tool MCUs requiring stable component supply, long-term manufacturability, and guaranteed parametric compliance.

Supply support for LP2985-33DBVTE4 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 connectivity technologies, with decades of expertise in power management ICs.

The LP2985 product line was designed specifically for cost-sensitive, space-constrained applications requiring low-noise, high-accuracy, and robust thermal performance - targeting industrial controls, portable RF, and consumer appliances.

FAQ

What is the output voltage tolerance of LP2985-33DBVTE4 across temperature and load?

The LP2985-33DBVTE4 features ±0.5% output voltage tolerance over full load (1mA–150mA) and temperature (–40°C to +125°C), verified per TI's SLVS522S datasheet revision May 2025. This specification applies exclusively to the "new chip" variant, which LP2985-33DBVTE4 belongs to, and ensures reliable operation for 3.3V logic and analog circuits without external trimming.

Does LP2985-33DBVTE4 require an external bypass capacitor, and what value is recommended?

Yes, LP2985-33DBVTE4 requires a 10nF capacitor between the BYPASS pin and GND to achieve its specified 30µVRMS output noise performance. This capacitor filters the internal reference voltage and is mandatory for noise-sensitive applications such as RF synthesizers and high-resolution ADCs. The LP2985-33DBVTE4 datasheet explicitly specifies this value and placement in Figure 7-2 and Section 6.3.2.

What is the maximum input voltage rating for LP2985-33DBVTE4?

The absolute maximum continuous input voltage for LP2985-33DBVTE4 is 18V, as stated in Section 5.1 Absolute Maximum Ratings of the TI SLVS522S datasheet. However, the recommended operating input voltage range is 2.5V to 16V. Exceeding 16V continuously may impact reliability, and operation above 18V risks permanent damage to the LP2985-33DBVTE4 device.

Can LP2985-33DBVTE4 operate stably with a 2.2µF ceramic output capacitor?

Yes, LP2985-33DBVTE4 is explicitly characterized and guaranteed stable with a 2.2µF ceramic output capacitor (X5R/X7R, ≤1Ω ESR), as confirmed in Section 1 Features and Section 5.3 Recommended Operating Conditions. This eliminates the need for larger, less reliable electrolytic capacitors and simplifies layout in space-constrained designs using the LP2985-33DBVTE4.

What is the thermal shutdown threshold of LP2985-33DBVTE4, and does it auto-recover?

The LP2985-33DBVTE4 thermal shutdown activates at 170°C (T_sd+) and resets at 150°C (T_sd−), providing hysteresis to prevent oscillation. This behavior is documented in Section 5.5 Electrical Characteristics and applies to the "new chip" variant. Upon cooling below 150°C, the LP2985-33DBVTE4 automatically resumes normal regulation without external intervention.