STMicroelectronics L5970D013TR

Overview

L5970D013TR from STMicroelectronics is a monolithic step-down switching regulator featuring an internal P-channel D-MOS switch (R_DS(on) = 250 mΩ), delivering up to 1 A output current across 1.2 V–35 V adjustable output range, with 4.4 V–36 V input voltage capability and fixed 250 kHz switching frequency - used in DC-DC conversion for LCD monitors, car radios, and industrial DC-DC modules.

For engineers reviewing the L5970D013TR datasheet, L5970D013TR pinout, L5970D013TR application, or L5970D013TR equivalent, key selection criteria include its 100% duty-cycle low-dropout operation, internal 3.3 V reference (±2%), synchronization capability, inhibit control for µA-level standby current, and thermal shutdown protection.

Technical Context

The L5970D013TR implements voltage-mode PWM control with feedforward compensation, enabling stable regulation across wide input ranges without external loop compensation complexity. Its error amplifier features 50–65 dB open-loop gain and 2.3 mS transconductance, driving the COMP pin for external frequency compensation networks.

It supports master/slave synchronization via the SYNC pin (2.5 V high threshold, 0.74 V low), operates down to zero load current, and includes dedicated protection against feedback disconnection and overtemperature via integrated thermal shutdown at 150 °C junction temperature.

Key Specifications

Pinout & Package

Supplied in SO-8 package (ECOPACK®, lead-free, JEDEC-standard dimensions), with exposed pad not electrically connected - requires standard SOIC-8 PCB footprint and thermal relief design per ST's mechanical data (D = 4.80–5.00 mm, E = 3.80–4.00 mm).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with LM2596S-ADJ and TPS54202DR, the L5970D013TR offers optimal balance of integration (internal P-FET, VREF, sync), thermal robustness (150 °C T_J), and industrial-grade input range - making it ideal for fixed-frequency, medium-current applications where reliability and simplicity outweigh programmability needs.

Availability

L5970D013TR is available at Aetrix Electronics and suitable for car radio power supplies, LCD monitor DC-DC modules, and industrial DC-DC converters requiring stable component supply, long-lifecycle support, and consistent SO-8 packaging.

Supply support for L5970D013TR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The L5970D013TR belongs to ST's monolithic DC-DC converter product line, engineered specifically for rugged, fixed-frequency buck regulation in cost-sensitive industrial and consumer power systems where simplicity, thermal resilience, and wide-input operation are critical.

FAQ

What is the minimum input voltage required for regulation at 3.3 V output?

The L5970D013TR maintains regulation down to 4.4 V input at 3.3 V output, enabled by its 100% duty-cycle capability and low R_DS(on). Below this, dropout occurs - verified per datasheet Section 2.1 and Figure 4 (line regulation). No external boost or auxiliary supply is needed for nominal 5 V bus operation.

Can the L5970D013TR be synchronized to an external clock?

Yes - the SYNC pin accepts TTL/CMOS-compatible external clocks (2.5 V high threshold) and can also act as master output (2.75–3 V amplitude, 0.2–0.35 µs pulse width). Synchronization is confirmed in Table 4 (Sync function section) and Figure 21 of the datasheet, supporting multi-rail coherence in dense PCB layouts.

Is an external capacitor required on the VREF pin?

No - the VREF pin delivers a stable 3.3 V ±2% reference without any external capacitor, as explicitly stated in Table 1 (Pin description) and Section 3 (Electrical characteristics). Adding capacitance is unnecessary and may destabilize the internal bandgap circuit per ST's design guidance.

How does the inhibit (INH) function reduce power consumption?

When INH is pulled >2.2 V, total standby current drops to 50–150 µA (depending on V_CC), verified in Table 4 (I_qst-by). This disables internal oscillator, gate drive, and error amplifier - confirmed by Figure 11 (shutdown current vs. T_J) and Section 1.2 (Pin description), enabling true zero-power hold states.