My Inquiry
My Account
STMicroelectronics L4972AD013TR
- Part No.:
- L4972AD013TR
- Manufacturer:
- STMicroelectronics
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
L4972AD013TR.pdf
- Description:
- IC REG BUCK ADJ 2A 20SO
- Quantity:
- Payment:
- Shipping:
Inventory:1,945
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
L4972AD013TR from STMicroelectronics is a 2A monolithic step-down switching regulator IC in SO20 package, delivering adjustable output voltage from 5.1V to 40V with internal 5.1V ±2% reference, 0–90% duty cycle control, and up to 200kHz switching frequency. It integrates DMOS power transistor, feed-forward line regulation, and reset/power-fail monitoring for microprocessor supply systems.
For engineers reviewing the L4972AD013TR datasheet, L4972AD013TR pinout, L4972AD013TR application, or L4972AD013TR equivalent, key selection criteria include continuous-mode 2A output capability, bootstrap-driven high-side DMOS gate drive, thermal shutdown with hysteresis, and synchronized multi-regulator operation via dedicated SYNC pin.
Technical Context
The L4972AD013TR operates in continuous conduction mode using BCD mixed-technology integration, combining isolated vertical DMOS power transistors with CMOS/bipolar control circuitry. Its PWM latch ensures single-pulse-per-period operation even under noise, while feed-forward oscillator control maintains line regulation across 15–50V input range.
Internal functions include soft-start (capacitor-programmable time constant), precise 5.1V reference with 0.4mV/°C tempco, undervoltage lockout (11V turn-on with 1V hysteresis), and open-drain reset output with external capacitor-determined delay. The device supports external frequency setting via Rosc/Cosc and synchronization across multiple units.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 2A continuous; internally current-limited to 2.5–3.5A for overload protection |
| Output Voltage Range | 5.1V to 40V; set by external feedback divider; 5.1V output requires direct connection to Vref |
| Switching Frequency | 90–110kHz typical; programmable up to 200kHz via external Rosc/Cosc network |
| Reference Voltage | 5.1V ±2% at pin 13; 0.4mV/°C temperature coefficient ensures stable regulation over –40°C to 125°C |
| Efficiency | 75–90% at 2A load; optimized for minimal external component count and reduced filter size at high fSW |
| Duty Cycle Range | 0–90%; enables wide VIN/VOUT ratios while maintaining stable PWM control loop stability |
| Input Voltage Range | 15–50V operating; absolute max 55V; UVLO activates below ~10V with 1V hysteresis |
Pinout & Package
Package: SO20 (Small Outline, 20-pin, 0.5mm pitch, body size 12.8 × 7.5 mm per Figure 52). Thermal resistance: Rth j-amb = 80°C/W (max) with standard PCB layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (BOOTSTRAP) | Bootstrap capacitor node | Connects external Cboot between pin 1 and OUTPUT (pin 20); enables proper gate drive of internal DMOS high-side switch |
| 3 (RESET OUT) | Open-collector reset signal | Asserts low when input drops below threshold or output falls below 5V; used for µP reset sequencing |
| 4 (RESET INPUT) | Power-fail sense input | Threshold ≈5.1V; accepts resistor divider from input rail to trigger early power-fail warning before brownout |
| 9 (FEEDBACK IN) | Regulation error amplifier input | Compares divided output voltage against internal 5.1V reference; sets output voltage via R-divider ratio |
| 10 (SYNC INPUT) | External synchronization input | Accepts TTL/CMOS clock signal to synchronize switching frequency across multiple L4972A regulators |
| 11 (SUPPLY VOLTAGE) | Main unregulated input | Accepts 15–50V DC input; powers internal circuitry and DMOS driver stage; includes UVLO and thermal shutdown logic |
| 13 (Vref) | Internal reference output | Stable 5.1V ±2% source; supplies feedback reference and can power external circuitry up to 1mA |
| 20 (OUTPUT) | Regulated power output | Delivers up to 2A switched DC; connects to bootstrap capacitor and output filter inductor |
Key Features
| Feature | Design Value |
|---|---|
| Integrated DMOS power switch | Enables >85% efficiency at 2A without external MOSFET; reduces BOM count and layout complexity |
| Feed-forward line regulation | Compensates input voltage variation in oscillator ramp, improving line regulation to 12mV over 15–50V input |
| Reset & power-fail monitoring | Provides system-level reliability: open-drain RESET OUT with programmable delay and dual-threshold detection |
| Soft-start function | Capacitor-programmable startup ramp prevents inrush current; avoids output overshoot during power-up |
| PWM latch with single-pulse control | Eliminates sub-harmonic oscillation and multiple switching pulses per cycle in noisy environments |
Applications
| Industrial PLC Power Supply | Automotive Body Control Module |
|---|---|
|
Use Scenario: Centralized 12V/24V-to-5.1V conversion for I/O modules, sensors, and communication interfaces in programmable logic controllers. IC Role / Device Role / Timing Role: Primary step-down regulator providing stable 5.1V rail; RESET OUT signals controller on input brownout or output fault. Use Value: Integrated current limiting and thermal shutdown prevent field failures during short-circuit events in harsh industrial environments. |
Use Scenario: Secondary power supply in vehicle body electronics, converting battery voltage (9–16V) to regulated 5.1V for microcontrollers and CAN transceivers. IC Role / Device Role / Timing Role: High-efficiency buck regulator with UVLO hysteresis ensuring clean startup above 11V and graceful shutdown below 10V. Use Value: Feed-forward line regulation maintains <12mV line regulation across wide automotive input range, reducing need for post-regulation LDOs. |
| Multi-Rail Telecom Shelf | Programmable Test Equipment |
|
Use Scenario: Synchronized multi-output power subsystem in telecom line cards, where multiple L4972A units generate 5.1V, 12V, and 24V rails. IC Role / Device Role / Timing Role: Master-slave synchronized buck regulator using pin 10 (SYNC INPUT) to eliminate beat frequencies and EMI peaks. Use Value: 200kHz max switching frequency allows compact LC filters; SO20 package supports high-density board layouts. |
Use Scenario: Lab-grade bench power supply module requiring precise, adjustable output (5.1–40V) with digital monitoring interface. IC Role / Device Role / Timing Role: Programmable step-down controller with external feedback divider; Vref (pin 13) provides calibration reference for ADC-based voltage sensing. Use Value: 0.4mV/°C reference tempco enables <±0.5% output accuracy over full industrial temperature range without trimming. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down switching regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2596S-5.0 | Fixed 5V output; no adjustable VOUT, no SYNC, no RESET OUT; lower max fSW (150kHz); no feed-forward line regulation | Suitable only for fixed 5V applications; lacks microprocessor supervision features and multi-rail sync capability | Select when cost sensitivity outweighs flexibility; not suitable for programmable or synchronized designs |
| TPS54202DRT | 2A synchronous buck; 4.5–28V input; integrated high/low-side FETs; 200kHz–2.2MHz programmable fSW; no internal Vref or RESET | Requires external feedback divider for VOUT; no built-in power-fail detection or reset generation | Choose for higher-frequency, smaller-filter designs where external supervision ICs handle reset/power-fail logic |
Compared with LM2596S-5.0 and TPS54202DRT, the L4972AD013TR uniquely combines adjustable output, integrated 5.1V reference, open-drain reset with delay, and feed-forward line regulation - enabling self-contained, microprocessor-supervised power systems without auxiliary ICs.
Availability
L4972AD013TR is available at Aetrix Electronics and suitable for industrial PLC power supplies, automotive body control modules, telecom shelf power subsystems, and programmable test equipment requiring stable component supply and long-term design continuity.
Supply support for L4972AD013TR 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, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.
The L4972A belongs to ST's legacy high-current monolithic switching regulator product line, engineered specifically for robust, low-component-count DC-DC conversion in microprocessor-based systems requiring integrated supervision and high efficiency.
FAQ
What is the minimum input voltage required for reliable startup?
The L4972AD013TR features undervoltage lockout with a turn-on threshold of 10–12V (typical 11V) and 1V hysteresis. Startup is guaranteed only when input voltage exceeds the upper threshold; operation ceases below the lower threshold (~10V), preventing erratic behavior during brownout conditions.
Can the L4972AD013TR be used for outputs below 5.1V?
No - the internal reference is fixed at 5.1V ±2%, and the feedback architecture requires the output to be ≥Vref for regulation. Attempting to set output below 5.1V violates the error amplifier's operating range and results in loss of regulation; use a different regulator family for sub-5V applications.
How is the switching frequency set and what is its tolerance?
Frequency is set externally via resistor Rosc (pin 17) and capacitor Cosc (pin 18); typical 100kHz operation uses Rosc = 30kΩ and Cosc = 2.7nF. Frequency stability is ±6% over input voltage (15–45V) and ±1% over junction temperature (0–125°C), per Table 5.
Is the BOOTSTRAP pin compatible with ceramic capacitors?
Yes - the BOOTSTRAP pin (pin 1) is designed for standard ceramic capacitors (e.g., 100nF–1µF X7R); ST recommends ≥220nF for 200kHz operation per Table 7. Ceramic types provide low ESR and fast charge/discharge, essential for reliable high-side DMOS gate drive.
L4972AD013TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 15V
- Voltage - Input (Max):
- 50V
- Voltage - Output (Min/Fixed):
- 5.1V
- Voltage - Output (Max):
- 40V
- Current - Output:
- 2A
- Frequency - Switching:
- 100kHz ~ 200kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SO
L4972AD013TR FAQ
1.How can I place an order for L4972AD013TR through Aetrix?
Please submit a Request for Quotation (RFQ) for L4972AD013TR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for L4972AD013TR reliable?
The price and inventory of L4972AD013TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L4972AD013TR is usually 5 days.
3.What payment methods are accepted for L4972AD013TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L4972AD013TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for L4972AD013TR?
L4972AD013TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your L4972AD013TR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for L4972AD013TR?
For technical support, including L4972AD013TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L4972AD013TR requirements.
6.How does Aetrix verify that L4972AD013TR is sourced from the original manufacturer or authorized distributors?
All L4972AD013TR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that L4972AD013TR meets industry standards.
7.What is the process for return or replacement of L4972AD013TR?
All L4972AD013TR units undergo pre-shipment inspection (PSI). If there is an issue with L4972AD013TR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The L4972AD013TR part is unused and in its original packaging.
Return procedure for L4972AD013TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
L4972AD013TR Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
