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STMicroelectronics L6986HTR
- Part No.:
- L6986HTR
- Manufacturer:
- STMicroelectronics
- Package:
- 16-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
L6986HTR.pdf
- Description:
- IC REG BUCK ADJ 2A 16HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:9,980
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Product details
Overview
L6986HTR from STMicroelectronics is a 2 A synchronous step-down switching regulator with 4 V–38 V input range, peak-current-mode control, and dual operating modes (LCM/LNM). It delivers adjustable output (0.85 V–VIN) or fixed 3.3 V/5 V, features embedded voltage supervisor (RST open-drain), synchronization capability, and 100% duty-cycle operation via integrated P-channel high-side MOSFET. Used in industrial PLCs and decentralized sensor nodes requiring stable, low-noise power conversion.
For engineers reviewing the L6986HTR datasheet, L6986HTR pinout, L6986HTR application, or L6986HTR equivalent, key selection criteria include quiescent current (30 µA in LCM at 3.3 V), RDS(on) values (180 mΩ HS / 150 mΩ LS), adjustable soft-start, overvoltage protection, and thermal shutdown at 165 °C - all critical for 12 V/24 V bus designs with sequencing and light-load efficiency requirements.
Technical Context
The L6986HTR implements peak-current-mode control with internal slope compensation and pulse-by-pulse current sensing on both high- and low-side switches for robust constant-current protection. Its P-channel high-side MOSFET enables true 100% duty-cycle operation, supporting ultra-low dropout in wide-input applications.
Two configurable operating modes define system behavior: Low Consumption Mode (LCM) enables discontinuous conduction with 30 µA IQ at light load and programmable skip-level current; Low Noise Mode (LNM) enforces forced PWM with constant fSW (275–2200 kHz) and minimized output ripple across load range. Synchronization supports up to six slave devices.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4 V to 38 V - supports direct connection to 12 V and 24 V industrial buses without pre-regulation. |
| Output Current | 2 A DC continuous - sufficient for powering microcontrollers, FPGAs, and analog sensor front-ends. |
| Quiescent Current (LCM) | 30 µA at light load (VOUT = 3.3 V) - extends battery life in always-on industrial monitoring nodes. |
| Switching Frequency | 250 kHz to 2 MHz - selectable via resistor strapping on FSW pin; enables compact magnetics and EMI optimization. |
| RDS(on) HS / LS | 180 mΩ / 150 mΩ - reduces conduction losses and thermal stress under full 2 A load at ambient temperature. |
| Thermal Shutdown | 165 °C with 30 °C hysteresis - protects IC and PCB during overload or poor heatsinking conditions. |
| Output Supervision | RST open-collector with adjustable delay (via external capacitor) - provides reset signaling and voltage sequencing capability. |
Pinout & Package
Package: HTSSOP-16 (exposed pad), RoHS-compliant, thermally enhanced for high-power density layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 RST | Open-collector reset output | Asserts low when VOUT falls below programmed threshold; delay set by external capacitor on Pin 8. |
| 2 VCC | Internal reference supply | Requires ≥470 nF ceramic capacitor; powers analog circuitry including error amplifier and bandgap. |
| 3 SS/INH | Soft-start/inhibit control | Charged by 4 µA internal current source; clamping to GND disables regulator (INH mode). |
| 4 SYNCH/ISKIP | Mode selection & sync input | Selects LCM/LNM and skip level in LCM; accepts external clock for master/slave synchronization in LNM. |
| 5 FSW | Frequency selection strap | Resistor-to-VCC or GND sets fSW before soft-start; supports E24 values for precise frequency tuning. |
| 6 MLF | Mode & RST threshold select | Configures LCM/LNM and RST trip point (e.g., 93% of VOUT for 3.3 V version = ~3.07 V). |
| 7 COMP | Error amplifier output | Connects external compensation network (type II or III) to stabilize loop response. |
| 8 DELAY | RST assertion timing | Capacitor here sets delay between VOUT regulation recovery and RST release (e.g., 10 ms typical). |
| 9 VOUT | Feedback sense input | Monitors regulated output via resistive divider; internal reference is 0.85 V (adjustable mode). |
| 10 SGND | Signal ground | Reference for analog blocks (error amp, comparators); must be separated from PGND in layout. |
| 11–12 PGND | Power ground (dual) | Carries high di/dt switching currents; tied to exposed pad for thermal and EMI performance. |
| 13–14 LX | Switching node (dual) | Connects to external inductor; dual pins reduce parasitic inductance and improve efficiency. |
| 15 VIN | Main input supply | Accepts 4–38 V; includes UVLO (2.7 V rising, 2.4 V falling) for reliable start-up. |
| 16 VBIAS | Bias supply switchover | Connect to regulated output (3–5.5 V) to reduce IQ at VIN; internal switchover threshold ~3.0 V. |
| EP | Exposed thermal pad | Must be soldered to SGND + PGND plane for thermal resistance of 5 °C/W junction-to-pad. |
Key Features
| Feature | Design Value |
|---|---|
| Peak-current-mode architecture with slope compensation | Enables stable loop control across wide VIN/VOUT ratios and prevents subharmonic oscillation at D > 50%. |
| Programmable low-noise mode (LNM) | Forces constant-frequency PWM with minimized output ripple - meets noise-sensitive analog/sensor supply specs. |
| Low-consumption mode (LCM) with skip-level control | Reduces IQ to 30 µA at light load while maintaining regulated output - ideal for energy-constrained edge nodes. |
| Embedded output voltage supervisor with RST | Provides hardware reset for µC/FPGA and enables cascaded power-up sequencing via RST→SS/INH interconnect. |
| Synchronous rectification with optimized RDS(on) | 180 mΩ HS / 150 mΩ LS MOSFETs deliver >90% efficiency at 1 A, reducing heat sink requirements in confined spaces. |
Applications
| Industrial PLC Power Rails | Decentralized Sensor Nodes |
|---|---|
|
Use Scenario: Powering I/O modules, communication interfaces (RS-485, CAN), and microcontrollers in modular PLC backplanes supplied from 24 V DC bus. IC Role / Device Role / Timing Role: Primary buck converter delivering regulated 3.3 V or 5 V with sequencing support for FPGA configuration and ADC biasing. Use Value: Wide 4–38 V input accommodates bus transients; RST output ensures deterministic reset of digital loads during brownout recovery. |
Use Scenario: Compact, battery-backed sensor units deployed in factory-floor condition monitoring (vibration, temperature, pressure). IC Role / Device Role / Timing Role: Efficient intermediate regulator converting 12 V battery or PoE-derived rail to low-noise 3.3 V for precision analog front-end and BLE/Wi-Fi SoC. Use Value: 30 µA LCM quiescent current extends operational lifetime; LNM mode suppresses switching noise during ADC sampling windows. |
| Programmable Logic Controller (PLC) Backplane | Industrial IoT Edge Gateway |
|
Use Scenario: Distributed power management across multi-slot PLC chassis where each slot requires independent, sequenced 5 V/3.3 V rails. IC Role / Device Role / Timing Role: Synchronized buck regulator enabling phase-aligned switching across multiple L6986HTRs to reduce input ripple and EMI peaks. Use Value: FSW pinstrapping and SYNCH input allow precise frequency alignment; RST-to-SS/INH chaining achieves strict power-up order per module. |
Use Scenario: Edge gateway aggregating data from field sensors and forwarding via Ethernet or cellular; requires reliable, low-heat 3.3 V supply for ARM Cortex-M7 host MCU. IC Role / Device Role / Timing Role: Main system regulator with thermal shutdown (165 °C) and overvoltage protection to maintain uptime in unventilated enclosures. Use Value: Exposed pad + dual PGND/LX pins enable <40 °C/W θJA in 4-layer board; VBIAS switchover cuts total system IQ by ~40% at light load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5164QDDARQ1 | 40 V max VIN, 1 A output, 3.5 µA IQ (shutdown), no integrated RST supervisor or LNM mode. | Automotive AEC-Q100 qualified; lacks voltage sequencing and low-noise mode - unsuitable for sensor-rail noise specs. | Choose only if automotive qualification and lower cost outweigh need for sequencing and LNM. |
| TPS54202DRCT | 6–17 V VIN, 2 A, 2 µA IQ (shutdown), no LCM/LNM modes, no RST, smaller 10-pin WSON package. | Targeted at space-constrained consumer electronics; missing industrial-grade supervision, wide VIN, and thermal robustness. | Consider only for non-industrial, narrow-input applications where footprint is primary constraint. |
Compared with LM5164QDDARQ1 and TPS54202DRCT, the L6986HTR uniquely integrates RST-based sequencing, dual LCM/LNM operation for efficiency/noise trade-off, and 4–38 V industrial input range - making it the sole fit for PLC and decentralized sensor node power architectures requiring coordinated startup and low-noise analog supply.
Availability
L6986HTR is available at Aetrix Electronics and suitable for industrial automation, programmable logic controllers, and decentralized sensor networks requiring stable component supply across extended product lifecycles and varying environmental conditions.
Supply support for L6986HTR 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, specializing in power management, microcontrollers, and analog/mixed-signal ICs for industrial, automotive, and embedded markets.
The L6986HTR belongs to ST's high-voltage synchronous buck regulator family, designed specifically for rugged 12 V/24 V industrial bus applications demanding reliability, sequencing, and adaptive efficiency modes.
FAQ
What is the purpose of the VBIAS pin on the L6986HTR?
The VBIAS pin enables internal supply switchover: when connected to a regulated output voltage (3–5.5 V), it powers part of the analog circuitry, reducing total quiescent current drawn from VIN. This feature lowers system IQ by up to 40% in light-load LCM operation, extending battery life in always-on sensor nodes without compromising regulation accuracy.
How does the RST pin support power sequencing in multi-rail systems?
The RST pin is an open-collector output that goes low when VOUT falls outside regulation and releases after a user-set delay (via external capacitor on DELAY pin). By connecting RST of a master L6986HTR to the SS/INH pin of a slave device, the slave remains inhibited until the master's output stabilizes - enabling precise, hardware-controlled power-up sequencing without external controllers or firmware.
Can the L6986HTR operate with 100% duty cycle, and how is this achieved?
Yes - the L6986HTR achieves true 100% duty cycle using an integrated P-channel high-side MOSFET. Unlike N-channel solutions requiring bootstrap circuitry, the P-channel device allows continuous conduction when VIN approaches VOUT, enabling ultra-low dropout operation essential for brownout resilience in 12 V/24 V industrial systems where input may dip near output voltage.
What distinguishes Low Noise Mode (LNM) from Low Consumption Mode (LCM)?
LNM forces constant-frequency PWM across all loads, minimizing output voltage ripple and EMI - critical for noise-sensitive analog circuits. LCM uses pulse-skipping at light load to reduce switching losses, achieving 30 µA IQ but introducing higher ripple. Mode selection is set via MLF pinstrapping before soft-start and cannot be changed dynamically during operation.
L6986HTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 16-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 38V
- Voltage - Output (Min/Fixed):
- 0.85V
- Voltage - Output (Max):
- 38V
- Current - Output:
- 2A
- Frequency - Switching:
- 250kHz ~ 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-HTSSOP
L6986HTR FAQ
1.How can I place an order for L6986HTR through Aetrix?
Please submit a Request for Quotation (RFQ) for L6986HTR 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 L6986HTR reliable?
The price and inventory of L6986HTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L6986HTR is usually 5 days.
3.What payment methods are accepted for L6986HTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L6986HTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for L6986HTR?
L6986HTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your L6986HTR 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 L6986HTR?
For technical support, including L6986HTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L6986HTR requirements.
6.How does Aetrix verify that L6986HTR is sourced from the original manufacturer or authorized distributors?
All L6986HTR 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 L6986HTR meets industry standards.
7.What is the process for return or replacement of L6986HTR?
All L6986HTR units undergo pre-shipment inspection (PSI). If there is an issue with L6986HTR, 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 L6986HTR part is unused and in its original packaging.
Return procedure for L6986HTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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