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Texas Instruments SM72485E/NOPB
- Part No.:
- SM72485E/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-WDFN Exposed Pad
- Datasheet:
-
SM72485E/NOPB.pdf
- Description:
- IC REG BUCK ADJ 150MA 8WSON
- Quantity:
- Payment:
- Shipping:
Inventory:1,719
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Product details
Overview
SM72485E/NOPB from Texas Instruments is a 100-V, 150-mA constant on-time buck switching regulator with integrated 100-V N-channel buck switch, 2.5-V internal reference, and no loop compensation required. It operates from 6 V to 95 V input, delivers adjustable output down to 2.5 V, and targets high-voltage DC-DC bias conversion in photovoltaic junction boxes and 42-V/48-V telecom systems.
For engineers reviewing the SM72485E/NOPB datasheet, SM72485E/NOPB pinout, SM72485E/NOPB application, or SM72485E/NOPB equivalent, key selection criteria include its VIN range (6–95 V), constant-frequency operation via inverse VIN-dependent on-time, intelligent current limit with RCL-programmable off-time, thermal shutdown at 165°C, and dual-package availability (VSSOP-8 and WSON-8).
Technical Context
The SM72485E/NOPB implements a constant on-time control architecture where tON ∝ 1/VIN, enabling stable switching frequency across line and load variations without external compensation. Its regulation relies on direct comparison of FB voltage against a precision 2.5-V internal reference, with overvoltage protection triggered at 2.875 V.
Current limiting uses a forced off-time generator whose duration is set by RCL and inversely proportional to VFB, delivering 35 µs maximum off-time during short-circuit (VFB = 0 V) and shorter durations under partial overload. The integrated N-channel buck switch features 2.2 Ω typical RDS(ON), driven via bootstrap circuitry requiring a 0.01-µF BST–SW capacitor.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 6 V to 95 V - supports wide-range industrial, PV, and automotive bus inputs without external pre-regulation |
| Output Current | 150 mA max - sufficient for bias rails in isolated gate drivers, sensors, and auxiliary power supplies |
| Internal Reference | 2.5 V ±20 mV - sets precise output voltage via resistor divider; enables 2.5 V minimum adjustable output |
| Switch RDS(ON) | 2.2 Ω (typ) - low conduction loss at 100-V rating; reduces heat generation in high-input applications |
| Thermal Shutdown | 165°C with 25°C hysteresis - protects device during sustained overload or poor heatsinking |
| Min On-Time | 400 ns at 95 V - constrains maximum operating frequency; ensures reliable current limit activation |
| FB Bias Current | 100 nA - enables high-impedance feedback networks without significant voltage error |
Pinout & Package
SM72485E/NOPB is available in two thermally optimized packages: 3.0 mm × 3.0 mm VSSOP-8 (DGK) and 4.0 mm × 4.0 mm WSON-8 (NGU), both featuring an exposed thermal pad connected to GND for enhanced power dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW | Power Switch Node | Connects to inductor, freewheeling diode, and bootstrap capacitor; carries full switching current and high dv/dt |
| VIN | Main Input Supply | Accepts 6–95 V DC; powers internal start-up regulator and provides energy to buck stage |
| RT/SD | On-Time Programming / Shutdown Control | Resistor to VIN sets tON; pulled low disables regulator - no external pull-down needed for remote shutdown |
| FB | Feedback Input | Inverting input of regulation comparator; 2.5-V threshold enables precise output voltage setting via resistive divider |
| RCL | Current Limit Off-Time Set | Resistor to RTN programs off-time duration during current limit; 35 µs default when FB = 0 V (short-circuit) |
| BST | Bootstrap Supply | Requires 0.01-µF ceramic cap to SW; supplies floating gate drive voltage for N-channel MOSFET |
| VCC | Internal Regulator Output | 7-V regulated supply for gate driver; requires 0.47-µF local decoupling; UVLO at 5.3 V prevents erratic startup |
| RTN | Signal Ground | Reference return for FB, RCL, and RT/SD; must be low-impedance path to minimize noise coupling into regulation loop |
Key Features
| Feature | Design Value |
|---|---|
| No loop compensation required | Constant on-time architecture eliminates need for external compensation network - simplifies layout and reduces BOM count |
| Ultra-fast transient response | On-time adjustment per cycle enables immediate reaction to load steps - maintains tight output regulation without large output capacitance |
| Intelligent current limit | Off-time scales with VFB - delivers full 35 µs protection during short-circuit while minimizing foldback during moderate overloads |
| Integrated start-up regulator | VIN-connected bias supply with bypass mode below 8.5 V - eliminates need for external LDO or charge pump for VCC generation |
| Precharge switch | 150-ns active discharge of SW node during minimum off-time - ensures reliable bootstrap capacitor recharge under light-load or pre-biased conditions |
Applications
| PV Panel Smart Junction Boxes | Nonisolated Telecommunication Buck Regulator |
|---|---|
Use Scenario: Distributed DC-DC conversion inside solar panel junction boxes to power monitoring ICs and communication modules from string voltages up to 95 V. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated 3.3-V or 5-V bias rail; operates continuously under variable irradiance and temperature. Use Value: Enables direct use of high-string PV voltage without intermediate pre-regulators; 100-V switch withstands transients and eliminates external TVS requirements. | Use Scenario: Secondary bias supply in telecom line cards converting -48 V or +48 V bus to 3.3 V/5 V for PHYs, microcontrollers, and interface logic. IC Role / Device Role / Timing Role: Nonisolated step-down converter delivering stable low-noise bias; handles rapid load transients from burst-mode Ethernet traffic. Use Value: Constant-frequency operation simplifies EMI filtering; no loop compensation reduces design iteration time for varying board parasitics. |
| Secondary High Voltage Post Regulator | 42-V Automotive Systems |
Use Scenario: Down-conversion after front-end isolation in industrial PLCs or motor drives where intermediate 24–48 V rails feed downstream 3.3-V logic. IC Role / Device Role / Timing Role: Efficient post-regulator supplying FPGA configuration, ADC references, and CAN transceivers from unregulated HV bus. Use Value: Wide 6–95 V input accommodates brownout and surge conditions; thermal shutdown prevents latch-up during fault propagation. | Use Scenario: Powering infotainment, ADAS camera modules, or body control units from next-generation 42-V vehicle electrical architecture. IC Role / Device Role / Timing Role: Primary DC-DC converter replacing legacy linear regulators; supports cold-crank (6 V) and load-dump (95 V) extremes. Use Value: Integrated 100-V switch eliminates external HV FET; VSSOP/WSON packages support compact, thermally robust placement near heat sources. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5164QDDARQ1 | 4.5–65 V input, 1.5-A output, current-mode control with external compensation; AEC-Q100 qualified | Targets higher-current automotive loads; requires compensation network and external MOSFET | Choose for AEC-Q100 compliance and >150 mA output; avoid if seeking plug-and-play simplicity |
| TPS54160AIDR | 3.5–60 V input, 1.5-A output, adjustable frequency, integrated high-side FET; no BST pin required | Optimized for lower-input industrial systems; lacks 95-V capability and intelligent current limit off-timer | Choose for cost-sensitive 60-V max designs needing higher current; not suitable for PV or 42-V automotive transients |
Compared with LM5164QDDARQ1 and TPS54160AIDR, the SM72485E/NOPB uniquely combines 95-V input tolerance, 150-mA integrated solution, and zero-compensation constant on-time control - making it optimal for space-constrained, high-voltage bias applications where reliability under extreme transients is critical.
Availability
SM72485E/NOPB is available at Aetrix Electronics and suitable for photovoltaic junction box designs, 42-V automotive subsystems, and nonisolated telecom power supplies requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for SM72485E/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 technologies, with decades of expertise in high-reliability power conversion ICs.
The SM72485E/NOPB belongs to TI's high-voltage buck regulator product line, engineered specifically for efficient, compact DC-DC conversion in photovoltaic, industrial, and automotive applications where input voltages exceed 60 V.
FAQ
What is the absolute maximum input voltage rating for the SM72485E/NOPB?
The SM72485E/NOPB has an absolute maximum input voltage (VIN to GND) rating of 100 V, as specified in Section 6.1 of the datasheet. This allows safe operation with 95-V nominal input under transient conditions such as load dump or lightning-induced surges. Operation above 95 V should be limited to short-duration transients within the device's SOA limits.
Does the SM72485E/NOPB require external loop compensation components?
No, the SM72485E/NOPB does not require external loop compensation components. Its constant on-time control architecture inherently stabilizes the regulation loop without capacitors or resistors in the feedback path - a key differentiator confirmed in the Features section and Section 7.1 of the datasheet.
How is the output voltage programmed on the SM72485E/NOPB?
The output voltage of the SM72485E/NOPB is programmed using two external resistors (RFB1 and RFB2) forming a voltage divider from VOUT to GND, with the FB pin connected to their junction. The formula is VOUT = 2.5 V × (RFB1 + RFB2)/RFB1, leveraging the device's internal 2.5-V reference. Standard values like 1 kΩ and 3.01 kΩ yield a 10-V output.
What package options are offered for the SM72485E/NOPB?
The SM72485E/NOPB is offered in two RoHS-compliant packages: the 3.0 mm × 3.0 mm VSSOP-8 (DGK) and the 4.0 mm × 4.0 mm WSON-8 (NGU). Both include an exposed thermal pad that must be soldered to a PCB ground plane to achieve specified thermal performance per the RθJB and RθJA metrics in Section 6.4.
Can the SM72485E/NOPB be used in automotive applications?
Yes, the SM72485E/NOPB is suitable for 42-V automotive systems, as explicitly listed in Section 2 (Applications) and validated in Section 7.1. Its 6–95 V input range covers cold-crank (6 V) and load-dump (95 V) conditions, and its thermal shutdown (165°C) and integrated protection features meet automotive reliability requirements - though it is not AEC-Q100 qualified.
SM72485E/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SolarMagic™
- Package/Case:
- 8-WDFN Exposed Pad
- 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):
- 6V
- Voltage - Input (Max):
- 95V
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- 85V
- Current - Output:
- 150mA
- Frequency - Switching:
- 50kHz ~ 1.1MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-WSON (4x4)
SM72485E/NOPB FAQ
1.How can I place an order for SM72485E/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for SM72485E/NOPB 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 SM72485E/NOPB reliable?
The price and inventory of SM72485E/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM72485E/NOPB is usually 5 days.
3.What payment methods are accepted for SM72485E/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM72485E/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM72485E/NOPB?
SM72485E/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM72485E/NOPB 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 SM72485E/NOPB?
For technical support, including SM72485E/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM72485E/NOPB requirements.
6.How does Aetrix verify that SM72485E/NOPB is sourced from the original manufacturer or authorized distributors?
All SM72485E/NOPB 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 SM72485E/NOPB meets industry standards.
7.What is the process for return or replacement of SM72485E/NOPB?
All SM72485E/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with SM72485E/NOPB, 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 SM72485E/NOPB part is unused and in its original packaging.
Return procedure for SM72485E/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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