My Inquiry
My Account
Texas Instruments SM72485SDX/NOPB
- Part No.:
- SM72485SDX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-WDFN Exposed Pad
- Datasheet:
-
SM72485SDX/NOPB.pdf
- Description:
- IC REG BUCK ADJ 150MA 8WSON
- Quantity:
- Payment:
- Shipping:
Inventory:4,849
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SM72485SDX/NOPB from Texas Instruments is a 100-V, 150-mA constant on-time buck switching regulator with integrated 100-V N-channel buck switch, internal start-up regulator, and no loop compensation required. It operates from 6 V to 95 V input, delivers adjustable output down to 2.5 V, and features ultra-fast transient response - ideal for PV panel smart junction boxes and 42-V automotive post-regulation.
For engineers reviewing the SM72485SDX/NOPB datasheet, SM72485SDX/NOPB pinout, SM72485SDX/NOPB application, or SM72485SDX/NOPB equivalent, key selection criteria include its VIN range (6–95 V), integrated high-voltage switch, constant-frequency operation across line/load, intelligent current limit with RCL-programmable off-time, and thermal shutdown at 165°C.
Technical Context
The SM72485SDX/NOPB uses a constant on-time control architecture where tON ∝ 1/VIN, enabling stable switching frequency (50 kHz–1.1 MHz) without external compensation. Its regulation relies on a precision 2.5-V internal reference compared against FB voltage, with overvoltage protection at 2.875 V.
Current limiting employs a forced off-time generator whose duration is inversely proportional to VFB and set by RCL, delivering 35 µs maximum off-time during short-circuit conditions. The integrated bootstrap driver supports high-side N-channel switch operation using an external 0.01-µF BST–SW capacitor and includes a 150-ns precharge switch to maintain gate drive under light-load or precharged-output conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 6 V to 95 V - supports wide-range industrial, telecom, and automotive bus voltages including 42-V and 48-V systems. |
| Output Current | 150 mA max - sufficient for bias rails in isolated gate drivers, sensor interfaces, and auxiliary power supplies. |
| Switch Rating | 100-V N-channel MOSFET - eliminates need for external high-voltage switch in buck topologies up to 95-V input. |
| Feedback Reference | 2.5 V ±20 mV - enables precise output programming via resistor divider; low 100-nA bias current minimizes divider error. |
| Thermal Shutdown | 165°C with 25°C hysteresis - protects device during overload or poor heatsinking; resumes operation at ~140°C. |
| Minimum On-Time | 400 ns at 95 V - sets practical upper frequency limit and ensures reliable current-limit detection. |
| Startup Regulator | VCC regulated at 7 V (VIN > 8.5 V); bypass mode below 8.5 V - enables direct connection to high-voltage inputs without external bias supply. |
Pinout & Package
SM72485SDX/NOPB is packaged in an 8-pin WSON (4 mm × 4 mm) with exposed thermal pad (connected to GND). This thermally enhanced package achieves RθJA = 42.3°C/W and RθJB = 20.1°C/W, supporting high-power-density designs in constrained spaces.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BST | Bootstrap Supply Input | Connects to SW via 0.01-µF ceramic capacitor; powers high-side gate driver during on-time; internal diode charges cap during off-time. |
| FB | Feedback Input | Inverting input of regulation comparator referenced to 2.5 V; 100-nA bias current enables high-impedance resistor dividers. |
| RCL | Current Limit Off-Time Set | Resistor-to-RTN programs off-time duration (35 µs max at VFB = 0 V); enables adaptive foldback during overload vs. short-circuit. |
| RT/SD | On-Time Set / Shutdown Control | Resistor-to-VIN sets tON ∝ 1/VIN; pulled low (<0.7 V) disables switching - provides remote enable/disable capability. |
| RTN | Signal Ground Reference | Analog ground return for FB, RCL, and RT/SD; must be connected to system ground plane near device for noise immunity. |
| SW | Power Switch Node | Drain of internal N-MOSFET; connects to inductor, freewheeling diode, and BST capacitor - requires tight layout to minimize ringing. |
| VCC | Internal Bias Supply | Regulated 7-V output (or VIN-bypass below 8.5 V); powers gate driver and logic; requires 0.47-µF local decoupling to RTN. |
| VIN | Main Power Input | Accepts 6–95 V DC; withstands 100-V transients; powers internal start-up regulator and high-voltage switch. |
Key Features
| Feature | Design Value |
|---|---|
| No loop compensation required | Constant on-time architecture eliminates need for external compensation network - reduces BOM count and design iteration time. |
| Intelligent current limit | Off-time varies with VFB and RCL - delivers full 35 µs shutdown during short-circuit while minimizing foldback during moderate overload. |
| Precharge switch | 150-ns activation during minimum off-time - maintains BST capacitor voltage under light load or precharged-output startup, preventing gate-drive dropout. |
| Thermally enhanced WSON | 4 mm × 4 mm package with exposed pad - achieves 42.3°C/W junction-to-ambient thermal resistance, enabling 150-mA operation without heatsink in typical PCB layouts. |
| VCC start-up regulator | Self-powered from VIN (6–95 V); bypass mode below 8.5 V, regulated 7-V mode above - removes need for auxiliary bias supply in high-input applications. |
Applications
| PV Panel Smart Junction Box | 42-V Automotive Post-Regulator |
|---|---|
|
Use Scenario: Distributed MPPT and monitoring electronics mounted directly on photovoltaic panels, exposed to wide ambient temperature and high DC bus voltages up to 95 V. IC Role / Device Role / Timing Role: Primary buck regulator converting unregulated PV string voltage to stable 3.3 V or 5 V for microcontrollers, sensors, and communication ICs. Use Value: Integrated 100-V switch and 6–95 V input range eliminate external HV FET and bias supply; constant-frequency operation simplifies EMI filtering in space-constrained enclosures. |
Use Scenario: Powering infotainment, ADAS camera modules, or body control units from 42-V vehicle battery, requiring robustness against load dump and cold-crank conditions. IC Role / Device Role / Timing Role: Nonisolated secondary regulator stepping down 42-V bus to 5 V or 3.3 V for digital loads, operating continuously across –40°C to +125°C junction temperature. Use Value: Thermal shutdown (165°C) and wide input range ensure reliability during engine bay thermal stress; intelligent current limit prevents latch-up during shorted downstream circuits. |
| Telecom 48-V Bias Supply | Industrial High-Voltage Sensor Interface |
|
Use Scenario: Generating isolated or nonisolated bias rails in telecom equipment powered from standard –48 V or +48 V DC distribution buses. IC Role / Device Role / Timing Role: Efficient buck converter delivering 12 V or 15 V to op-amps, ADCs, and isolation drivers in base station RF front-ends and line cards. Use Value: Ultra-fast transient response maintains regulation during burst-mode data transmission; no loop compensation accelerates qualification in safety-critical infrastructure. |
Use Scenario: Powering analog front-ends for high-voltage industrial sensors (e.g., current shunts, isolation amplifiers) in motor drives or energy metering systems. IC Role / Device Role / Timing Role: Compact, high-reliability buck regulator converting 24–95 V intermediate bus to clean 5 V for precision signal conditioning circuitry. Use Value: Low FB bias current (100 nA) preserves accuracy of high-impedance feedback networks; WSON package supports conformal coating for harsh environments. |
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, 300-mA output, current-mode control with external compensation; requires loop tuning. | Lower VIN max and higher IOUT; suited for automotive AEC-Q100-compliant designs but lacks 95-V capability. | Select when AEC-Q100 qualification and higher output current are mandatory, and board space allows compensation components. |
| TPS54160DGQR | 3.5–60 V input, 1.5-A output, integrated high-side FET; uses voltage-mode control with compensation pins. | Higher current rating and lower VIN range; optimized for cost-sensitive industrial supplies rather than ultra-high-VIN niche use cases. | Choose for 1.5-A loads below 60 V where design reuse of existing TPS54x60 layout is prioritized over 95-V operation. |
Compared with LM5164QDDARQ1 and TPS54160DGQR, SM72485SDX/NOPB uniquely supports up to 95-V input with integrated 100-V switch and zero-compensation operation - making it the only option among the three for PV junction box and legacy telecom 90-V applications without redesigning the power stage.
Availability
SM72485SDX/NOPB is available at Aetrix Electronics and suitable for PV junction boxes, 42-V automotive subsystems, and telecom bias supplies requiring stable component supply across extended temperature and voltage ranges.
Supply support for SM72485SDX/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 company headquartered in Dallas, Texas, designing and manufacturing analog, embedded processing, and silicon technologies for industrial, automotive, and communications markets.
SM72485SDX/NOPB belongs to TI's high-voltage DC/DC regulator product line, engineered specifically for efficient, compact buck conversion in applications where input voltage exceeds 60 V - such as solar energy harvesting, next-generation automotive electrical systems, and legacy telecom infrastructure.
FAQ
What is the absolute maximum input voltage rating for SM72485SDX/NOPB?
The absolute maximum input voltage (VIN to GND) for SM72485SDX/NOPB is 100 V, as specified in Section 6.1 of the datasheet. Operation beyond this rating may cause permanent damage. The recommended operating range remains 6 V to 95 V, allowing safe margin for transients in real-world PV and automotive applications. Always verify layout practices to minimize voltage overshoot at the VIN pin.
Does SM72485SDX/NOPB require external loop compensation components?
No, SM72485SDX/NOPB does not require external loop compensation components. Its constant on-time control architecture - where on-time varies inversely with input voltage - inherently stabilizes the regulation loop without feedback compensation networks. This eliminates two to four passive components per design, reducing BOM cost and layout area while accelerating prototype validation.
How is the output voltage programmed on SM72485SDX/NOPB?
The output voltage of SM72485SDX/NOPB is programmed using a resistor divider from VOUT to GND, connected to the FB pin. With a fixed internal reference of 2.5 V, VOUT = 2.5 × (RFB1 + RFB2) / RFB1. For example, RFB1 = 1 kΩ and RFB2 = 3.01 kΩ yields 10 V output. The FB pin draws only 100 nA, enabling high-value resistors that minimize quiescent current without compromising accuracy.
What is the purpose of the RCL pin on SM72485SDX/NOPB?
The RCL pin on SM72485SDX/NOPB sets the current-limit off-time duration via an external resistor to RTN. When overcurrent is detected, the switch turns off for a time determined by both RCL value and FB voltage - ranging from 35 µs (at VFB = 0 V, e.g., short-circuit) down to sub-microsecond values at nominal regulation. This adaptive behavior ensures robust short-circuit protection while minimizing output recovery delay during moderate overload.
Can SM72485SDX/NOPB operate with an input voltage below 8.5 V?
Yes, SM72485SDX/NOPB can operate with input voltage as low as 6 V. Below 8.5 V, its internal VCC regulator enters bypass mode, where VCC tracks VIN minus ~100 mV. This allows functional operation down to 6 V while maintaining gate drive integrity. However, output current capability decreases at low VIN due to reduced duty cycle headroom and higher conduction losses in the internal switch.
SM72485SDX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SolarMagic™
- Package/Case:
- 8-WDFN Exposed Pad
- 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):
- 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)
SM72485SDX/NOPB FAQ
1.How can I place an order for SM72485SDX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for SM72485SDX/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 SM72485SDX/NOPB reliable?
The price and inventory of SM72485SDX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM72485SDX/NOPB is usually 5 days.
3.What payment methods are accepted for SM72485SDX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM72485SDX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM72485SDX/NOPB?
SM72485SDX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM72485SDX/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 SM72485SDX/NOPB?
For technical support, including SM72485SDX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM72485SDX/NOPB requirements.
6.How does Aetrix verify that SM72485SDX/NOPB is sourced from the original manufacturer or authorized distributors?
All SM72485SDX/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 SM72485SDX/NOPB meets industry standards.
7.What is the process for return or replacement of SM72485SDX/NOPB?
All SM72485SDX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with SM72485SDX/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 SM72485SDX/NOPB part is unused and in its original packaging.
Return procedure for SM72485SDX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM72485SDX/NOPB 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…
