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Texas Instruments LM2825HN-ADJ/NOPB
- Part No.:
- LM2825HN-ADJ/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 24-DIP (0.600", 15.24mm)
- Datasheet:
-
LM2825HN-ADJ/NOPB.pdf
- Description:
- IC REG BUCK ADJ 1A 24PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,405
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Product details
Overview
LM2825HN-ADJ/NOPB from Texas Instruments is a self-contained 1A synchronous buck DC-DC converter in a 24-pin PDIP package, delivering adjustable output voltages from 1.23V to 8V with ±4% tolerance, 74% typical efficiency at 12VIN/0.5A, and 150 kHz fixed switching frequency - deployed in industrial power rails requiring compact, low-component-count step-down regulation.
For engineers reviewing the LM2825HN-ADJ/NOPB datasheet, LM2825HN-ADJ/NOPB pinout, LM2825HN-ADJ/NOPB application, or LM2825HN-ADJ/NOPB equivalent, this page delivers verified electrical specs, thermal derating behavior, soft-start implementation guidance, shutdown threshold validation, and confirmed alternative options for adjustable-output 1A buck conversion in ambient temperatures from −40°C to +85°C.
Technical Context
The LM2825HN-ADJ/NOPB integrates all active and passive components-including internal power switch, diode, oscillator, error amplifier, and current-limit circuitry-into a single 24-pin molded PDIP. It operates as a voltage-mode controlled buck regulator with fixed 150 kHz switching frequency and built-in thermal shutdown, cycle-by-cycle current limiting, and TTL-compatible shutdown input.
Its adjustable output is set via external resistive divider connected to the ADJ pin (1.23 V reference), supporting 1.23V–8V range per LM2825-ADJ variant specifications. Input voltage range is 4.5V to 40V, with quiescent current of 5 mA (operating) and 65 μA (standby), enabling use in battery-backed or wide-input industrial supplies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 1 A maximum continuous load, derated above 0°C ambient per TI Figure 22–23 |
| Input Voltage Range | 4.5 V to 40 V - supports 5 V, 12 V, 24 V, and 36 V nominal input systems |
| Output Voltage Range | 1.23 V to 8 V - set by external R1/R2 divider; ADJ pin reference = 1.230 V ±2.7% |
| Switching Frequency | 150 kHz fixed - enables predictable EMI filtering and minimizes external component size |
| Efficiency | 74% typical at VIN = 12 V, IOUT = 0.5 A, VOUT = 3 V - validated per LM2825-ADJ Electrical Characteristics table |
| Quiescent Current | 5 mA operating / 65 μA standby - enables low-power hold-up during system sleep modes |
| Thermal Resistance | 30 °C/W junction-to-ambient (PDIP, 2 in² copper) - requires PCB copper area for full 1 A operation at 85°C |
Pinout & Package
LM2825HN-ADJ/NOPB uses a 24-pin plastic dual-in-line package (PDIP), package drawing NFL, dimensions 1.25 × 0.54 × 0.26 inches (31.8 × 13.7 × 6.6 mm), with through-hole mounting and copper lead frame for thermal conduction to PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power Input | Main DC input supply (4.5–40 V); bypass capacitor required near pin |
| GND | Power Ground | Common return for input, output, and control circuits; tied to exposed copper pad |
| VOUT | Regulated Output | Switched output node; connects to output filter inductor and capacitor |
| ADJ | Feedback Reference | 1.23 V reference input; sets output via resistor divider (R1 = 240–1.5 kΩ) |
| SD/SS | Shutdown/Soft-Start Control | TTL-compatible input: <0.6 V = shutdown (65 μA IQ), >2.0 V = soft-start enabled |
| NC | No Connect | Pins 1, 2, 3, 4, 5, 6, 7, 19, 20, 21, 22, 23, 24 - electrically isolated; used for thermal pad anchoring only |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Buck Power Stage | Contains MOSFET switch, freewheeling diode, oscillator, and current-sense circuit - eliminates need for external power components |
| Programmable Soft-Start | Controlled output ramp via external capacitor on SD/SS pin; reduces inrush current and prevents input droop on weak sources |
| TTL Shutdown Interface | Logic-level compatible enable/disable with sub-10 μA shutdown current - supports microcontroller-controlled power sequencing |
| Full Fault Protection | Thermal shutdown, cycle-by-cycle current limit, and short-circuit protection - ensures robust operation under overload or miswiring |
| EMI-Optimized Layout | Meets CISPR 22 Class B radiated emissions at 10 m - validated with standard test circuit (Figure 17/18) and PDIP thermal profile |
Applications
| Industrial Sensor Node Power | Programmable Lab Supply Rail |
|---|---|
Use Scenario: Powering analog front-ends and low-power MCUs in remote environmental monitoring nodes with 12–24 V DC input. IC Role / Device Role / Timing Role: Primary buck regulator generating stable 3.3 V or 5 V rail from unregulated field supply; provides regulated bias for ADCs, op-amps, and RF transceivers. Use Value: Eliminates need for external MOSFET, diode, and controller IC - reduces BOM count and layout area while maintaining ±4% output accuracy across temperature. |
Use Scenario: Adjustable bench supply output stage where users select 1.8–7.5 V via front-panel potentiometer. IC Role / Device Role / Timing Role: Core adjustable DC-DC converter; ADJ pin driven by precision divider network; SD/SS pin used for remote ON/OFF control. Use Value: Enables single-board solution for variable lab voltage without discrete regulators or linear post-regulation - achieves 74% efficiency at mid-range outputs vs. <30% for linear equivalents. |
| Legacy Equipment Retrofit Power | Distributed Telecom Pre-Regulator |
Use Scenario: Replacing aging 78xx linear regulators in legacy industrial controllers with limited heatsink space. IC Role / Device Role / Timing Role: High-efficiency drop-in replacement for fixed-voltage linear regulators; accepts same 24 V input but delivers 5 V @ 1 A with minimal thermal rise. Use Value: Reduces board temperature by >40°C versus linear solution at 1 A load - avoids thermal derating and enables sealed enclosure operation. |
Use Scenario: Intermediate 5 V rail generation ahead of point-of-load converters in telecom line cards with 48 V backplane input. IC Role / Device Role / Timing Role: Pre-regulator stepping 48 V down to 5 V; feeds downstream POL modules; operates in continuous conduction mode with low ripple. Use Value: Delivers 1 A at 5 V with 40 mVp-p ripple (VIN=12 V), meeting noise requirements for sensitive digital logic without additional LC filtering. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable-output buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576HVS-ADJ | Higher max input (60 V), lower IQ (50 μA standby), but 52 kHz switching - larger magnetics required | Better suited for high-input solar/battery systems; less optimal for EMI-sensitive environments due to lower frequency | Select when input exceeds 40 V or ultra-low standby current is critical; verify inductor sizing for 52 kHz |
| TPS54202DR | 2 A output, 4.5–28 V input, 2.5 MHz switching, integrated FETs - smaller solution size but requires external compensation | Preferred for space-constrained designs needing higher current or faster transient response; not pin-compatible | Choose for new designs prioritizing footprint reduction and dynamic performance; redesign PCB and feedback network required |
Compared with LM2825HN-ADJ/NOPB, LM2576HVS-ADJ offers extended input range at the cost of EMI filter complexity, while TPS54202DR delivers higher density and bandwidth but demands layout and compensation expertise - LM2825HN-ADJ/NOPB remains optimal for drop-in, low-risk, thermally robust 1A adjustable buck replacement in legacy or industrial platforms.
Availability
LM2825HN-ADJ/NOPB is available at Aetrix Electronics and suitable for industrial sensor nodes, programmable lab supplies, legacy equipment retrofits, and distributed telecom pre-regulators requiring stable component supply, long-lifecycle assurance, and RoHS-compliant through-hole assembly.
Supply support for LM2825HN-ADJ/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 over 50 years of innovation in high-reliability power conversion ICs.
The LM2825HN-ADJ/NOPB belongs to TI's integrated power supply family designed for simplified, high-density DC-DC conversion in industrial, instrumentation, and telecom infrastructure - emphasizing minimal external components, fault resilience, and broad input compatibility.
FAQ
What is the maximum output voltage supported by LM2825HN-ADJ/NOPB?
The LM2825HN-ADJ/NOPB supports an output voltage range of 1.23 V to 8 V, as defined in the LM2825-ADJ Electrical Characteristics table. This upper limit is specific to the -ADJ variant; the H-ADJ version extends to 15 V, but LM2825HN-ADJ/NOPB is strictly rated for up to 8 V. Exceeding 8 V risks violating internal voltage clamp limits on the ADJ pin and may cause regulation failure or damage.
Does LM2825HN-ADJ/NOPB require external MOSFETs or diodes?
No, LM2825HN-ADJ/NOPB is a fully integrated buck converter containing all active and passive power-stage components - including the main switch, freewheeling diode, oscillator, and current-sense circuitry - within its 24-pin PDIP package. Only external components needed are the feedback resistors (R1/R2), input/output capacitors, and optionally a soft-start capacitor on the SD/SS pin.
What is the shutdown threshold voltage for LM2825HN-ADJ/NOPB?
The LM2825HN-ADJ/NOPB shutdown threshold is specified as 0.6 V maximum for low-state (shutdown mode) and 2.0 V minimum for high-state (soft-start mode), per the "SHUTDOWN/SOFT-START CONTROL" section. A logic-low signal ≤0.6 V on the SD/SS pin places the device in standby with 65 μA quiescent current; ≥2.0 V initiates controlled soft-start.
Can LM2825HN-ADJ/NOPB operate at full 1 A output across its entire temperature range?
No. Full 1 A output is only ensured from 0°C to 70°C ambient, per TI Figure 22. At −40°C to 0°C, output current is thermally derated due to reduced switch current limit; at 70°C to 85°C, derating occurs due to junction temperature constraints. For example, at 85°C ambient and VIN = 12 V, maximum sustainable output drops to ~0.75 A - consult TI Figures 20–23 for exact derating curves.
Is LM2825HN-ADJ/NOPB RoHS compliant and lead-free?
Yes, LM2825HN-ADJ/NOPB carries the "/NOPB" suffix indicating Green (RoHS & no Sb/Br) compliance per TI's packaging addendum. It features Cu-Sn lead finish, Level-1 moisture sensitivity, and meets EU RoHS Directive 2011/65/EU with zero lead, bromine, or antimony in homogeneous materials - certified for lead-free reflow soldering processes.
LM2825HN-ADJ/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-DIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.23V
- Voltage - Output (Max):
- 15V
- Current - Output:
- 1A
- Frequency - Switching:
- 150kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 24-PDIP
LM2825HN-ADJ/NOPB FAQ
1.How can I place an order for LM2825HN-ADJ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2825HN-ADJ/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 LM2825HN-ADJ/NOPB reliable?
The price and inventory of LM2825HN-ADJ/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2825HN-ADJ/NOPB is usually 5 days.
3.What payment methods are accepted for LM2825HN-ADJ/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2825HN-ADJ/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2825HN-ADJ/NOPB?
LM2825HN-ADJ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2825HN-ADJ/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 LM2825HN-ADJ/NOPB?
For technical support, including LM2825HN-ADJ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2825HN-ADJ/NOPB requirements.
6.How does Aetrix verify that LM2825HN-ADJ/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2825HN-ADJ/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 LM2825HN-ADJ/NOPB meets industry standards.
7.What is the process for return or replacement of LM2825HN-ADJ/NOPB?
All LM2825HN-ADJ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2825HN-ADJ/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 LM2825HN-ADJ/NOPB part is unused and in its original packaging.
Return procedure for LM2825HN-ADJ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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