My Inquiry
My Account
Texas Instruments LM2825HN-ADJ
- Part No.:
- LM2825HN-ADJ
- Manufacturer:
- Texas Instruments
- Package:
- 24-DIP (0.600", 15.24mm)
- Datasheet:
-
LM2825HN-ADJ.pdf
- Description:
- IC REG BUCK ADJ 1A 24PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,749
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2825HN-ADJ from Texas Instruments is a 24-pin PDIP-packaged, 1A adjustable-output DC-DC buck converter with 1.23V to 8V output range, 4.5V–40V input voltage capability, and ±4% output voltage tolerance. It integrates all active and passive components for high-efficiency step-down regulation and supports TTL shutdown and programmable soft-start in industrial power supplies.
For engineers reviewing the LM2825HN-ADJ datasheet, LM2825HN-ADJ pinout, LM2825HN-ADJ application, or LM2825HN-ADJ equivalent, key selection considerations include its fixed 24-pin PDIP package, internal current limit (1.2A min), 65μA standby quiescent current, thermal shutdown protection, and compatibility with external feedback resistors for precise output programming.
Technical Context
The LM2825HN-ADJ implements a self-contained synchronous buck topology with integrated power switch, PWM controller, oscillator, and protection circuitry. Its internal 150kHz switching frequency and adjustable feedback reference (1.23V ±3%) enable stable regulation across wide input/output combinations without external compensation.
It features dual-stage current limiting, thermal shutdown at ~125°C junction temperature, and dedicated SD/SS pin logic that enables both hard shutdown (≤0.6V) and controlled soft-start (≥2.0V). The device operates over −40°C to +85°C ambient and supports output derating per thermal constraints shown in TI's Figure 22–23.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 1A maximum continuous load; derated above 70°C ambient or at high VIN/VOUT ratios per TI Figure 22–23 |
| Input Voltage Range | 4.5V to 40V - supports wide industrial input rails including 12V, 24V, and 36V systems |
| Output Voltage Range | 1.23V to 8V - set externally via R1/R2 feedback divider; VADJ = 1.23V ±3% |
| Efficiency | 74% typical at 12VIN/3VOUT/0.5A - enables low thermal footprint in enclosed designs |
| Quiescent Current | 65μA in shutdown mode - minimizes battery drain in always-on systems |
| Switching Frequency | 150kHz fixed - simplifies EMI filtering and avoids AM radio band interference |
| Thermal Resistance | 30°C/W junction-to-ambient (PDIP, 2 in² copper) - defines heatsinking requirements for 1A operation |
Pinout & Package
LM2825HN-ADJ uses a 24-pin plastic dual-in-line package (PDIP), package drawing NFL, with 1.25 × 0.54 × 0.26 inch profile. Thermal performance relies on PCB copper area as primary heatsink; NC pins are electrically isolated but connected to copper pads for thermal conduction only.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 7, 18, 19, 20, 21, 22, 23, 24 | NC (No Connect) | Electrically isolated; tied to copper pads solely for thermal dissipation - must not be routed |
| 8, 9 | Internal Ripple Reduction Node | Shorting pins 8 and 9 reduces output ripple by 25–33%; requires feed-forward capacitor (CFF) for stability |
| 10 | GND | Power ground reference for internal circuitry and output return path |
| 11 | VIN | Main input supply connection; accepts 4.5V–40V with internal clamping |
| 12 | VOUT | Regulated output terminal; delivers up to 1A with ±4% tolerance |
| 13 | SD/SS | Shutdown/Soft-start control input; <0.6V = shutdown, >2.0V = soft-start enabled |
| 14 | ADJ | Feedback reference node; sinks 6nA bias current; sets VOUT = 1.23V × (1 + R2/R1) |
| 15, 16, 17 | SW | Internal switch node; connects to external inductor; carries pulsed high-current waveform |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Buck Converter | Full 1A step-down solution in single PDIP package - eliminates need for external MOSFET, driver, or controller IC |
| Adjustable Output Programming | 1.23V to 8V range via two-resistor divider - enables flexible rail generation without redesigning power stage |
| TTL-Compatible Shutdown | Logic-level SD/SS pin accepts 0V/3.3V/5V signals - allows microcontroller or system-level power sequencing |
| Programmable Soft-Start | External capacitor on SD/SS pin controls output ramp rate - prevents inrush current in capacitive loads |
| Thermal & Overcurrent Protection | Auto-recovering shutdown at ~125°C junction and cycle-by-cycle current limiting - ensures robustness under fault conditions |
Applications
| Industrial Power Supply | Embedded System Pre-Regulator |
|---|---|
Use Scenario: Distributed 24V bus powering multiple 3.3V/5V subsystems in factory automation PLCs. IC Role / Device Role / Timing Role: Primary buck regulator converting 24V input to user-adjustable 3.3V–5V outputs for logic and I/O rails. Use Value: Eliminates need for external MOSFET and controller; 65μA shutdown current extends backup battery life during maintenance mode. | Use Scenario: On-board pre-regulation ahead of low-noise LDOs in medical sensor modules. IC Role / Device Role / Timing Role: Efficient intermediate-stage converter reducing 12V input to 3.3V before final LDO filtering. Use Value: 74% efficiency at 12V→3.3V/0.5A lowers heat generation versus linear pre-regulation, enabling compact PCB layout. |
| DC/DC Module Replacement | Ruggedized Telecom Power |
Use Scenario: Drop-in replacement for obsolete 1A DC/DC modules in legacy telecom shelf power systems. IC Role / Device Role / Timing Role: Standalone buck IC replacing multi-component module; retains same 24-pin footprint and thermal interface. Use Value: PDIP package allows through-hole rework compatibility; 40V max input supports transient-tolerant 24V/48V telecom inputs. | Use Scenario: Power conversion in outdoor base station equipment operating from −40°C to +85°C ambient. IC Role / Device Role / Timing Role: Main 1A point-of-load regulator delivering stable 5V to FPGA and transceiver ICs. Use Value: Guaranteed operation across full −40°C to +85°C range with no derating below 0°C; thermal shutdown prevents field failures. |
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 | 5-pin TO-220 package; 3A output; 150kHz fixed frequency; requires external diode | Higher current, higher thermal mass; less suitable for space-constrained 24-pin DIP layouts | Select when >1A load or higher VIN (>60V) required; not pin-compatible |
| TPS54202DDCR | 6-pin SOT-23; 2A output; 500kHz switching; integrated FETs; requires external compensation | Smaller footprint, higher frequency, lower quiescent current (25μA); no PDIP option | Select for modern surface-mount designs prioritizing size and efficiency; not drop-in compatible |
Compared with LM2825HN-ADJ, LM2576HVS-ADJ offers higher current and input voltage but lacks integrated passives and PDIP packaging, while TPS54202DDCR provides superior efficiency and miniaturization at the cost of layout redesign and loss of through-hole serviceability.
Availability
LM2825HN-ADJ is available at Aetrix Electronics and suitable for industrial power supplies, embedded system pre-regulators, DC/DC module replacements, and ruggedized telecom power applications requiring stable component supply and long-term manufacturability.
Supply support for LM2825HN-ADJ 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, specializing in analog, embedded processing, and power management technologies with over 90 years of innovation in industrial and automotive electronics.
The LM2825 product line was designed as an integrated, self-contained buck converter family targeting cost-sensitive, reliability-critical industrial power applications where minimal external components and proven thermal robustness are essential.
FAQ
What is the maximum output voltage supported by the LM2825HN-ADJ?
The LM2825HN-ADJ supports an output voltage range of 1.23V to 8V, set by external feedback resistors R1 and R2. This range is confirmed in the LM2825-ADJ Electrical Characteristics table (page 4), where VADJ = 1.23V and VOUT is programmable up to 8V. The LM2825HN-ADJ variant specifically follows this specification and does not support the 7V–15V range of the H-ADJ version.
Does the LM2825HN-ADJ require external components for basic operation?
Yes, the LM2825HN-ADJ requires external components for functional operation: at minimum, an input capacitor (if >6″ from source), output capacitor, inductor, and two feedback resistors (R1/R2) to set the output voltage. Unlike fixed-output versions, the LM2825HN-ADJ cannot operate without the R1/R2 divider because its ADJ pin is the sole feedback reference - no internal resistor network is present.
What is the purpose of shorting pins 8 and 9 on the LM2825HN-ADJ?
Shorting pins 8 and 9 on the LM2825HN-ADJ reduces output ripple voltage by 25–33%, as documented in the "Lowering Output Ripple" section (page 10). However, doing so requires adding a feed-forward capacitor (CFF) between 680 pF and 2700 pF, selected based on VOUT and R2 value, to maintain loop stability - omitting CFF causes regulator instability.
How does the LM2825HN-ADJ handle thermal overload conditions?
The LM2825HN-ADJ incorporates thermal shutdown protection that activates at approximately 125°C junction temperature. When triggered, the device halts switching and enters a safe, non-latching state until junction temperature falls below the hysteresis threshold (~110°C). This behavior is specified in the Features list and verified in the Absolute Maximum Ratings and Operating Ratings sections of the datasheet.
Is the LM2825HN-ADJ RoHS compliant and what is its lead finish?
Yes, the LM2825HN-ADJ/NOPB variant is RoHS compliant and carries a Green (RoHS & no Sb/Br) eco-plan with Cu-Sn (copper-tin) lead finish, as confirmed in the PACKAGE OPTION ADDENDUM (page 1, 8-Mar-2015). The "NOPB" suffix explicitly denotes lead-free, RoHS-compliant packaging with bromine- and antimony-free flame retardants.
LM2825HN-ADJ 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 FAQ
1.How can I place an order for LM2825HN-ADJ through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2825HN-ADJ 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 reliable?
The price and inventory of LM2825HN-ADJ 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 is usually 5 days.
3.What payment methods are accepted for LM2825HN-ADJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2825HN-ADJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2825HN-ADJ?
LM2825HN-ADJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2825HN-ADJ 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?
For technical support, including LM2825HN-ADJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2825HN-ADJ requirements.
6.How does Aetrix verify that LM2825HN-ADJ is sourced from the original manufacturer or authorized distributors?
All LM2825HN-ADJ 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 meets industry standards.
7.What is the process for return or replacement of LM2825HN-ADJ?
All LM2825HN-ADJ units undergo pre-shipment inspection (PSI). If there is an issue with LM2825HN-ADJ, 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 part is unused and in its original packaging.
Return procedure for LM2825HN-ADJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2825HN-ADJ 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…
