My Inquiry
My Account
Texas Instruments LMS1587ISX-ADJ/NOPB
- Part No.:
- LMS1587ISX-ADJ/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-4, D2PAK (3 Leads + Tab), TO-263AA
- Datasheet:
-
LMS1587ISX-ADJ/NOPB.pdf
- Description:
- IC REG LIN POS ADJ 3A DDPAK
- Quantity:
- Payment:
- Shipping:
Inventory:401
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LMS1587ISX-ADJ/NOPB from Texas Instruments is a 3A adjustable low-dropout linear regulator in DDPAK/TO-263 (KTT) package, featuring 1.25V internal reference, 1.3V typical dropout at 3A, and fast transient response optimized for microprocessor power rails. It delivers stable output voltage across −40°C to 125°C industrial temperature range with integrated thermal shutdown and current limiting.
For engineers reviewing the LMS1587ISX-ADJ/NOPB datasheet, LMS1587ISX-ADJ/NOPB pinout, LMS1587ISX-ADJ/NOPB application, or LMS1587ISX-ADJ/NOPB equivalent, this page provides verified technical context, confirmed pin functions, real-world use cases in embedded CPU supplies, and validated alternative options for design-in flexibility.
Technical Context
The LMS1587ISX-ADJ/NOPB implements a zener-trimmed bandgap reference and error amplifier driving an NPN pass transistor, enabling precise output regulation via external R1/R2 divider. Its architecture supports ≤1.3V input-to-output differential at full 3A load while maintaining ≥72dB ripple rejection at 120Hz.
Thermal regulation is specified at 0.003%/W, and quiescent current remains ≤13mA under fixed-output conditions. The device requires only two external resistors to set output voltage per VOUT = VREF(1 + R2/R1) + IADJR2, with IADJ ≤120µA ensuring minimal adjustment-pin error.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 3A maximum continuous - supports high-current logic rails without derating at TA ≤85°C with adequate heatsinking. |
| Dropout Voltage | 1.3V typical at 3A - enables operation with VIN as low as VOUT + 1.3V, critical for low-voltage CPU core supplies. |
| Reference Voltage | 1.250V ±1.2% - sets baseline accuracy for externally adjusted outputs; enables 1.25V–24V range with standard resistor tolerances. |
| Line Regulation | 0.005% typical - ensures <±0.17mV change per 1V input variation, preserving tight voltage margins in noisy supply environments. |
| Load Regulation | 0.05% typical - guarantees ≤±1.65mV shift from no-load to full 3A, essential for stable digital logic operation. |
| Ripple Rejection | 72dB at 120Hz - suppresses switching noise from upstream DC/DC converters feeding the LDO input. |
| Operating Temp | −40°C to 125°C junction - qualified for industrial and automotive under-hood applications without derating. |
Pinout & Package
Package: DDPAK/TO-263 (KTT), 3-lead surface-mount with exposed thermal pad. Pin 1 = OUTPUT, Pin 2 = INPUT, Pin 3 = ADJ/GND (adjust terminal for adjustable versions).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (OUT) | Regulated output node | High-current source terminal; connects directly to load and output capacitor (≥10µF required for stability). |
| Pin 2 (IN) | Unregulated input supply | Accepts 2.75V–7V input; must be ≥VOUT + 1.3V to maintain regulation at 3A. |
| Pin 3 (ADJ) | Adjust reference feedback | Connects to voltage divider (R1/R2); 120µA max bias current enables accurate VOUT setting with 1% resistors. |
Key Features
| Feature | Design Value |
|---|---|
| Fast transient response | Stabilizes within microseconds after load step - prevents brownout during CPU burst-mode operation. |
| Integrated protection | Current limiting (3.1–4.3A) and thermal shutdown - eliminates need for external fault management circuitry. |
| Low-noise operation | 0.003% RMS output noise - avoids clock jitter or analog sensor interference in mixed-signal systems. |
| Industrial temp grade | −40°C to 125°C operation - supports deployment in extended-temperature industrial controllers and motor drives. |
| Direct LT1585A/87 replacement | P2P compatible with Linear Technology's legacy regulators - enables drop-in upgrade without layout changes. |
Applications
| Pentium® Processor Supply | PowerPC® Core Rail |
|---|---|
Use Scenario: Powers 3.3V or adjustable core voltage for legacy x86 CPUs requiring clean, low-noise supply with fast load-step recovery. IC Role / Device Role / Timing Role: Primary post-regulator delivering stable VCORE after buck converter; handles dynamic current spikes up to 3A. Use Value: 1.3V dropout enables efficient operation from 5V intermediate bus; 72dB ripple rejection cleans switcher noise before CPU power pins. |
Use Scenario: Supplies 1.5V–2.5V core voltage to PowerPC-based industrial controllers operating in wide ambient temperatures. IC Role / Device Role / Timing Role: Adjustable LDO providing precise, thermally robust core rail with built-in overcurrent and thermal protection. Use Value: −40°C to 125°C rating ensures reliability in uncooled control cabinets; 0.05% load regulation maintains timing margin across full load range. |
| Low-Voltage Logic Supply | Industrial FPGA I/O Bank |
Use Scenario: Generates 1.8V, 2.5V, or 3.3V for ASIC/FPGA I/O banks where PSRR and transient response impact signal integrity. IC Role / Device Role / Timing Role: Local point-of-load regulator decoupling high-speed digital interfaces from noisy system rails. Use Value: 0.005% line regulation minimizes voltage drift during system-level supply fluctuations; fast response prevents setup/hold violations. |
Use Scenario: Provides configurable 1.2V–3.3V supply to FPGA I/O banks in programmable logic controllers with extended temperature requirements. IC Role / Device Role / Timing Role: Adjustable LDO supporting multiple I/O standards (LVCMOS, SSTL) with thermal protection for field-deployed units. Use Value: Exposed thermal pad in KTT package enables >2.7°C/W junction-to-board conduction - sustains 3A output at 85°C ambient without heatsink. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMS1587CSX-ADJ/NOPB | Same silicon, commercial temp range (0°C to 125°C) vs. industrial (−40°C to 125°C); identical electrical specs and pinout. | Suitable for non-extended-temperature consumer or lab equipment; not rated for cold-start industrial environments. | Select LMS1587ISX-ADJ/NOPB when operation below 0°C is required; otherwise LMS1587CSX-ADJ/NOPB offers cost parity. |
| TLV1117-ADJ | 1A output, 1.2V dropout, SO-8 package; lower current, smaller footprint, no exposed thermal pad. | Applicable only for sub-1A loads; lacks thermal performance for sustained 3A operation; requires different PCB layout. | Choose TLV1117-ADJ only for space-constrained, low-power designs where 3A capability is unnecessary. |
Compared with LMS1587CSX-ADJ/NOPB, the LMS1587ISX-ADJ/NOPB adds guaranteed −40°C startup and operation, critical for outdoor or factory-floor deployments; versus TLV1117-ADJ, it delivers triple the current in a thermally superior package but requires larger board area.
Availability
LMS1587ISX-ADJ/NOPB is available at Aetrix Electronics and suitable for industrial automation controllers, embedded CPU power supplies, and FPGA I/O rail regulation requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for LMS1587ISX-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 ICs, with decades of expertise in high-reliability linear regulators and power solutions.
The LMS1587 series was designed specifically for low-dropout, high-current microprocessor and logic supply applications, emphasizing fast transient response, thermal robustness, and compatibility with legacy LT1585A/87 designs.
FAQ
What is the minimum input voltage required for LMS1587ISX-ADJ/NOPB to regulate at 3.3V output?
The LMS1587ISX-ADJ/NOPB requires VIN ≥ VOUT + 1.3V (typical dropout) = 4.6V to maintain regulation at 3A load. At lighter loads, dropout decreases - e.g., 1.15V at 3A minimum load - but 4.6V ensures full 3A capability across temperature and process variation. Always verify with worst-case 1.4V max dropout from datasheet.
Can LMS1587ISX-ADJ/NOPB be used in parallel to increase output current beyond 3A?
No - the LMS1587ISX-ADJ/NOPB is not designed for parallel operation. Its internal architecture lacks current-sharing features like remote sensing or master-slave control. Attempting parallel connection risks thermal runaway due to mismatched reference voltages and dropout characteristics. For >3A, select LMS1585A-series (5A) or discrete solutions.
What is the purpose of the ADJ pin on LMS1587ISX-ADJ/NOPB, and how is it configured?
The ADJ pin on LMS1587ISX-ADJ/NOPB serves as the feedback reference node for external voltage setting. It connects to the junction of R1 (between OUT and ADJ) and R2 (between ADJ and GND). Output voltage follows VOUT = 1.25V × (1 + R2/R1) + IADJR2, where IADJ ≤120µA. Use R1 ≈100Ω to minimize IADJ error.
Does LMS1587ISX-ADJ/NOPB require an input capacitor, and if so, what value is recommended?
Yes - an input capacitor is required for stability and EMI suppression. TI recommends ≥10µF tantalum or low-ESR ceramic at the IN pin, placed as close as possible to the device. This reduces input impedance at high frequencies and prevents oscillation during fast load transients. Larger values (e.g., 22µF) improve ripple rejection further.
How does the thermal performance of LMS1587ISX-ADJ/NOPB compare between TO-263 (KTT) and TO-220 (NDE) packages?
The LMS1587ISX-ADJ/NOPB uses the DDPAK/TO-263 (KTT) package with 0.65°C/W junction-to-case thermal resistance for the control section. This is identical to the TO-220 version's spec, but the KTT's exposed thermal pad enables superior board-level conduction - achieving ~2.7°C/W junction-to-board with proper copper pour and vias, versus ~4.5°C/W for TO-220 in typical layouts.
LMS1587ISX-ADJ/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-263-4, D2PAK (3 Leads + Tab), TO-263AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Adjustable
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 13V
- Voltage - Output (Min/Fixed):
- 1.25V
- Voltage - Output (Max):
- 11.7V
- Voltage Dropout (Max):
- 1.3V @ 3A
- Current - Output:
- 3A
- Current - Quiescent (Iq):
- 7 mA
- Current - Supply (Max):
- 13 mA
- PSRR:
- 72dB (120Hz)
- Control Features:
- -
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263 (DDPAK-3)
LMS1587ISX-ADJ/NOPB FAQ
1.How can I place an order for LMS1587ISX-ADJ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LMS1587ISX-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 LMS1587ISX-ADJ/NOPB reliable?
The price and inventory of LMS1587ISX-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 LMS1587ISX-ADJ/NOPB is usually 5 days.
3.What payment methods are accepted for LMS1587ISX-ADJ/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMS1587ISX-ADJ/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMS1587ISX-ADJ/NOPB?
LMS1587ISX-ADJ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMS1587ISX-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 LMS1587ISX-ADJ/NOPB?
For technical support, including LMS1587ISX-ADJ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMS1587ISX-ADJ/NOPB requirements.
6.How does Aetrix verify that LMS1587ISX-ADJ/NOPB is sourced from the original manufacturer or authorized distributors?
All LMS1587ISX-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 LMS1587ISX-ADJ/NOPB meets industry standards.
7.What is the process for return or replacement of LMS1587ISX-ADJ/NOPB?
All LMS1587ISX-ADJ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LMS1587ISX-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 LMS1587ISX-ADJ/NOPB part is unused and in its original packaging.
Return procedure for LMS1587ISX-ADJ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMS1587ISX-ADJ/NOPB Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
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…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
