My Inquiry
My Account
Texas Instruments LM2598SX-12
- Part No.:
- LM2598SX-12
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-8, D2PAK (7 Leads + Tab), TO-263CA
- Datasheet:
-
LM2598SX-12.pdf
- Description:
- IC REG BUCK 12V 1A TO263
- Quantity:
- Payment:
- Shipping:
Inventory:4,272
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2598SX-12 from Texas Instruments is a monolithic 150-kHz nonsynchronous step-down (buck) DC-DC converter delivering 1-A output current with fixed 12-V output, ±4% output voltage tolerance over line and load, input voltage range up to 40 V, and thermal shutdown/current limit protection - used in on-card power supplies for industrial control modules.
For engineers reviewing the LM2598SX-12 datasheet, LM2598SX-12 pinout, LM2598SX-12 application, or LM2598SX-12 equivalent, key selection criteria include fixed 12-V output accuracy, TO-263-7 package thermal performance, shutdown/soft-start control interface, and error flag timing behavior under load transients.
Technical Context
The LM2598SX-12 integrates a PWM controller, power switch, oscillator, error amplifier, and protection circuitry into a single IC. It operates at a fixed 150-kHz switching frequency (±15%), enabling compact external filter components, and uses internal frequency compensation to simplify design.
Its feedback loop monitors output voltage via an internal 1.23-V reference and external resistor divider; regulation is maintained across 15–40 V input and 0.1–1 A load, with ±4% output tolerance and <0.5% line/load regulation drift confirmed in system-level testing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V ±4% over full temperature and load range - ensures stable rail for microcontrollers and analog sensors without external adjustment. |
| Max Input Voltage | 40 V - supports wide-input industrial and automotive battery-supplied systems without pre-regulation. |
| Output Current | 1 A continuous - sufficient for powering FPGA I/O banks, motor drivers, or multi-rail PMICs in embedded systems. |
| Switching Frequency | 150 kHz ±15% - enables use of low-cost, high-saturation-current inductors (e.g., 68–100 µH) with minimal EMI filtering. |
| Quiescent Current | 85 µA in shutdown mode - extends battery life in standby applications such as remote telemetry nodes. |
| Efficiency | 90% at VIN = 25 V, IOUT = 1 A - reduces thermal load in enclosed enclosures and lowers system cooling requirements. |
| Protection Features | Thermal shutdown, peak current limiting (1.2–2.4 A), and out-of-regulation error flag - prevents damage during overload, short-circuit, or ambient overheating. |
Pinout & Package
LM2598SX-12 is supplied in a 7-pin TO-263 (DDPAK) surface-mount package with exposed thermal pad, measuring 10.10 mm × 8.89 mm, optimized for PCB heat dissipation without external heatsink below 50°C ambient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OUT) | Power Switch Drain | Switching node connecting to external catch diode and inductor - requires minimal copper area to reduce EMI coupling. |
| 2 (+VIN) | Input Supply | Primary DC input (4.5–40 V); must be bypassed with ≥100 µF low-ESR capacitor placed adjacent to pin. |
| 3 (FLAG) | Error Flag Output | Open-collector signal pulled low when VOUT drops >5%; delays going high by external capacitor on Delay pin. |
| 4 (GND) | Power Ground | Common return for input/output paths and internal circuitry - must connect directly to thermal pad and large ground plane. |
| 5 (DELAY) | Flag Delay Control | Capacitor-connected pin setting time delay between VOUT reaching 95% and FLAG going high - used for processor reset sequencing. |
| 6 (FB) | Feedback Input | Monitors regulated output via resistor divider; internal 1.23-V reference sets 12-V output with R1/R2 = 8.73kΩ/1.2kΩ. |
| 7 (SD/SS) | Shutdown/Soft-start | Logic-level input: <0.6 V enables shutdown (IQ ≈ 85 µA); >2 V enables operation; capacitor adds soft-start ramp to limit inrush current. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12-V Output | Eliminates external feedback resistors and calibration, reducing BOM count and layout sensitivity in cost-sensitive designs. |
| Integrated Soft-start | Capacitor-programmable output voltage ramp minimizes inrush current - critical for systems powered from current-limited sources like PoE or USB-C PD. |
| Error Flag with Delay | Provides synchronized, glitch-free reset signal to microcontrollers after stable 12-V rail establishment - avoids premature firmware execution. |
| Thermal Shutdown + Current Limit | Dual-stage protection prevents latch-up during sustained overload or poor heatsinking - enables robust field operation without external monitoring circuits. |
| 150-kHz Fixed Oscillator | Enables predictable EMI profile and simplifies compliance testing; eliminates need for external timing components or frequency trimming. |
Applications
| Industrial PLC I/O Module Power | Automotive Body Control Unit (BCU) |
|---|---|
Use Scenario: Powers digital I/O drivers, isolation logic, and sensor interface circuitry in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Primary 12-V buck regulator supplying isolated 5-V/3.3-V rails via secondary LDOs; provides regulated bus for CAN transceivers and optocouplers. Use Value: Delivers 1-A continuous current with ±4% output stability across –25°C to +85°C ambient, ensuring reliable operation in unventilated control cabinets. | Use Scenario: Supplies 12-V rail to window lift controllers, seat position sensors, and interior lighting modules in 12-V vehicle electrical architecture. IC Role / Device Role / Timing Role: Pre-regulator stepping down battery voltage (9–16 V nominal, up to 40 V load dump) before LDOs feeding MCU and analog front-ends. Use Value: Withstands 40-V transients per ISO 7637-2; 90% efficiency at 25-V input reduces thermal stress in confined fuse box locations. |
| Medical Point-of-Care Diagnostic Device | Telecom Remote Radio Head (RRH) |
Use Scenario: Generates clean 12-V supply for precision ADC references, op-amp biasing, and LED excitation in portable blood analyzers. IC Role / Device Role / Timing Role: Main DC-DC stage converting Li-ion battery pack (8.4–12.6 V) to stable 12-V rail; error flag signals power-good to safety monitor MCU. Use Value: ±4% output tolerance and <0.5% load regulation ensure measurement repeatability; soft-start prevents false fault detection during battery insertion. | Use Scenario: Provides 12-V bias for RF power amplifiers and analog beamforming ICs in outdoor 5G small-cell base stations. IC Role / Device Role / Timing Role: High-efficiency intermediate bus converter operating from 48-V telecom rectifier; thermal shutdown protects against enclosure overheating in sealed housings. Use Value: 90% efficiency at full load reduces heat generation in thermally constrained enclosures; TO-263 package enables direct mounting to aluminum heatsink. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2596SX-12 | Same 12-V fixed output, but 150-kHz frequency and 3-A rating; larger TO-220-5 package; no error flag or delay pin. | Lacks integrated error flag and delay functionality - requires external supervisor IC for reset sequencing. | Choose when higher output current (3 A) is needed and reset signaling is handled separately. |
| TPS54202DRCT | 2-A synchronous buck with 4.5–28-V input, adjustable output, 500-kHz switching, and enable/PG pins - smaller 10-pin WSON package. | Higher frequency enables smaller magnetics; lacks built-in thermal protection flag - relies on external thermal sensor or junction temp monitoring. | Prefer for space-constrained designs needing >1-A current and tighter output regulation, accepting added complexity for sync rectification. |
Compared with LM2596SX-12, LM2598SX-12 offers integrated power-good signaling and finer thermal management; versus TPS54202DRCT, it trades higher efficiency and smaller size for simpler layout, lower EMI, and robust fault reporting - making it optimal for industrial and automotive applications where reliability and ease of qualification outweigh miniaturization goals.
Availability
LM2598SX-12 is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, and medical diagnostic equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2598SX-12 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 logic products for industrial, automotive, and communications markets.
The LM2598 series belongs to TI's SIMPLE SWITCHER® power converter family, engineered for ease-of-use in non-isolated DC-DC buck applications where minimal external components, robust protection, and predictable thermal behavior are prioritized over ultra-high efficiency or ultra-small footprint.
FAQ
What is the maximum input voltage rating for the LM2598SX-12?
The LM2598SX-12 has an absolute maximum input voltage rating of 45 V, with recommended operating range from 4.5 V to 40 V. This allows safe operation across automotive load-dump transients (up to 40 V) and industrial 24-V and 36-V supply rails. Exceeding 45 V risks permanent damage per Absolute Maximum Ratings in the datasheet.
Does the LM2598SX-12 require an external catch diode, and what type is recommended?
Yes, the LM2598SX-12 requires an external catch diode due to its nonsynchronous buck topology. A Schottky diode rated for ≥3 A average current and ≥45 V PIV is recommended - such as the SB560 or MBRB340 - to minimize conduction loss and reverse recovery noise. The diode must be placed adjacent to the OUT and GND pins with short, low-inductance traces.
How does the error flag (FLAG) pin function on the LM2598SX-12?
The FLAG pin on the LM2598SX-12 is an open-collector output that pulls low when the regulated 12-V output drops more than 5% below nominal (i.e., below 11.4 V). At startup, it remains low until VOUT reaches 95% of 12 V (11.4 V) and the delay set by the capacitor on the DELAY pin expires - providing a clean, debounced power-good signal for microcontroller reset assertion.
Can the LM2598SX-12 be used in an inverting (positive-to-negative) configuration?
Yes, the LM2598SX-12 can be configured as a positive-to-negative inverter by bootstrapping the GND pin to the negative output rail and grounding the FB pin - generating a –12-V output. However, the maximum sum of |VIN| + |VOUT| must not exceed 40 V, and startup inrush current may reach 1.5 A; soft-start capacitance on the SD/SS pin is strongly recommended to manage this.
What thermal considerations apply to the LM2598SX-12 in TO-263-7 package?
In the TO-263-7 (KTW) package, the LM2598SX-12 achieves θJA = 20°C/W with 3 in² double-sided copper on the LM2598S side and ~16 in² on the opposite layer. For ambient temperatures below 50°C and output loads ≤1 A, no external heatsink is required if the thermal pad is fully soldered to ≥2.5 in² of 1 oz. copper. Thermal shutdown activates at TJ = 150°C.
LM2598SX-12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-263-8, D2PAK (7 Leads + Tab), TO-263CA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 12V
- Voltage - Output (Max):
- -
- Current - Output:
- 1A
- Frequency - Switching:
- 150kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263 (DDPAK-7)
LM2598SX-12 FAQ
1.How can I place an order for LM2598SX-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2598SX-12 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 LM2598SX-12 reliable?
The price and inventory of LM2598SX-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2598SX-12 is usually 5 days.
3.What payment methods are accepted for LM2598SX-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2598SX-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2598SX-12?
LM2598SX-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2598SX-12 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 LM2598SX-12?
For technical support, including LM2598SX-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2598SX-12 requirements.
6.How does Aetrix verify that LM2598SX-12 is sourced from the original manufacturer or authorized distributors?
All LM2598SX-12 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 LM2598SX-12 meets industry standards.
7.What is the process for return or replacement of LM2598SX-12?
All LM2598SX-12 units undergo pre-shipment inspection (PSI). If there is an issue with LM2598SX-12, 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 LM2598SX-12 part is unused and in its original packaging.
Return procedure for LM2598SX-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2598SX-12 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…
