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Texas Instruments LM43603QPWPTQ1
- Part No.:
- LM43603QPWPTQ1
- Manufacturer:
- Texas Instruments
- Package:
- 16-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM43603QPWPTQ1.pdf
- Description:
- IC REG BUCK ADJ 3A 16HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,241
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Product details
Overview
LM43603QPWPTQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-qualified synchronous step-down DC-DC converter delivering up to 3 A output current across a 3.5 V to 36 V input range, featuring 27 µA quiescent current, internal compensation, and EN55022 Class B radiated EMI compliance - deployed in sub-AM band automotive power rails and industrial point-of-load systems.
For engineers reviewing the LM43603QPWPTQ1 datasheet, LM43603QPWPTQ1 pinout, LM43603QPWPTQ1 application, or LM43603QPWPTQ1 equivalent, key selection criteria include its 500 kHz default switching frequency (adjustable 200 kHz–2.2 MHz), precision enable threshold (2.20 V ±0.22 V), power-good flag with 13% overvoltage/23% undervoltage hysteresis, and HTSSOP-16 thermal performance (RθJA = 38.9°C/W).
Technical Context
The LM43603QPWPTQ1 employs peak current mode control for stable loop response and cycle-by-cycle current limiting, with integrated high-side (120 mΩ) and low-side (65 mΩ) MOSFETs enabling high-efficiency regulation without external switches. Its internal LDO supplies VCC (3.28 V) and supports optional BIAS pin connection to VOUT (3.3–28 V) for improved light-load efficiency.
EMI performance is enhanced via spread-spectrum-capable SYNC input, optimized pin layout for minimal SW node area, and integrated soft-start (4.1 ms internal, extendable via SS/TRK capacitor). Discontinuous conduction mode (DCM) and automatic pulse-frequency modulation (PFM) maintain >85% efficiency at 1 mA load under 12 VIN/3.3 VOUT.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.5 V to 36 V - supports wide automotive battery transients (42 V abs max); enables single-rail operation across cold-crank (4.5 V) to load-dump (36 V) conditions. |
| Output Current | 3 A continuous - sufficient for powering ADAS camera modules, infotainment SoCs, or industrial PLC I/O stages without external current boosting. |
| Quiescent Current | 27 µA in regulation - extends battery runtime in always-on automotive subsystems such as telematics or body control modules. |
| Switching Frequency | 200 kHz to 2.2 MHz (500 kHz default) - allows optimization of inductor size vs. EMI; synchronization to external clock avoids beat frequencies in multi-rail systems. |
| Feedback Reference | 1.015 V ±0.013 V (–40°C to +125°C) - enables accurate 1% output voltage tolerance with standard resistor dividers; supports tracking via SS/TRK pin. |
| Thermal Shutdown | 160°C shutdown / 150°C recovery - protects against sustained overload or poor PCB heatsinking; HTSSOP-16 package uses exposed PAD for direct thermal coupling to ground plane. |
| EMI Compliance | Meets EN55022 Class B radiated emissions - validated on TI evaluation board; eliminates need for external EMI filters in cost-sensitive automotive modules. |
Pinout & Package
LM43603QPWPTQ1 is housed in a thermally enhanced HTSSOP-16 (PWP) package measuring 6.6 mm × 5.1 mm × 1.2 mm, with an exposed thermal pad (PAD) that must be soldered to a PCB ground plane for effective heat dissipation and electrical grounding.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW (1,2) | Power switch node | Connects internally to both MOSFETs; requires low-inductance path to power inductor and COUT; critical for EMI and efficiency. |
| CBOOT (3) | Bootstrap capacitor terminal | Supplies gate drive for high-side FET; requires 470 nF ceramic capacitor between CBOOT and SW for reliable bootstrapping. |
| VCC (4) | Internal bias supply output | Provides regulated 3.28 V for internal circuitry; bypass with 1–10 µF capacitor to AGND; no external loading permitted. |
| BIAS (5) | Optional LDO input | Tie to VOUT (3.3–28 V) or external rail to reduce VIN current draw; improves light-load efficiency; never exceed VIN. |
| SYNC (6) | External clock input | Accepts 200 kHz–2.2 MHz square wave; enables multi-converter synchronization to suppress beat frequencies and simplify EMI filtering. |
| RT (7) | Frequency programming | Resistor to AGND sets switching frequency; open circuit defaults to 500 kHz; 1% tolerance resistors recommended for accuracy. |
| PGOOD (8) | Open-drain power-good flag | Asserts high when VOUT is within 13% OVP / 23% UVP window; requires 10–100 kΩ pull-up to logic rail ≤12 V. |
| FB (9) | Feedback sense input | Monitors voltage divider midpoint; 1.015 V reference enables precise output setting; leakage <65 nA minimizes divider error. |
| AGND (10) | Analog ground reference | Ground return for internal references, comparators, and soft-start circuitry; must connect to system ground with low-impedance path. |
| SS/TRK (11) | Soft-start and tracking control | Internal 4.1 ms ramp when floating; add capacitor to extend soft-start time; apply external ramp for output voltage tracking. |
| EN (12) | Enable input | Logic-compatible enable with 2.20 V rising threshold and 290 mV hysteresis; supports precision UVLO sequencing in multi-rail systems. |
| VIN (13,14) | Main input supply | High-current input pins for internal LDO and high-side FET; require short, low-impedance path to CIN and PGND. |
| PGND (15,16) | Power ground return | Low-side FET source connection; must tie to AGND, PAD, and CIN/COUT grounds; forms primary current return path. |
| PAD | Exposed thermal pad | Internally connected to AGND; mandatory solder connection to PCB ground plane for thermal management and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated synchronous rectification | Eliminates external Schottky diode; reduces conduction loss by replacing low-side diode with 65 mΩ MOSFET, improving full-load efficiency by ≥3%. |
| Internal compensation | Reduces design complexity and BOM count; supports stable operation with ceramic, polymer, tantalum, or aluminum output capacitors without external compensation network. |
| Pre-biased soft-start | Enables safe startup into powered loads (e.g., FPGA banks or DDR memory rails) without reverse current flow or output voltage undershoot. |
| Output short-circuit protection with hiccup mode | Trips at 4.4–6.4 A peak inductor current; enters 5.5 ms retry cycle after fault clearance, preventing thermal runaway during sustained shorts. |
| Adjustable frequency & synchronization | Allows EMI optimization across board layouts; SYNC input accepts TTL/CMOS clocks up to 2.2 MHz with 10–90% duty cycle tolerance. |
| Stable over temperature | Feedback reference drift ≤±13 mV (–40°C to +125°C); enable threshold hysteresis remains stable at 290 mV; ensures robust sequencing in engine bay environments. |
Applications
| Automotive Sub-AM Band Power Supply | Industrial Point-of-Load Regulation |
|---|---|
Use Scenario: Powering radar sensor modules and rear-view camera ECUs in vehicles where input voltage varies from 5.5 V (cold crank) to 36 V (load dump). IC Role / Device Role / Timing Role: Primary 3.3 V/3 A buck regulator providing clean, sequenced power with PGOOD confirmation and thermal shutdown. Use Value: AEC-Q100 Grade 1 qualification ensures reliability at 125°C junction; EN55022 Class B compliance eliminates external EMI filters, reducing solution size by 30%. |
Use Scenario: Generating 5 V/3 A for programmable logic controllers (PLCs) operating in factory-floor environments with wide ambient temperature swings. IC Role / Device Role / Timing Role: High-efficiency, wide-VIN DC-DC converter delivering stable output despite 24 V DC bus fluctuations and transient surges. Use Value: 27 µA quiescent current extends uptime during standby; internal soft-start prevents inrush into downstream capacitive loads like Ethernet PHYs. |
| Telecom Remote Radio Unit (RRU) | General-Purpose Wide-VIN Regulation |
Use Scenario: Providing isolated 12 V/2.5 A bias for RF power amplifiers in 4G/5G base station remote radio units powered from -48 V DC telecom supplies. IC Role / Device Role / Timing Role: Intermediate buck stage stepping down from intermediate 24 V rail to 12 V, synchronized to system clock via SYNC pin. Use Value: Frequency synchronization avoids interference with sensitive RF front-end; hiccup-mode short-circuit protection maintains system availability during field faults. |
Use Scenario: Universal input adapter for test equipment requiring stable 3.3 V/3 A from unregulated 9–36 V lab supplies or battery packs. IC Role / Device Role / Timing Role: Flexible buck converter supporting adjustable output via FB divider, tracking via SS/TRK, and precise enable sequencing. Use Value: Internal compensation and ceramic-capacitor compatibility simplify prototyping; RT pin enables quick frequency tuning for noise-sensitive analog circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM43602QPWPTQ1 | 2 A output current, identical pinout and feature set; lower RDS(on) (100 mΩ HS / 55 mΩ LS) but reduced current capability. | Suitable for lower-power automotive modules (e.g., door control units) where 3 A headroom is unnecessary. | Select when thermal budget or cost constraints favor lower-current rating without redesigning PCB layout. |
| LM46002QPWPTQ1 | 2 A rating, same HTSSOP-16 package, but optimized for higher-frequency operation (up to 2.5 MHz) and lower IQ (15 µA). | Better suited for space-constrained applications needing >1 MHz switching (e.g., portable medical devices) but lacks BIAS pin flexibility. | Choose for ultra-compact designs prioritizing frequency headroom and lowest possible quiescent current over wide-VIN robustness. |
Compared with LM43602QPWPTQ1 and LM46002QPWPTQ1, the LM43603QPWPTQ1 delivers 50% higher output current in the same footprint while retaining full automotive qualification, EMI compliance, and BIAS pin efficiency optimization - making it the optimal choice for 3 A automotive and industrial loads where thermal margin and transient robustness are critical.
Availability
LM43603QPWPTQ1 is available at Aetrix Electronics and suitable for automotive sub-AM band power supplies, industrial PLC I/O stages, and telecom remote radio units requiring stable component supply with AEC-Q100 Grade 1 assurance and long-term production continuity.
Supply support for LM43603QPWPTQ1 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 automotive-grade product development and manufacturing excellence.
The LM4360x-Q1 family was designed specifically for demanding automotive power conversion applications - emphasizing wide input range, low quiescent current, EMI robustness, and AEC-Q100 reliability - targeting ADAS, infotainment, and body electronics subsystems.
FAQ
What is the absolute maximum input voltage rating for the LM43603QPWPTQ1?
The LM43603QPWPTQ1 has an absolute maximum input voltage of 42 V across VIN to PGND, as specified in Section 6.1 of the datasheet. This rating allows safe operation during automotive load-dump transients. Continuous operation above 36 V is not recommended; the device is rated for 3.5 V to 36 V normal input range. Exceeding 42 V risks permanent damage regardless of duration.
Does the LM43603QPWPTQ1 support output voltage tracking, and how is it implemented?
Yes, the LM43603QPWPTQ1 supports output voltage tracking via the SS/TRK pin. When an external voltage ramp (e.g., from another regulator's soft-start pin) is applied to SS/TRK, the LM43603QPWPTQ1's output follows that ramp with unity gain. This enables precise power sequencing in multi-rail systems such as FPGAs or processors with strict AVDD/DVDD ramp requirements.
What is the purpose of the BIAS pin on the LM43603QPWPTQ1, and how should it be configured?
The BIAS pin on the LM43603QPWPTQ1 provides an optional input to the internal LDO, improving light-load efficiency. For VOUT between 3.3 V and 28 V, TI recommends connecting BIAS directly to VOUT. If VOUT is outside this range or unavailable, tie BIAS to a stable 3.3 V or 5 V rail. Never leave BIAS floating or exceed VIN at this pin.
How does the LM43603QPWPTQ1 handle short-circuit conditions on the output?
The LM43603QPWPTQ1 responds to output short circuits with hiccup-mode protection. Upon detecting valley current limit violation (2.6–3.3 A), it shuts down for 5.5 ms before attempting restart. This cycle repeats until the fault clears, preventing thermal runaway and enabling automatic recovery without manual reset - critical for unattended automotive and industrial systems.
Is the LM43603QPWPTQ1 pin-compatible with other devices in the LM4360x-Q1 family?
Yes, the LM43603QPWPTQ1 is pin-compatible with the LM43602QPWPTQ1 (2 A) and LM43601QPWPTQ1 (1 A) in the same HTSSOP-16 package. This enables scalable power design: users can select current rating based on load requirements without changing PCB layout, simplifying variant management and reducing NRE costs across vehicle platforms.
LM43603QPWPTQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 16-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Not For New Designs
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.5V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 1V
- Voltage - Output (Max):
- 28V
- Current - Output:
- 3A
- Frequency - Switching:
- 200kHz ~ 2.2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-HTSSOP
LM43603QPWPTQ1 FAQ
1.How can I place an order for LM43603QPWPTQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM43603QPWPTQ1 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 LM43603QPWPTQ1 reliable?
The price and inventory of LM43603QPWPTQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM43603QPWPTQ1 is usually 5 days.
3.What payment methods are accepted for LM43603QPWPTQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM43603QPWPTQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM43603QPWPTQ1?
LM43603QPWPTQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM43603QPWPTQ1 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 LM43603QPWPTQ1?
For technical support, including LM43603QPWPTQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM43603QPWPTQ1 requirements.
6.How does Aetrix verify that LM43603QPWPTQ1 is sourced from the original manufacturer or authorized distributors?
All LM43603QPWPTQ1 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 LM43603QPWPTQ1 meets industry standards.
7.What is the process for return or replacement of LM43603QPWPTQ1?
All LM43603QPWPTQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LM43603QPWPTQ1, 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 LM43603QPWPTQ1 part is unused and in its original packaging.
Return procedure for LM43603QPWPTQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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