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Texas Instruments LM43603AQPWPTQ1
- Part No.:
- LM43603AQPWPTQ1
- Manufacturer:
- Texas Instruments
- Package:
- 16-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM43603AQPWPTQ1.pdf
- Description:
- IC REG BUCK ADJ 3A 16HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:542
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Product details
Overview
LM43603AQPWPTQ1 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 in regulation, internal compensation, and a precision 1.015 V feedback reference. It operates at a default 500 kHz switching frequency (adjustable 200 kHz–2.2 MHz), supports soft-start into pre-biased loads, and integrates power-good flag and hiccup-mode short-circuit protection for use in sub-AM band automotive power rails.
For engineers reviewing the LM43603AQPWPTQ1 datasheet, LM43603AQPWPTQ1 pinout, LM43603AQPWPTQ1 application, or LM43603AQPWPTQ1 equivalent, key selection considerations include its HTSSOP-16 package thermal performance (RθJA = 38.9°C/W), EN pin precision UVLO (2.20 V ±0.22 V), PGOOD accuracy (±3% FB threshold), and EMI-compliant operation meeting EN55022 Class B radiated emissions limits without external filters.
Technical Context
The LM43603AQPWPTQ1 employs peak current mode control with cycle-by-cycle current limiting and internal slope compensation, enabling stable operation with minimal external components and compatibility with ceramic, polymer, tantalum, and aluminum output capacitors. Its architecture integrates synchronous high-side (120 mΩ) and low-side (65 mΩ) MOSFETs, a dedicated BIAS pin for efficiency optimization, and a programmable RT pin for frequency tuning.
It features dual operating modes-DCM at light load and forced PWM at heavy load-with automatic transition, plus PFM optimization in the 'A' variant for improved light-load efficiency. The device implements precision enable thresholds with 290 mV hysteresis, internal soft-start (4.1 ms), and tracking capability via the SS/TRK pin, all while maintaining thermal shutdown at 160°C and robust ESD protection (±2000 V HBM).
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) |
| Output Current | Up to 3 A continuous - sufficient for infotainment, ADAS sensors, and body control modules |
| Feedback Reference | 1.015 V ±0.017 V - enables accurate 3.3 V, 5 V, or 12 V regulation with <±1% output error |
| Quiescent Current | 27 µA in regulation - extends battery life in always-on automotive systems |
| Switching Frequency | 200 kHz to 2.2 MHz adjustable - allows EMI optimization and inductor size reduction |
| Thermal Shutdown | 160°C trip / 150°C recovery - protects against sustained overload or poor PCB heatsinking |
| EMI Compliance | Meets EN55022 Class B radiated emissions - reduces need for external shielding or filtering |
Pinout & Package
LM43603AQPWPTQ1 is housed in a thermally enhanced 16-pin HTSSOP (PWP) package measuring 6.6 mm × 5.1 mm × 1.2 mm, with an exposed thermal pad connected internally to AGND for efficient heat dissipation to the PCB ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW (1,2) | Power switch node | Connects to inductor; carries full switching current and high dv/dt - requires tight layout to PGND |
| CBOOT (3) | Bootstrap capacitor connection | Supplies gate drive for high-side FET; requires 470 nF X7R ceramic capacitor to SW |
| VCC (4) | Internal LDO output | 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 3.3/5 V rail to reduce VIN current and improve efficiency |
| SYNC (6) | External clock input | Enables synchronization to system clock; requires proper high-speed termination |
| RT (7) | Frequency programming | Resistor to AGND sets frequency; open circuit = 500 kHz default |
| PGOOD (8) | Open-drain power-good flag | Indicates VOUT within ±3% of target; requires 10–100 kΩ pullup to ≤12 V logic rail |
| FB (9) | Feedback voltage sense | Connects to resistor divider midpoint; 1.015 V reference sets output voltage |
| AGND (10) | Analog ground reference | Reference for internal references and logic; connect directly to system ground |
| SS/TRK (11) | Soft-start and tracking control | Capacitor extends soft-start time; external ramp enables output voltage tracking |
| EN (12) | Enable input | Logic-compatible; 2.20 V rising threshold with 290 mV hysteresis for precise system sequencing |
| VIN (13,14) | Main input supply | Connect to bulk and high-frequency bypass capacitors; shortest possible path to PGND |
| PGND (15,16) | Power ground return | Low-impedance return for low-side FET and input/output capacitors; tie to PAD and AGND |
| PAD | Exposed thermal pad | Internally connected to AGND; must be soldered to large PCB copper area for thermal management |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q100 Grade 1 (–40°C to +125°C TJ) - validated for under-hood and cabin applications |
| Integrated synchronous FETs | 120 mΩ high-side / 65 mΩ low-side RDS(on) - eliminates external MOSFETs and reduces solution footprint |
| EMI-compliant design | Passes EN55022 Class B radiated emissions without ferrite beads or common-mode chokes |
| Pre-biased soft-start | Safe startup into powered outputs - prevents reverse current flow in multi-rail systems |
| Internal compensation | Single feedback loop with no external compensation network - simplifies design and improves stability margin |
| Power-good flag accuracy | ±3% FB threshold with 220 µs deglitch - ensures reliable system power sequencing and fault detection |
Applications
| Sub-AM Band Automotive Power | Industrial Wide-VIN Point-of-Load |
|---|---|
Use Scenario: Powering infotainment head units, digital clusters, and telematics modules from 12 V or 24 V vehicle batteries with cold-crank (4.5 V) and load-dump (42 V) transients. IC Role / Device Role / Timing Role: Primary buck regulator providing stable 3.3 V or 5 V rail with fast transient response and low quiescent current. Use Value: Enables direct battery connection without pre-regulator, reducing bill-of-materials and improving system efficiency over full temperature range. |
Use Scenario: Regulating 24 V industrial bus down to 5 V or 12 V for PLC I/O modules, motor drives, and sensor interfaces in harsh environments. IC Role / Device Role / Timing Role: High-reliability DC-DC converter with thermal shutdown and hiccup-mode protection for unattended operation. Use Value: Delivers 3 A output with <1% output error and meets EN55022 Class A/B emissions - avoids costly EMI rework. |
| High-Efficiency Telecom Supply | Automotive ADAS Camera Power |
Use Scenario: Generating intermediate 5 V or 12 V rails in telecom base station equipment where standby power and thermal management are critical. IC Role / Device Role / Timing Role: Synchronous buck controller with PFM/DCM light-load mode and 27 µA IQ for energy-sensitive applications. Use Value: Achieves >90% efficiency at 10 mA load and >95% at full load - extends uptime during backup battery operation. |
Use Scenario: Powering CMOS image sensors and SerDes links in rear-view or surround-view camera modules requiring low noise and fast startup. IC Role / Device Role / Timing Role: Low-noise, EMI-optimized buck regulator with precise enable and power-good signaling for safety-critical vision systems. Use Value: Meets ISO 11452-2 radiated immunity requirements and provides clean, sequenced power with <100 µs PGOOD assertion delay. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM43602AQPWPTQ1 | 2 A output current, identical pinout and feature set, lower RDS(on) (100 mΩ HS / 55 mΩ LS) | Suitable for lower-current automotive modules where thermal margin is constrained | Select when 2 A suffices and board space or cost optimization is prioritized over 3 A headroom |
| TPS54360BQDDAQ1 | 3.5 A output, wider 3.5–60 V input, but higher 145 µA IQ and no integrated BIAS pin | Better for 48 V industrial or commercial truck applications; less optimal for ultra-low-IQ automotive sleep modes | Choose for extended input range needs, accepting trade-offs in quiescent current and BIAS flexibility |
Compared with LM43602AQPWPTQ1 and TPS54360BQDDAQ1, the LM43603AQPWPTQ1 uniquely balances 3 A capability, 27 µA IQ, BIAS pin efficiency enhancement, and Class B EMI compliance in a single AEC-Q100 Grade 1 package - making it optimal for next-generation automotive domain controllers requiring both performance and regulatory readiness.
Availability
LM43603AQPWPTQ1 is available at Aetrix Electronics and suitable for sub-AM band automotive electronics, industrial wide-VIN point-of-load regulation, and high-efficiency telecom power supplies requiring stable component supply, long-term lifecycle support, and AEC-Q100 compliance.
Supply support for LM43603AQPWPTQ1 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 deep expertise in automotive-grade IC design and manufacturing.
The LM43603-Q1 family was developed specifically for automotive power conversion applications demanding AEC-Q100 qualification, low quiescent current, EMI robustness, and seamless integration into domain controller and ADAS subsystems.
FAQ
What is the maximum allowable input voltage for the LM43603AQPWPTQ1?
The LM43603AQPWPTQ1 has an absolute maximum input voltage rating of 42 V, with recommended operation from 3.5 V to 36 V. This range accommodates automotive battery transients including cold-crank (down to ~4.5 V) and load-dump (up to 42 V), ensuring reliable operation in real-world vehicle electrical systems without external clamping circuitry.
Does the LM43603AQPWPTQ1 require external compensation components?
No, the LM43603AQPWPTQ1 features internal compensation, eliminating the need for external Type II or Type III compensation networks. This simplifies PCB layout, reduces component count, and improves stability margin across varying output capacitor types - including ceramic, polymer, tantalum, and aluminum - without requiring loop compensation recalculations.
How does the BIAS pin improve efficiency in the LM43603AQPWPTQ1?
The BIAS pin on the LM43603AQPWPTQ1 allows the internal LDO to be powered from the regulated output (3.3–28 V) or an external 3.3 V/5 V rail instead of VIN. This reduces power dissipation in the internal LDO, lowering total input current and improving overall efficiency - especially at high VIN-to-VOUT ratios - while maintaining full functionality of all control features.
Can the LM43603AQPWPTQ1 start up into a pre-biased output?
Yes, the LM43603AQPWPTQ1 supports soft-start into a pre-biased output. Its control architecture prevents reverse current flow during startup by disabling the low-side FET until the internal soft-start ramp reaches the output voltage level, protecting downstream circuitry and enabling safe hot-plug operation in multi-rail systems.
What is the purpose of the SS/TRK pin on the LM43603AQPWPTQ1?
The SS/TRK pin on the LM43603AQPWPTQ1 serves dual functions: connecting a capacitor extends the internal 4.1 ms soft-start time linearly, while applying an external voltage ramp enables output voltage tracking for coordinated power-up with other regulators. This provides flexible sequencing control essential for FPGA, processor, and multi-voltage SoC applications.
LM43603AQPWPTQ1 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:
- Active
- 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
LM43603AQPWPTQ1 FAQ
1.How can I place an order for LM43603AQPWPTQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM43603AQPWPTQ1 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 LM43603AQPWPTQ1 reliable?
The price and inventory of LM43603AQPWPTQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM43603AQPWPTQ1 is usually 5 days.
3.What payment methods are accepted for LM43603AQPWPTQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM43603AQPWPTQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM43603AQPWPTQ1?
LM43603AQPWPTQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM43603AQPWPTQ1 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 LM43603AQPWPTQ1?
For technical support, including LM43603AQPWPTQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM43603AQPWPTQ1 requirements.
6.How does Aetrix verify that LM43603AQPWPTQ1 is sourced from the original manufacturer or authorized distributors?
All LM43603AQPWPTQ1 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 LM43603AQPWPTQ1 meets industry standards.
7.What is the process for return or replacement of LM43603AQPWPTQ1?
All LM43603AQPWPTQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LM43603AQPWPTQ1, 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 LM43603AQPWPTQ1 part is unused and in its original packaging.
Return procedure for LM43603AQPWPTQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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