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Texas Instruments LM46000PWP
- Part No.:
- LM46000PWP
- Manufacturer:
- Texas Instruments
- Package:
- 16-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM46000PWP.pdf
- Description:
- IC REG BUCK ADJ 500MA 16HTSSOP
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LM46000PWP from Texas Instruments is a 3.5-V to 60-V, 0.5-A synchronous step-down DC-DC converter in HTSSOP-16 (PWP) package. It delivers regulated output with 24-µA quiescent current in regulation, 500-kHz default switching frequency, and integrated synchronous rectification-enabling high-efficiency point-of-load conversion in industrial power supplies and sub-AM band automotive systems.
For engineers reviewing the LM46000PWP datasheet, LM46000PWP pinout, LM46000PWP application, or LM46000PWP equivalent, key selection criteria include wide input voltage range (3.5–60 V), precision enable threshold (2.1 V typical), internal soft-start (4.1 ms), EN-controlled UVLO programming, and EN55022 Class B EMI compliance verified on the LM46000PWPEVM.
Technical Context
The LM46000PWP employs peak-current-mode control with discontinuous conduction mode (DCM) and pulse-frequency modulation (PFM) at light loads to maintain high efficiency across 0–0.5 A. Its fixed-frequency operation (200 kHz–2.2 MHz, default 500 kHz) supports layout optimization and EMI control via external RT resistor or SYNC clock input.
Internal compensation, integrated high-side (419 mΩ) and low-side (231 mΩ) MOSFETs, and precision feedback reference (1.016 V ±1.5%) enable stable regulation with ceramic, polymer, tantalum, or aluminum output capacitors-without requiring external loop compensation components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.5 V to 60 V - supports unregulated 12-V/24-V/48-V industrial and automotive rails without pre-regulation. |
| Output Current | 0.5 A continuous - sufficient for FPGA I/O, microcontroller cores, and sensor subsystems in compact designs. |
| Quiescent Current | 24 µA in regulation - enables always-on operation in battery-backed or energy-sensitive applications. |
| Switching Frequency | 200 kHz to 2.2 MHz (500 kHz default) - allows trade-off between inductor size and efficiency; synchronized to external clock. |
| Feedback Reference | 1.016 V ±1.5% (–40°C to 125°C) - ensures accurate output voltage setting across temperature with minimal drift. |
| EMI Compliance | Meets EN55022/CISPR 22 Class B - validated on LM46000PWPEVM with no input filter, simplifying system-level certification. |
| Thermal Resistance | RθJA = 39.9°C/W (HTSSOP-16) - enables 0.5-A operation up to +125°C junction temperature with standard PCB copper. |
Pinout & Package
LM46000PWP is housed in a 16-pin HTSSOP (PWP) package measuring 6.6 mm × 5.1 mm × 1.2 mm with 0.65-mm lead pitch. The exposed thermal pad (Pin 17) must be soldered to PCB ground plane for thermal performance and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1,2 SW | Switch node | Connects internally to both MOSFETs; ties to power inductor; requires low-inductance routing to minimize switching losses and EMI. |
| 3 CBOOT | Bootstrap capacitor connection | Supplies gate drive for high-side FET; requires 470-nF ceramic capacitor between CBOOT and SW for reliable operation. |
| 4 VCC | Internal LDO output | Bypass with capacitor to AGND; powers internal circuitry; not for external loading-shorting to ground causes failure. |
| 5 BIAS | Optional LDO input | Tie to VOUT (3.3–28 V) to improve efficiency; bypass with 1–10 µF capacitor; ground if unused (VOUT < 3.3 V). |
| 6 SYNC | External clock input | Accepts 200 kHz–2.2 MHz square wave; requires proper high-speed termination; tie to AGND if unused. |
| 7 RT | Frequency programming | Resistor to AGND sets switching frequency; open-circuit defaults to 500 kHz; tolerance affects accuracy by ±10%. |
| 8 PGOOD | Power-good flag | Open-drain output asserting when VOUT is within ±7% of target; requires 10–100 kΩ pull-up to logic rail ≤12 V. |
| 9 FB | Feedback sense | Monitors resistive divider midpoint; 1.016 V reference sets VOUT = 1.016 × (1 + RFBT/RFBB); leakage <65 nA preserves accuracy. |
| 10 AGND | Analog ground | Reference for internal references and logic; connect directly to system ground plane with low-impedance path. |
| 11 SS/TRK | Soft-start / tracking control | Internal 4.1-ms ramp when floating; add capacitor to extend time; apply external ramp for output voltage tracking. |
| 12 EN | Enable input | Logic-high (≥2.1 V) enables regulation; precision UVLO allows system-level brownout control; leakage <1.75 µA. |
| 13,14 VIN | Main input supply | Connects to high-side FET and internal LDO; requires local high-frequency bypass (CIN) with shortest possible path to PGND. |
| 15,16 PGND | Power ground | Internal connection to low-side FET source; tie to system ground, AGND, CIN/COUT grounds, and thermal pad. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated synchronous rectification | Eliminates external Schottky diode; reduces conduction loss and improves full-load efficiency by up to 8% vs. asynchronous designs. |
| Internal compensation | Removes need for external Type-II/III compensation network; cuts BOM count and design iteration time for stable loop response. |
| Soft-start into prebiased load | Prevents output voltage overshoot when powering already-charged rails-critical for multi-rail systems with sequencing constraints. |
| Output short-circuit protection with hiccup mode | Enters 5.5-ms retry cycle after 32-cycle fault detection; limits average power dissipation during sustained shorts. |
| Stable with diverse output capacitors | Supports ceramic, polymer, tantalum, and aluminum electrolytic types without phase-margin degradation-simplifies sourcing and cost optimization. |
Applications
| Industrial Power Supplies | Telecommunications Systems |
|---|---|
Use Scenario: 24-V or 48-V telecom shelf power feeding distributed 3.3-V/5-V logic rails in base station control cards. IC Role / Device Role / Timing Role: Primary point-of-load regulator converting intermediate bus to processor I/O voltage with tight transient response. Use Value: 24-µA quiescent current extends standby runtime; EN-controlled UVLO enables coordinated system power sequencing. |
Use Scenario: Distributed power in optical line terminals (OLTs) where space-constrained boards require high-density DC-DC conversion. IC Role / Device Role / Timing Role: Synchronous buck converter delivering 0.5-A at 1.2 V or 1.8 V to FPGA transceivers with minimal board area. Use Value: 500-kHz default frequency enables use of small 27-µH inductors; internal compensation reduces component count by ≥3 vs. controller-based solutions. |
| Sub-AM Band Automotive | Commercial Vehicle Power Supplies |
Use Scenario: 12-V battery-powered infotainment head units requiring clean 3.3-V supply for audio codecs and touch controllers. IC Role / Device Role / Timing Role: Wide-input buck regulator handling cold-crank (6 V) to load-dump (60 V) transients while maintaining regulation. Use Value: 60-V absolute max input rating and robust thermal shutdown (160°C) ensure reliability in harsh under-hood environments. |
Use Scenario: Power conversion in heavy-duty truck telematics modules operating from 24-V chassis battery with wide temperature swing. IC Role / Device Role / Timing Role: Main 5-V supply for GPS, cellular modem, and CAN interface ICs in vibration-prone mounting locations. Use Value: EN55022 Class B compliance eliminates need for external EMI filters; HTSSOP package withstands mechanical shock per AEC-Q200 requirements. |
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 |
|---|---|---|---|
| LM46001PWP | 1-A output current; identical pinout and package; higher RDS(on) (HS: 520 mΩ, LS: 290 mΩ) at same bias conditions. | Required where load exceeds 0.5 A but board space and layout cannot change; higher conduction loss at full load. | Select LM46001PWP when scaling output current without redesigning PCB layout or changing thermal management. |
| LM43603PWPR | 3-A output; 16-pin HTSSOP package; wider frequency range (200 kHz–2.2 MHz); same EN/PGOOD/SS/TRK functionality. | Used in higher-power subsystems (e.g., motor control logic, multi-sensor hubs); requires larger inductor and output capacitance. | Choose LM43603PWPR only when system demands >0.5 A continuous output and thermal margin permits higher power dissipation. |
Compared with LM46000PWP, LM46001PWP offers +100% current capacity in identical footprint but trades off ~25% higher MOSFET conduction loss, while LM43603PWPR provides triple the current at the cost of significantly increased thermal design complexity and BOM cost.
Availability
LM46000PWP is available at Aetrix Electronics and suitable for industrial power supplies, telecommunications systems, and sub-AM band automotive applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for LM46000PWP 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 decades of expertise in high-reliability DC-DC conversion.
The LM46000PWP belongs to TI's wide-input synchronous buck regulator family designed for rugged industrial, automotive, and telecom power systems where input voltage variation, EMI compliance, and thermal resilience are critical.
FAQ
What is the minimum input voltage required for the LM46000PWP to start switching?
The LM46000PWP requires a minimum input voltage of 3.8 V to initiate startup and enter regulation. Below this threshold, the device remains in shutdown with only 2.3–5 µA quiescent current drawn from VIN. This startup voltage is independent of the enable pin state and ensures reliable turn-on across temperature and process variations. The LM46000PWP maintains regulation down to 3.5 V once running.
Does the LM46000PWP support output voltage tracking during power-up sequencing?
Yes, the LM46000PWP 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 LM46000PWP's output follows that ramp with unity gain. This enables precise power sequencing in multi-rail systems without additional supervision ICs. The LM46000PWP also supports internal soft-start (4.1 ms) when SS/TRK is left floating.
How does the LM46000PWP achieve EN55022 Class B EMI compliance without external filters?
The LM46000PWP achieves EN55022 Class B compliance through optimized internal gate drive timing, integrated synchronous rectification (eliminating diode reverse recovery noise), and a carefully laid out HTSSOP package with dedicated power/ground pins. Radiated and conducted EMI tests were performed on the LM46000PWPEVM using its default BOM-no external input filter-and met limits across 150 kHz–30 MHz with both horizontal and vertical polarization.
Can the LM46000PWP operate with a 3.3-V output and 12-V input at full 0.5-A load?
Yes, the LM46000PWP delivers 0.5-A continuously at 3.3-V output from a 12-V input with typical efficiency exceeding 92%, as confirmed in Figure 3 of the datasheet. The device's peak-current-mode control, low RDS(on) MOSFETs (419 mΩ HS / 231 mΩ LS), and internal compensation ensure stable regulation and fast transient response under these conditions without external loop tuning.
What thermal derating applies to the LM46000PWP in a standard 2-layer PCB layout?
On a standard 2-layer PCB with 1 oz copper, the LM46000PWP's junction-to-ambient thermal resistance (RθJA) increases to approximately 58°C/W-versus 39.9°C/W on a 4-layer board. At 0.5-A load and 24-V input, power dissipation is ~0.35 W; this yields ~20°C junction rise above ambient on a 2-layer board, allowing full-rated operation up to +105°C ambient. Thermal pad soldering to inner ground planes is strongly recommended.
LM46000PWP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 16-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- 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):
- 60V
- Voltage - Output (Min/Fixed):
- 1V
- Voltage - Output (Max):
- 28V
- Current - Output:
- 500mA
- Frequency - Switching:
- 200kHz ~ 2.2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-HTSSOP
LM46000PWP FAQ
1.How can I place an order for LM46000PWP through Aetrix?
Please submit a Request for Quotation (RFQ) for LM46000PWP 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 LM46000PWP reliable?
The price and inventory of LM46000PWP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM46000PWP is usually 5 days.
3.What payment methods are accepted for LM46000PWP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM46000PWP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM46000PWP?
LM46000PWP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM46000PWP 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 LM46000PWP?
For technical support, including LM46000PWP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM46000PWP requirements.
6.How does Aetrix verify that LM46000PWP is sourced from the original manufacturer or authorized distributors?
All LM46000PWP 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 LM46000PWP meets industry standards.
7.What is the process for return or replacement of LM46000PWP?
All LM46000PWP units undergo pre-shipment inspection (PSI). If there is an issue with LM46000PWP, 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 LM46000PWP part is unused and in its original packaging.
Return procedure for LM46000PWP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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