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Texas Instruments LM3429Q1MHX/NOPB
- Part No.:
- LM3429Q1MHX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 14-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM3429Q1MHX/NOPB.pdf
- Description:
- IC LED DRIVER CTRLR PWM 14HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:14,907
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Product details
Overview
LM3429Q1MHX/NOPB from Texas Instruments is an AEC-Q100 Grade 1 qualified high-voltage N-channel MOSFET controller for constant-current LED drivers, supporting buck, boost, buck-boost, and SEPIC topologies. It operates from 4.5 V to 75 V input, features predictive off-time (PRO) control, high-side current sensing with 1.235 V typical CSH reference, and delivers up to 1-A peak gate drive for external NFETs in automotive lighting systems.
For engineers reviewing the LM3429Q1MHX/NOPB datasheet, LM3429Q1MHX/NOPB pinout, LM3429Q1MHX/NOPB application, or LM3429Q1MHX/NOPB equivalent, key selection considerations include its 75 V VIN rating, 1.24 V OVP threshold, 245 mV current limit threshold, thermal shutdown at 165 °C, and compatibility with high-side LED current sense configurations using HSP/HSN pins.
Technical Context
The LM3429Q1MHX/NOPB implements Predictive Off-Time (PRO) control - a hybrid of peak current-mode regulation and input-voltage-proportional off-timer - enabling stable operation up to 2 MHz without sub-harmonic oscillation, even at >50% duty cycles. Its high-side transconductance amplifier (20–119 mA/V) and differential HSP/HSN inputs support precise LED current regulation via external sense resistors.
It integrates a 6.9 V internal LDO regulator (7.35 V max, 27 mA current limit), programmable switching frequency via RCT pin (using VIN/25 reference), cycle-by-cycle current limiting (245 mV threshold), and dual dimming: analog via CSH pin biasing and PWM via nDIM input with 1.24 V UVLO threshold and 20 µA hysteresis current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 4.5 V to 75 V - supports wide-input automotive battery and industrial DC bus applications without pre-regulation. |
| CSH Reference Voltage | 1.235 V (typ) - sets high-side current sense threshold; enables accurate LED current regulation with external RSNS. |
| OVP Threshold | 1.24 V - triggers overvoltage lockout when OVP pin exceeds this level; hysteresis provided by 20 µA current source. |
| Current Limit Threshold | 245 mV (typ) - terminates switch on-time if IS pin voltage exceeds this value; provides cycle-by-cycle protection. |
| GATE Drive Strength | 2 Ω sourcing / 1.3 Ω sinking - drives external N-channel MOSFET gates with fast rise/fall times for high-efficiency switching. |
| Thermal Shutdown | 165 °C - disables operation to prevent junction damage; 25 °C hysteresis ensures safe restart after cooling. |
| Switching Frequency Range | Up to 2 MHz - programmable via RCT pin; VIN-proportional timing enables near-constant fSW in boost/buck-boost. |
Pinout & Package
LM3429Q1MHX/NOPB is housed in a thermally enhanced 14-pin HTSSOP package (5.00 mm × 4.40 mm) with exposed DAP pad connected to AGND and PGND for low-thermal-resistance PCB mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Main power input | Supplies startup regulator and internal circuitry; bypassed with 100 nF capacitor to AGND near pin. |
| COMP | Error amplifier output | Connects to compensation network (capacitor to AGND); regulates CSH voltage to 1.24 V for current control. |
| CSH | Current sense reference | Sinks regulated 1.24 V referenced current (ICSH); used for analog dimming and high-side sense feedback. |
| RCT | Timing control input | Accepts resistor-capacitor network to set off-time; references VIN/25 (565 mV @ VIN=14 V) for PRO control. |
| AGND | Analog ground return | Reference for CSH, COMP, RCT; must be tied to DAP and separated from noisy PGND where possible. |
| OVP | Overvoltage protection input | Monitors output via resistor divider; trips at 1.24 V with hysteresis enabled by internal 20 µA current source. |
| nDIM | Inverted enable/dim input | Active-low PWM dimming control or UVLO programming; 1.24 V threshold with 20 µA hysteresis current. |
| NC | No connection | Pin 8 is unconnected; must remain floating per datasheet. |
| PGND | Power ground return | Return path for GATE driver and IS current sense; connects to DAP copper pad for thermal conduction. |
| GATE | NFET gate driver output | Drives external N-channel MOSFET gate; 1-A peak sourcing/sinking capability with 2 Ω/1.3 Ω on-resistance. |
| VCC | Internal LDO output | 6.9 V regulated supply for internal logic; bypassed with 2.2–3.3 µF ceramic capacitor to PGND. |
| IS | Main switch current sense | Inputs MOSFET RDS-ON or source-sense resistor voltage; triggers 245 mV cycle-by-cycle current limit. |
| HSP / HSN | High-side LED current sense | Differential inputs to transconductance amplifier; enable floating LED load sensing with ±7 mV offset. |
| DAP | Thermal pad | Exposed bottom pad; must be soldered to AGND/PGND copper for thermal dissipation and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Predictive Off-Time (PRO) Control | Eliminates sub-harmonic oscillation at all duty cycles; simplifies loop compensation and enables stable >50% duty operation in boost topologies. |
| High-Side Differential Current Sensing | HSP/HSN inputs support floating LED loads with 10 µA input bias current and ±7 mV offset - enabling accurate current regulation without ground-referenced LEDs. |
| Integrated 6.9 V Startup Regulator | Operates across full 4.5–75 V VIN range; delivers up to 27 mA to power internal circuitry and external bias networks. |
| Programmable Dimming Interfaces | Supports both analog dimming (via CSH pin current injection) and PWM dimming (via nDIM pin) - no external components required for basic PWM control. |
| Robust Protection Suite | Includes overvoltage lockout (OVP), input undervoltage lockout (UVLO), cycle-by-cycle current limit, and thermal shutdown with 25 °C hysteresis. |
Applications
| Automotive Headlamp Drivers | Industrial High-Bay LED Lighting |
|---|---|
|
Use Scenario: Constant-current driving of multi-string HBLED arrays in 12 V/24 V vehicle electrical systems with wide input transients (load dump, cold crank). IC Role / Device Role: N-channel controller managing external MOSFET in boost topology to regulate LED current independent of forward voltage variation. Use Value: AEC-Q100 Grade 1 qualification (−40 °C to +125 °C), 75 V VIN tolerance, and thermal shutdown ensure reliability under harsh automotive conditions. |
Use Scenario: High-efficiency LED driver for warehouse and factory lighting operating from 36–72 V DC industrial power supplies. IC Role / Device Role: Controller in buck-boost configuration delivering stable 1–3 A LED current despite wide input/output voltage differentials. Use Value: PRO control enables stable operation up to 2 MHz, reducing magnetics size; high-side sensing avoids ground-loop interference in large metal fixtures. |
| Outdoor Streetlight Drivers | Architectural Accent Lighting |
|
Use Scenario: Outdoor-rated LED luminaires powered from solar-charged batteries or PoE-derived DC, requiring wide VIN range and dimming flexibility. IC Role / Device Role: SEPIC topology controller supporting bidirectional voltage conversion while maintaining constant LED current during battery discharge. Use Value: Adjustable current sense threshold (1.24 V) and dual dimming modes allow seamless integration with DALI or 0–10 V control systems. |
Use Scenario: Low-profile architectural lighting modules with tight thermal constraints and need for smooth analog dimming down to 1%. IC Role / Device Role: Buck topology controller with high-side current sensing enabling compact layout and minimal EMI from floating LED strings. Use Value: CSH pin-based analog dimming achieves linear 100:1 dimming ratio without audible noise or color shift, verified in TI AN-1985. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar N-channel LED controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3429MHX/NOPB | Non-automotive grade; same pinout, specs, and PRO control architecture but lacks AEC-Q100 qualification and extended temperature validation. | Not suitable for safety-critical automotive systems; acceptable for commercial/industrial LED drivers with −40 °C to +125 °C ambient. | Select LM3429MHX/NOPB only when AEC-Q100 compliance is not required and cost optimization is prioritized. |
| TPS92692QPWPRQ1 | Integrated high-side current sense amplifier + gate driver; includes I2C interface, fault reporting, and programmable soft-start - no external COMP compensation needed. | Better suited for smart LED modules requiring diagnostics and digital control; higher BOM cost and larger footprint than LM3429Q1MHX/NOPB. | Choose TPS92692QPWPRQ1 when system-level monitoring, configurability, or reduced external component count outweighs discrete controller flexibility. |
Compared with LM3429MHX/NOPB, the LM3429Q1MHX/NOPB adds automotive-grade reliability and validated operation across −40 °C to +125 °C junction temperature, while TPS92692QPWPRQ1 trades external design freedom for integrated intelligence and diagnostics - making LM3429Q1MHX/NOPB optimal for cost-sensitive, high-reliability analog LED drivers.
Availability
LM3429Q1MHX/NOPB is available at Aetrix Electronics and suitable for automotive headlamps, industrial high-bay lighting, outdoor streetlights, and architectural accent lighting requiring stable component supply with long-term lifecycle assurance.
Supply support for LM3429Q1MHX/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 technologies, with decades of experience in automotive-grade IC development.
The LM3429Q1MHX/NOPB belongs to TI's LED lighting controller product line, designed specifically for high-reliability constant-current LED drivers in automotive and industrial environments where wide input range, thermal robustness, and topology flexibility are critical.
FAQ
What is the maximum input voltage supported by the LM3429Q1MHX/NOPB?
The LM3429Q1MHX/NOPB supports a continuous input voltage range from 4.5 V to 75 V, with absolute maximum rating of 76 V on the VIN pin. This wide range enables direct connection to 12 V, 24 V, and 48 V automotive and industrial DC buses without external pre-regulation, and accommodates load-dump transients common in automotive systems.
How does the LM3429Q1MHX/NOPB implement high-side LED current sensing?
The LM3429Q1MHX/NOPB uses differential HSP and HSN pins to sense voltage across an external LED-string sense resistor. Its internal transconductance amplifier forces VHSP = VHSN, regulating CSH current to 1.24 V. This allows accurate, ground-independent current measurement - essential for floating LED configurations in boost and SEPIC topologies.
Does the LM3429Q1MHX/NOPB support both analog and PWM dimming?
Yes, the LM3429Q1MHX/NOPB supports both dimming methods: analog dimming via current injection into the CSH pin (adjusting effective current sense threshold), and PWM dimming via the active-low nDIM pin. No external components are required for basic PWM dimming, while analog dimming offers smooth 100:1 range with proper external biasing.
What protection features are integrated into the LM3429Q1MHX/NOPB?
The LM3429Q1MHX/NOPB integrates overvoltage protection (OVP), input undervoltage lockout (UVLO), cycle-by-cycle current limiting (245 mV threshold), thermal shutdown (165 °C), and leading-edge blanking (75–450 ns). These features ensure robust operation in demanding environments without requiring external protection circuitry.
Is the LM3429Q1MHX/NOPB pin-compatible with the standard LM3429MHX/NOPB?
Yes, the LM3429Q1MHX/NOPB is fully pin-compatible and functionally identical to the LM3429MHX/NOPB, sharing the same 14-pin HTSSOP package, pinout, electrical specifications, and PRO control architecture. The Q1 variant adds AEC-Q100 Grade 1 qualification and extended temperature validation - no PCB or schematic changes are needed for upgrade.
LM3429Q1MHX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 14-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Controller
- Topology:
- SEPIC, Step-Down (Buck), Step-Up (Boost)
- Internal Switch(s):
- No
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 4.5V
- Voltage - Supply (Max):
- 75V
- Voltage - Output:
- -
- Current - Output / Channel:
- -
- Frequency:
- 2MHz
- Dimming:
- Analog, PWM
- Applications:
- -
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-HTSSOP
LM3429Q1MHX/NOPB FAQ
1.How can I place an order for LM3429Q1MHX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3429Q1MHX/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 LM3429Q1MHX/NOPB reliable?
The price and inventory of LM3429Q1MHX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3429Q1MHX/NOPB is usually 5 days.
3.What payment methods are accepted for LM3429Q1MHX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3429Q1MHX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3429Q1MHX/NOPB?
LM3429Q1MHX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3429Q1MHX/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 LM3429Q1MHX/NOPB?
For technical support, including LM3429Q1MHX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3429Q1MHX/NOPB requirements.
6.How does Aetrix verify that LM3429Q1MHX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3429Q1MHX/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 LM3429Q1MHX/NOPB meets industry standards.
7.What is the process for return or replacement of LM3429Q1MHX/NOPB?
All LM3429Q1MHX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3429Q1MHX/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 LM3429Q1MHX/NOPB part is unused and in its original packaging.
Return procedure for LM3429Q1MHX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3429Q1MHX/NOPB Tags
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