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Texas Instruments LM3429Q1MH/NOPB
- Part No.:
- LM3429Q1MH/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 14-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM3429Q1MH/NOPB.pdf
- Description:
- IC LED DRIVER CTRLR PWM 14HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,701
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Product details
Overview
LM3429Q1MH/NOPB from Texas Instruments is an AEC-Q100 Grade 1 qualified 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 reference, and delivers up to 1-A peak gate drive for external NFETs in automotive lighting systems.
For engineers reviewing the LM3429Q1MH/NOPB datasheet, LM3429Q1MH/NOPB pinout, LM3429Q1MH/NOPB application, or LM3429Q1MH/NOPB equivalent, key selection considerations include its 75-V input rating, programmable switching frequency up to 2 MHz, cycle-by-cycle current limit at 245 mV, thermal shutdown at 165°C, and compatibility with high-side LED current sense configurations using HSP/HSN pins.
Technical Context
The LM3429Q1MH/NOPB implements Predictive Off-Time (PRO) control-a hybrid of peak current-mode regulation and VIN-proportional off-timer-to eliminate subharmonic oscillation and enable stable operation at any duty cycle. Its high-side transconductance amplifier (20–119 mA/V) forces equal potential at HSP/HSN to regulate LED current via external RSNS, while the CSH pin maintains 1.235 V reference for analog dimming.
Internal circuitry includes a 6.9-V LDO startup regulator (27-mA current limit), 2-Ω sourcing / 4.5-Ω sinking gate driver, and dual protection logic: OVP threshold at 1.24 V (20 µA hysteresis source), nDIM UVLO at 1.24 V (20 µA hysteresis), and leading-edge blanking (75–450 ns) on IS pin for robust current-limit response.
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. |
| Current Sense Reference | 1.235 V (±2.5 mV) at CSH - enables precise LED current regulation with <0.5% typical error over temperature. |
| Gate Drive Strength | 2 Ω sourcing / 4.5 Ω sinking - drives 1-nF gate capacitance with <100-ns rise/fall times for efficient high-frequency switching. |
| Switching Frequency | Up to 2 MHz - set by RCT pin timing network; VIN-proportional off-time ensures stable frequency in boost/buck-boost topologies. |
| Thermal Shutdown | 165°C with 25°C hysteresis - protects against sustained overload or poor PCB thermal design in enclosed automotive housings. |
| OVP Threshold | 1.24 V ±60 mV at OVP pin - triggers lockout when output exceeds safe level; 20 µA hysteresis current enables clean recovery. |
| IS Current Limit | 245 mV ±30 mV - terminates switch-on cycle within 75 ns to prevent MOSFET overstress during fault conditions. |
Pinout & Package
LM3429Q1MH/NOPB uses a thermally enhanced 14-lead HTSSOP package (5.00 mm × 4.40 mm) with exposed DAP pad soldered to AGND/PGND for low-thermal-resistance PCB mounting (RθJA = 47.8°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VIN | Input voltage supply | High-voltage input rail (4.5–75 V); bypass with 100-nF ceramic capacitor close to pin for stability. |
| 2 COMP | Error amplifier output | Compensation node for loop stability; connect RC network to AGND to set dominant pole and phase margin. |
| 3 CSH | Current sense high reference | 1.235-V regulated node for analog dimming; sources/sinks current to adjust LED current setpoint. |
| 4 RCT | Timing network input | Accepts resistor-to-switch-node + capacitor-to-AGND to program off-time and switching frequency. |
| 5 AGND | Analog ground reference | Low-noise return for CSH, COMP, RCT; must be isolated from PGND except at single-point DAP connection. |
| 6 OVP | Overvoltage protection input | Monitor output voltage via resistor divider; trips at 1.24 V with 20-µA hysteresis current for clean reset. |
| 7 nDIM | Inverted PWM dim enable | Active-low dim control; also programs UVLO threshold (1.24 V) when used as undervoltage lockout input. |
| 8 NC | No connection | Unbonded pin; must remain unconnected and floating per TI design guidelines. |
| 9 PGND | Power ground return | High-current return path for GATE driver and IS sense; connect directly to DAP thermal pad. |
| 10 GATE | NFET gate drive output | Drives external N-channel MOSFET gate; 1-A peak capability supports fast turn-on/turn-off at 2-MHz switching. |
| 11 VCC | Internal LDO output | 6.9-V regulated supply for internal circuitry; bypass with 2.2–3.3-µF ceramic capacitor to PGND. |
| 12 IS | Main switch current sense | Connects to MOSFET source or RDS(on) for cycle-by-cycle current limiting; 245-mV threshold with 75-ns response. |
| 13 HSP | LED current sense positive | High-side sense input; forms differential pair with HSN to reject common-mode noise in LED string monitoring. |
| 14 HSN | LED current sense negative | High-side sense input; requires matched series resistor (RHSN = RHSP) to cancel input bias current error. |
| DAP | Thermal pad | Exposed copper pad on bottom; must be soldered to solid AGND/PGND plane for thermal dissipation and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Predictive Off-Time (PRO) Control | Eliminates subharmonic oscillation at all duty cycles; enables stable high-ratio boost conversion without slope compensation. |
| High-Side Differential Current Sensing | HSP/HSN inputs support floating LED strings with >80-dB CMRR; eliminates ground-referenced shunt limitations in automotive systems. |
| Integrated 6.9-V Startup Regulator | Operates directly from 4.5–75 V input; delivers 27 mA to power internal circuitry-no external bias supply required. |
| Programmable Analog & PWM Dimming | CSH pin enables 0–100% analog dimming via current injection; nDIM pin accepts standard 100–500-Hz PWM signals without external logic. |
| AEC-Q100 Grade 1 Qualification | Rated for −40°C to +125°C junction operation; validated for automotive front/rear lighting, headlamps, and DRL modules. |
Applications
| Automotive Headlamp Drivers | Industrial High-Bay LED Lighting |
|---|---|
|
Use Scenario: Constant-current driver for multi-string white LED arrays in adaptive front-lighting systems (AFS), operating from 9–16 V battery with load dump tolerance. IC Role / Device Role / Timing Role: N-channel controller implementing boost topology with PRO control; regulates LED current via HSP/HSN sensing while synchronizing dimming commands from vehicle CAN bus. Use Value: Enables precise 1% current matching across LED strings under wide input voltage swings and ambient temperature shifts (−40°C to 125°C). |
Use Scenario: High-efficiency buck-boost driver powering 48-V LED fixtures in warehouse lighting, powered from 24–72 V DC distribution rails. IC Role / Device Role / Timing Role: Controller managing external MOSFETs in buck-boost configuration; uses RCT timing to maintain 1.2-MHz switching for compact magnetics and low EMI. Use Value: Delivers >94% efficiency at full load across 24–72 V input range, reducing thermal stress and enabling fanless fixture designs. |
| Outdoor Streetlight Power Supplies | Commercial Signage Backlighting |
|
Use Scenario: Outdoor-rated LED driver for smart streetlights with 0–10 V dimming interface and surge protection up to 6 kV. IC Role / Device Role / Timing Role: Core controller in SEPIC topology accepting wide AC-DC rectified input (30–100 VDC); implements OVP and thermal shutdown for field reliability. Use Value: Survives repeated lightning-induced transients via robust 75-V absolute max rating and integrated 20-µA OVP hysteresis recovery. |
Use Scenario: Slim-profile backlight driver for retail signage, requiring flicker-free dimming and tight current uniformity across parallel LED zones. IC Role / Device Role / Timing Role: High-side sensing controller in buck configuration; uses CSH-based analog dimming for smooth 0.1–100% brightness control without PWM artifacts. Use Value: Achieves <±1.5% LED current variation between zones using matched RHSP/RHSN resistors and low-offset transconductance amplifier. |
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 |
|---|---|---|---|
| LM3424Q1MH/NOPB | Fixed 200-kHz frequency; no RCT programmability; lower gate drive (0.5-A peak); lacks high-side sense (CSH only) | Targeted for simpler, cost-sensitive automotive tail-light drivers where fixed frequency suffices | Select when board space and BOM count are prioritized over topology flexibility and dimming precision |
| TPS92692QPWPRQ1 | Integrated 1.5-A gate driver; current-mode control with external ramp; supports I²C dimming; higher quiescent current (3.5 mA) | Designed for high-end adaptive driving beam (ADB) systems requiring digital control and diagnostics | Select when system-level communication, fault reporting, or tighter current accuracy (<0.3%) is required |
Compared with LM3429Q1MH/NOPB, LM3424Q1MH/NOPB trades programmability and high-side sensing for lower cost and smaller footprint, while TPS92692QPWPRQ1 adds digital interface and diagnostics at the expense of higher complexity and power consumption-making LM3429Q1MH/NOPB optimal for analog-controlled, topology-flexible automotive LED drivers.
Availability
LM3429Q1MH/NOPB is available at Aetrix Electronics and suitable for automotive lighting, industrial high-bay fixtures, outdoor streetlight power supplies, and commercial signage backlighting requiring stable component supply across extended temperature and voltage ranges.
Supply support for LM3429Q1MH/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 delivering analog, embedded processing, and connectivity solutions with focus on reliability, efficiency, and system integration.
LM3429Q1MH/NOPB belongs to TI's automotive-grade LED controller product line, engineered specifically for AEC-Q100-compliant constant-current LED drivers in safety-critical exterior lighting applications.
FAQ
What topology configurations does the LM3429Q1MH/NOPB support?
The LM3429Q1MH/NOPB supports buck, boost, buck-boost, and SEPIC topologies through external MOSFET and passive component selection. Its PRO control architecture and high-side current sensing make it especially effective in boost and buck-boost configurations for automotive LED drivers. The LM3429Q1MH/NOPB does not require topology-specific IC variants-designers configure operation via RCT timing, feedback network, and layout.
How is analog dimming implemented on the LM3429Q1MH/NOPB?
Analog dimming on the LM3429Q1MH/NOPB is achieved by injecting or sinking current at the CSH pin, which adjusts the effective current-sense reference voltage and thereby modulates LED current. A 100-µA signal current is recommended for optimal noise immunity and accuracy. The LM3429Q1MH/NOPB supports both potentiometer-based and active current-source methods, with Figure 16 in the datasheet showing verified implementation circuits.
Does the LM3429Q1MH/NOPB require an external bootstrap capacitor?
No, the LM3429Q1MH/NOPB does not require an external bootstrap capacitor because it drives only the gate of a low-side N-channel MOSFET. Its GATE output is referenced to PGND and provides 1-A peak sourcing/sinking capability directly. This eliminates bootstrapping complexity and improves reliability in high-duty-cycle or high-frequency LED driver designs using the LM3429Q1MH/NOPB.
What is the purpose of the DAP thermal pad on the LM3429Q1MH/NOPB package?
The DAP (Die Attach Pad) on the LM3429Q1MH/NOPB is an exposed copper thermal pad on the underside of the HTSSOP package. It must be soldered to a dedicated AGND/PGND copper plane to provide low-thermal-resistance heat transfer-critical for maintaining ≤125°C junction temperature under continuous 1-A gate drive loads. TI specifies RθJB = 22.3°C/W when DAP is properly connected, directly impacting long-term reliability in automotive environments.
Can the LM3429Q1MH/NOPB be used in non-automotive applications?
Yes, the LM3429Q1MH/NOPB is fully functional in industrial and commercial LED driver applications, including high-bay lighting, streetlights, and signage. Its 4.5–75 V input range, 125°C max junction temperature, and robust protection features (OVP, UVLO, thermal shutdown) make it suitable beyond automotive use. However, the "Q1" suffix denotes AEC-Q100 qualification-non-automotive users benefit from this enhanced reliability without paying a premium for automotive-specific testing documentation.
LM3429Q1MH/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 14-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- 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
LM3429Q1MH/NOPB FAQ
1.How can I place an order for LM3429Q1MH/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3429Q1MH/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 LM3429Q1MH/NOPB reliable?
The price and inventory of LM3429Q1MH/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3429Q1MH/NOPB is usually 5 days.
3.What payment methods are accepted for LM3429Q1MH/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3429Q1MH/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3429Q1MH/NOPB?
LM3429Q1MH/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3429Q1MH/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 LM3429Q1MH/NOPB?
For technical support, including LM3429Q1MH/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3429Q1MH/NOPB requirements.
6.How does Aetrix verify that LM3429Q1MH/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3429Q1MH/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 LM3429Q1MH/NOPB meets industry standards.
7.What is the process for return or replacement of LM3429Q1MH/NOPB?
All LM3429Q1MH/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3429Q1MH/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 LM3429Q1MH/NOPB part is unused and in its original packaging.
Return procedure for LM3429Q1MH/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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