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Texas Instruments LM3421Q0MHX/NOPB
- Part No.:
- LM3421Q0MHX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 16-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM3421Q0MHX/NOPB.pdf
- Description:
- IC LED DRIVER CTRLR PWM 16HTSSOP
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LM3421Q0MHX/NOPB from Texas Instruments is an AEC-Q100 Grade 0 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, 2-Ω/1-A peak gate drive, and high-side adjustable current sensing with 1.24 V reference. It is used in automotive exterior lighting and industrial solid-state lighting systems requiring robust thermal performance up to +150°C junction temperature.
For engineers reviewing the LM3421Q0MHX/NOPB datasheet, LM3421Q0MHX/NOPB pinout, LM3421Q0MHX/NOPB application, or LM3421Q0MHX/NOPB equivalent, key selection criteria include its AEC-Q100 Grade 0 qualification, 75 V max VIN rating, PRO control architecture for stable loop compensation, high-side differential current sense capability, and compatibility with external N-channel main and dimming FETs in high-reliability LED driver designs.
Technical Context
The LM3421Q0MHX/NOPB implements Predictive Off-Time (PRO) control - a hybrid of peak current-mode regulation and input-voltage-proportional off-timer - enabling inherent input voltage feed-forward, cycle-by-cycle current limiting, and stable operation without sub-harmonic oscillation at any duty cycle. Its high-side transconductance amplifier (20 mA/V gM) senses LED current differentially across HSP/HSN with ±7 mV offset and 250–500 kHz bandwidth, referenced to a 1.24 V internal CSH threshold.
It integrates a 6.3–7.35 V internal start-up regulator (VCC), 2.4 V EN threshold with 0.245–2.85 MΩ pulldown resistance, and programmable OVP via 1.24 V threshold with 23 µA hysteresis current. Thermal shutdown activates at 165°C with 25°C hysteresis, and RCT pin sets switching frequency up to 2 MHz using external RC network.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 4.5 V to 75 V - supports wide-input LED drivers for 12 V/24 V/48 V automotive and industrial rails without pre-regulation. |
| CSH Reference Voltage | 1.21–1.26 V (typ 1.235 V) - sets high-side current sense threshold; enables precise LED current regulation via external RSNS. |
| GATE Drive Strength | 6 Ω source / 4.5 Ω sink (typ) - drives N-channel MOSFET gates directly with <35 ns rise/fall times for efficient high-frequency switching. |
| Switching Frequency | Up to 2 MHz - set by RCT pin RC network; enables compact magnetics and low-output-ripple LED solutions. |
| Junction Temperature Range | –40°C to +150°C - AEC-Q100 Grade 0 qualification ensures reliability in under-hood automotive environments. |
| OVP Threshold | 1.185–1.285 V with 23 µA hysteresis current - allows programmable overvoltage lockout via resistor divider on OVP pin. |
| EN Threshold | 2.4 V turn-on / 0.8 V turn-off with 0.1 V hysteresis - provides clean enable/disable control with integrated pulldown resistor. |
Pinout & Package
LM3421Q0MHX/NOPB is housed in a 16-pin HTSSOP (PWP) package measuring 5.00 mm × 4.40 mm with exposed thermal pad (DAP) for enhanced thermal dissipation. The DAP must be star-grounded to both AGND and PGND per TI layout guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VIN | Main input supply | Bypassed with 100 nF ceramic capacitor to AGND; powers internal regulator and high-voltage circuitry. |
| 2 EN | Enable control | Logic-level input with internal 0.245–2.85 MΩ pulldown; <0.8 V disables IC, >2.4 V enables operation. |
| 3 COMP | Error amplifier output | Connects to compensation network (capacitor to AGND); regulates CSH to 1.24 V for LED current control. |
| 4 CSH | Current sense high reference | Serves as 1.24 V reference node for high-side current sense amplifier; also supports analog dimming. |
| 5 RCT | Off-time timing | RC network sets predictive off-time and thus switching frequency; VIN/25 reference (565 mV @ VIN=14 V) aids design. |
| 6 AGND | Analog ground | Reference for CSH, COMP, RCT, OVP; connected to PGND via DAP copper pad for low-noise sensing. |
| 7 OVP | Overvoltage protection input | Resistor divider from output connects here; 1.24 V threshold triggers latch-off during overvoltage fault. |
| 8 nDIM | PWM dimming & UVLO input | Accepts PWM signal for LED dimming; also programs input UVLO via resistor divider (1.24 V threshold). |
| 9 VCC | Internal regulator output | 6.3–7.35 V regulated supply; bypassed with 2.2–3.3 µF ceramic capacitor to PGND for gate driver stability. |
| 10 GATE | Main MOSFET gate driver | 2-Ω source / 4.5-Ω sink peak drive; directly controls external N-channel switch in buck/boost/buck-boost topologies. |
| 11 PGND | Power ground | Return path for GATE and DDRV outputs; connected to AGND via DAP for thermal and noise integrity. |
| 12 DDRV | Dimming MOSFET gate driver | Drives external dimming FET (N- or P-channel); supports fast PWM dimming with dedicated gate drive. |
| 13 IS | Main switch current sense | Connects to MOSFET drain (RDS-ON sensing) or source-sense resistor for cycle-by-cycle current limiting. |
| 14 HSN | High-side sense negative | Low-side terminal of LED current sense resistor; forms differential pair with HSP for accurate high-side sensing. |
| 15 HSP | High-side sense positive | High-side terminal of LED current sense resistor; forces equal potential with HSN via feedback to regulate ILED. |
| 16 RPD | Resistor pulldown | Common return for all external resistor dividers (nDIM, OVP); enables zero-current shutdown when pulled low. |
Key Features
| Feature | Design Value |
|---|---|
| Predictive Off-Time (PRO) Control | Eliminates sub-harmonic oscillation at any duty cycle; simplifies loop compensation while delivering inherent input voltage feed-forward and cycle-by-cycle current limit. |
| High-Side Differential Current Sense | 1.24 V CSH reference with ±7 mV offset and 20 mA/V transconductance enables accurate LED current regulation independent of LED string voltage. |
| AEC-Q100 Grade 0 Qualification | Validated for –40°C to +150°C operation with full electrical test coverage; suitable for automotive front lighting, fog lamps, and DRL systems. |
| Integrated 2-Ω/1-A Gate Driver | Reduces external component count; supports fast MOSFET switching up to 2 MHz with minimal gate charge delay and low conduction loss. |
| Programmable UVLO & OVLO | nDIM and OVP pins accept resistor dividers with 1.24 V thresholds and 23 µA hysteresis current - enabling precise input/output protection tuning. |
Applications
| Automotive Exterior Lighting | Industrial Area Lighting |
|---|---|
|
Use Scenario: Driving high-brightness LED arrays in headlamps, fog lamps, and daytime running lights (DRL) on 12 V/24 V vehicle platforms with wide battery voltage swing. IC Role / Device Role / Timing Role: N-channel controller implementing boost topology with high-side current sensing to maintain constant LED current despite input ripple and thermal drift. Use Value: AEC-Q100 Grade 0 qualification and 150°C junction rating ensure functional safety compliance; PRO control delivers stable dimming response and EMI-controlled switching. |
Use Scenario: Powering multi-string LED luminaires in warehouse, street, and parking lot lighting where long cable runs cause significant input voltage drop. IC Role / Device Role / Timing Role: Buck-boost controller regulating constant current across 10–75 V input range, using high-side sensing to reject common-mode noise from shared ground paths. Use Value: 75 V VIN rating eliminates need for input pre-regulators; RCT-programmable frequency allows optimization for efficiency vs. size trade-offs in outdoor enclosures. |
| Architectural Accent Lighting | UV-C Disinfection Systems |
|
Use Scenario: Controlling color-tunable (RGB/RGBA) LED modules in hospitality and retail environments requiring smooth analog and PWM dimming. IC Role / Device Role / Timing Role: Dual-dimming controller using CSH for analog amplitude control and nDIM for synchronized PWM dimming with <1% flicker. Use Value: Independent dimming inputs and low-offset high-side sensing preserve color point accuracy across 100:1 dimming range. |
Use Scenario: Driving high-current UVC LEDs (265–285 nm) in portable sterilization devices where thermal management and current precision are critical. IC Role / Device Role / Timing Role: Constant-current buck controller with IS-based cycle-by-cycle limiting and thermal shutdown at 165°C to protect fragile UVC emitters. Use Value: Tight 1.24 V CSH reference and 25°C thermal hysteresis prevent thermal runaway; high-side sensing avoids ground-loop interference in isolated power stages. |
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 |
|---|---|---|---|
| LM3423Q0MHX/NOPB | 20-pin HTSSOP; adds LED output status flag (LRDY), fault status flag (FLT), and timer (TIMR) pins not present on LM3421Q0MHX/NOPB. | Required for designs needing real-time LED current regulation monitoring or fault latching with programmable timeout. | Select LM3423Q0MHX/NOPB only if LRDY/FLT/TIMR functionality is needed; otherwise LM3421Q0MHX/NOPB offers identical core control with smaller footprint. |
| LM3421MHX/NOPB | Same 16-pin HTSSOP package and pinout; commercial-grade (–40°C to +125°C), non-AEC-Q100 qualified; lacks Grade 0 thermal validation. | Suitable for non-automotive industrial or consumer lighting where extended temperature operation is not required. | Choose LM3421MHX/NOPB for cost-sensitive non-automotive applications; LM3421Q0MHX/NOPB is mandatory for AEC-Q100-compliant designs. |
Compared with LM3423Q0MHX/NOPB, LM3421Q0MHX/NOPB saves board space and BOM cost while retaining full PRO control, high-side sensing, and AEC-Q100 Grade 0 operation; compared with LM3421MHX/NOPB, it adds automotive-grade thermal robustness and qualification traceability without changing circuit design or layout.
Availability
LM3421Q0MHX/NOPB is available at Aetrix Electronics and suitable for automotive lighting, industrial area illumination, and UV-C disinfection systems requiring stable component supply, AEC-Q100 compliance, and high-voltage LED driver control.
Supply support for LM3421Q0MHX/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 company specializing in analog and embedded processing technologies, with leadership in power management, signal chain, and automotive electronics.
The LM342x family was designed specifically for high-reliability constant-current LED driver applications across automotive, industrial, and architectural lighting - emphasizing wide input range, predictive control, and AEC-Q100 qualification.
FAQ
What is the maximum input voltage supported by the LM3421Q0MHX/NOPB?
The LM3421Q0MHX/NOPB supports a maximum input voltage of 75 V, as specified in its absolute maximum ratings. This enables direct operation from 48 V industrial buses or 24 V automotive systems with transient tolerance. Operation above 75 V risks permanent damage, and the device includes input undervoltage lockout (UVLO) triggered at 1.24 V on the nDIM pin to prevent startup below 4.5 V.
Does the LM3421Q0MHX/NOPB support both analog and PWM dimming?
Yes, the LM3421Q0MHX/NOPB supports both dimming methods: analog dimming via the CSH pin (by injecting current to adjust the 1.24 V reference), and PWM dimming via the nDIM pin (accepting logic-level signals up to 2 MHz). The device's high-side current sense architecture preserves dimming linearity across 100:1 range without affecting color consistency in multi-channel LED systems.
What is the purpose of the RPD pin on the LM3421Q0MHX/NOPB?
The RPD (Resistor Pulldown) pin on the LM3421Q0MHX/NOPB serves as the common return node for all external resistor dividers - including those on nDIM (for UVLO) and OVP (for OVLO). When RPD is pulled low, it enables zero-current shutdown mode, reducing quiescent current to 0.1 µA. This feature simplifies system-level power sequencing and improves standby efficiency in always-on lighting applications.
How does the Predictive Off-Time (PRO) control in the LM3421Q0MHX/NOPB improve LED driver design?
The PRO control in the LM3421Q0MHX/NOPB combines peak current-mode regulation with an input-voltage-proportional off-timer, eliminating sub-harmonic oscillation at any duty cycle and reducing loop compensation complexity. This allows stable operation in boost and buck-boost topologies across wide input/output ranges, while delivering inherent input voltage feed-forward and precise cycle-by-cycle current limiting without external slope compensation.
Is the LM3421Q0MHX/NOPB pin-compatible with the standard LM3421MHX/NOPB?
Yes, the LM3421Q0MHX/NOPB is pin-compatible with the LM3421MHX/NOPB - both use the same 16-pin HTSSOP (PWP) package and identical pin functions. The Q0 variant adds AEC-Q100 Grade 0 qualification and extended temperature validation (–40°C to +150°C), but requires no PCB layout changes or schematic modifications when replacing the commercial-grade version in automotive or high-temperature industrial designs.
LM3421Q0MHX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-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:
- 3V ~ 72V
- Current - Output / Channel:
- -
- Frequency:
- 2MHz
- Dimming:
- Analog, PWM
- Applications:
- -
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-HTSSOP
LM3421Q0MHX/NOPB FAQ
1.How can I place an order for LM3421Q0MHX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3421Q0MHX/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 LM3421Q0MHX/NOPB reliable?
The price and inventory of LM3421Q0MHX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3421Q0MHX/NOPB is usually 5 days.
3.What payment methods are accepted for LM3421Q0MHX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3421Q0MHX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3421Q0MHX/NOPB?
LM3421Q0MHX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3421Q0MHX/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 LM3421Q0MHX/NOPB?
For technical support, including LM3421Q0MHX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3421Q0MHX/NOPB requirements.
6.How does Aetrix verify that LM3421Q0MHX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3421Q0MHX/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 LM3421Q0MHX/NOPB meets industry standards.
7.What is the process for return or replacement of LM3421Q0MHX/NOPB?
All LM3421Q0MHX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3421Q0MHX/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 LM3421Q0MHX/NOPB part is unused and in its original packaging.
Return procedure for LM3421Q0MHX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3421Q0MHX/NOPB Tags
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BCR402RE6327HTSA1
Infineon Technologies
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BCR430UXTSA2
Infineon Technologies
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BCR420UE6433HTMA1
Infineon Technologies
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BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
-
CL2N8-G
Microchip Technology
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BCR420UW6-7
Diodes Incorporated
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BCR421UW6-7
Diodes Incorporated
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BCR420UFD-7
Diodes Incorporated
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BCR421UFD-7
Diodes Incorporated
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