My Inquiry
My Account
Texas Instruments LM3423Q1MH/NOPB
- Part No.:
- LM3423Q1MH/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 20-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM3423Q1MH/NOPB.pdf
- Description:
- IC LED DRIVER CTRLR PWM 20HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,711
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3423Q1MH/NOPB from Texas Instruments is a high-voltage N-channel MOSFET LED controller for constant-current regulation in 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 driver, high-side adjustable current sense (1.24 V threshold), and integrated fault status flag and timer. It is used in automotive LED headlamps and outdoor area lighting requiring robust overvoltage/thermal protection.
For engineers reviewing the LM3423Q1MH/NOPB datasheet, LM3423Q1MH/NOPB pinout, LM3423Q1MH/NOPB application, or LM3423Q1MH/NOPB equivalent, key selection considerations include its AEC-Q100 Grade 1 qualification (–40°C to +125°C), 20-pin HTSSOP package with thermal pad, programmable switching frequency up to 2 MHz, and dual dimming support (PWM + analog via CSH/nDIM).
Technical Context
The LM3423Q1MH/NOPB implements Predictive Off-Time (PRO) control - a hybrid of peak current-mode control and input-voltage-proportional off-timer - enabling stable loop compensation without external slope compensation and inherent input voltage feed-forward. Its high-side transconductance amplifier (20 mA/V gM) senses differential voltage across an external LED string resistor with 1.24 V reference, supporting tight ±1% LED current regulation.
It integrates two independent gate drivers: GATE (6 Ω source / 4.5 Ω sink) for the main N-channel switch and DDRV (30 Ω source / 10 Ω sink) for external dimming FETs. Fault management includes OVP (1.24 V threshold with 23 µA hysteresis current), thermal shutdown at 165°C (25°C hysteresis), and latched FLT output with programmable delay via TIMR capacitor.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 4.5 V to 75 V - supports wide-input industrial and automotive battery systems including 12 V, 24 V, and 48 V rails. |
| Switching Frequency | Up to 2 MHz - enables compact magnetics and low-profile designs using small inductors and ceramic capacitors. |
| Current Sense Threshold | 1.24 V (±3%) - sets LED current accuracy; combined with external RSNS, enables precise constant-current regulation. |
| GATE Driver Strength | 2 Ω sourcing / 4.5 Ω sinking - drives N-channel MOSFETs up to 1 A peak, minimizing switching losses in high-frequency operation. |
| OVP Threshold | 1.24 V with 23 µA hysteresis current - allows resistor-divider programming of output overvoltage lockout for LED open-circuit protection. |
| Thermal Shutdown | 165°C with 25°C hysteresis - prevents damage during sustained overload or poor heatsinking; automatic recovery after cooldown. |
| Operating Temperature | –40°C to +125°C - qualified per AEC-Q100 Grade 1, suitable for under-hood automotive LED driver applications. |
Pinout & Package
LM3423Q1MH/NOPB is housed in a thermally enhanced 20-pin HTSSOP (PWP) package (6.50 mm × 4.40 mm) with exposed thermal pad (DAP) for star-ground connection between AGND and PGND.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VIN | Main input supply | Bypassed with 100 nF ceramic capacitor to AGND; powers internal start-up regulator and high-voltage circuitry. |
| 2 EN | Enable input | Logic-level enable with 2.4 V turn-on threshold; internal 0.245–2.85 MΩ pulldown enables zero-current shutdown when grounded. |
| 3 COMP | Error amplifier output | Connects to RC compensation network to AGND; sets loop stability for current regulation feedback path. |
| 4 CSH | Current sense high reference | Regulated at 1.24 V; sinks current proportional to LED string voltage drop across RSNS for analog dimming and regulation. |
| 5 RCT | Predictive off-time timing | RC network sets switching frequency; internal VIN/25 reference (565 mV @ VIN=14 V) defines off-time duration. |
| 6 AGND | Analog ground reference | Star-ground node for sensitive analog circuits (COMP, CSH, RCT, TIMR); connected to PGND via DAP copper. |
| 7 OVP | Output overvoltage sense | Resistor divider from LED output to AGND programs OVLO; 1.24 V threshold with 23 µA hysteresis current. |
| 8 nDIM | PWM dimming input / UVLO | Accepts PWM signal for fast LED dimming; also configures input undervoltage lockout via resistor divider from VIN. |
| 9 VCC | Internal LDO output | 7.35 V regulated supply (6.3–7.35 V); bypassed with 2.2–3.3 µF ceramic cap to PGND for gate driver stability. |
| 10 TIMR | Fault timer timing | Capacitor to AGND sets delay before fault latch; only present on LM3423/LM3423-Q1 (not LM3421). |
| 11 GATE | Main MOSFET gate driver | 2 Ω source / 4.5 Ω sink drive capability; directly controls high-side or low-side N-channel switch in any topology. |
| 12 PGND | Power ground return | High-current return path for GATE and DDRV outputs; connected to AGND via DAP for EMI and thermal performance. |
| 13 DDRV | Dimming FET gate driver | 30 Ω source / 10 Ω sink; drives external series N- or P-channel dimming MOSFET for PWM intensity control. |
| 14 IS | Main switch current sense | Connects to MOSFET drain (RDS-ON sensing) or source-sense resistor for cycle-by-cycle current limiting. |
| 15 HSP | High-side sense positive | Differential input to high-side transconductance amplifier; tied to LED+ side of current sense resistor RSNS. |
| 16 HSN | High-side sense negative | Differential input to high-side transconductance amplifier; tied to LED− side of RSNS; enables floating LED string. |
| 17 RPD | Resistor pulldown | Common return for all external resistor dividers (nDIM, OVP); enables zero-current shutdown when pulled low. |
| 18 FLT | Fault status flag | Open-drain output pulled high by external resistor; asserts low on latched fault (OVP, thermal, timer timeout). |
| 19 LRDY | LED ready flag | Open-drain output pulled high externally; pulls low when LED current is out of regulation (e.g., open-circuit). |
| 20 Thermal PAD (DAP) | Thermal and ground plane | Exposed copper pad on bottom; must be soldered to PCB thermal plane and star-grounded to AGND/PGND. |
Key Features
| Feature | Design Value |
|---|---|
| Predictive Off-Time (PRO) Control | Eliminates subharmonic oscillation at >50% duty cycles; enables stable operation in boost/buck-boost without slope compensation. |
| High-Side Differential Current Sense | Supports floating LED strings with 1.24 V reference and 20 mA/V transconductance; minimizes power loss vs. low-side sensing. |
| Dual Dimming Interface | Hardware PWM on nDIM pin + analog dimming via CSH voltage modulation - enables smooth 1000:1 dimming ratio. |
| AEC-Q100 Grade 1 Qualification | Validated for automotive use from –40°C to +125°C junction temperature; includes fault flag (FLT), timer (TIMR), and LRDY outputs. |
| Integrated Protection Suite | Input UVLO, output OVP, cycle-by-cycle current limit, thermal shutdown, and zero-current shutdown reduce external component count. |
Applications
| Automotive Headlamp Drivers | Outdoor Area Lighting |
|---|---|
|
Use Scenario: High-brightness LED arrays in vehicle headlamps requiring adaptive beam control and thermal derating. IC Role / Device Role / Timing Role: Constant-current controller managing buck-boost topology to maintain 1.5 A LED current across 9–16 V battery range. Use Value: PRO control ensures stable regulation during cold cranking (6.5 V) and load dump (36 V); FLT and LRDY flags enable ASIL-B diagnostic coverage. |
Use Scenario: Streetlight LED drivers operating in harsh ambient conditions with wide temperature swings and lightning-induced surges. IC Role / Device Role / Timing Role: Boost controller regulating 700 mA through 12-series white LEDs with 36–57 V output range. Use Value: 75 V absolute max VIN rating and OVP protection prevent failure during surge events; thermal shutdown protects against enclosure overheating. |
| Industrial Machine Vision Lighting | Architectural Accent Lighting |
|
Use Scenario: High-CRI, flicker-free illumination for automated optical inspection systems requiring precise intensity repeatability. IC Role / Device Role / Timing Role: Buck-boost controller with analog dimming via CSH for 0–10 V interface and PWM for strobing. Use Value: 1.24 V current sense reference and <±1% regulation accuracy ensure consistent light output across production units. |
Use Scenario: RGBW LED modules in façade lighting where color mixing requires independent current control per channel. IC Role / Device Role / Timing Role: Constant-current controller in SEPIC configuration to decouple input (24 V DC) from variable LED string voltage (12–42 V). Use Value: High-side sensing allows common-anode RGBW architecture; RPD pin simplifies shared UVLO/OVP divider networks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3423MH/NOPB | Commercial-grade version (–40°C to +125°C), no FLT/TIMR pins; identical pinout and electrical specs except AEC-Q100 qualification. | Lacks fault flag and timer functions; not suitable for automotive safety-critical diagnostics. | Select LM3423MH/NOPB for cost-sensitive industrial lighting where AEC-Q100 and fault reporting are unnecessary. |
| LM3423Q0MH/NOPB | AEC-Q100 Grade 0 (–40°C to +150°C), same pinout and feature set; differs only in extended temperature qualification and screening. | Validated for under-hood engine bay placement; supports higher ambient thermal design limits. | Choose LM3423Q0MH/NOPB when operating junction temperature exceeds 125°C or full Grade 0 compliance is mandated. |
Compared with LM3423MH/NOPB, the LM3423Q1MH/NOPB adds fault diagnostics and automotive qualification; compared with LM3423Q0MH/NOPB, it trades maximum junction temperature (125°C vs. 150°C) for lower cost and broader availability in Grade 1 applications.
Availability
LM3423Q1MH/NOPB is available at Aetrix Electronics and suitable for automotive lighting, outdoor area lighting, and industrial machine vision applications requiring stable component supply, AEC-Q100 compliance, and long-term lifecycle support.
Supply support for LM3423Q1MH/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 ICs with decades of automotive and industrial qualification expertise.
The LM342x family was designed specifically for high-reliability constant-current LED driver applications across buck, boost, buck-boost, and SEPIC topologies - emphasizing wide input range, predictive control, and integrated protection.
FAQ
What is the primary function of the LM3423Q1MH/NOPB in an LED driver system?
The LM3423Q1MH/NOPB serves as a high-voltage N-channel MOSFET controller that regulates constant LED current in buck, boost, buck-boost, and SEPIC topologies. It uses predictive off-time (PRO) control and high-side current sensing to achieve tight current regulation across wide input (4.5–75 V) and temperature (–40°C to +125°C) ranges. The LM3423Q1MH/NOPB does not integrate power switches but drives external MOSFETs with its GATE and DDRV outputs.
How does the LM3423Q1MH/NOPB implement analog dimming?
The LM3423Q1MH/NOPB implements analog dimming by modulating the voltage at the CSH pin, which is internally regulated to 1.24 V. When an external current source or potentiometer is connected between CSH and AGND, it alters the signal current (ICSH) flowing through the high-side sense amplifier, thereby adjusting the effective current sense threshold and reducing average LED current proportionally. This method enables smooth, low-noise dimming without PWM frequency artifacts.
What protection features are integrated into the LM3423Q1MH/NOPB?
The LM3423Q1MH/NOPB integrates input undervoltage lockout (UVLO), output overvoltage protection (OVP), cycle-by-cycle current limiting, thermal shutdown (165°C with 25°C hysteresis), and zero-current shutdown. It also provides fault status flag (FLT) and LED ready flag (LRDY) outputs, plus a programmable fault timer (TIMR) - all essential for automotive-grade reliability and diagnostics in the LM3423Q1MH/NOPB.
Can the LM3423Q1MH/NOPB be used in a buck topology with a high-side switch?
Yes - the LM3423Q1MH/NOPB supports buck topology with a high-side N-channel switch by leveraging its high-side current sense inputs (HSP/HSN) and PRO control architecture. The controller regulates LED current regardless of switch position; the high-side sensing allows the LED string to float relative to ground, making it compatible with both high-side and low-side switch configurations in buck, boost, and buck-boost topologies using the LM3423Q1MH/NOPB.
What is the purpose of the RPD pin on the LM3423Q1MH/NOPB?
The RPD (Resistor Pulldown) pin on the LM3423Q1MH/NOPB serves as the common low-side connection point for all external resistor dividers - including those for nDIM (UVLO) and OVP. When RPD is pulled low, it disables all referenced divider networks, enabling zero-current shutdown mode. This feature simplifies system-level power sequencing and reduces quiescent current to 1 µA in standby, a key capability of the LM3423Q1MH/NOPB for automotive always-on applications.
LM3423Q1MH/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 20-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:
- 20-HTSSOP
LM3423Q1MH/NOPB FAQ
1.How can I place an order for LM3423Q1MH/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3423Q1MH/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 LM3423Q1MH/NOPB reliable?
The price and inventory of LM3423Q1MH/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3423Q1MH/NOPB is usually 5 days.
3.What payment methods are accepted for LM3423Q1MH/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3423Q1MH/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3423Q1MH/NOPB?
LM3423Q1MH/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3423Q1MH/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 LM3423Q1MH/NOPB?
For technical support, including LM3423Q1MH/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3423Q1MH/NOPB requirements.
6.How does Aetrix verify that LM3423Q1MH/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3423Q1MH/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 LM3423Q1MH/NOPB meets industry standards.
7.What is the process for return or replacement of LM3423Q1MH/NOPB?
All LM3423Q1MH/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3423Q1MH/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 LM3423Q1MH/NOPB part is unused and in its original packaging.
Return procedure for LM3423Q1MH/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3423Q1MH/NOPB Tags
-
BCR402RE6327HTSA1
Infineon Technologies
-
BCR430UXTSA2
Infineon Technologies
-
BCR420UE6433HTMA1
Infineon Technologies
-
BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
-
CL2N8-G
Microchip Technology
-
BCR420UW6-7
Diodes Incorporated
-
BCR421UW6-7
Diodes Incorporated
-
BCR420UFD-7
Diodes Incorporated
-
BCR421UFD-7
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
