My Inquiry
My Account
Texas Instruments LM3432SQ/NOPB
- Part No.:
- LM3432SQ/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM3432SQ/NOPB.pdf
- Description:
- IC LED DRV RGLTR PWM 40MA 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,414
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3432SQ/NOPB from Texas Instruments is a 6-channel high-voltage LED current regulator for LCD backlighting, delivering ±2.0% current matching at 40 mA across all strings, supporting up to 80 V output voltage per channel, and enabling dynamic headroom control (DHC) with the LM3430 boost controller in automotive and industrial display systems.
For engineers reviewing the LM3432SQ/NOPB datasheet, LM3432SQ/NOPB pinout, LM3432SQ/NOPB application, or LM3432SQ/NOPB equivalent, this device is selected for precise multi-string LED current regulation, analog/PWM dimming interface flexibility, fault signaling to MCU, thermal monitoring, and DHC-enabled efficiency optimization in space-constrained WQFN-24 designs.
Technical Context
The LM3432SQ/NOPB integrates six independent current-sink channels with bandgap-referenced IREF-based programming (15–40 mA), fast 60 ns typical rise time, and phase-delayed PWM switching (0.5 µs inter-channel offset) to minimize input surge currents. It embeds a 5 V linear regulator (VCC) with UVLO (4.15 V rising threshold) and supports dual dimming modes via MODE pin configuration.
Its fault detection includes open-circuit indication (LM3432 only), short-circuit latching (7.9 V threshold, 150 µs delay), and over-temperature warning (125 °C trip, 20 °C hysteresis) with active-low open-drain FAULTb and OTMb outputs. DHC operation requires external CDHC capacitor and resistor-coupled VDHC connection to LM3430.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Channels | 6 independent current sinks, each adjustable 15–40 mA via RIREF resistor |
| Max Output Voltage | 80 V per IOUT pin - enables ≥12 white LEDs/string at 20 mA |
| Current Matching | ±2.0% at 40 mA - ensures uniform brightness across display zones |
| Rise Time | 60 ns typical - supports high-frequency PWM dimming without visible flicker |
| Dimming Ratio | Up to 4000:1 at 500 Hz - meets contrast requirements for premium LCD panels |
| Operating Temp | −40 °C to +125 °C junction - qualified for automotive cabin and industrial HMI environments |
| Package | WQFN-24 (5 mm × 4 mm × 0.8 mm) with exposed thermal pad - optimized for thermal dissipation in thin displays |
Pinout & Package
LM3432SQ/NOPB uses the thermally enhanced WQFN-24 package (5 mm × 4 mm × 0.8 mm) with exposed pad (EP) connected to PGND for thermal management. Pin count and layout match TI's LM3432/LM3432B family specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Supply input | 6–40 V DC input; withstands 42 V transients - powers internal regulator and bias circuits |
| VCC | Internal LDO output | Stable 5 V ±5% @ ≤2 mA load; requires ≥680 nF CVCC for stability |
| IREF | Current reference node | 1.245 V bandgap reference; sets string current via RIREF (e.g., 54.7 kΩ → 20 mA) |
| IOUT1–IOUT6 | Current sink outputs | Each drives one LED string; withstands 80 V; channels 5/6 disableable by grounding pre-power-up |
| MODE | Dimming mode select | Ground = digital PWM; capacitor-to-GND = analog dimming - configures internal modulator |
| DIM | Dimming control input | 0–5 V analog or 1.7 V min PWM HIGH - directly controls duty cycle of all six channels |
| FAULTb / OTMb | Fault indicator outputs | Open-drain, active-low signals to MCU - FAULTb reports LED short/open (LM3432 only); OTMb warns at 125 °C |
| VDHC / CDHC | DHC interface | VDHC outputs regulated voltage (0.625 V @ 20 mA); CDHC sets DHC loop response time via external capacitor |
| EN | Enable control | Active-HIGH logic; toggling resets latched faults - enables system-level power sequencing |
| AGND / PGND | Ground references | Separate analog and power grounds - minimizes noise coupling into current regulation path |
Key Features
| Feature | Design Value |
|---|---|
| Dynamic Headroom Control (DHC) | Reduces LED supply voltage to minimum required headroom (e.g., 0.625 V @ 20 mA), cutting boost converter losses by up to 30% in backlight systems |
| Dual Dimming Interface | Single DIM pin accepts either 0–3 V analog voltage or 500 Hz–20 kHz PWM - eliminates need for external dimming IC or DAC |
| String Current Matching | ±2.0% matching at full scale (40 mA) - eliminates manual calibration and enables consistent luminance across large-area displays |
| Fault Detection & Reporting | Dedicated FAULTb and OTMb pins provide immediate MCU notification of LED short, open (LM3432 only), or die overtemperature - supports fail-safe display behavior |
| Thermally Optimized Package | WQFN-24 with EP achieves θJA = 33.2 °C/W - sustains 6 × 40 mA operation at 85 °C ambient without derating in properly heatsinked layouts |
Applications
| Automotive Instrument Clusters | Industrial HMI Displays |
|---|---|
|
Use Scenario: High-brightness TFT-LCD cluster with 6 LED strings driving 12 white LEDs each under wide temperature (-40 °C to +85 °C) and vibration conditions. IC Role / Device Role / Timing Role: Primary current regulator providing matched 20 mA per string, synchronized dimming via CAN-linked MCU PWM signal, and real-time fault reporting during ignition cycles. Use Value: Eliminates brightness drift across gauges; enables automatic backlight dimming during night driving; prevents single-string failure from disabling entire cluster. |
Use Scenario: Ruggedized 10.4-inch HMI panel in factory automation cabinet, requiring 20,000-hour lifetime and immunity to EMI from nearby motor drives. IC Role / Device Role / Timing Role: Constant-current sink managing 6 parallel LED strings, using analog dimming (0–10 V input) for ambient light adaptation and DHC to reduce heat generation in sealed enclosure. Use Value: Maintains display readability across lighting conditions; extends LED life by minimizing excess forward voltage; reduces thermal stress on adjacent PLC components. |
| Medical Diagnostic Monitors | Avionics Display Units |
|
Use Scenario: DICOM-compliant grayscale monitor with strict luminance uniformity (ΔL* < 2) across 1920×1080 resolution and 1000:1 contrast ratio. IC Role / Device Role / Timing Role: Precision current source delivering ±2.0% matched 30 mA to each of six backlight zones, controlled via SPI-configured PWM generator for zone-specific dimming. Use Value: Meets clinical image fidelity standards; enables localized dimming for improved contrast without backlight bleed; supports FDA-required fault logging via FAULTb/OTMb. |
Use Scenario: DO-160G-compliant multifunction display (MFD) in commercial aircraft cockpit, operating from 28 VDC aircraft bus with stringent EMI and reliability requirements. IC Role / Device Role / Timing Role: LED driver implementing redundant fault signaling (FAULTb + OTMb) to flight control computer, with EN pin tied to avionics master power sequencer. Use Value: Ensures no single-point failure disables critical flight data; maintains display visibility during electrical transients; complies with RTCA DO-160 Section 20 radiated emissions limits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED current regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3432TME/NOPB | Same silicon, eHTSSOP-28 package (θJA = 29 °C/W); includes all LM3432 features including open-fault detection | Better thermal performance in high-power layouts; larger footprint suits through-hole prototyping or legacy PCBs | Select when higher continuous current per string (>35 mA) or board-level thermal relief is prioritized over size |
| TPS61165DRVR | Single-channel 40 V, 1.2 A boost LED driver with integrated MOSFET; no multi-string current matching or DHC | Requires external current-setting resistors per string; lacks FAULTb/OTMb reporting; no analog dimming support | Choose for cost-sensitive, low-channel-count designs where MCU handles fault aggregation and dimming logic |
Compared with LM3432TME/NOPB, LM3432SQ/NOPB trades thermal margin for compactness in space-constrained displays; versus TPS61165DRVR, it delivers guaranteed string matching and integrated fault signaling but requires external boost controller - making it optimal for high-reliability, multi-zone backlight systems.
Availability
LM3432SQ/NOPB is available at Aetrix Electronics and suitable for automotive instrument clusters, industrial HMI displays, medical diagnostic monitors, and avionics display units requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM3432SQ/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 expertise in automotive, industrial, and consumer power solutions.
The LM3432SQ/NOPB belongs to TI's LED backlight driver product line, engineered specifically for high-precision, multi-string current regulation in LCD and OLED display systems demanding uniform luminance, robust fault handling, and system-level efficiency optimization.
FAQ
What is the maximum LED string voltage supported by the LM3432SQ/NOPB?
The LM3432SQ/NOPB supports up to 80 V across each IOUT pin relative to PGND, enabling configurations with 12+ white LEDs per string at 20 mA. This rating is absolute maximum; recommended operating voltage is 0–80 V. Exceeding 80 V risks permanent damage. The device's 82 V absolute max IOUT rating provides margin against transient spikes, but sustained operation above 80 V violates specifications and voids warranty. LM3432SQ/NOPB must be used with appropriate clamping or filtering on the LED rail.
How does the LM3432SQ/NOPB implement Dynamic Headroom Control (DHC)?
The LM3432SQ/NOPB implements DHC by outputting a regulated voltage on the VDHC pin (0.625 V typical at 20 mA), which connects via an external gain-setting resistor to the VDHC pin of the LM3430 boost controller. This feedback lowers the LED supply voltage to the minimum needed for regulation, reducing power loss in the boost stage. CDHC capacitor sets loop response time. DHC is inactive if VDHC is left floating or if any IOUT is open (LM3432B only). LM3432SQ/NOPB requires proper CDHC sizing to avoid instability with the LM3430.
Does the LM3432SQ/NOPB support open-circuit fault detection?
No, the LM3432SQ/NOPB does not support open-circuit fault detection. That feature is exclusive to the LM3432 (e.g., LM3432TME/NOPB) and is explicitly omitted in the LM3432B variant, which includes LM3432SQ/NOPB. Only short-circuit (7.9 V threshold, 150 µs delay) and over-temperature (125 °C) faults trigger FAULTb assertion in LM3432SQ/NOPB. If open-fault reporting is required, LM3432TME/NOPB or LM3432EVAL board evaluation is recommended. LM3432SQ/NOPB remains fully functional for short-circuit protection in backlight systems where open faults are mitigated by design redundancy.
What external components are mandatory for basic LM3432SQ/NOPB operation?
Three external components are mandatory: (1) RIREF resistor (e.g., 54.7 kΩ for 20 mA) on IREF pin to set string current; (2) CVCC capacitor (≥680 nF ceramic) on VCC pin for LDO stability; and (3) CVIN capacitor (0.1–1 µF ceramic) on VIN pin to suppress supply noise and support transient current. Additional components - CDHC capacitor, MODE-to-GND jumper or CMODE capacitor, and VDHC-to-LM3430 resistor - are optional and enable DHC or analog dimming. All mandatory parts are specified in the LM3432SQ/NOPB datasheet Figure 17 schematic.
Can multiple LM3432SQ/NOPB outputs be paralleled to increase per-string current?
Yes, LM3432SQ/NOPB allows paralleling of IOUT pins (e.g., IOUT1 + IOUT2) to achieve >40 mA per string, as documented in TI's Application Report SLVA455A. However, current matching degrades - two paralleled channels yield ~±3.5% matching versus ±2.0% for single channels. Thermal coupling must be ensured, and the combined current must stay within total package power limits (θJA = 33.2 °C/W). For 60 mA strings, consider dedicated high-current drivers instead. LM3432SQ/NOPB supports this configuration but does not guarantee matched performance beyond its rated 40 mA per channel.
LM3432SQ/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 6
- Voltage - Supply (Min):
- 6V
- Voltage - Supply (Max):
- 40V
- Voltage - Output:
- 80V
- Current - Output / Channel:
- 40mA
- Frequency:
- -
- Dimming:
- Analog, PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-WQFN (4x5)
LM3432SQ/NOPB FAQ
1.How can I place an order for LM3432SQ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3432SQ/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 LM3432SQ/NOPB reliable?
The price and inventory of LM3432SQ/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3432SQ/NOPB is usually 5 days.
3.What payment methods are accepted for LM3432SQ/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3432SQ/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3432SQ/NOPB?
LM3432SQ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3432SQ/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 LM3432SQ/NOPB?
For technical support, including LM3432SQ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3432SQ/NOPB requirements.
6.How does Aetrix verify that LM3432SQ/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3432SQ/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 LM3432SQ/NOPB meets industry standards.
7.What is the process for return or replacement of LM3432SQ/NOPB?
All LM3432SQ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3432SQ/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 LM3432SQ/NOPB part is unused and in its original packaging.
Return procedure for LM3432SQ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3432SQ/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…
