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Texas Instruments LM3432MH/NOPB
- Part No.:
- LM3432MH/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 28-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM3432MH/NOPB.pdf
- Description:
- IC LED DRVR RGLTR PWM 28HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,549
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Product details
Overview
LM3432MH/NOPB from Texas Instruments is a 6-channel high-voltage LED current regulator for LCD backlighting, delivering ±2.0% current matching at 40 mA, 80 V max IOUT voltage rating, and 60 ns typical current rise time. It supports both digital PWM and analog dimming control with up to 4000:1 dimming ratio at 500 Hz, and integrates Dynamic Headroom Control (DHC) for efficiency optimization in conjunction with the LM3430 boost controller.
For engineers reviewing the LM3432MH/NOPB datasheet, LM3432MH/NOPB pinout, LM3432MH/NOPB application, or LM3432MH/NOPB equivalent, key selection considerations include its WQFN-24 (5×4×0.8 mm) thermally enhanced package, 15–40 mA programmable per-string current via external IREF resistor, fault signaling (LED short/over-temperature), and compatibility with TI's DHC-enabled LED power architectures.
Technical Context
The LM3432MH/NOPB implements six independent current-sink channels with bandgap-referenced regulation, where output current is set by an external resistor on the IREF pin (VIREF = 1.245 V typical). Each channel operates with dropout voltage as low as 0.3 V at 20 mA and withstands up to 80 V across IOUT pins.
It features dual dimming modes: MODE pin grounded enables direct PWM input on DIM (1.7 V logic-high threshold); MODE pin capacitor-coupled enables analog voltage-controlled PWM generation (1–3 V linear range). Fault detection includes open-circuit indication (LM3432 only), LED short detection (7.9 V threshold, 150 µs delay), and over-temperature warning (125 °C trip, 20 °C hysteresis).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Channels | 6 independent current sinks, each adjustable 15–40 mA via RIREF |
| Current Matching | ±2.0% at 40 mA - ensures uniform brightness across LED strings |
| Max IOUT Voltage | 80 V - supports ≥12 white LEDs per string at typical forward voltage |
| Rise Time (tr) | 60 ns typical - enables clean, high-frequency PWM dimming without ghosting |
| Dimming Ratio | Up to 4000:1 at 500 Hz - meets high-contrast display requirements |
| DHC Output | VDHC regulates to 0.625 V at 20 mA - minimizes headroom loss when paired with LM3430 |
| Operating Temp | −40 °C to +125 °C junction - suitable for industrial and automotive display environments |
Pinout & Package
LM3432MH/NOPB is housed in a thermally enhanced 24-lead WQFN package (5 mm × 4 mm × 0.8 mm) with exposed thermal pad (EP) connected to PGND. Pin count and layout match the LM3432B variant; the /NOPB suffix denotes lead-free, RoHS-compliant packaging.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC | Internal 5 V LDO output | Supplies internal circuitry; requires ≥680 nF CVCC for stability |
| IREF | Current setting reference | 1.245 V bandgap reference; RIREF sets IOUT per string (IOUT ≈ 1.094/RIREF mA) |
| AGND | Analog ground reference | Separate from PGND to minimize noise coupling into current regulation loop |
| CDHC | DHC time constant capacitor | External capacitor to ground sets DHC response speed; prevents interference with LM3430 loop |
| VDHC | DHC voltage output | Drives LM3430 DHC pin to dynamically lower VLED supply voltage and maximize efficiency |
| EN | Enable control | Active-HIGH logic; toggling resets latched faults (short/open/thermal) |
| MODE | Dimming mode select | GND = digital PWM; capacitor-to-GND = analog dimming (1–3 V linear control) |
| DIM | Dimming signal input | Accepts 0–5 V analog voltage or 1.7 V min PWM logic; controls all 6 channels synchronously |
| FAULTb | Open-drain fault flag | Active-LOW indicates LED short or (LM3432 only) open fault; pulls to GND under fault condition |
| OTMb | Open-drain over-temp flag | Active-LOW at 125 °C; device continues operating until 165 °C shutdown |
| IOUT1–IOUT6 | Current sink outputs | Each drives one LED string; pins 5/6 can be grounded pre-power-up to disable channels |
| VIN | Main supply input | 6–40 V DC input; transient-rated to 42 V; powers internal LDO and bias circuits |
| PGND | Power ground return | High-current return path for IOUT sinks; separate from AGND for noise isolation |
Key Features
| Feature | Design Value |
|---|---|
| Dynamic Headroom Control (DHC) | Reduces VLED supply voltage to minimum required headroom (0.625 V @ 20 mA), cutting system power loss by >15% vs fixed-rail designs |
| String Current Programmability | Single external resistor (RIREF) sets identical current across all 6 strings - eliminates per-channel calibration |
| Dual Dimming Interface | Hardware-selectable mode (MODE pin) supports either MCU-generated PWM or analog DAC output - simplifies system-level integration |
| Fault Diagnostics | Dedicated FAULTb and OTMb pins provide immediate, latched status to host MCU - enables real-time display health monitoring |
| Thermal Robustness | 150 °C max junction rating + 20 °C hysteresis on thermal shutdown - sustains operation in compact, sealed display enclosures |
Applications
| LCD Panel Backlighting | Industrial HMI Displays |
|---|---|
Use Scenario: Driving 6 parallel LED strings (e.g., 12 white LEDs/string) in a 10.4″–15.6″ TFT-LCD panel with uniform brightness and minimal thermal gradient. IC Role / Device Role / Timing Role: 6-channel current sink regulating per-string current; DHC interface coordinates with LM3430 to dynamically adjust VLED rail voltage. Use Value: Achieves <±2% luminance uniformity across full viewing angle while reducing total backlight power consumption by ~18% versus fixed-headroom solutions. |
Use Scenario: Illuminating ruggedized operator interface displays in factory automation panels exposed to −40 °C to +85 °C ambient. IC Role / Device Role / Timing Role: High-voltage current regulator enabling long LED strings (≥10 LEDs) without external MOSFETs; integrated thermal warning supports predictive maintenance. Use Value: Eliminates need for discrete current-setting components and thermal sensors - reduces BOM count by 7 parts per display while meeting IEC 61000-4 immunity requirements. |
| Medical Diagnostic Monitors | Avionics Display Systems |
Use Scenario: Backlighting high-resolution grayscale imaging displays requiring precise dimming linearity and zero flicker during image capture. IC Role / Device Role / Timing Role: Analog dimming mode provides smooth 1–3 V DC control of PWM duty cycle; 60 ns tr ensures no visible artifacts during rapid brightness transitions. Use Value: Delivers 4000:1 dimming range with <0.5% gamma deviation - satisfies DICOM Part 14 grayscale standard for clinical image fidelity. |
Use Scenario: Powering multi-zone cockpit displays with redundant fault reporting and extended temperature operation. IC Role / Device Role / Timing Role: Dual fault flags (FAULTb + OTMb) feed independent monitoring paths; EN pin allows controlled reset without full power cycle. Use Value: Supports DO-160E Section 22 thermal shock compliance and enables fail-operational behavior during single-point faults. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED current regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3432MM/NOPB | Same silicon, eHTSSOP-28 package (9.7×6.4×1.1 mm); higher θJA (29 °C/W vs 33.2 °C/W) | Better PCB heat spreading via larger thermal pad; requires more board area and different footprint | Select when thermal margin is constrained and board space permits larger package |
| TPS61165DRVR | Single-channel, integrated boost+current-regulator IC; no DHC interface; max 30 mA per channel | Eliminates external boost controller but lacks multi-string coordination and DHC efficiency gain | Select for cost-sensitive, low-channel-count applications where system-level efficiency is secondary to BOM simplicity |
Compared with LM3432MM/NOPB, LM3432MH/NOPB offers superior thermal performance in space-constrained layouts; compared with TPS61165DRVR, it delivers higher channel count, tighter current matching, and system-level efficiency gains via DHC-making it optimal for multi-string, high-brightness display systems.
Availability
LM3432MH/NOPB is available at Aetrix Electronics and suitable for LCD backlighting, industrial HMI displays, medical imaging monitors, and avionics display systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM3432MH/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 display power solutions.
The LM3432 product line was designed specifically for high-efficiency, multi-string LED backlighting in LCD panels-emphasizing current accuracy, thermal resilience, and seamless integration with TI's complementary boost controllers like the LM3430.
FAQ
What is the maximum LED string voltage supported by the LM3432MH/NOPB?
The LM3432MH/NOPB supports up to 80 V across each IOUT pin relative to PGND. This enables driving strings of 12–15 white LEDs (typical VF ≈ 3.2 V) or 20–25 red/green LEDs (VF ≈ 2.0–2.4 V) without external high-voltage transistors. The absolute maximum rating is 82 V, but continuous operation above 80 V is not recommended per datasheet limits.
How does the Dynamic Headroom Control (DHC) function improve system efficiency in the LM3432MH/NOPB?
The LM3432MH/NOPB's DHC function outputs a regulated voltage (VDHC) that interfaces with the LM3430 boost controller to dynamically lower the LED supply rail (VLED) to the minimum needed for current regulation-typically 0.625 V above the highest LED string cathode voltage at 20 mA. This reduces power dissipation in the current sinks and overall system losses by up to 22% compared to fixed-rail designs, especially at partial brightness.
Can the LM3432MH/NOPB detect open-circuit LED faults?
Yes, the LM3432MH/NOPB includes open-fault detection and reports it via the FAULTb pin. If any IOUT channel draws no current for >50 µs, that channel is latched off and FAULTb is pulled LOW. This feature is present in the LM3432 (including LM3432MH/NOPB) but omitted in the LM3432B variant. Open-fault detection remains active regardless of DHC usage.
What external components are required to configure the LM3432MH/NOPB for 30 mA per string?
To set 30 mA per string, connect a 36.5 kΩ ±1% resistor between IREF and AGND (using IOUT ≈ 1.094 / RIREF mA). Add a 680 nF (min) ceramic capacitor between VCC and AGND, and a 0.1–1 µF low-ESR ceramic capacitor between VIN and PGND. For analog dimming, connect a 5.6 nF capacitor between MODE and AGND; for digital PWM, tie MODE directly to AGND.
Does the LM3432MH/NOPB support simultaneous switching of all six channels during PWM dimming?
No-the LM3432MH/NOPB staggers channel switching with 0.5 µs phase delay between successive IOUT pins to prevent large inrush currents on the VLED rail. This reduces peak supply current demand and EMI. As a result, the minimum controllable pulse width is 0.5 µs; pulses narrower than this are rounded to 0% or 100% duty cycle depending on timing alignment.
LM3432MH/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 28-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- 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:
- 28-HTSSOP
LM3432MH/NOPB FAQ
1.How can I place an order for LM3432MH/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3432MH/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 LM3432MH/NOPB reliable?
The price and inventory of LM3432MH/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3432MH/NOPB is usually 5 days.
3.What payment methods are accepted for LM3432MH/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3432MH/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3432MH/NOPB?
LM3432MH/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3432MH/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 LM3432MH/NOPB?
For technical support, including LM3432MH/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3432MH/NOPB requirements.
6.How does Aetrix verify that LM3432MH/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3432MH/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 LM3432MH/NOPB meets industry standards.
7.What is the process for return or replacement of LM3432MH/NOPB?
All LM3432MH/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3432MH/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 LM3432MH/NOPB part is unused and in its original packaging.
Return procedure for LM3432MH/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3432MH/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
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BCR421UE6327HTSA1
Infineon Technologies
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LYT1604D-TL
Power Integrations
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HV9910CLG-G
Microchip Technology
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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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