Overview
The LM3409MYX/NOPB is a P-channel MOSFET (PFET) buck controller designed by Texas Instruments for high-power LED drivers. This device is part of the LM3409 family, which includes variants such as LM3409, LM3409-Q1, LM3409HV, and LM3409HV-Q1. The LM3409MYX/NOPB is packaged in a 10-pin HVSSOP (DGQ) package, offering a thermally enhanced design. It is ideal for applications requiring constant current sources, particularly in driving LEDs with forward currents up to 5 A.
The device features a wide input voltage range, high-side differential current sensing, and a constant off-time (COFT) control mechanism that eliminates the need for external control loop compensation. It also supports both analog and PWM dimming, providing a highly linear dimming range with excellent contrast ratios.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| VIN Range | 6 to 42 | V |
| Junction Temperature Range | -40 to 125 | °C |
| MOSFET Gate Drive Resistance | 2 Ω | Ω |
| MOSFET Gate Drive Current | 1 A (peak) | A |
| UVLO Turn-on Threshold | 1.24 V | V |
| UVLO Hysteresis Current | 22 µA | µA |
| Current Sense Threshold Voltage | 250 mV | mV |
| PWM Dimming Range | 10,000:1 | |
| Analog Dimming Range | 250:1 | |
| Package Type | HVSSOP (10-pin) | |
| Body Size | 3.00 mm × 3.00 mm | mm |
Key Features
- AEC-Q100 Grade 1 Qualified for automotive applications (LM3409-Q1 and LM3409HV-Q1)
- Wide input voltage range: 6 V to 42 V (LM3409, LM3409-Q1) and 6 V to 75 V (LM3409HV, LM3409HV-Q1)
- 2-Ω, 1-A peak MOSFET gate drive
- Differential, high-side current sense with low adjustable threshold voltage
- Cycle-by-cycle current limit
- No control loop compensation required
- 10,000:1 PWM dimming range and 250:1 analog dimming range
- Supports all-ceramic output capacitors and capacitor-less outputs
- Low-power shutdown and thermal shutdown
- Thermally enhanced 10-pin HVSSOP package
Applications
- LED Driver
- Constant Current Source
- Automotive Lighting
- General Illumination
Q & A
- What is the input voltage range of the LM3409MYX/NOPB?
The input voltage range is 6 V to 42 V.
- What type of package does the LM3409MYX/NOPB come in?
The device is packaged in a 10-pin HVSSOP (DGQ) package.
- What is the maximum junction temperature for the LM3409MYX/NOPB?
The maximum junction temperature is 125°C.
- Does the LM3409MYX/NOPB support PWM dimming?
Yes, it supports a 10,000:1 PWM dimming range.
- What is the purpose of the UVLO pin on the LM3409MYX/NOPB?
The UVLO pin is for input undervoltage lockout, with a turn-on threshold of 1.24 V and hysteresis provided by a 22 µA current source.
- Can the LM3409MYX/NOPB be used in automotive applications?
Yes, the LM3409-Q1 and LM3409HV-Q1 variants are AEC-Q100 Grade 1 Qualified for automotive use.
- What is the maximum current sense threshold voltage for the LM3409MYX/NOPB?
The maximum current sense threshold voltage is 250 mV.
- Does the LM3409MYX/NOPB require external control loop compensation?
No, it does not require external control loop compensation due to its constant off-time (COFT) control mechanism.
- What are the thermal shutdown features of the LM3409MYX/NOPB?
The device includes low-power shutdown and thermal shutdown features.
- How does the LM3409MYX/NOPB support dimming?
The device supports both analog and PWM dimming, providing a highly linear dimming range with excellent contrast ratios.
