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Q: What's the realistic output current?

1-1.5A continuous in free air, about 1.7A absolute from 12V to 24V. The 4A rating is switch current, not output: Iout ≈ Isw × (Vin/Vout) × efficiency. The TO263 tab sheds about 2W in free air - beyond that, add a heatsink or airflow.

Q: Can I boost a 3.7V LiPo with it?

No - the XL6009 is a 5V-minimum part. Below about 5V input the converter loses regulation: forum users report output wandering past 9V at ~3V input. For single-cell LiPo boost, use a 2V-minimum part like the MT3608 instead.

Q: Why does my output drift upward under a light load?

Light-load regulation is the module's weak spot. Current-mode control at 400kHz with light inductor current sits near the sensing noise floor. Add a minimum load of roughly 10mA - forum users have measured setpoints drifting from 6V past 19V with only a solenoid connected.

Q: My module shows huge ripple. Is it the converter?

Often it's the measurement, not the module. Scope ground-lead pickup and long sense wires fake big spikes. Solder coax directly across the output capacitor - with proper probing, most XL6009 rails measure clean. Then judge the converter.

Q: Why does my module cut out on bass notes or motor pulses?

The module's transient response can't track fast current steps. EEVblog users powering class-D amps saw exactly this. Adding output capacitance can help but risks oscillation. For pulsed loads, size for the peak current or use a converter with real transient headroom.

Q: Is EN floating okay for a battery design?

Only if you want it on forever. Floating EN means the chip is enabled - 2.5mA switching quiescent plus divider current, around the clock. Drive EN low (below 0.8V) for shutdown at 70µA standby, and enable from a logic rail when the system wakes.

Q: How do I spot a counterfeit XL6009?

Measure switching frequency and switch resistance. Genuine parts switch at 400kHz ±20% with ~110mΩ internal switch. Smaller-die fakes read higher on-resistance and drop out of regulation at lower current. A part with no traceable XLSEMI lot code is a red flag.

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XL6009 Pinout, Specifications & Common Mistakes | ICMASS

2026/9/7 21:45:27

The XL6009 is the 400kHz boost/SEPIC/inverting converter from XLSEMI — TO263-5L, 5-32V input, 4A internal switch — the chip inside half the adjustable boost modules on the market.

Three pin facts matter more than the rest: the metal tab is SW (same net as pin 3, and the heatsink), EN floats to ON (below 0.8V off, above 1.4V on), and FB regulates to 1.25V through the divider.

From what we see across Shenzhen lots (2025–2026), most XL6009 module failures trace back to layout and drive mistakes, not the chip itself — and most "ripple" complaints trace back to the scope lead, not the converter.

XL6009 Pinout and Pin Functions

TO263-5L pinout: pin 1 GND, pin 2 EN (below 0.8V off, above 1.4V on, floating = on), pin 3 SW, pin 4 VIN (5-32V), pin 5 FB (1.25V reference). The metal tab is SW — same net as pin 3, and the heatsink path. The XL6019 uses the identical layout.

Pin	Name	Function
1	GND	Ground — connect to the tab-side copper pour, close to the input cap return.
2	EN	Enable — below 0.8V off, above 1.4V on, TTL-compatible. Floating = on.
3	SW	Switch output — the inductor and Schottky anode meet here. Swings 0 to Vout at 400kHz.
4	VIN	Input, 5-32V — bypass with a 220μF low-ESR capacitor near the pin.
5	FB	Feedback — regulates to 1.25V through the R1/R2 divider: Vout = 1.25 × (1 + R2/R1).
Tab	SW	Same net as pin 3 — the heatsink path. Ground it electrically, but know it is hot while switching.

Key Specifications of XL6009

Parameter	Value
Manufacturer / Package	XLSEMI / TO263-5L (10.2 × 8.9mm)
Topologies	Boost, Buck-Boost (SEPIC), Inverting
Input Voltage Range	5V to 32V
Feedback Reference Voltage	1.25V
Switching Frequency	400kHz typ (320-480kHz)
Internal Switch Current Limit	4A (switch current, not output)
Internal MOSFET R_DS(on)	~110mΩ
Max Switch Pin Voltage	60V
Max Duty Cycle	90%
Peak Efficiency	94% (92% typ at 12V→18.5V / 2A)
Quiescent Current (switching, no load)	2.5mA typ
Standby Current (EN low)	70μA typ
EN Thresholds	High >1.4V / Low <0.8V (TTL-compatible, floating = on)
Protections	Current limit, thermal shutdown, SW over-voltage
Thermal Resistance R_θJA	30°C/W (free air, no heatsink)

Key numbers that matter: per the XLSEMI datasheet, the 4A rating is switch current, not output current — I_out ≈ I_sw × (V_in/V_out) × efficiency. From 12V to 24V that is roughly 1.7A absolute, and 1-1.5A continuous in free air is the realistic number.

At 400kHz the magnetics stay small — a 47μH SMD inductor replaces the heavy toroids of 50kHz-era parts. The SW pin is rated to 60V, which bounds the output for boost duty.

The EN pin and its 70μA standby are the battery answer: tie EN low to shut the converter down properly — floating runs the chip at 2.5mA plus divider current forever.

Typical Application Circuit

Boost power path: VIN → L → SW node → D (SS34, anode at SW) → VOUT, with Cout returning to GND. The chip's SW pin (3, plus the tab) drives that node at 400kHz.

The R1/R2 divider samples VOUT into FB (pin 5, 1.25V reference): Vout = 1.25 × (1 + R2/R1). EN (pin 2) floating means on — tie it to VIN or a logic rail; driving it low holds the chip at 70μA standby.

Layout rules that matter at 400kHz: the SW node (pin 3, tab, inductor, diode anode) swings 0 to Vout every cycle — keep it a short fat trace.

Ground the tab through a solid pour back to the input cap return. Put the divider close to pin 5, and sense the output at the cap, not at the load.

And the diode choice is not decorative: a Schottky (SS34-class) is required at 400kHz — a standard recovery diode burns in reverse recovery at this frequency.

Common Mistakes When Using XL6009

Mistake 1: Feeding it below the 5V minimum

The XL6009 is a 5V-minimum part — not a 3.3V or LiPo-booster chip. Arduino forum users boosting a 3.7V LiPo to 5V report the output going "all over the place" past 9V once the input sags below ~3.5V. The datasheet's 5-32V window assumes a stiff source.

Mistake 2: Light-load output drift

On All About Circuits, XL6009E1 modules set to 6V drifted up to 19V under a light solenoid load. Current-mode control at 400kHz sits near the noise floor at light load — add roughly 10mA of minimum load, or a load resistor sized for your regulation spec.

Mistake 3: Blaming the converter for measurement artifacts

A Stack Exchange thread on an XL6009 module's "40mV noise" turned out to be scope ground-lead pickup — with coax soldered directly across the output cap, the rail was clean. Probe the cap, not the leads, before adding filters that fight ghosts.

Mistake 4: Audio or pulsed loads on a module

EEVblog users powering a class-D amp found the module cutting out on bass transients. The module's transient response can't track sudden current steps; adding output capacitance experimentally can push it into oscillation. For pulsed loads, size the converter for the peaks, not the average.

Mistake 5: EN left floating on a battery rail

Floating EN means ON — the chip draws 2.5mA switching quiescent plus divider current, forever. Tie EN to VIN for always-on, or drive it from a logic rail for real shutdown (70μA standby). A battery design that never turns off pays 2.5mA of tax around the clock.

Mistake 6: Ignoring the tab's electrical net

The tab is SW, not GND — the mistake that kills boards and module clones. Insulating pads and mounting holes must not short the tab to ground copper. A shorted tab feeds the full switching waveform into whatever touches it — forum reports of smoking electrolytics trace back to exactly this.

Frequently Asked Questions About XL6009

Q1: What's the realistic output current?

A: 1-1.5A continuous in free air, about 1.7A absolute from 12V to 24V. The 4A rating is switch current, not output: I_out ≈ I_sw × (V_in/V_out) × efficiency. The TO263 tab sheds about 2W in free air — beyond that, add a heatsink or airflow.

Q2: Can I boost a 3.7V LiPo with it?

A: No — the XL6009 is a 5V-minimum part. Below about 5V input the converter loses regulation: forum users report output wandering past 9V at ~3V input. For single-cell LiPo boost, use a 2V-minimum part like the MT3608 instead.

Q3: Why does my output drift upward under a light load?

A: Light-load regulation is the module's weak spot. Current-mode control at 400kHz with light inductor current sits near the sensing noise floor. Add a minimum load of roughly 10mA — forum users have measured setpoints drifting from 6V past 19V with only a solenoid connected.

Q4: My module shows huge ripple. Is it the converter?

A: Often it's the measurement, not the module. Scope ground-lead pickup and long sense wires fake big spikes. Solder coax directly across the output capacitor — with proper probing, most XL6009 rails measure clean. Then judge the converter.

Q5: Why does my module cut out on bass notes or motor pulses?

A: The module's transient response can't track fast current steps. EEVblog users powering class-D amps saw exactly this. Adding output capacitance can help but risks oscillation. For pulsed loads, size for the peak current — or use a converter with real transient headroom.

Q6: Is EN floating okay for a battery design?

A: Only if you want it on forever. Floating EN means the chip is enabled — 2.5mA switching quiescent plus divider current, around the clock. Drive EN low (below 0.8V) for shutdown at 70μA standby, and enable from a logic rail when the system wakes.

Q7: How do I spot a counterfeit XL6009?

A: Measure switching frequency and switch resistance. Genuine parts switch at 400kHz (±20%) with ~110mΩ internal switch. Smaller-die fakes read higher on-resistance and drop out of regulation at lower current. A part with no traceable XLSEMI lot code is a red flag.