XL4015 — 5A 180kHz 36V Step-Down (Buck) DC-DC Converter

Overview

The XL4015 (specifically XL4015E1 in a 5-lead TO-263 package) is one of the most widely used high-power $5.0\text{ A}$ step-down (buck) DC-DC converter ICs, manufactured by XLSEMI. Famous as the core chip on red/blue 5A buck breakout modules with dual potentiometers for Constant Voltage (CV) and Constant Current (CC) limiting, it converts input voltages from $8.0\text{ V}$ to $36.0\text{ V}$ down to adjustable output voltages from $1.25\text{ V}$ to $32.0\text{ V}$ .

Operating at a $180\text{ kHz}$ switching frequency, the XL4015 achieves power conversion efficiencies up to $96\%$ , generating significantly less heat than legacy LM2596 modules when powering heavy loads like lithium battery charging or high-power LED arrays.

Quick reference


Regulator Type	Monolithic High-Current Step-Down (Buck) DC-DC Regulator
Package	TO-263-5L (D2PAK 5-Pin) / 5A CC/CV Buck Module
Input Voltage Range ( $V_{IN}$ )	$8.0\text{ V}$ to $36.0\text{ V}$ DC
Output Voltage Range ( $V_{OUT}$ )	$1.25\text{ V}$ to $32.0\text{ V}$ DC (Adjustable)
Continuous Output Current ( $I_{OUT}$ )	Up to $5.0\text{ A}$ (Heatsink recommended above 3.5A)
Switching Frequency	$180\text{ kHz}$ fixed internal oscillator
Conversion Efficiency	$90\% \dots 96\%$
Protection Features	Thermal shutdown, short-circuit protection, internal soft-start

Pinout (TO-263-5L Package)

text

        ┌──────────────────┐
        │     XL4015E1     │  (Front Package Face)
        └─┬───┬───┬───┬────┘
          1   2   3   4   5
         GND FB  ON  VIN SW

Pin	Name	Description
1	`GND`	Ground reference (0 V)
2	`FB`	Voltage feedback sense pin ( $1.25\text{V}$ internal reference)
3	`ON`/`OFF`	Logic shutdown pin (Connect to GND for normal operation, High to shut down)
4	`VIN`	Unregulated DC power supply input (+8.0V to +36V DC)
5	`OUTPUT` / `SW`	Switch node output connecting internal MOSFET switch to catch diode & inductor

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Input Voltage Range	$V_{IN}$	8.0	12 / 24	36	V	DC input operational range
Feedback Reference Voltage	$V_{FB}$	1.225	1.250	1.275	V	$V_{IN} = 12\text{V}, I_{OUT} = 0.5\text{A}$
Continuous Output Current	$I_{OUT}$	—	5.0	—	A	$V_{IN} - V_{OUT} \ge 1.5\text{V}$
Current Limit Threshold	$I_{CL}$	6.0	7.0	—	A	Internal switch peak current limit
Switching Frequency	$f_{SW}$	144	180	216	kHz	Internal clock frequency
Quiescent Current	$I_Q$	—	2.5	5.0	mA	Operating state ( $V_{FB} = 1.5\text{V}$ )

Typical Application Circuit (CC/CV Module)

text

       +V_IN (8.0V - 36V DC Input)
          │
       [Pin 4: VIN]
        XL4015E1 ──── [Pin 5: SW] ──── [ 47µH Inductor ] ────┬─── +V_OUT Regulated DC Output
          │                                 │                 │
       [Pin 1: GND]               [B540 / SS54 Schottky]   [ R1 ]
          │                                 │                 │
         GND ───────────────────────────────┴─────────────────┼─── [Pin 2: FB]
                                                              │
                                                            [ R2 ]
                                                              │
                                                             GND

$V_{OUT} = 1.25\text{V} \times \left( 1 + \frac{R_1}{R_2} \right)$

Common mistakes

Attempting to step UP voltage: The XL4015 is strictly a Buck (Step-Down) converter. $V_{IN}$ must be at least $1.5\text{V}$ higher than $V_{OUT}$ .
Running at 5A continuous without an external heatsink: Although rated for 5A peak, drawing more than 3.5A continuous on standard breakout modules without an adhesive aluminum heatsink on the TO-263 package will trigger thermal throttling.

Notes

XL4015 vs LM2596: The XL4015 delivers up to 5A (vs 3A for LM2596) at higher switching frequency ( $180\text{ kHz}$ vs $150\text{ kHz}$ ) and efficiency up to 96%.

Interface	DC Input, DC Output, High-Current Switch Node
Package	TO-263-5L (D2PAK) / 5A CC/CV Buck Module