component
LM5039SQX
Public Made by Adomby adom
Texas Instruments DC-DC Controllers, WQFN-24-EP(4x5). Datasheet-verified pinout, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownLM5039SQX
Texas Instruments · DC-DC Controllers · WQFN-24-EP(4x5)
LM5039SQX from Texas Instruments, in a WQFN-24-EP(4x5). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | NC | unconnected | No electrical contact. |
| 2 | ACL | input | A capacitor connected between the ACL pin and GND operates as an integrator in the average current limit circuitry. |
| 3 | COMP | input | An external opto-coupler connected to the COMP pin sources current into an internal NPN current mirror to control PWM duty cycle. |
| 4 | RT | input | An external resistor connected between RT and AGND sets the internal oscillator frequency, normally regulated at 2V. |
| 5 | AGND | power_in | Analog Ground, connect directly to Power Ground. |
| 6 | CS | input | Current sense input driven by a signal representative of the primary current, with 600mV threshold for peak cycle-by-cycle limiting and 500mV threshold for average current limiting. |
| 7 | SS | input | An internal 110µA current source charges an external capacitor to set the soft-start rate. |
| 8 | DLY | input | An external resistor to ground sets the timing for the non-overlap time of HO to SR1 and LO to SR2. |
| 9 | RES | input | If the current limit is exceeded during any cycle, a 22µA current is sourced to the RES pin capacitor for hiccup mode restart control. |
| 10 | NC | unconnected | No electrical contact. |
| 11 | HB | power_in | Boost voltage for the HO driver; an external diode is required from VCC to HB and an external capacitor is required from HS to HB to power the gate driver. |
| 12 | HS | power_in | Switch node connection common to the transformer and both power switches, providing a return path for the HO gate driver. |
| 13 | HO | output | Output of the high side PWM gate driver, capable of sinking 2A peak current. |
| 14 | LO | output | Output of the low side PWM gate driver, capable of sinking 2A peak current. |
| 15 | PGND | power_in | Power Ground, connect directly to Analog Ground. |
| 16 | VCC | power_out | Output of the high voltage start-up regulator regulated to 7.6V. |
| 17 | SR2 | output | Synchronous rectifier driver output for control of the synchronous FET gate, capable of 0.5A peak current. |
| 18 | SR1 | output | Synchronous rectifier driver output for control of the synchronous FET gate, capable of 0.5A peak current. |
| 19 | REF | power_out | Output of 5V Reference with typical output current of 20mA, requiring local decoupling with a 0.1µF capacitor. |
| 20 | NC | unconnected | No electrical contact. |
| 21 | VIN | power_in | Input voltage source to the Start-up Regulator with operating input range of 13V to 100V with transient capability to 105V. |
| 22 | NC | unconnected | No electrical contact. |
| 23 | RAMP | input | Modulator ramp signal set by an external RC circuit from VIN, discharged at the conclusion of every cycle by an internal FET. |
| 24 | UVLO | input | Line Under-Voltage Lockout determined by an external voltage divider from the power source for shutdown and standby control. |
| 25 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | WQFN-24-EP(4x5) |
| Category | Power Supply Chip |
| Pins | 25 |
CAD (KiCad official)
- Symbol:
LM5039SQX - Footprint:
Package_DFN_QFN:QFN-24-1EP_4x5mm_P0.5mm_EP2.65x3.65mm - 3D model: WQFN-24-EP(4x5) (KiCad packages3D, STEP)
- 3D model files:
lm5039sqx-etched.step/lm5039sqx-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);lm5039sqx.step/lm5039sqx.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Texas Instruments datasheet (35 pp, sha256
a662d4b1f77df0cf, retrieved 2026-09-17, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.2, primaryclaude-haiku-4-5-20251001(text), consensusclaude-sonnet-4-6(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).