# LM2596S-ADJ

**UMW** · DC-DC Converters · TO-263-5

LM2596S-ADJ from UMW, in a TO-263-5. 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 | VIN | power_in | Input supply voltage. Operating range 4.75V to 40V (LM2596) / 4.75V to 60V (LM2596HV). Absolute maximum 45V (63V for HV). Bypass with a low-ESR input capacitor (typ. 680 µF). |
| 2 | Output | output | Switching output pin. Emitter of the internal NPN power switch; connects to the external catch diode (e.g. 1N5824) and to the inductor of the buck output filter (typ. 33 µH). Steady-state voltage rated down to -1V; peak switch current limit typ. 4.5A. |
| 3 | GND | power_in | Device ground. Common return for the input capacitor, output capacitor, catch diode, and feedback divider. |
| 4 | Feedback | input | Output voltage feedback input to the internal error amplifier. For the ADJ version, connect to the mid-point of an external resistor divider from VOUT; internal reference VFB = 1.23V (typ). Bias current 10 nA typ (100 nA max). Absolute max -0.3V to +25V. |
| 5 | ON/OFF | input | Active-low shutdown / enable input (bar over ON/OFF). Regulator is ON when the pin is Low (<0.6V) or left floating; regulator is OFF (standby, IQ typ 80 µA) when the pin is High (>2V). TTL-compatible; absolute max -0.3V to +25V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | UMW |
| Package | TO-263-5 |
| Category | PMIC |
| Pins | 5 |

## Ordering variants

Same part, different packaging or reel option.

- `LM2596S-ADJ`

## Related parts (NOT interchangeable)

The extractor listed these alongside LM2596S-ADJ, but they are **different parts** with different electrical characteristics. Do not order them as substitutes.

- `LM2596HVS-ADJ`
- `LM2596T-ADJ`
- `LM2596HVT-ADJ`

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Feedback voltage | VFB | 1.193 | 1.23 | 1.267 | V | 4.5V≤VIN≤40V, 0.2A≤ILOAD≤3A, VOUT programmed for 3V, Figure 1 circuit; printed pairs are 1.193/1.180 (min) and 1.267/1.280 (max), the second value applying over full operating temperature range | 5 |
| Oscillator frequency | fO | 117 | 150 | 183 | kHz | VIN=12V, ILOAD=500mA; printed pairs 117/117 and 183/183 are identical at 25°C and over full temperature range | 6 |
| Current limit (peak) | ICL | 3.6 | 4.5 | 6.9 | A | Peak current (Notes 7, 8); printed pairs 3.6/3.4 (min) and 6.9/7.5 (max), the second value applying over full operating temperature range | 6 |
| Saturation voltage | VSAT |  | 1.16 | 1.4 | V | IOUT=3A (Notes 7, 8); printed pair 1.4/1.5, the second value applying over full operating temperature range | 6 |
| Feedback bias current | IB |  | 10 | 50 | nA | VFB=1.3V, adjustable version only; printed pair 50/100, the second value applying over full operating temperature range | 6 |
| Output leakage current, output=0V | IL |  |  | 50 | µA | Output=0V (Notes 7, 9) | 6 |
| Output leakage current, output=-1V | IL |  | 2 | 30 | mA | Output=-1V (Note 10) | 6 |
| Quiescent current | IQ |  | 5 | 10 | mA | Note 9: feedback pin connected to 12V to force output switch OFF | 6 |
| Standby quiescent current | ISTBY |  | 80 | 200 | µA | ON/OFF pin=5V (OFF); printed pair 200/250, the second value applying over full operating temperature range | 6 |
| ON/OFF pin logic input threshold voltage, high (regulator OFF) | VIH | 2 | 1.3 |  | V | High (Regulator OFF); typ 1.3 is the single printed threshold typical value | 7 |
| ON/OFF pin logic input threshold voltage, low (regulator ON) | VIL |  | 1.3 | 0.6 | V | Low (Regulator ON); typ 1.3 is the single printed threshold typical value | 7 |
| ON/OFF pin input current, high | IH |  | 5 | 15 | µA | VLOGIC=2.5V (Regulator OFF) | 7 |
| ON/OFF pin input current, low | IL |  | 0.02 | 5 | µA | VLOGIC=0.5V (Regulator ON) | 7 |
| Maximum supply voltage (LM2596, non-HV) |  |  |  | 45 | V | Absolute maximum rating (Note 1); LM2596HV 63V rating not applicable to this part | 4 |
| ON/OFF pin input voltage |  | -0.3 |  | 25 | V | Absolute maximum rating (Note 1) | 4 |
| Feedback pin voltage |  | -0.3 |  | 25 | V | Absolute maximum rating (Note 1) | 4 |
| Output voltage to ground (steady state) |  | -1 |  |  | V | Steady state (Note 1) | 4 |
| Storage temperature range |  | -65 |  | 150 | °C | Absolute maximum rating (Note 1) | 4 |
| Soldering temperature, vapor phase |  |  |  | 215 | °C | Vapor phase, 60 sec. | 4 |
| Soldering temperature, infrared |  |  |  | 245 | °C | Infrared, 10 sec. | 4 |
| Maximum junction temperature | TJ |  |  | 150 | °C | Absolute maximum rating (Note 1) | 4 |
| Operating junction temperature range | TJ | -40 |  | 125 | °C | -40°C ≤ TJ ≤ +125°C | 4 |
| Supply voltage (LM2596, non-HV) |  | 4.75 |  | 40 | V | Operating conditions (LM2596); LM2596HV 4.75V~60V not applicable to this part | 4 |
| Maximum duty cycle (ON) | DC |  | 100 |  | % |  | 6 |
| Minimum duty cycle (OFF) | DC |  | 0 |  | % |  | 6 |
| Thermal resistance, junction to case (TO-220 or TO-263) | θJC |  | 2 |  | °C/W | TO-220 or TO-263 package, junction to case | 7 |
| Thermal resistance, junction to ambient, TO-263 (0.5 in² 1 oz copper) | θJA |  | 50 |  | °C/W | TO-263 tab soldered to single PCB with 0.5 in² (1 oz.) copper (Note 12) | 7 |
| Thermal resistance, junction to ambient, TO-263 (2.5 in² single-sided) | θJA |  | 30 |  | °C/W | TO-263 tab soldered to single-sided PCB with 2.5 in² (1 oz.) copper (Note 13) | 7 |
| Thermal resistance, junction to ambient, TO-263 (3 in² double-sided) | θJA |  | 20 |  | °C/W | TO-263 tab soldered to double-sided PCB with 3 in² (1 oz.) copper on LM2596S side (Note 14) | 7 |

## CAD (KiCad official)

- Symbol: `LM2596S-ADJ`
- Footprint: `Package_TO_SOT_SMD:TO-263-5_TabPin6`
- 3D model: TO-263-5 (KiCad packages3D, STEP)
- 3D model files: `lm2596s-adj-etched.step` / `lm2596s-adj-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm2596s-adj.step` / `lm2596s-adj.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`lm2596s-adj.step`](lm2596s-adj.step) | 180 KB | You want the bare part, or you mark your own boards. |
| [`lm2596s-adj-etched.step`](lm2596s-adj-etched.step) | 2.1 MB | You want the part with `LM2596S-ADJ` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 560 faces against 135 in the bare model. It
survives export, section views, and rendering in any CAD tool, and it drops straight
into KiCad or Fusion with no extra setup.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [UMW datasheet](docs/lm2596s-adj-datasheet.pdf) (28 pp, sha256 `26d031e9696524e9`, retrieved 2026-08-17, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm2596s-adj-datasheet.pdf)