# AP62300TWU-7: 3 A Synchronous Buck Converter, 4.2 to 18 V (Diodes Inc)

**Diodes Incorporated AP62300T** is a 3 A synchronous step-down converter with integrated
75 mΩ high-side and 45 mΩ low-side MOSFETs. Constant on-time (COT) control means fast
transient response and almost no loop compensation work: an inductor, three capacitors and
a feedback divider make a supply. It drops to PFM at light load for 155 µA quiescent
current, and the gate driver is shaped for low radiated EMI.

| | |
|---|---|
| **MPN** | AP62300TWU-7 (tape and reel, 3000 pcs) |
| **Manufacturer** | Diodes Incorporated |
| **Package** | TSOT26 (Standard) = TSOT-23-6, body 2.90 × 1.60 mm, 2.80 mm lead span, 0.95 mm pitch, 1.00 mm max height |
| **Part marking** | `TP` |
| **KiCad symbol** | `AP62300TWU-7:AP62300TWU-7` |
| **KiCad footprint** | `AP62300TWU-7:SOT95P280X100-6N` (SamacSys) |
| **3D** | `ap62300twu-7.glb` (page viewer) + `ap62300twu-7.step` (manufacturer model) |
| **Fusion / EAGLE** | `AP62300TWU-7.lbr`, canonical hub `ap62300twu-7.adom-lbr.json` |
| **Datasheet** | [DS41958 Rev 4-2](docs/AP62300-datasheet.pdf), [diodes.com](https://www.diodes.com/assets/Datasheets/AP62300_AP62301_AP62300T.pdf) |
| **Order** | DigiKey `31-AP62300TWU-7TR-ND`, Mouser `621-AP62300TWU-7`, LCSC `C1883519` |

> **This is the `T` variant.** `AP62300TWU-7` is the AP62300**T**: feedback reference
> **0.763 V**, not the 0.800 V of `AP62300WU-7`. Same pinout, same footprint, same package,
> but the divider math differs and the two are not drop-in equivalent at a fixed output.
> `AP62301` is the third sibling: 0.800 V reference, PWM only (no PFM), 275 µA IQ.

## Electrical (AP62300T, from DS41958)

| Parameter | Value |
|---|---|
| Input voltage | 4.2 … 18 V (abs max 20 V DC, 22 V for 400 ms) |
| Output voltage | 0.8 … 7 V, set by an external divider |
| Feedback reference V<sub>FB</sub> | **0.763 V** ±1% at 25 °C (0.747 … 0.778 V over temperature) |
| Continuous output current | 3 A |
| Low-side valley current limit | 3.2 / 3.7 / 4.2 A (min / typ / max) |
| Switching frequency | 750 kHz typ (V<sub>IN</sub> 12 V, V<sub>OUT</sub> 5 V, CCM) |
| Minimum on-time / off-time | 90 ns / 220 ns |
| R<sub>DS(ON)</sub> | 75 mΩ high-side, 45 mΩ low-side |
| Quiescent current | 155 µA (PFM, not switching), 1.5 µA in shutdown |
| POR rising / UVLO falling | 3.90 … 4.15 V / 3.6 V typ |
| EN thresholds | 1.20 … 1.25 V high, 1.04 … 1.10 V low; 7 µA typ at V<sub>EN</sub> = 1.5 V |
| Soft-start | 2.5 ms internal |
| Control | Constant on-time (COT), PFM at light load / PWM at load |
| Protection | UVLO, cycle-by-cycle valley current limit, output UVP, thermal shutdown 160 °C (20 °C hysteresis) |
| Thermal resistance | θ<sub>JA</sub> 70 °C/W, θ<sub>JC</sub> 12 °C/W (TSOT26, 2-layer 2 oz board) |
| ESD | ±2 kV HBM, ±500 V CDM |
| Temperature | T<sub>A</sub> –40 … +85 °C, T<sub>J</sub> –40 … +125 °C |

## Pinout

| Pin | Name | Type | Notes |
|---|---|---|---|
| 1 | GND | power in | power ground, and the thermal path for this package |
| 2 | SW | power out | switch node, to the inductor and the BST capacitor |
| 3 | VIN | power in | 4.2 … 18 V, 10 µF ceramic to GND right at the pin |
| 4 | FB | input | divider tap, regulates to 0.763 V |
| 5 | EN | input | high = on, low = off, float = automatic start; 1.2 V precision threshold for programming UVLO |
| 6 | BST | passive | high-side gate drive bootstrap, 100 nF from BST to SW |

## Setting the output voltage

R1 sits between V<sub>OUT</sub> and FB, R2 from FB to GND:

    R1 = R2 × (VOUT / 0.763 − 1)

Diodes' recommended values for this variant, all with R2 = 10 kΩ:

| V<sub>OUT</sub> | R1 (AP62300T) | L | C<sub>IN</sub> | C<sub>OUT</sub> | C<sub>FF</sub> (optional) |
|---|---|---|---|---|---|
| 1.2 V | 5.76 kΩ | 1.5 µH | 10 µF | 2 × 22 µF | open |
| 1.5 V | 9.76 kΩ | 1.5 µH | 10 µF | 2 × 22 µF | open |
| 1.8 V | 13.7 kΩ | 2.2 µH | 10 µF | 2 × 22 µF | 10 … 100 pF |
| 2.5 V | 22.6 kΩ | 2.2 µH | 10 µF | 2 × 22 µF | 10 … 100 pF |
| 3.3 V | 33.2 kΩ | 3.3 µH | 10 µF | 2 × 22 µF | 10 … 100 pF |
| 5.0 V | 56.2 kΩ | 3.3 µH | 10 µF | 2 × 22 µF | 10 … 100 pF |

The R1 column is different for the 0.800 V parts (AP62300/AP62301), so do not copy a
divider from an `AP62300WU-7` design onto this part.

## Files

- `AP62300TWU-7.kicad_sym`: KiCad 9/10 symbol, 5 standard fields, 6 pins
- `SOT95P280X100-6N.kicad_mod`: KiCad 9 footprint, modern `(footprint …)` syntax
- `ap62300twu-7.step`: manufacturer STEP. `ap62300twu-7.glb`: color-preserving GLB
- `AP62300TWU-7.lbr`: EAGLE / Fusion 360 Electronics library (symbol + package + deviceset)
- `ap62300twu-7.adom-lbr.json`: canonical adom-lbr hub (exports to Altium, KiCad, IntLib)
- `docs/AP62300-datasheet.pdf`: Diodes DS41958 Rev 4-2, July 2023
- `docs/symbol.svg`, `docs/footprint.svg`: rendered symbol and footprint previews
- `skills/ap62300twu-7-usage/SKILL.md`: how to design in, lay out and order the part

CAD came from the SamacSys bundle. The symbol was rebuilt in the Adom house style and the
footprint converted to modern KiCad syntax; pad geometry is unchanged from the vendor model
(0.60 × 1.15 mm pads on a 0.95 mm pitch, 2.60 mm span between pad centres), which is
IPC-7351 nominal and runs a longer toe than the 0.70 × 1.00 mm pads in Diodes' own
suggested land pattern.
