# SK6253B

**Suntek** · DC-DC Converters · SOT-23-6

SK6253B from Suntek, in a SOT-23-6. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | GND | power_in | Ground pin; the datasheet recommends connecting GND to a large copper area to cool the chip and improve thermal performance. |
| 2 | SW | output | Switching pin; SW voltage is rated -0.3 V to VIN+1 V (-5 V to VIN+2 V for 10 ns transients), and a capacitor between SW and BS forms the high-side driver supply. |
| 3 | IN | power_in | Power supply pin; the input voltage range is 4.5 V to 16 V, with an absolute maximum VIN of 16 V. |
| 4 | FB | input | Adjustable-version feedback input, connected to the center point of the external resistor divider; the feedback voltage is 0.765 V nominal (0.746 V to 0.784 V) and the FB absolute maximum is 6 V. |
| 5 | EN | input | Drive to logic-high to enable the IC and to logic-low to disable it into micro-power shutdown; the EN rising threshold is 1.2 V, the falling threshold is 0.8 V, and the EN absolute maximum is 16 V. |
| 6 | BS | passive | Bootstrap pin; a capacitor connected between SW and BS is required to form a floating supply for the high-side switch driver, with BS voltage to SW limited to 6.5 V maximum. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Suntek |
| Package | SOT-23-6 |
| Category | Power Management (PMIC) |
| Pins | 6 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Input Voltage Range |  | 4.5 |  | 16 | V |  | 4 |
| Output Voltage Range |  | 0.765 |  | 7 | V |  | 4 |
| Feedback Voltage |  | 0.746 | 0.765 | 0.784 | V |  | 4 |
| Supply Current (Quiescent) |  | 0.6 |  | 0.8 | mA | VEN =3.0V | 4 |
| Under-Voltage Lockout Threshold, Wake up VIN Voltage |  | 3.9 |  | 4.3 | V |  | 4 |
| Under-Voltage Lockout Threshold, Shutdown VIN Voltage |  | 2.9 |  | 3.2 | V |  | 4 |
| VIN voltage (absolute maximum) | VIN | -0.3 |  | 16 | V |  | 3 |
| EN voltage (absolute maximum) | EN | -0.3 |  | 16 | V |  | 3 |
| SW voltage (absolute maximum, printed max VIN+1V) | SW | -0.3 |  |  | V |  | 3 |
| SW voltage 10ns transient (absolute maximum, printed max VIN+2V) | SW | -5 |  |  | V | 10ns transient | 3 |
| BS voltage (to sw) (absolute maximum) | BS | -0.3 |  | 6.5 | V |  | 3 |
| BS voltage (absolute maximum) | BS | -0.3 |  | 23.5 | V |  | 3 |
| FB voltage (absolute maximum) |  | -0.3 |  | 6 | V |  | 3 |
| Operating junction temperature (absolute maximum) | TJ | -40 |  | 150 | °C |  | 3 |
| Storage temperature | Tstg | -55 |  | 150 | °C |  | 3 |
| Lead Temperature (Soldering, 10sec.) |  |  |  | 260 | °C | Soldering, 10sec. | 3 |
| Operating junction temperature (recommended) | TJ | -40 |  | 125 | °C |  | 3 |
| Operating temperature range (recommended) |  | -40 |  | 85 | °C |  | 3 |
| Input voltage (recommended) | VIN | 4.5 |  | 16 | V |  | 3 |
| Output current (recommended) |  | 0 |  | 3 | A |  | 3 |
| Supply Current (Shutdown) |  |  | 4 |  | uA | VEN =0 or EN = GND | 4 |
| High-Side Switch On-Resistance |  |  | 70 |  | mΩ | ISW=100mA | 4 |
| Low-Side Switch On-Resistance |  |  | 50 |  | mΩ | ISW=-100mA | 4 |
| Valley Switch Current Limit |  |  | 3.1 |  | A |  | 4 |
| Output UVP threshold |  |  | 60 |  | % | Hiccup detect (H > L) | 4 |
| Hiccup wait time |  |  | 2 |  | ms |  | 4 |
| Hiccup time before restart |  |  | 36 |  | ms |  | 4 |
| Over Voltage Protection Threshold |  |  | 18 |  | V |  | 4 |
| Switching Frequency |  |  | 500 |  | KHz |  | 4 |
| Maximum Duty Cycle |  |  | 94 |  | % | VFB=90% | 4 |
| Minimum Off-Time |  |  | 89 |  | nS |  | 4 |
| EN Rising Threshold |  |  | 1.2 |  | V |  | 4 |
| EN Falling Threshold |  |  | 0.8 |  | V |  | 4 |
| Soft Start |  |  | 1.5 |  | mS |  | 4 |
| Thermal Shutdown |  |  | 160 |  | ℃ |  | 4 |
| Thermal Hysteresis |  |  | 30 |  | ℃ |  | 4 |
| Junction-to-ambient thermal resistance | RθJA |  | 105 |  | °C/W |  | 4 |
| Junction-to-case (top) thermal resistance | RθJC(top) |  | 55 |  | °C/W |  | 4 |
| Junction-to-board thermal resistance | RθJB |  | 17.5 |  | °C/W |  | 4 |
| Junction-to-top characterization parameter | ψJT |  | 3.5 |  | °C/W |  | 4 |
| Junction-to-board characterization parameter | ψJB |  | 17.5 |  | °C/W |  | 4 |

## CAD (KiCad official)

- Symbol: `SK6253B`
- Footprint: `Package_TO_SOT_SMD:SOT-23-6`
- 3D model: SOT-23-6 (KiCad packages3D, STEP)
- 3D model files: `sk6253b-etched.step` / `sk6253b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sk6253b.step` / `sk6253b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Suntek datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590268843051278336) (13 pp, sha256 `3a6c225f16df4a75`, retrieved 2026-10-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-5-5` (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).

[Datasheet PDF](docs/sk6253b-datasheet.pdf)