component
TMI3253
Public Made by Adomby adom
TMI DC-DC Converters, SOT-23-6. Pinout extracted from the datasheet, 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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Contents
README
markdownTMI3253
TMI · DC-DC Converters · SOT-23-6
TMI3253 from TMI, in a SOT-23-6. 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 | GND | power_in | Ground pin. Return for all internal circuitry and the low-side MOSFET source. Connect to the system ground plane with a low-impedance path. |
| 2 | LX | output | Switching node. Common connection of the internal high-side and low-side power MOSFETs; connects to the external inductor. Absolute maximum -0.3V to 20V (steady) / -4.5V to 22V (<10ns transient). |
| 3 | IN | power_in | Power supply input. 4.5V to 18V operating range (20V abs max). Bypass to GND with a low-ESR ceramic capacitor (22µF typical) placed close to the pin. |
| 4 | FB | input | Output voltage feedback input. Connect to the center tap of the external resistor divider between VOUT and GND. Regulated to VREF = 0.8V (TMI3253), 0.6V (TMI3253S), or 0.765V (TMI3253T). |
| 5 | EN | input | Enable input. Drive logic-high (>0.95V typ threshold) to enable the IC; drive logic-low to disable and enter micro-power shutdown (~5µA). Do NOT leave floating. |
| 6 | BS | passive | Bootstrap. A capacitor (typ 0.1µF) between LX and BS forms a floating supply that powers the high-side N-MOSFET gate driver. Absolute maximum 26V to GND, 6V BS-to-LX. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | TMI |
| Package | SOT-23-6 |
| Category | PMIC |
| Pins | 6 |
Ordering variants
Same part, different packaging or reel option.
TMI3253TMI3253TTMI3253S
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 Supply Voltage, EN | -0.3 | 20 | V | 2 | |||
| LX Voltages | -0.3 | 20 | V | 2 | |||
| LX Voltages (<10ns transient) | -4.5 | 22 | V | <10ns transient | 2 | ||
| FB Voltage | -0.3 | 6 | V | 2 | |||
| BS Voltage | -0.3 | 26 | V | 2 | |||
| BS to LX Voltage | -0.3 | 6 | V | 2 | |||
| Storage Temperature Range | -65 | 150 | °C | 2 | |||
| Junction Temperature | TJ | 160 | °C | Note 2 | 2 | ||
| Power Dissipation | PD | 1000 | mW | 2 | |||
| Lead Temperature (Soldering, 10s) | 260 | °C | Soldering, 10s | 2 | |||
| ESD Human Body Model (all pins) | VESD_HBM | -2000 | 2000 | V | JEDEC specification JS-001 | 3 | |
| ESD Charged Device Model (all pins) | VESD_CDM | -1000 | 1000 | V | JEDEC specification JS-001 | 3 | |
| Voltage Range IN | VIN | 4.5 | 18 | V | 3 | ||
| TJ Operating Junction Temperature | TJ | -40 | 125 | °C | 3 | ||
| Input Voltage Range | 4.5 | 18 | V | 4 | |||
| OVP Threshold | 18.7 | 19.3 | 19.8 | V | 4 | ||
| Shutdown Current | 5 | 10 | μA | VIN=12V, EN=0V | 4 | ||
| Regulated Feedback Voltage (3253) | VFB | 0.784 | 0.8 | 0.816 | V | TA=25°C, 4.5V≤VIN≤18V | 4 |
| Switch Valley Current Limit | 3.7 | 4 | 4.5 | A | Minimum Duty Cycle | 4 | |
| High-Side Switch Leakage Current | 1 | 10 | μA | VEN=0V, VLX=0V | 4 | ||
| On Time | 132 | 166 | 200 | ns | VIN=12V, VOUT=1.2V, IOUT=1A | 4 | |
| Oscillation Frequency | 450 | 600 | 750 | kHz | Maximum Duty Cycle | 4 | |
| Soft Start Time | 0.5 | 0.8 | 1.2 | ms | 4 | ||
| EN Rising Threshold | 0.85 | 0.95 | 1.05 | V | 4 | ||
| Junction-to-ambient thermal resistance | θJA | 100 | °C/W | Note 3: measured on JESD51-7, 4-layer PCB | 3 | ||
| Junction-to-case(top) thermal resistance | θJC | 56 | °C/W | Note 3: measured on JESD51-7, 4-layer PCB | 3 | ||
| Junction-to-board thermal resistance | θJB | 16.2 | °C/W | Note 3: measured on JESD51-7, 4-layer PCB | 3 | ||
| Junction-to-case(top) characterization parameter | ψJC | 2 | °C/W | Note 3: measured on JESD51-7, 4-layer PCB | 3 |
CAD (KiCad official)
- Symbol:
TMI3253 - Footprint:
Package_TO_SOT_SMD:SOT-23-6 - 3D model: SOT-23-6 (KiCad packages3D, STEP)
- 3D model files:
tmi3253-etched.step/tmi3253-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);tmi3253.step/tmi3253.glbare the bare package body.
3D model downloads
Two STEP files. Same geometry, different body top:
| File | Size | Use it when |
|---|---|---|
tmi3253.step |
97 KB | You want the bare part, or you mark your own boards. |
tmi3253-etched.step |
1.6 MB | You want the part with TMI3253 already on it. |
The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 387 faces against 117 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: TMI datasheet (16 pp, sha256
b58c2a4a18985f81, 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).