# T491A684M020AT

**KEMET** · Tantalum Capacitors · A (EIA 3216-18)

T491A684M020AT from KEMET, in a A (EIA 3216-18). 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 | + | passive | Positive terminal; pad 1 of the KiCad polarised-capacitor footprint (CP_, pad 1 = +). |
| 2 | - | passive | Negative terminal. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | KEMET |
| Package | A (EIA 3216-18) |
| Category | Capacitors |
| Pins | 2 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Rated capacitance | C |  | 0.68 |  | µF | 120 Hz/25°C | 10 |
| Capacitance tolerance (M = ±20%) |  | -20 |  | 20 | % | M suffix in part number | 2 |
| Rated voltage |  |  | 20 |  | VDC | VDC at 85°C | 10 |
| DC leakage current | DCL |  |  | 0.5 | µA | +25°C, maximum/5 minutes | 10 |
| Dissipation factor | DF |  |  | 4 | % | +25°C, 120 Hz maximum | 10 |
| Equivalent series resistance | ESR |  |  | 12 | Ω | +25°C, 100 kHz maximum | 10 |
| Maximum allowable ripple current |  |  |  | 79 | mA | 100 kHz, +25°C | 10 |
| Maximum allowable ripple current |  |  |  | 71 | mA | 100 kHz, +85°C | 10 |
| Maximum allowable ripple current |  |  |  | 32 | mA | 100 kHz, +125°C | 10 |
| Capacitance change vs temperature at −55°C | Δ C/C | -10 |  | 10 | % | Temperature stability, −55°C step | 3 |
| Capacitance change vs temperature at +85°C | Δ C/C | -10 |  | 10 | % | Temperature stability, +85°C step | 3 |
| Capacitance change vs temperature at +125°C | Δ C/C | -20 |  | 20 | % | Temperature stability, +125°C step | 3 |
| Endurance capacitance change | Δ C/C | -10 |  | 10 | % | 85°C at rated voltage, 2,000 hours | 3 |
| Storage life capacitance change | Δ C/C | -10 |  | 10 | % | 125°C at 0 volts, 2,000 hours | 3 |
| Thermal shock capacitance change | Δ C/C | -5 |  | 5 | % | MIL-STD-202 Method 107 Condition B, −55°C to 125°C, 1,000 cycles | 3 |
| Surge voltage capacitance change | Δ C/C | -5 |  | 5 | % | 85°C, 1.32 x rated voltage, 1,000 cycles | 3 |
| Mechanical shock/vibration capacitance change | Δ C/C | -10 |  | 10 | % | MIL-STD-202 Method 213 Condition I and Method 204 Condition D | 3 |
| Operating temperature range |  | -55 |  | 125 | °C |  | 2 |
| Maximum power dissipation (case A) | P max |  |  | 75 | mW | 25°C w/+20°C rise | 14 |
| Recommended maximum application voltage |  |  |  | 50 | % of VR | −55°C to 85°C | 14 |
| Recommended maximum application voltage |  |  |  | 33 | % of VR | 85°C to 125°C | 14 |
| Permissible transient reverse voltage |  |  |  | 15 | % of rated voltage | 25°C, short periods | 15 |
| Permissible transient reverse voltage |  |  |  | 5 | % of rated voltage | 85°C, short periods | 15 |
| Permissible transient reverse voltage |  |  |  | 1 | % of rated voltage | 125°C, short periods | 15 |
| Reflow temperature |  |  |  | 260 | °C | Reflow, ≤ 260 °C rating column | 5 |
| Maximum storage temperature |  |  |  | 40 | °C | Storage | 16 |
| Maximum storage humidity |  |  |  | 60 | % RH | Storage | 16 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts |  | gold | solder systems. Tin/lead (Sn/Pb) terminations are available upon request for any part number. Gold-plated terminations | 1 |

## CAD (KiCad official)

- Symbol: `T491A684M020AT`
- Footprint: `Capacitor_Tantalum_SMD:CP_EIA-3216-18_Kemet-A`
- 3D model: A (EIA 3216-18) (KiCad packages3D, STEP)
- 3D model files: `t491a684m020at-etched.step` / `t491a684m020at-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `t491a684m020at.step` / `t491a684m020at.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [KEMET datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590437065650708480) (23 pp, sha256 `c90877715d84e98b`, retrieved 2026-11-10, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins`, primary `polarised-capacitor convention` (convention), consensus `off` (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/t491a684m020at-datasheet.pdf)