STE SMD NTC 2522 Thermistors for Higher Steady-State Current
STE NEWS
STE has introduced the compact SMD NTC 2522 series for surface-mount applications that need higher steady-state current.
In the 2522 size, maximum steady-state current is up to 4 A.
STE’s SMD NTC 2522 is a molded power thermistor for inrush-current suppression. The 2522 package code identifies a body measuring 6.0 ±0.1 × 5.55 ±0.1 × 2.38 ±0.1 mm, with inward-formed terminals and tape-and-reel packaging.
Which resistance options support 4 A?
Maximum steady-state current is specified at 25 °C. The 2.5 Ω and 3 Ω options are rated at 4 A; the 5 Ω option is rated at 3 A. The 4 A maximum applies to the relevant resistance options.
| Zero-power resistance at 25 °C | Maximum steady-state current at 25 °C | Residual resistance at maximum current, 25 °C |
|---|---|---|
| 2.5 Ω | 4 A | 0.113 Ω |
| 3 Ω | 4 A | 0.100 Ω |
| 5 Ω | 3 A | 0.156 Ω |
| 10 Ω | 2 A | 0.275 Ω |
Design for startup and continuous operation
A power NTC begins with a higher cold resistance to limit startup current. Its resistance falls as current heats the device. Selection therefore needs to account for both startup limiting and continuous current, residual resistance and heat dissipation.
The operating temperature range is −40 °C to +175 °C. Above 25 °C ambient, use the current derating curve in the datasheet. Check the thermal time constant, cooling conditions, land pattern and soldering requirements as well.
This is a power NTC. Temperature-sensing NTCs have different selection requirements; matching a resistance or package code alone does not establish interchangeability.
See the 2522 datasheet for dimensions, electrical characteristics and current derating.
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