2N7000
| Type | MOSFET Transistor |
|---|---|
| Working principle | N-channel |
| Pin names | G = Gate, D = Drain, S = Source. The symbol doesn't always show the internal diode formed between the substrate and the source/drain/channel. |
| Electronic symbol | |
 | |
The 2N7000 and BS170 are two different N-channel, enhancement-mode MOSFETs used for low-power switching applications, with different lead arrangements and current ratings. They are sometimes listed together on the same datasheet with other variants 2N7002, VQ1000J, and VQ1000P.[1]
The 2N7000 is a widely available and popular part, often recommended as useful and common components to have around for hobbyist use.[2] The BS250P is "a good p-channel analog of the 2N7000."[3]
Packaged in a TO-92 enclosure, both the 2N7000 and BS170 are 60 V devices. The 2N7000 can switch 200 mA. The BS170 can switch 500 mA, with a maximum on-resistance of 5 Ω at 10 V Vgs.
The 2N7002 is another different part with different resistance, current rating and package. The 2N7002 is in a TO-236 package, also known as "small outline transistor" SOT-23 surface-mount, which is the most commonly used three-lead surface-mount package.[4]
Applications
The 2N7000 has been referred to as a "FETlington" and as an "absolutely ideal hacker part."[5] The word "FETlington" is a reference to the Darlington-transistor-like saturation characteristic.
A typical use of these transistors is as a switch for moderate voltages and currents, including as drivers for small lamps, motors, and relays.[1] In switching circuits, these FETs can be used much like bipolar junction transistors, but have some advantages:
- low threshold voltage means no gate bias required
- high input impedance of the insulated gate means almost no gate current is required
- consequently no current-limiting resistor is required in the gate input
- MOSFETs, unlike PN junction devices (such as LEDs) can be paralleled because resistance increases with temperature
The main disadvantages of these FETs over bipolar transistors in switching are the following:
- susceptibility to cumulative damage from static discharge prior to installation
- circuits with external gate exposure require a protection gate resistor or other static discharge protection
- Non-zero ohmic response when driven to saturation, as compared to a constant junction voltage drop in a bipolar junction transistor
References
- ^ a b "2N7000/2N7002, VQ1000J/P, BS170" (PDF). Vishay Siliconix datasheet. Retrieved 28 March 2011.
- ^ H. Ward Silver (2005). Two-way radios & scanners for dummies. p. 237. ISBN 0-7645-9582-2.
- ^ Lucio Di Jasio; Tim Wilmshurst; Dogan Ibrahim (2007). PIC microcontrollers. Newnes. p. 520. ISBN 0-7506-8615-4.
- ^ Ray P. Prasad (1997). Surface mount technology: principles and practice (2nd ed.). Springer. p. 112. ISBN 0-412-12921-3.
- ^ Lancaster, Don (February 1986). "Hardware hacker". Modern Electronics. 3 (2). Richard Ross: 115. ISSN 0748-9889.
External links
- Application Notes for Experimenters
- Electric Field Sensor demonstrates extremely high gate impedance with a simple LED circuit
- Driving a single MOSFET Detailed description of usage of a similar MOSFET
- Datasheets
- 2N7002, 300mA, SOT-23 case, NXP Semiconductors
- NX7002AK, 300mA, SOT-23 case, NXP Semiconductors
- 2N7000, 200mA, TO-92 case, On Semiconductor
- BS170, 500mA, TO-92 case, On Semiconductor