BS170 N-Channel Mosfet Pinout, features & Applications

Introduction to BS170 N-Channel Mosfet:

The BS170 is a small yet powerful N-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) that has found its place in various electronic circuits. Its compact size and impressive performance make it a favorite among electronics enthusiasts and professionals alike. In this article, we will delve deeper into what the BS170 is, its breakdown, features, specifications, pinout, applications, and equivalent alternatives.

What is BS170?

The BS170 is a low-power N-channel MOSFET designed for switching applications. MOSFETs are essential components in electronics, used for various purposes, including amplification, signal processing, and switching. The “N-channel” designation means that it conducts when a positive voltage is applied to its gate relative to its source.

Breakdown of BS170:

The BS170 is a tiny semiconductor device with three main terminals: Gate (G), Drain (D), and Source (S). It operates based on the principle of controlling the flow of current between the Drain and Source terminals by applying a voltage to the Gate terminal. It can handle low to moderate power levels and is primarily better for low-voltage, low-current switching applications.

Features of BS170:

TypeN-channel MOSFET
Threshold Voltage (Vgs)Low (typically around 2.0V)
Switching SpeedFast
Form FactorSmall (TO-92, SOT-23, D2PAK options)
On-Resistance (Rds(on))Low (typically around 5 Ohms)
Current Rating (Id)500mA
Temperature StabilityExcellent
ESD ProtectionYes
RoHS ComplianceYes
Voltage Range (Vds)Up to 60V
AvailabilityReadily available

Specifications of BS170 (Table):

BS170N-channel MOSFET
VdsDrain-Source Voltage (Maximum): 60V
VgsGate-Source Voltage (Maximum): ±20V
IdContinuous Drain Current: 500mA
Rds(on)On-Resistance (Maximum): 5 Ohms
PackageTO-92, SOT-23, and D2PAK (varies by manufacturer)

Pinout of BS170 MOSFET

Pin Configuration of BS170 MOSFET

Pin NamePin Description
Gate (G)Controls the MOSFET
Drain (D)Current flows out of here
Source (S)Current flows in here

Applications of BS170:

  1. Switching low-power loads in electronic devices.
  2. Signal amplification in audio circuits.
  3. LED dimming and control.
  4. Voltage level shifting.
  5. Motor control in robotics.
  6. Battery management systems.
  7. Solar power converters.
  8. Overcurrent protection.
  9. Audio signal switching.
  10. Pulse-width modulation (PWM) control.

Equivalent Alternatives:

  1. 2N7000
  2. IRFZ44N
  3. FQP30N06L
  4. NDP6020P
  5. BSS138

In conclusion, the BS170 is a versatile N-channel MOSFET with a wide range of applications in the world of electronics. Its compact size, low on-resistance, and affordability make it a popular choice among designers and hobbyists. Whether you’re working on a small-scale project or a more significant electronic endeavor, the BS170 is worth considering for your switching needs.


1. What is the BS170 MOSFET used for?

  • The BS170 MOSFET is primarily used for switching applications in electronic circuits.

2. What does “N-channel” mean in the context of the BS170?

  • “N-channel” indicates that the BS170 conducts when a positive voltage is applied to its gate terminal relative to its source.

3. What is the typical threshold voltage for the BS170?

  • The typical threshold voltage (Vgs) for the BS170 is around 2.0 volts.

4. What is the maximum Drain-Source Voltage (Vds) it can handle?

  • The BS170 can handle a maximum Drain-Source Voltage (Vds) of 60 volts.

5. What is the maximum continuous Drain current (Id) rating for the BS170?

  • The maximum continuous Drain current (Id) rating for the BS170 is 500mA.

6. Can I use the BS170 for high-power applications?

  • No, the BS170 is better for low to moderate-power applications due to its limited current-handling capacity.

7. What packages are available for the BS170?

  • The BS170 is available in various packages, including TO-92, SOT-23, and D2PAK, depending on the manufacturer.

8. Is the BS170 environmentally friendly?

  • Yes, the BS170 is RoHS compliant, which means it adheres to environmental regulations.

9. What are some common alternatives to the BS170?

  • Common alternatives to the BS170 include 2N7000, IRFZ44N, FQP30N06L, NDP6020P, and BSS138.

10. What are some typical applications for the BS170? – The BS170 is used in a variety of applications, including LED dimming, motor control, audio signal switching, battery management systems, and voltage level shifting, among others.

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