BSS138 MOSFET

BSS138 MOSFET specification

• BSS138 is an N-channel logic level enhancement mode field effect transistor device
• Drain to source voltage (V_DSS) is 50V
• Gate to source voltage (V_GSS) is +/- 20V
• Gate to the threshold voltage (V_{GS (th)}) is 8V to 1.5V
• Drain current (I_D) is 22A
• Pulsed drain current (I_DM) is 88A
• Power dissipation is (P_D) is 300mW
• Total gate charge (Q_g) is 7 to 2.4nC
• Drain to source on-state resistance (R_{DS (ON)}) 7 to 5.8Ω
• Zero gate voltage drain current (I_DSS) is 5uA
• Turn on rise time (tr) is 9 to 18ns
• Turn on fall time (tf) is 7 to 14ns
• Input capacitance (C_iss) is 27pf
• Thermal resistance junction to ambient (R_th j-A) is 350℃/W
• Junction temperature (T_J) is between -55 to 150℃
• High cell density
• DMOS technology
• Designed to minimize on-state resistance
• Fast switching performance

BSS138 MOSFET Pinout

Pin Number	Pin Name	Description
1	GATE	The gate is used to trigger the MOSFET
2	SOURCE	In the source, terminal current flows out from the MOSFET
3	DRAIN	The drain terminal is the input of the MOSFET

 

The BSS138 is a surface-mounted transistor type mainly used to minimize on-state resistance.

BSS138 MOSFET package

The BSS138 N-channel logic level enhancement mode field effect transistor had a SOT-23 package, it is a surface mount package used for driver and power supply applications.

The SOT-23 is a three-terminal SMD version of the BSS138 MOSFET device, it is made up of a mixture of epoxy/plastic material.

The SOT-23 SMD version transistor package had higher heat resistance and was also very compact, these capabilities are due to the specialty of material used to build the component.

IRFP460 MOSFET

BSS138 MOSFET electrical specification explanation 

In this section, we try to explain the electrical specifications of the BSS138 MOSFET device.

These specification descriptions about the BSS138 MOSFET device will be very useful for a better understanding and it is very helpful for opting for the proper application for the BSS138 MOSFET device.

Voltage specs

The terminal voltage specs of BSS138 MOSFET are a drain to source voltage is 50V, the gate to source voltage is 20V, and the gate threshold voltage is 0.8V to 1.5V, it is the main voltage specs of this MOSFET device.

The voltage electrical specifications of this MOSFET show that this device is good at low voltage power supply and low load switching applications.

Current specs

The current specs of the BSS138 MOSFET drain current value is 0.22A, it is the current value this device produces.

The pulsed drain current value is 0.88A, it is the current value produced at the condition where pulse width increases.

The current specs of BSS138 MOSFET show that it is a less load-capable device mainly used for low-load applications.

Zero gate voltage drain current

The value for zero gate voltage drain current is 0.5uA, it is the current value of BSS138 MOSFET at a specific condition.

Dissipation specs

The power dissipation value of BSS138 MOSFET is 300mW, it is the power dissipation capacity of a MOSFET device in a thermal condition.

Drain to source on-state resistance

The drain to source on-state resistance is 0.7Ω to 5.8Ω, it is the overall resistance offered by the MOSFET.

Junction temperature

The junction temperature of the BSS138 MOSFET is –55 to +150℃.

Thermal resistance junction to ambient

The thermal resistance of BSS138 MOSFET is 350℃/W

Total gate charge

The total gate charge value of BSS138 is 1.7 to 2.4nC, it is the charge needed to trigger the MOSFET.

Input capacitance

The input capacitance of BSS138 MOSFET is 27Pf, it is the capacitance value offered by the MOSFET at its input.

Rise time

The rise time value for BSS138 MOSFET is 9 to 18ns, it is the switching time offered by the MOSFET.

Fall time

The fall time value for BSS138 MOSFET is 7 to 14ns

BSS138 MOSFET DATASHEET

If you need the datasheet in pdf please click this link

BSS138 MOSFET EQUIVALENT

The MOSFET equivalent of BSS138 is IRF540N, IRF1010E, 2N7000, 2N7002, FDC666, and NTR4003.

The electrical specification and PINOUT details of these MOSFET devices are the same, the applications based on BSS138 MOSFET are low voltage and low current circuits.

We need to check and verify the PINOUT details of each MOSFET before the replacement process.

BSS138 vs 2N7000 vs MMBF170 (BC170)

In this table, we try to list the electrical specifications of BSS138, 2N7000, and MMBF170, this is a better way to understand these MOSFET devices.

Characteristics	BSS138	2N7000	MMBF170 (BS170)
Drain to source  voltage (VDS))	50V	60V	60V
Gate to source voltage (Vgs)	20V	20V	20V
Gate threshold voltage (Vg(th))	0.8 to 1.5V	0.8 to 3V	0.8 to 3V
Drain current (Id)	0.22A	200mA	500mA
Zero gate voltage drain current (I­DSS)	0.5uA	1 to 10uA	0.5uA
Total gate charge (Qg)	1.7 to 2.4nC	1.4 to 2nC	-
Power dissipation (PD)	300mW	400mW	300mW
Junction temperature (TJ)	-55 to +150°C	-55 to +150°C	-55  to +150°C
Drain to source on-state resistance (RDS)	0.7 to 5.8Ω	1.2 to 9Ω	1.2 to 5Ω
Rise time (tr)	9 to 18ns	10ns	10ns
Input capacitance	27pf	20 to 50pf	24 to 40ns
Package	SOT-23	TO-92/SOT-23	SOT-23

Both BSS138 and 2N7000 MOSFETs have almost the same electrical specifications, they had the surface mount versions.

The MMBF170 MOSFET is the SMD version device mainly used for power supply and load driver circuits.

Characteristics curves of BSS138 MOSFET

The figure shows the On-region characteristics of BSS138 MOSFET, the graph is plotted with drain current vs drain to source voltage.

At a fixed gate to source voltage, the current increases with respect to drain to source voltage.

The figure shows the on-state resistance characteristics of BSS138 MOSFET, the graph is plotted with the drain to source on-state resistance vs drain current.

At different voltage variations, the on-state resistance value increases with voltage increases, and the drain current will be higher at initial current variations.

Applications of BSS138 MOSFET

• LOW voltage applications
• Low current applications
• Servo motor control
• Power MOSFET gate drivers