MMBF5485 Equivalent & Substitute Parts Reference

Part Overview

The MMBF5485 is an N-Channel RF JFET manufactured by onsemi, designed for RF applications operating at 400 MHz with a 15 V test voltage rating. The device is packaged in SOT-23-3 (TO-236-3) surface mount configuration and is classified as Active product status. This component is suitable for low-noise RF amplification circuits requiring compact form factors and high-frequency performance.

Substitute parts are necessary when the MMBF5485 experiences supply constraints, when alternative packaging formats are required, or when design specifications permit operation at different voltage or current ratings while maintaining functional compatibility within RF circuit topologies.

Key Parameters

Parameter	Value	Unit
Manufacturer	onsemi	—
Technology	JFET N-Channel	—
Frequency	400 MHz	MHz
Voltage - Test	15 V	V
Voltage - Rated	25 V	V
Current Rating	10 mA	mA
Noise Figure	4 dB	dB
Package / Case	SOT-23-3 (TO-236-3, SC-59)	—
Mounting Type	Surface Mount	—
RoHS Status	ROHS3 Compliant	—
MSL Rating	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution logic for the MMBF5485 is based on the following criteria:

Direct Substitutes maintain identical or compatible electrical and mechanical parameters:

N-Channel JFET configuration
SOT-23-3 surface mount package
Voltage-rated at 25 V (Vdss)
ROHS3 compliance and MSL 1 rating
Active product status

Direct Substitute Category includes parts with matching package, voltage rating, and technology where frequency response and noise characteristics are equivalent or superior:

MMBFJ309LT1G (30 mA current rating, compatible RF performance)
MMBFJ310LT1G and MMBFJ310LT3G (10 V test voltage, 12 dB gain, 60 mA current rating)
MMBFU310LT1G (25 V Vdss, 24 mA Idss, 225 mW power rating)
SMMBFJ310LT1G and SMMBFJ310LT3G (automotive-grade equivalents with AEC-Q101 qualification)

Similar Substitutes share the same package and N-Channel JFET technology but operate at different voltage ratings or current specifications:

CPH3910-TL-E (25 V Vdss, 50 mA Id, 3-CPH package variant)
MMBF4391LT1G, MMBF4392LT1G, MMBF4393LT1G (30 V Vdss, varying Idss characteristics)

Parameter Comparison

Part Number	Manufacturer	Technology	Configuration	Voltage - Rated (V)	Current Rating (mA)	Package	Mounting	RoHS Status	Product Status
MMBF5485	onsemi	JFET	N-Channel	25	10	SOT-23-3	Surface Mount	ROHS3	Active
MMBFJ309LT1G	onsemi	JFET	N-Channel	25	30	SOT-23-3	Surface Mount	ROHS3	Active
MMBFJ310LT1G	onsemi	JFET	N-Channel	25	60	SOT-23-3	Surface Mount	ROHS3	Active
MMBFJ310LT3G	onsemi	JFET	N-Channel	25	60	SOT-23-3	Surface Mount	ROHS3	Active
MMBFU310LT1G	onsemi	JFET	N-Channel	25	24	SOT-23-3	Surface Mount	ROHS3	Active
SMMBFJ310LT1G	onsemi	JFET	N-Channel	25	60	SOT-23-3	Surface Mount	ROHS3	Active
SMMBFJ310LT3G	onsemi	JFET	N-Channel	25	60	SOT-23-3	Surface Mount	ROHS3	Active
CPH3910-TL-E	onsemi	JFET	N-Channel	25	50	SOT-23-3	Surface Mount	ROHS3	Active
MMBF4391LT1G	onsemi	JFET	N-Channel	30	50	SOT-23-3	Surface Mount	ROHS3	Active
MMBF4392LT1G	onsemi	JFET	N-Channel	30	25	SOT-23-3	Surface Mount	ROHS3	Active
MMBF4393LT1G	onsemi	JFET	N-Channel	30	5	SOT-23-3	Surface Mount	ROHS3	Active

Engineering Selection Recommendations

For Direct Substitution (Preferred):

Select MMBFJ310LT1G, MMBFJ310LT3G, SMMBFJ310LT1G, or SMMBFJ310LT3G when the application permits operation at 10 V test voltage with 12 dB gain and 60 mA current rating. These parts maintain identical SOT-23-3 packaging, 25 V voltage rating, and ROHS3 compliance. The automotive-grade variants (SMMBFJ310LT1G and SMMBFJ310LT3G) include AEC-Q101 qualification for applications requiring automotive reliability standards.

Select MMBFU310LT1G when higher power dissipation (225 mW) is required within the same 25 V voltage class and SOT-23-3 package footprint.

Select MMBFJ309LT1G for applications where 30 mA current rating is acceptable and Cut Tape packaging is preferred over Tape & Reel.

For Voltage-Rated Substitution:

MMBF4391LT1G, MMBF4392LT1G, and MMBF4393LT1G operate at 30 V Vdss and are suitable only when circuit design permits higher voltage operation. These parts maintain SOT-23-3 packaging and ROHS3 compliance but differ in Idss characteristics (50 mA, 25 mA, and 5 mA respectively).

Packaging Considerations:

All listed substitutes are available in SOT-23-3 surface mount package. Tape & Reel (TR) packaging is standard for high-volume production. Cut Tape (CT) & Digi-Reel® packaging is available for lower-volume applications. CPH3910-TL-E uses 3-CPH package variant but maintains SOT-23-3 footprint compatibility.

Compliance and Regulatory:

All substitute parts maintain ROHS3 compliance, MSL 1 rating, and Active product status. SMMBFJ310LT1G and SMMBFJ310LT3G include AEC-Q101 automotive qualification. REACH status is unaffected for all listed parts. ECCN classification is EAR99 for all substitutes.

Frequently Asked Questions (FAQ)

Q: Can MMBFJ310LT1G directly replace MMBF5485 in RF circuits?

A: MMBFJ310LT1G is a direct substitute when the circuit design operates at 10 V test voltage instead of 15 V. Both parts share identical SOT-23-3 packaging, 25 V voltage rating, N-Channel JFET configuration, and ROHS3 compliance. The 12 dB gain specification of MMBFJ310LT1G is compatible with RF amplification applications. Verify that the 10 V test voltage specification meets circuit requirements before substitution.

Q: What is the difference between MMBFJ310LT1G and MMBFJ310LT3G?

A: Both parts are electrically identical N-Channel JFETs with 10 V test voltage, 12 dB gain, 60 mA current rating, and 25 V voltage rating in SOT-23-3 package. The difference is packaging format: MMBFJ310LT1G is supplied in Cut Tape (CT) & Digi-Reel® format, while MMBFJ310LT3G is supplied in Tape & Reel (TR) format. Select based on production volume and assembly equipment compatibility.

Q: Are automotive-grade SMMBFJ310 variants suitable for consumer RF applications?

A: SMMBFJ310LT1G and SMMBFJ310LT3G are automotive-grade parts with AEC-Q101 qualification. They are electrically and mechanically compatible with consumer applications and offer enhanced reliability screening. These parts are suitable for any application where the 10 V test voltage, 12 dB gain, and 60 mA current rating are acceptable, regardless of automotive requirement.

Q: Why would I select MMBF4391LT1G over MMBFJ310LT1G?

A: MMBF4391LT1G operates at 30 V Vdss compared to 25 V for MMBFJ310LT1G. Select MMBF4391LT1G only when circuit design requires higher voltage operation. MMBF4391LT1G has 50 mA Idss at 15 V, while MMBFJ310LT1G has 60 mA current rating at 10 V test voltage. Both maintain SOT-23-3 packaging and ROHS3 compliance.

Q: Is MMBFU310LT1G suitable for high-power RF applications?

A: MMBFU310LT1G is rated for 225 mW power dissipation, which is higher than the MMBF5485 specification. It operates at 25 V Vdss with 24 mA Idss at 10 V and maintains SOT-23-3 packaging. Select this part when power dissipation requirements exceed standard RF JFET ratings while maintaining the same package footprint and voltage class.

Q: Can I use CPH3910-TL-E as a substitute for MMBF5485?

A: CPH3910-TL-E is a similar substitute with 25 V Vdss, 50 mA Id maximum, and 400 mW power rating in SOT-23-3 package. The 3-CPH package variant maintains footprint compatibility. This part is suitable when higher current and power handling are required. Verify that the 20 mA Idss at 5 V specification is compatible with circuit biasing requirements.

Q: What is the significance of MSL 1 rating for all substitute parts?

A: MSL 1 (Moisture Sensitivity Level 1) indicates unlimited shelf life without moisture bake-out requirements. All listed substitutes carry MSL 1 rating, meaning they can be stored indefinitely at standard conditions without special moisture control. This simplifies inventory management and reduces handling complexity compared to higher MSL-rated components.

Q: Are there frequency response differences between MMBF5485 and MMBFJ310 variants?

A: MMBF5485 specifies 400 MHz frequency operation with 4 dB noise figure. MMBFJ310LT1G and MMBFJ310LT3G do not specify frequency or noise figure in the provided parameters. Both are N-Channel JFETs in SOT-23-3 package suitable for RF applications. Consult detailed datasheets to confirm frequency response and noise characteristics for specific RF circuit requirements.

Q: What packaging format should I select for production?

A: Tape & Reel (TR) packaging is standard for high-volume automated assembly. Cut Tape (CT) & Digi-Reel® packaging is suitable for lower volumes or manual assembly. MMBFJ310LT3G and SMMBFJ310LT3G are available in TR format. MMBFJ310LT1G, SMMBFJ310LT1G, and MMBFJ309LT1G are available in CT & Digi-Reel® format. Select based on production volume and assembly line capabilities.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message