MMBT589 bipolar transistor — Specifications & Equivalents

About the MMBT589

The MMBT589 is a PNP bipolar transistor with a collector–emitter voltage (V_CEO) rating of 30 V, a continuous collector current (I_C) of 1 A and a DC current gain (h_FE) of minimum 100. It can dissipate up to 0.31 W and is rated to a junction temperature of 150 °C. It is supplied in the SOT23 package.

At a glance

• Type: PNP bipolar transistor
• Max collector–emitter voltage (V_CEO): 30 V
• Max collector current (I_C): 1 A
• DC current gain (h_FE): minimum 100
• Transition frequency (f_T): 100 MHz
• Power dissipation (P_D): 0.31 W
• Max junction temperature (T_J): 150 °C
• Package: SOT23

Typical applications

Judging from its ratings the MMBT589 is generally applied in RF and high-speed switching stages.

A transition frequency (f_T) of 100 MHz indicates the frequency range over which useful current gain remains available.

The quoted current gain of minimum 100 determines the base drive needed: divide your target collector current by the minimum h_FE, not the typical figure, when sizing the base resistor.

Biasing and absolute maximum ratings

Absolute-maximum breakdown limits are V_CEO 30 V, V_CBO 50 V and V_EBO 5 V (magnitudes). The emitter–base rating is the easiest to overlook and is often only a few volts, so protect the junction against reverse drive.

Dissipation is capped at 0.31 W, and that figure assumes the datasheet's mounting and ambient conditions — derate it for your own thermal design.

Choosing a replacement for the MMBT589

A drop-in substitute for the MMBT589 must be the same PNP type and offer a collector–emitter rating of at least 30 V, a collector current rating of at least 1 A, current gain in the same ballpark as minimum 100 and a transition frequency of at least 100 MHz for the same bandwidth.

Mechanically, check the replacement against the SOT23 footprint and confirm the pin order — parts sharing a package outline do not always share a pinout.

Where the application switches inductive loads or runs near the voltage limit, keep extra headroom rather than choosing a part that only just meets the original numbers.

Frequently asked questions

What is the MMBT589?

The MMBT589 is a PNP bipolar junction transistor (BJT). It is rated for 30 V collector-emitter and 1 A continuous collector current.

What is the maximum voltage of the MMBT589?

Maximum collector-emitter voltage (Vceo) is 30 V, and collector-base (Vcbo) is 50 V.

How much current can the MMBT589 handle?

Continuous collector current is rated at 1 A, with dissipation limited to 0.31 W.

What is the hFE of the MMBT589?

DC current gain (hFE) is quoted as minimum 100. Size base drive from the minimum value so the transistor saturates fully across production spread.

What package does the MMBT589 come in?

It is listed in SOT23. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the MMBT589?

This page lists 17 candidate equivalents matched on electrical ratings and package. Any replacement should meet or exceed the original voltage, current and dissipation figures and use a compatible drive level.