FMMT634TA Diodes Inc. Transistor Darlington Pair (SOT23 (3-Pin)) In Stock
Diodes Inc. FMMT634TA is an NPN Darlington transistor in a compact SOT-23 3-pin package with 100 V collector-emitter voltage, 0.9 A collector current, and an extremely high DC current gain of 15000 minimum. It targets low-power switching, relay driving, and signal amplification applications requiring ultra-high current gain from a small surface mount device.
- Manufacturer
- Diodes Inc.
- Package
- SOT23 (3-Pin)
- Pin Count
- 3
- Lifecycle
- ACTIVE
- Datasheet
- FMMT634TA Datasheet PDF
- Category
- Transistor Darlington Pair
- Price
- From $0.2600(MOQ 50)
- Temp Range
- ?°C to 150.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What are the key features of FMMT634TA?
- Ultra-high DC current gain (hFE) minimum of 15000 enables microcontroller I/O pins to directly drive relay coils and LED arrays
- 100 V collector-emitter breakdown voltage (VCEO) supports switching in higher-voltage industrial and automotive-adjacent circuits
- 0.9 A maximum collector current handles small motor inrush and relay switching loads from a tiny SOT-23 footprint
- NPN Darlington configuration in SOT-23 saves board space vs. discrete two-transistor alternatives while achieving equivalent gain
What is FMMT634TA used for?
The FMMT634TA is used to interface low-current microcontroller outputs with relay coils, solenoids, and LED driver stages in industrial automation and consumer electronics. Its 15000 minimum hFE allows a single 1 mA base drive to switch up to 0.9 A collector loads, making it ideal for battery-powered IoT sensors where driving power must be minimized. The SOT-23 package suits compact motor control boards, home automation modules, and wearable device actuator drivers requiring a high-gain NPN Darlington in a minimal footprint.
What are the specifications of FMMT634TA?
| Pbfree Code | Yes |
| Factory Lead Time | 12Weeks |
| YTEOL | 7 |
| Collector Current-Max (IC) | 0.9A |
| Collector-Emitter Voltage-Max | 100V |
| Configuration | DARLINGTON |
| DC Current Gain-Min (hFE) | 15000 |
| JESD-30 Code | R-PDSO-G3 |
| JESD-609 Code | e3 |
| Number of Elements | 1 |
| Package Body Material | PLASTIC/EPOXY |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 260 |
| Polarity/Channel Type | NPN |
| Power Dissipation-Max (Abs) | 0.806W |
| Qualification Status | Not Qualified |
| Surface Mount | YES |
| Terminal Finish | MATTE TIN |
| Terminal Form | GULL WING |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Transistor Element Material | SILICON |
| Package | SOT23 (3-Pin) |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| Country of Origin | Mainland China |
Where can I find the FMMT634TA datasheet?
FMMT634TA Datasheet DownloadOfficial datasheet from Diodes Inc.
What are equivalent replacements for FMMT634TA?
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
How does the FMMT634TA's 15000 minimum hFE benefit microcontroller-to-relay interface designs?
With a minimum DC current gain of 15000, the FMMT634TA allows a microcontroller GPIO pin sourcing as little as 0.1 mA to drive a relay coil requiring 1 A; this eliminates the need for a driver IC or discrete Darlington pair in 3.3 V or 5 V logic systems, simplifying the schematic and reducing BOM cost for relay-heavy automation controllers.
Can the FMMT634TA switch inductive loads on 48 V DC relay coils given its 100 V VCEO rating?
Yes, the FMMT634TA's 100 V collector-emitter breakdown voltage safely handles 48 V DC coils with inductive flyback spikes; a flyback diode across the coil is still required to clamp the spike below 100 V, and the 0.9 A collector current rating must not be exceeded continuously to keep junction temperature within the SOT-23 package's thermal limits.
When would an engineer select the FMMT634TA over a single NPN BJT such as the 2N3904 for a sensor output stage?
An engineer selects the FMMT634TA when the load current exceeds the base drive capability of a single NPN like the 2N3904 (hFE typically 100-300); the FMMT634TA's 15000 hFE Darlington stage drives 0.9 A loads from under 100 µA base current, while the 2N3904 would require 3 mA to 9 mA base current for the same load, making the Darlington a better choice for energy-constrained IoT and wearable applications.
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Why Buy from FindMyChip
About Diodes Inc.
Diodes Inc. is a leading electronic component manufacturer. FindMyChip sources Diodes Inc. ICs directly from authorized China distributors, offering competitive pricing and reliable stock.
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 50+ | $0.5430 | $27.15 |
| 100+ | $0.4412 | $44.12 |
| 250+ | $0.4120 | $103.00 |
| 500+ | $0.3403 | $170.16 |
| 1000+ | $0.3078 | $307.81 |
| 3000+ | $0.2600 | $780.00 |
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