MMBT2907A-7-F

The MMBT2907A-7-F is a PNP small-signal bipolar junction transistor (BJT) manufactured by Diodes Incorporated using an epitaxial planar die construction process. Designed for low-power amplification and general-purpose switching, this device offers a collector-emitter voltage rating of -60 V and a continuous collector current capability of -600 mA, making it versatile enough for a wide range of signal-level and low-power load-driving applications. The transistor achieves a minimum DC current gain (hFE) of 100 at IC = -150 mA, providing strong signal amplification with minimal base drive current. Its low collector-emitter saturation voltage of typically -0.4 V at IC = -150 mA ensures efficient switching with minimal conduction losses, which is critical in battery-powered and portable device applications where power efficiency directly impacts operating lifetime. The device features a transition frequency of 200 MHz, enabling use in medium-frequency amplifier circuits. Encapsulated in a compact SOT-23-3 surface-mount package, the MMBT2907A-7-F is ideally suited for high-density PCB layouts. It is AEC-Q101 qualified, meeting the stringent reliability requirements of automotive electronics, and is fully lead-free, halogen-free, and antimony-free (Green device). The complementary NPN counterpart, MMBT2222A, enables designers to implement balanced push-pull amplifier stages and complementary switching circuits with matched electrical characteristics.

The MMBT2907A-7-F operates as a PNP bipolar junction transistor through three distinct operating regions:

1. Active Region (Amplification): When the base-emitter junction is forward-biased (VBE negative for PNP) and the base-collector junction is reverse-biased, the transistor operates in the active region. A small base current (IB) controls a much larger collector current (IC), with the ratio defined by the DC current gain hFE. At IC = -150 mA and VCE = -10 V, hFE ranges from 100 to 300, providing substantial signal amplification. The epitaxial planar construction ensures consistent gain characteristics across the operating temperature range.

2. Saturation Region (Switching ON): When both the base-emitter and base-collector junctions are forward-biased, the transistor enters saturation. In this state, the collector-emitter voltage drops to VCE(sat), which is typically -0.4 V at IC = -150 mA and IB = -15 mA. The low saturation voltage minimizes power dissipation during the ON state, making the device efficient as a load switch. At higher currents (IC = -500 mA), VCE(sat) increases to a maximum of -1.6 V.

3. Cut-Off Region (Switching OFF): When the base-emitter junction is not sufficiently forward-biased (VEB < |VBE(on)|), the transistor is in cut-off. Collector current reduces to the leakage level (ICBO max = -10 nA at VCB = -50 V), effectively isolating the load from the supply. The Ioff condition ensures minimal standby power consumption, critical for battery-operated circuits. The transition frequency (fT) of 200 MHz defines the upper bandwidth limit where current gain drops to unity. In practical amplifier circuits, useful gain is available up to approximately fT / hFE, providing adequate bandwidth for audio and medium-frequency signal processing applications.

• Low-power audio and sensor signal amplification: Provides high gain (hFE 100-300) for amplifying weak signals from microphones, temperature sensors, and photodiodes in portable and battery-operated devices
• General-purpose load switching: Drives relays, LEDs, buzzers, and small DC motors with efficient low-saturation switching (VCE(sat) = -0.4 V typ)
• Logic-level and voltage translation: Interfaces between different voltage domains in mixed-signal systems, leveraging the -60 V VCEO rating
• Complementary push-pull amplifiers: Paired with the MMBT2222A (NPN complement) for Class B/AB audio output stages and totem-pole driver configurations
• Automotive electronics (AEC-Q101): Signal conditioning and load control in body electronics, lighting modules, and sensor interfaces