onsemi PN3640_D75Z

Overview

PN3640_D75Z from ON Semiconductor is a PNP bipolar junction transistor optimized for high-speed saturated switching at collector currents up to 100 mA. It features V_CEO = −12 V, I_C = −200 mA continuous, f_T = 500 MHz, V_CE(sat) = −0.20 V (at I_C = −10 mA, I_B = −1.0 mA), and SOT-23 package - used in compact DC-DC converter control stages and logic-level interface drivers.

For engineers reviewing the PN3640_D75Z datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed V_CEO/V_CB rating symmetry, low saturation voltage under fast-switching conditions, thermal resistance (R_θJA = 556 °C/W), and compatibility with standard SOT-23 PCB footprints and tape-and-reel handling.

Technical Context

This device implements a planar epitaxial PNP structure fabricated on Fairchild's Process 65, enabling tight parameter distribution and stable gain (h_FE = 30–120 at I_C = −10 mA) across temperature. Its low Cob (3.5 pF) and Cib (3.5 pF) support clean edge transitions in digital switching applications.

Designed for saturated-mode operation, it delivers sub-35 ns turn-off time (t_off) and 25 ns turn-on time (t_on) under −50 mA load with −5.0 mA base drive, making it suitable for pulse-width modulation (PWM) signal inversion and level-shifting where propagation delay and storage time must be minimized.

Key Specifications

Pinout & Package

SOT-23 (TO-236AB) 3-lead surface-mount package with gull-wing leads; marked "2J" on top surface. Standard JEDEC footprint with 0.95 mm lead pitch and 1.30 mm body width.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP switching amplifier applications.

Compared with MMBT3906LT1G and DXT3640-7, PN3640_D75Z offers the best balance of speed (500 MHz f_T, 35 ns t_off) and thermal performance (556 °C/W) in the standard SOT-23 form factor - making it preferred for high-frequency, thermally sensitive switching nodes.

Availability

PN3640_D75Z is available at Aetrix Electronics and suitable for DC-DC converter drivers, logic-level inverters, and LED current-sink applications requiring stable component supply, consistent parametric binning, and long-term production continuity.

Supply support for PN3640_D75Z includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

ON Semiconductor (formerly Fairchild Semiconductor) is a global supplier of energy-efficient semiconductor components, specializing in power management, analog, and discrete devices for automotive, industrial, and computing markets.

PN3640_D75Z belongs to ON Semiconductor's legacy high-speed PNP transistor product line, originally developed for precision saturated switching in power conversion and digital interface circuits - emphasizing speed, consistency, and manufacturability in SOT-23 packaging.

FAQ

What is the maximum continuous collector current rating for PN3640_D75Z?

The PN3640_D75Z has a maximum continuous collector current (I_C) rating of −200 mA at T_A = 25°C. This rating decreases linearly above 25°C at 1.8 mW/°C due to thermal derating. Operation at −200 mA requires adequate PCB copper area and ambient temperature control to maintain junction temperature below 150°C - verified in the absolute maximum ratings table of the official PN3640_D75Z datasheet.

Does PN3640_D75Z support operation at elevated temperatures such as +105°C ambient?

Yes, PN3640_D75Z is rated for junction temperatures from −55°C to +150°C and storage temperatures across the same range. At +105°C ambient, its usable collector current drops to approximately −80 mA (based on 1.8 mW/°C derating from 225 mW PD). The device remains fully functional within specifications as long as the calculated junction temperature stays ≤150°C - confirmed by thermal characterization data in the PN3640_D75Z datasheet.

What is the typical base-emitter saturation voltage (V_BE(sat)) for PN3640_D75Z under standard switching conditions?

The typical V_BE(sat) for PN3640_D75Z is −0.80 V to −1.00 V at I_C = −10 mA and I_B = −1.0 mA, per the electrical characteristics table. This range reflects process variation and ensures sufficient base drive margin for reliable saturation across production lots - a key parameter for designing robust base resistor networks in PN3640_D75Z-based switch circuits.

Is PN3640_D75Z pin-compatible with the MMBT3906 series?

No, PN3640_D75Z is not pin-compatible with the MMBT3906 series. While both are PNP transistors in SOT-23 packages, PN3640_D75Z uses emitter-base-collector (E-B-C) pinout (Pin 1 = E, Pin 2 = B, Pin 3 = C), whereas MMBT3906 uses emitter-collector-base (E-C-B) pinout (Pin 1 = E, Pin 2 = C, Pin 3 = B). Swapping them without layout revision will cause circuit failure - verified by comparing the PN3640_D75Z and MMBT3906LT1G package drawings and pin function tables.

Can PN3640_D75Z be used in linear amplifier configurations, or is it strictly for switching?

PN3640_D75Z is characterized and optimized for saturated switching applications, with specified parameters like t_on, t_off, and V_CE(sat) reflecting that use case. While its h_FE (30–120) supports basic linear amplification, the datasheet does not guarantee linearity, distortion, or frequency response in analog gain stages. For linear operation, dedicated general-purpose PNP transistors with AC performance characterization - not PN3640_D75Z - should be selected.