onsemi MPS3638AG

Overview

MPS3638AG from ON Semiconductor is a PNP silicon switching transistor in TO-92 package, rated for −25 V V_CEO, −500 mA I_C, and 625 mW P_D at T_A = 25°C. It delivers h_FE ≥ 80 at I_C = −1.0 mA, V_CE = −10 V, and exhibits fast switching with t_on ≤ 75 ns and t_off ≤ 170 ns - used in low-voltage DC-DC converter control stages and relay driver circuits.

For engineers reviewing the MPS3638AG datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, guaranteed −25 V breakdown rating, confirmed TO-92 (CASE 29−11) lead configuration, and documented f_T = 150 MHz small-signal gain-bandwidth performance under specified bias conditions.

Technical Context

The MPS3638AG operates as a medium-speed, general-purpose PNP bipolar junction transistor optimized for saturated switching. Its design supports base-driven on/off control with V_BE(sat) ≤ −0.80 V at I_C = −50 mA and I_B = −2.5 mA, and V_CE(sat) ≤ −0.25 V under identical conditions.

Thermal performance is defined by R_JA = 200°C/W (PCB-mounted) and R_JC = 83.3°C/W, enabling operation across −55°C to +150°C junction temperature range. Small-signal parameters include h_fe = 100, C_ibo = 25 pF, and C_obo = 10 pF at specified test frequencies and bias points.

Key Specifications

Pinout & Package

Package: TO-92 (CASE 29−11, STYLE 1), plastic through-hole package with 3 leads, JEDEC-standard footprint and thermal profile for manual or wave soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPS3638AG, the 2N4403 offers higher voltage tolerance and current capacity but trades off switching speed, while the MPS2907A provides superior voltage rating and h_FE consistency at the expense of verified high-frequency response - making MPS3638AG optimal for cost-sensitive, medium-speed PNP switching where 150 MHz f_T and tight t_on/t_off are design-critical.

Availability

MPS3638AG is available at Aetrix Electronics and suitable for relay driver circuits, DC-DC converter switches, LED current sinks, and industrial sensor interfaces requiring stable component supply across automotive, industrial control, and embedded instrumentation programs.

Supply support for MPS3638AG 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MPS3638AG belongs to ON Semiconductor's general-purpose bipolar transistor product line, designed specifically for cost-effective, reliable discrete switching in low-to-medium frequency power control and signal interface applications.

FAQ

What is the maximum junction temperature for the MPS3638AG?

The MPS3638AG has an operating junction temperature range of −55°C to +150°C, as specified in its Thermal Characteristics table. This allows use in under-hood automotive environments and high-temperature industrial enclosures. Derating begins above 25°C ambient per the 5.0 mW/°C PD slope, and thermal resistance values (R_JA = 200°C/W, R_JC = 83.3°C/W) enable accurate thermal modeling for PCB layout. The MPS3638AG must be operated within this absolute maximum rating to ensure long-term reliability.

Is the MPS3638AG RoHS-compliant and halogen-free?

Yes, the MPS3638AG is available in Pb-free packaging compliant with RoHS Directive 2011/65/EU and meets J-STD-609 Category 1 moisture sensitivity requirements. ON Semiconductor confirms that both standard and Pb-free versions share identical electrical specifications. The MPS3638AG does not contain brominated flame retardants (BFRs), antimony trioxide, or other restricted halogenated compounds per IPC-1752A reporting standards.

What are the exact pin assignments for the MPS3638AG in TO-92 package?

The MPS3638AG uses TO-92 (CASE 29−11, STYLE 1) with standardized pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector - verified in the official ON Semiconductor datasheet Figure 1 and Package Dimensions section. This configuration is consistent across all MPS3638A-series variants and differs from complementary NPN devices like MPS2222A. Correct orientation is critical for proper PNP biasing, as reversing emitter and collector will prevent saturation.

Does the MPS3638AG support linear (analog) operation, or is it optimized only for switching?

The MPS3638AG supports both saturated switching and linear operation, evidenced by its published h-parameters (h_ie, h_re, h_fe, h_oe) and small-signal characteristics including f_T = 150 MHz and noise figure data. While optimized for fast switching (t_on/t_off ≤ 75/170 ns), its h_fe stability across I_C = 0.1–300 mA and V_CE = −1.0 to −10 V makes it suitable for analog current mirrors and low-noise preamplifier stages. The MPS3638AG performs reliably in either mode when biased within its absolute maximum ratings.

How does the MPS3638AG compare to the MPS3638A in terms of specifications and compatibility?

The MPS3638AG is the Pb-free variant of the MPS3638A, sharing identical electrical, thermal, and mechanical specifications per ON Semiconductor's documentation. Both parts have identical V_CEO, I_C, h_FE, switching times, and TO-92 package dimensions. The "G" suffix denotes green (lead-free) compliance, with no functional or performance differences. The MPS3638AG may be used as a drop-in replacement for MPS3638A in new designs and is recommended for RoHS-constrained applications without layout or schematic changes.