NXP Semiconductors BAS21/MI,215

Overview

BAS21/MI,215 from NXP Semiconductors is a general-purpose silicon switching diode in SOT23 package, featuring 250 V repetitive peak reverse voltage (V_RRM), 200 mA continuous forward current (I_F), and 50 ns reverse recovery time (t_rr). It serves as a high-speed signal path switch or clamp in surface-mounted power management and interface circuits.

For engineers reviewing the BAS21/MI,215 datasheet, BAS21/MI,215 pinout, BAS21/MI,215 application, or BAS21/MI,215 equivalent, key selection criteria include its 250 V V_RRM, 50 ns t_rr, SOT23 footprint compatibility, and 100 nA reverse leakage at 200 V - critical for low-leakage, medium-voltage switching in space-constrained designs.

Technical Context

The BAS21/MI,215 is a planar-structured silicon diode optimized for general-purpose switching with fast turn-off behavior. Its 50 ns reverse recovery time and 5 pF junction capacitance support operation up to ~100 MHz in clipping, clamping, and logic-level translation.

It operates with a maximum junction temperature of 150 °C and thermal resistance of 500 K/W (junction-to-ambient on FR4), requiring minimal heatsinking in typical SMT layouts. The device has no internal connection on pin 2, confirming its use as a two-terminal diode in a three-pin SOT23 outline.

Key Specifications

Pinout & Package

Package: SOT23 (TO-236AB), plastic surface-mounted, 3-lead outline with pin 2 internally unconnected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar general-purpose switching diode applications.

Compared with MMBD2004LT1G and BAV21W-7-F, the BAS21/MI,215 uniquely combines 250 V V_RRM, SOT23-3 mechanical compatibility including NC pin 2, and 500 K/W R_{th j-a} - making it optimal for space-constrained, medium-voltage switching where pinout retention and thermal performance are jointly critical.

Availability

BAS21/MI,215 is available at Aetrix Electronics and suitable for power supply clamping, logic level translation, DC-DC feedback isolation, and high-voltage signal sampling requiring stable component supply across industrial and embedded production cycles.

Supply support for BAS21/MI,215 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer applications.

The BAS21/MI,215 belongs to NXP's general-purpose discrete diode product line, designed specifically for cost-sensitive, high-volume SMT switching applications demanding reliability, consistent parametric distribution, and JEDEC-standard packaging.

FAQ

What is the maximum repetitive peak reverse voltage for BAS21/MI,215?

The BAS21/MI,215 has a maximum repetitive peak reverse voltage (V_RRM) of 250 V, as specified in the NXP product data sheet dated March 2003. This rating applies under standard test conditions and defines the highest reverse voltage the diode can withstand repeatedly without breakdown. Exceeding this value risks irreversible avalanche failure. The BAS21/MI,215 achieves this rating while maintaining 100 nA reverse leakage at 200 V, supporting robust operation in medium-voltage circuits.

Is BAS21/MI,215 pin-compatible with other SOT23 diodes like BAS19 or BAS20?

Yes, the BAS21/MI,215 shares the same SOT23 package and pinout (anode–NC–cathode) with BAS19 and BAS20, but differs in voltage ratings: BAS19 has V_RRM = 120 V, BAS20 = 200 V, and BAS21/MI,215 = 250 V. All three use identical marking (JS∗), thermal characteristics, and 50 ns t_rr. Substitution requires verifying that the higher V_RRM does not affect circuit timing or leakage-sensitive nodes - the BAS21/MI,215 remains a direct physical replacement in existing SOT23 footprints.

What is the function of pin 2 on BAS21/MI,215?

Pin 2 of the BAS21/MI,215 is not connected (NC) - it has no internal semiconductor connection and must remain electrically floating. This is confirmed in the NXP datasheet pinning diagram and package outline. Unlike active three-terminal devices, the NC pin serves only mechanical alignment and thermal mass in the SOT23 mold; routing or grounding pin 2 may cause assembly defects or unintended parasitic coupling. The functional diode terminals are pin 1 (anode) and pin 3 (cathode).

Does BAS21/MI,215 support high-frequency signal switching?

Yes, the BAS21/MI,215 supports high-frequency signal switching up to approximately 100 MHz due to its 5 pF junction capacitance and 50 ns reverse recovery time. These parameters enable clean transitions in RF detector circuits, video sync clamping, and digital waveform shaping. However, its 200 mA I_F rating and 250 mW P_tot limit sustained RF power handling; for >10 MHz continuous operation, thermal derating per the FR4 ambient temperature curve (Figure 2) must be applied to avoid junction overheating.

What is the forward voltage drop of BAS21/MI,215 at typical operating current?

The forward voltage drop (V_F) of the BAS21/MI,215 is 1.0 V at 100 mA and 1.25 V at 200 mA, measured at T_j = 25 °C. This low V_F minimizes conduction loss in series-switched paths and ensures predictable clamping thresholds. The diode's planar construction provides tight V_F distribution across lots, supporting consistent performance in production assemblies. At elevated temperatures, V_F decreases by ~2 mV/°C, which must be considered in precision bias networks.