Taiwan Semiconductor Corporation BAS19 RFG

Overview

BAS19 RFG from Taiwan Semiconductor is a surface-mount fast-switching diode rated for 200 mA forward current and 100 V repetitive peak reverse voltage in SOT-23 package, with 1.25 V forward voltage at 200 mA and 50 ns reverse recovery time - used in compact SMPS secondary-side rectification and flyback snubber circuits.

For engineers reviewing the BAS19 RFG datasheet, BAS19 RFG pinout, BAS19 RFG application, or BAS19 RFG equivalent, key selection criteria include V_RRM margin vs. circuit transient stress, trr-driven switching loss in high-frequency converters, thermal resistance (R_θJA = 500°C/W) in constrained layouts, and halogen-free compliance for RoHS-aligned production.

Technical Context

The BAS19 RFG implements a single-die silicon PN junction optimized for fast recovery (trr ≤ 50 ns) under IF = IR = 30 mA, IRR = 0.1 × IR test conditions, enabling efficient operation in 100–500 kHz SMPS topologies. Its 100 V V_RRM rating targets mid-voltage secondary-side rectification where surge immunity and low leakage (<0.1 μA at 100 V, 25°C) are critical.

Thermally, the SOT-23 package delivers R_θJA = 500°C/W at standard JEDEC PCB layout, limiting continuous power dissipation to 250 mW at TA = 25°C. Junction temperature operates from –65°C to +150°C, supporting industrial ambient environments without derating below 125°C.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package with matte tin-plated leads, UL 94 V-0 molding compound, and JESD201 Class 1A whisker resistance. Weight: 8 ± 0.5 mg.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBD199LT1G and BAV19W-7-F, the BAS19 RFG provides identical switching performance and voltage rating while adding halogen-free construction and moisture sensitivity level 1 - making it preferred for export-bound, environmentally regulated, or high-reliability automated assembly programs.

Availability

BAS19 RFG is available at Aetrix Electronics and suitable for switching mode power supply (SMPS) rectification, flyback snubber networks, low-power bias generation, and signal-level transient protection requiring stable component supply and full RoHS/halogen-free compliance.

Supply support for BAS19 RFG 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving industrial, computing, and consumer markets since 1979.

The BAS19 RFG belongs to TSC's general-purpose fast-switching diode product line, engineered specifically for high-efficiency, space-constrained power conversion in cost-sensitive yet reliability-demanding applications.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) for the BAS19 RFG?

The BAS19 RFG has a specified V_RRM of 100 V, meaning it can safely block up to 100 V of reverse-biased voltage repeatedly without breakdown. This rating is validated per JEDEC test conditions with IR = 100 μA at TJ = 25°C. Exceeding this voltage risks irreversible avalanche failure. The BAS19 RFG must not be substituted with BAS20 RFG (150 V) unless circuit analysis confirms no transient overshoot exceeds 100 V.

Does the BAS19 RFG have halogen-free construction?

Yes, the "G" suffix in BAS19 RFG explicitly denotes halogen-free molding compound compliant with IEC 61249-2-21. This is confirmed in the ordering information section of the official Taiwan Semiconductor datasheet (Version C2001), where "G means green compound (halogen free)" is stated. The BAS19 RFG meets both RoHS and halogen-free requirements without trade-offs in flammability performance (UL 94 V-0).

What is the reverse recovery time (t_rr) of the BAS19 RFG and how is it measured?

The BAS19 RFG has a maximum reverse recovery time (t_rr) of 50 ns, measured under standardized conditions: IF = IR = 30 mA, IRR = 0.1 × IR, with specified test waveform per JEDEC. This value reflects the time required for minority carriers to clear after forward conduction ceases - directly impacting switching loss and EMI in high-frequency SMPS. The BAS19 RFG's t_rr is identical to that of BAS20 RFG and matches industry benchmarks for SOT-23 fast diodes.

Can the BAS19 RFG be used as a direct replacement for the BAV19W-7-F?

The BAS19 RFG shares identical V_RRM (100 V), t_rr (50 ns), V_F (1.25 V @ 200 mA), and SOT-23 package with BAV19W-7-F, enabling functional equivalence in most circuits. However, BAS19 RFG adds halogen-free construction and moisture sensitivity level 1 - so while electrical substitution is viable, qualification for environmental compliance or reflow process changes may be required before drop-in use in existing BAV19W-7-F designs.

What is the thermal resistance (R_θJA) of the BAS19 RFG and how does it affect PCB layout?

The BAS19 RFG has a junction-to-ambient thermal resistance (R_θJA) of 500°C/W under standard JEDEC test conditions. This high value means even modest power dissipation (e.g., 150 mW) raises junction temperature by 75°C above ambient - necessitating minimal copper pour on the anode/cathode pads and avoiding enclosed vias under the package. For sustained 200 mA operation, the BAS19 RFG should be placed away from heat sources and verified with thermal imaging per actual board layout.