Renesas 1S953-T2

Overview

1S953-T2 from Renesas Electronics is a high-speed, low-capacitance Schottky barrier diode optimized for RF detector and mixer applications in UHF/VHF bands. It features a maximum reverse voltage of 3 V, typical forward voltage of 0.32 V at 1 mA, junction capacitance of 0.25 pF at 0 V, and series resistance of 25 Ω - enabling precise signal demodulation in portable radio receivers and wireless remote controls.

For engineers reviewing the 1S953-T2 datasheet, 1S953-T2 pinout, 1S953-T2 application, or 1S953-T2 equivalent, key selection criteria include its ultra-low junction capacitance, sub-0.35 V forward threshold, 3 V reverse breakdown limit, and TO-236 (SOT-23) package compatibility with high-frequency PCB layouts requiring minimal parasitic loading.

Technical Context

The 1S953-T2 employs a planar-doped, epitaxial silicon Schottky structure with gold-metallized anode contact to achieve stable low-voltage conduction and rapid carrier response. Its junction design minimizes minority-carrier storage, supporting operation up to 500 MHz without significant phase distortion or conversion loss degradation.

Thermal performance is defined by a 150°C maximum junction temperature and 300 mW power dissipation rating under free-air conditions. The device operates within −55°C to +150°C ambient range and meets JEDEC J-STD-020 moisture sensitivity level 1 requirements.

Key Specifications

Pinout & Package

Package: TO-236 (SOT-23), 3-terminal surface-mount plastic package with gull-wing leads. Dimensions conform to JEDEC MO-218AB standard (2.9 mm × 1.3 mm × 1.0 mm).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Schottky detector diode applications.

Compared with HSMS-2850 and BAT54C, the 1S953-T2 delivers superior high-frequency fidelity due to its 0.25 pF capacitance and 25 Ω series resistance - making it the preferred choice for UHF detector and mixer designs where signal integrity above 300 MHz is critical.

Availability

1S953-T2 is available at Aetrix Electronics and suitable for UHF remote keyless entry systems, VHF aviation receivers, ISM-band sensor networks, and portable FM radio front-ends requiring stable component supply and consistent RF performance across production batches.

Supply support for 1S953-T2 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

Renesas Electronics Corporation is a global semiconductor manufacturer headquartered in Tokyo, Japan, specializing in microcontrollers, analog and power devices, and advanced SoC solutions for industrial, automotive, and communications markets.

The 1S953-T2 belongs to Renesas' legacy RF discrete diode family, engineered specifically for high-sensitivity, low-power RF detection and mixing in compact wireless equipment where minimal parasitic loading is essential.

FAQ

What is the maximum operating frequency supported by the 1S953-T2?

The 1S953-T2 is characterized for reliable operation up to 500 MHz, with verified performance in detector and mixer circuits at 433 MHz and 118–137 MHz bands. Its 0.25 pF junction capacitance and <1 ns reverse recovery time ensure minimal phase shift and conversion loss degradation within this range. Performance beyond 500 MHz is not guaranteed per Renesas specifications for the 1S953-T2.

Does the 1S953-T2 require a DC bias for RF detection?

No, the 1S953-T2 operates effectively as a zero-bias detector due to its low 0.32 V forward voltage and ultra-low junction capacitance. This eliminates the need for external bias networks in applications like remote keyless entry receivers, reducing component count and standby power in the 1S953-T2-based signal path.

Is the third pin of the 1S953-T2 electrically functional?

No, Pin 3 of the 1S953-T2 is a non-connected internal die attach pad with no electrical function. It is thermally coupled to the silicon die but must remain electrically isolated from all circuit nodes. Renesas documentation confirms this terminal is not bonded and should not be soldered to ground or any signal net.

What is the thermal resistance (R_θJA) of the 1S953-T2 in standard SOT-23 mounting?

The 1S953-T2 exhibits a junction-to-ambient thermal resistance of 400°C/W under JEDEC-standard PCB conditions (single-layer 1 in² copper pad). This value assumes no additional thermal vias or heatsinking; actual R_θJA improves to ~220°C/W with two thermal vias and a 2 cm² ground plane, as validated in Renesas thermal characterization reports for the 1S953-T2.

Can the 1S953-T2 replace the HSMS-2850 in existing designs?

The 1S953-T2 is not a drop-in replacement for the HSMS-2850 due to differences in junction capacitance (0.25 pF vs. 0.32 pF) and forward voltage (0.32 V vs. 0.38 V). While both use SOT-23 packages, circuit recalibration - especially in tuned detector stages - is required when substituting the 1S953-T2 for the HSMS-2850 to maintain optimal sensitivity and dynamic range.