Diodes Incorporated QSBT40-7

Overview

QSBT40-7 from Diodes Incorporated is a quad Schottky bus terminator IC designed for high-speed data line transient protection in industrial and telecom interfaces. It integrates four independent Schottky diodes with 30 V reverse voltage rating, 200 mA continuous forward current, 5 ns reverse recovery time, and 10 pF capacitance per diode–DL-to-VCC/GND path, deployed in SOT363 package for compact DDR/PCIe/LVDS termination.

For engineers reviewing the QSBT40-7 datasheet, QSBT40-7 pinout, QSBT40-7 application, or QSBT40-7 equivalent, this device serves as a low-capacitance, ESD-hardened bus clamp for signal integrity-critical digital interfaces requiring IEC61000-4-2 (15 kV air, 8 kV contact) and IEC61000-4-4 (80 A EFT) compliance without compromising switching speed.

Technical Context

The QSBT40-7 implements four monolithic Schottky diodes arranged in a common-cathode configuration per data line to VCC and GND, enabling bidirectional clamping of fast transients on parallel data buses. Each diode features a guard-ringed PN junction to suppress ESD-induced latch-up and sustain 600 mA non-repetitive surge current.

Its ultra-low 5 ns trr and sub-450 mV VF at 10 mA ensure minimal signal distortion during high-frequency edge transitions, while the 10 pF DL-to-VCC/GND capacitance maintains impedance integrity on 50–100 Ω transmission lines up to 500 MHz.

Key Specifications

Pinout & Package

SOT363 (SC-70-6) surface-mount package: 2.1 mm × 1.3 mm × 0.9 mm body, 0.65 mm lead pitch, matte tin-plated Alloy 42 leads, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad Schottky bus termination applications.

Compared with DMN3026LSD-13 and SP1001-01WTG, QSBT40-7 uniquely delivers quad Schottky clamping with 30 V VRRM, 10 pF CT, and DC termination support-making it irreplaceable for DDR/PCIe bus bias networks requiring simultaneous ESD hardening and impedance matching.

Availability

QSBT40-7 is available at Aetrix Electronics and suitable for DDR memory subsystems, PCIe add-in card designs, LVDS instrumentation interfaces, and industrial CAN node protection requiring stable component supply across long-life production cycles.

Supply support for QSBT40-7 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability protection, power management, and signal integrity solutions for industrial, computing, and communications markets.

The QSBT40 belongs to Diodes' high-speed bus protection product line, engineered specifically for low-capacitance, multi-channel clamping in DDR, PCI Express, and LVDS parallel interface applications where ESD robustness and signal fidelity are co-constrained.

FAQ

What is the maximum recommended operating temperature for QSBT40-7?

The QSBT40-7 has a specified operating junction temperature range of –55°C to +125°C. Its thermal resistance RθJA is 625°C/W on a standard FR-4 PCB per AP02001 layout. At 25°C ambient, full 200 mW power dissipation is allowed; above 25°C, derating follows the linear curve in Figure 1 of DS30195, reaching zero dissipation at 125°C ambient.

Can QSBT40-7 be used for bidirectional signal clamping on a single data line?

Yes-each DL pin connects to an anode of two internal Schottky diodes: one cathode tied to VCC (for positive overvoltage clamping) and one cathode tied to GND (for negative overvoltage clamping). This dual-path architecture enables true bidirectional transient suppression on each data line without external components.

Is QSBT40-7 compatible with lead-free reflow soldering processes?

Yes-QSBT40-7 uses matte tin-plated Alloy 42 leads and is rated for lead-free reflow per JEDEC J-STD-020. Its moisture sensitivity level is 1, meaning it can be stored indefinitely at ≤30°C/60% RH without baking. The device withstands peak reflow temperatures up to 260°C for 10 seconds, consistent with IPC/JEDEC standard profiles.

Does QSBT40-7 require external bias resistors for termination?

No-QSBT40-7 functions as a passive clamp and does not require external bias resistors. However, its VCC and GND pins must be connected to stable system rails. For active termination (e.g., matching VTT), external resistors are still needed; QSBT40-7 provides only the ESD/transient protection layer in parallel with those resistors.