PRTR5V0U2X

The PRTR5V0U2X is an ultra low capacitance double rail-to-rail ESD protection diode manufactured by Nexperia (formerly NXP Standard Products). It is designed to protect two high-speed data lines or high-frequency signal lines from electrostatic discharge (ESD) and other transients in a compact SOT-143B surface-mount package.

The device incorporates two pairs of ultra low capacitance rail-to-rail ESD protection diodes plus an additional ESD protection diode between VCC and GND. This additional diode ensures signal line protection even when no supply voltage is present, and prevents supply rail charging during ESD events. The key capacitance specification is C(I/O-GND) = 1 pF typical, making it suitable for Hi-Speed USB 2.0 (480 Mbps) and other high-frequency interfaces without signal degradation.

ESD protection performance is rated at 8 kV contact discharge per IEC 61000-4-2 Level 4. The reverse standoff voltage (VRWM) is 5.5V, matching standard 5V logic and USB voltage levels. Breakdown voltage (VBR) is typically 9V at 1 mA. Clamping voltage is typically 17V at IPP = 2.5 A (8/20 us). Reverse leakage current is less than 1 nA at VRWM. The I/O-to-I/O capacitance is 0.6 pF typical.

The unidirectional configuration is optimized for positive-rail referenced protection of D+/D- data lines. The device is AEC-Q101 qualified (PRTR5V0U2X-Q variant) for automotive applications. Operating temperature range is -40 to +85C (extended range -55 to +125C for some variants). The SOT-143B package measures 2.9 x 1.3 x 1.0 mm with 1.9 mm lead pitch. RoHS compliant, ECCN EAR99. Product status: Active.

The PRTR5V0U2X operates as a rail-to-rail ESD clamp for two data lines:

1. Rail-to-Rail Topology: Each of the two protected data lines (I/O1, I/O2) connects to a pair of steering diodes — one diode to VCC and one diode to GND. During normal operation, both diodes are reverse-biased and present only their junction capacitance (1 pF) to the signal path, preserving signal integrity at high data rates.

2. Positive ESD Event: When a positive ESD strike occurs on a data line, the upper steering diode (I/O to VCC) forward-biases and conducts the ESD current to the VCC rail. If VCC is present, the energy is absorbed by the supply bypass capacitors and the VCC-to-GND protection diode. If VCC is not present, the VCC-to-GND diode provides a discharge path to ground.

3. Negative ESD Event: When a negative ESD strike occurs on a data line, the lower steering diode (I/O to GND) forward-biases and conducts the ESD current directly to ground. The forward voltage of this diode clamps the negative excursion to approximately -1V to -2V, well within the safe range of most IC inputs.

4. Additional VCC-to-GND Diode: The integrated diode between VCC and GND serves two purposes. First, it provides a direct clamping path for ESD energy reaching the VCC rail, preventing voltage spikes on the supply. Second, it ensures that even when VCC is floating or powered down, ESD energy from the data lines has a complete path to ground through the steering diodes and this VCC-GND diode.

5. Low Capacitance Design: The ultra-low 1 pF I/O-to-GND capacitance is achieved through specialized diode construction and layout. At USB 2.0 Hi-Speed (480 Mbps), this capacitance adds minimal signal distortion and maintains the signal eye diagram within USB specifications. The 0.6 pF I/O-to-I/O capacitance minimizes crosstalk between D+ and D- lines.

6. Clamping Performance: The clamping voltage of 17V at 2.5 A (8/20 us) is significantly lower than what simple steering diode networks would achieve, thanks to the integrated additional ESD diode that provides a low-impedance path during high-current events.