SMX1J STMICROELECTRONICS | Alldatasheet

Document overview

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Technical content

Features

■ Peak pulse power: – 85 W (10/1000 µs) – 800 W (8/20 µs) ■ Stand off voltage 7.5 V ■ Unidirectional ■ Low leakage current: – 1 µA at 25 °C – 2 µA at 85 °C ■ Operating Tj max: 150 °C ■ High power capability at Tj max: 78 W Complies with the following standards ■ IEC 61000-4-2 level 4: – 15 kV (air discharge) – 8 kV (contact discharge) ■ MIL STD 883G - Method 3015-7 Class 3B: – 25 kV HBM (human body model)

Description

The SMX1J Transil has been designed to protect sensitive equipment against electro-static discharges according to IEC 61000-4-2, MIL STD 883 Method 3015, and electrical over stress such as IEC 61000-4-4 and 5. They are generally for surges below 85 W 10/1000 µs. The Planar technology makes it compatible with high-end equipment and SMPS where low leakage current and high junction temperature are required to provide reliability and stability over time. The SMX1J is packaged in µQFN-2L. Figure 1. Functional diagram (top view)

1 Characteristics

Figure 2. Electrical characteristics (definitions) Figure 3. Pulse waveform Table 1. Absolute maximum ratings (T amb = 25 °C)

  1. For a surge greater than the maximum val ues, the diode will fail in short-circuit.

Table 2. Electrical characteristics - parameter values (T amb = 25 °C)

  1. Surge capability given for both directi ons for unidirectional and bidirectional types
  2. To calculate maximum clamping voltage at ot her surge level, use the following formula
  3. To calculate V BR or VCL versus junction temperature, use the following formule:

2 Ordering information scheme

Figure 10. Ordering information scheme

3 Package information

  • Terminals: Solder plated, solderable per MIL-STD-750, Method 2026
  • Flammability: Epoxy is rated UL94V-0
  • RoHS package In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. Note: Product marking may be rotated by 90° for assembly plant differentiation. In no case should this product marking be used to orient the component for its placement on a PCB. Only pin 1 mark is to be used for this purpose

Table 3. µQFN-2L dimensions Figure 11. Footprint dimensions in mm Figure 12. Marking

Figure 13. Tape and reel specifications

4 Recommendation on PCB assembly

4.1 Stencil opening design

  1. General recommendation on stencil opening design

a) Stencil opening dimensions: L (Length), W (Width), T (Thickness). Figure 14. Stencil opening dimensions b) Stencil opening for leads: Opening to footprint ratio - between 65% and 70%. Figure 15. Recommended stencil windows position

Recommendation on PCB assembly SMX1J 8/11 Doc ID 16180 Rev 3

4.2 Solder paste

  1. Halide-free flux qualification ROL0 according to ANSI/J-STD-004. 2. Solder paste without cleaning flux is recommended. 3. Offers a high tack force to resist component movement during high speed. 4. Solder paste with fine particles: powder particle size is 20-45 µm.

4.3 Placement

  1. Manual positioning is not recommended. 2. It is recommended to use the lead recognition capabilities of the placement system, not the outline centering 3. Standard tolerance of ± 0.05 mm is recommended. 4. 3.5 N placement force is recommended. Too much placement force can lead to squeezed out solder paste and cause solder joints to short. Too low placement force can lead to insufficient contact between package and solder paste that could cause open solder joints or badly centered packages. 5. To improve the package placement accuracy, a bottom side optical control should be performed with a high resolution tool. 6. For assembly, a perfect supporting of the PCB (all the more on flexible PCB) is recommended during solder paste printing, pick and place and reflow soldering by using optimized tools.

4.4 PCB design preference

  1. To control the solder paste amount, the closed via is recommended instead of open vias. 2. The position of tracks and open vias in the solder area should be well balanced. The symmetrical layout is recommended, in case any tilt phenomena caused by asymmetrical solder paste amount due to the solder flow away.

4.5 Reflow profile

Figure 16. ST ECOPACK® recommended soldering reflow profile for PCB mounting Note: Minimize air convection currents in the reflow oven to avoid component movement.

5 Ordering information

6 Revision history

Table 4. Ordering information Table 5. Document revision history 03-Nov-2009 2 Updated : Features, Table 2, Table 4 and Figure 11. 27-Oct-2010 3 Updated base quantity Table 4.