There are various packaging forms for TVS diodes (transient voltage suppression diodes), which can be divided into the following categories based on power, application scenarios, and installation methods. The characteristics and typical models of each type of packaging are as follows:
1、 Surface mount packaging (surface mount type)
Suitable for high-density PCB layout, small size, suitable for automated production, mainly divided into:
SMA series
Power range: 400W (such as SMAJ series)
Voltage range: 5.0V~188V (such as SMAJ5.0A to SMAJ188CA)
Features: Universal packaging, widely used for power port and signal line protection.
SMB series
Power range: 600W (such as SMBJ, P6SMB series)
Voltage range: 5.0V~200V (such as SMBJ5.0CA, P6SMB200A)
Features: Slightly higher power than SMA, suitable for medium surge current scenarios.
SMC series
Power range: 1500W (such as SMCJ, 1.5SMC series)
Voltage range: 5.0V~220V (such as SMCJ5.0CA, 1.5SMC220A)
Features: High power density, suitable for power bus or industrial equipment protection.
SMDJ series
Power range: 3000W~5000W (such as SMDJ, 5.0 SMDJ series)
Voltage range: 5.0V~188V (such as 5.0SMDJ12A)
Features: High power design, used for harsh environments such as automotive electronics or lightning protection.
Low capacitance series
Representative models: SAC (50pF), LCE (100pF)
Application: High frequency signal lines (such as USB, HDMI), models with capacitance ≤ 3pF are used for high-speed circuits ≥ 100MHz.
2、 Axial lead packaging (plug-in type)
Suitable for power feeders or manual welding scenarios, with better heat dissipation performance:
Standard Power Series
P4KE series: 400W, voltage 6.8V~440V
P6KE series: 600W, voltage 6.8V~440V
SA series: 500W, voltage 5.0V~180V
High Power Series
1.5KE series: 1500W, voltage 6.8V~440V
5KP series: 5000W, voltage 5.0V~110V (such as 5KP 5.0~5KP110)
15KPA/30KPA series: 15kW~30kW, voltage 5.0V~220V
3、 Special packaging type
Airtight metal shell packaging
Representative model: DO-41 (military/aerospace field)
Features: High reliability, resistant to extreme environments.
Leadless flat plastic seal
Representative models: TSMA/TMSBM/TMSC series (400W~1500W)
Appearance: SMA/SMB/SMC standard dimensions.
Array packaging
Dual In Line (DIP): Multi signal protection (such as data bus)
Integrated solution: such as TVS+fast recovery diode combination to reduce total capacitance.
4、 Packaging selection suggestions
Power and voltage matching
Low voltage microprocessor: select 2.8V~3.8V low voltage TVS;
AC circuit: Priority should be given to bidirectional TVS (model with "CA").
High frequency scenario
Signal frequency ≥ 100MHz: capacitance ≤ 20pF (such as SACB series);
If necessary, use TVS+diode bridging scheme to reduce capacitance.
Heat dissipation and environment
High temperature scenario: Need to reduce the rated usage to avoid exceeding the steady-state power limit;
Repetitive surge: Choose a model with stronger pulse tolerance (such as 30KPA).
summarize
The core differences of TVS packaging lie in power capacity, installation method, and high-frequency adaptability. Surface mount packaging (SMA/SMB/SMC) is suitable for compact circuits, axial packaging (P6KE/5KP) is suitable for high-power scenarios, and special packaging (DO-41/array) is designed for military or multi-channel protection needs. When selecting, it is necessary to comprehensively consider the breakdown voltage, clamping ability, and capacitance parameters to ensure compatibility with the circuit.