Littelfuse SP721APP

The SP721 is an array of SCR/Diode bipolar structures for ESD and over-voltage protection to sensitive input circuits. The SP721 has 2 protection SCR/Diode device structures per input. There are a total of 6 available inputs that can be used to protect up to 6 external signal or bus lines. Overvoltage protection is from the IN (Pins 1 - 3 and Pins 5 - 7) to V+ or V-. The SCR structures are designed for fast triggering at a threshold of one +VBE diode threshold above V+ (Pin 8) or a -VBE diode threshold below V- (Pin 4). From an IN input, a clamp to V+ is activated if a transient pulse causes the input to be increased to a voltage level greater than one VBE above V+. A similar clamp to V- is activated if a negative pulse, one VBE less than V-, is applied to an IN input. Standard ESD Human Body Model (HBM) Capability is:

• ESD Interface Capability for HBM Standards - MIL STD 3015.7...15kV - IEC 61000-4-2, Direct Discharge, - Single Input... 4kV (Level 2) - Two Inputs in Parallel.. 8kV (Level 4) - IEC 61000-4-2, Air Discharge.... 15kV (Level 4)
• High Peak Current Capability - IEC 61000-4-5 (8/20µs)...... ±3A - Single Pulse, 100µs Pulse Width...... ±2A - Single Pulse, 4µs Pulse Width...... ±5A
• Designed to Provide Over-Voltage Protection - Single-Ended Voltage Range to...... +30V - Differential Voltage Range to...... ±15V
• Fast Switching...... 2ns Rise Time
• Low Input Leakages... 1nA at 25°C Typical
• Low Input Capacitance... 3pF Typical
• An Array of 6 SCR/Diode Pairs
• Operating Temperature Range... -40°C to 105°C

• Microprocessor/Logic Input Protection
• Analog Device Input Protection
• Data Bus Protection
• Voltage Clamp