ADUM125X

Part: ADuM1250/ADuM1251, Analog Devices

Type: Hot Swappable, Dual I2C Isolators

Description: Hot swappable digital isolators with nonlatching, bidirectional communication channels compatible with I2C interfaces, supporting 1000 kHz operation and 3.0 V to 5.5 V supply/logic levels.

Operating Conditions:

• Supply voltage: 3.0 V to 5.5 V
• Operating temperature: -40°C to +125°C (S, W Grades)
• Max frequency: 1000 kHz
• Side 2 static output loading: 0.5 mA to 30 mA

Absolute Maximum Ratings:

• Max supply voltage: -0.5 V to +7.0 V (VDD1 to GND1, VDD2 to GND2)
• Max continuous current: ±100 mA (Side 2, IO2)
• Max junction/storage temperature: +150°C

Key Specs:

• Input Supply Current (ADuM1250, Side 1, 5 V): 2.8 mA (Typ), 5.0 mA (Max)
• Leakage Currents (ISDA1, ISDA2, ISCL1, ISCL2): 10 µA (Max)
• Side 2 Logic Low Output Voltage (VSDA2OL, VSCL2OL): 400 mV (Max) at ISDA2 = ISCL2 = 30 mA
• Input Capacitance (CIN): 4.0 pF (Typ)
• Maximum Frequency: 1000 kHz (Min)
• Common-Mode Transient Immunity (|CMH|, |CML|): 25 kV/µs (Min), 35 kV/µs (Typ)
• Maximum Repetitive Peak Isolation Voltage (VIORM): 560 V peak
• Maximum Isolation Working Voltage (VIOWM): 396 V rms (AC voltage, end of life test, f = 60 Hz)

Features:

• Bidirectional I2C communication
• Open-drain interfaces
• Suitable for hot swap applications
• 30 mA current sink capability
• 1000 kHz operation
• 3.0 V to 5.5 V supply/logic levels
• 8-lead, RoHS compliant SOIC package
• High temperature operation: 125°C
• Qualified for automotive applications
• Safety and regulatory approvals (DIN EN IEC 60747-17, UL 1577, IEC/EN/CSA 62368-1, IEC/CSA 61010-1, CQC GB4943.1)

Applications:

• Isolated I2C, SMBus, or PMBus interfaces
• Multilevel I2C interfaces
• Power supplies
• Networking
• Power over Ethernet
• Hybrid electric vehicle battery management

Package:

• SOIC-8 (8-lead, narrow-body)

• ► Bidirectional I2C communication
• ► Open-drain interfaces
• ► Suitable for hot swap applications
• ► 30 mA current sink capability
• ► 1000 kHz operation
• ► 3.0 V to 5.5 V supply/logic levels
• ► 8-lead, RoHS compliant SOIC package
• ► High temperature operation: 125°C
• ► Qualified for automotive applications
• ► Safety and regulatory approvals
  • ► DIN EN IEC 60747-17 (VDE 0884-17)
    • ► VIORM = 560 V peak
  • ► UL 1577
    • ► VISO = 2500 V rms for 1 minute
  • ► IEC/EN/CSA 62368-1
  • ► IEC/CSA 61010-1
  • ► CQC GB4943.1

• ► Isolated I2C, SMBus, or PMBus interfaces
• ► Multilevel I2C interfaces
• ► Power supplies
• ► Networking
• ► Power over Ethernet
• ► Hybrid electric vehicle battery management

GENERAL DESCRIPTION

The ADuM1250/ADuM1251¹ are hot swappable digital isolators with nonlatching, bidirectional communication channels that are compatible with I2C interfaces. This eliminates the need for splitting I ²C signals into separate transmit and receive signals for use with standalone optocouplers.

The ADuM1250 provides two bidirectional channels, supporting a complete isolated I2C interface. The ADuM1251 provides one bidirectional channel and one unidirectional channel for applications where a bidirectional clock is not required.

Both the ADuM1250 and the ADuM1251 contain hot swap circuitry to prevent glitching data when an unpowered card is inserted onto an active bus.

Figure 4. ADuM1250/ADuM1251 Pin Configuration

Table 8. ADuM1250 Pin Function Descriptions

Table 9. ADuM1251 Pin Function Descriptions

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All voltages are relative to their respective ground. All minimum and maximum specifications apply over the entire recommended operating range, unless otherwise noted. All typical specifications are at T^A = 25°C, VDD1 = 3.3 V or 5 V, and VDD2 = 3.3 V or 5 V, unless otherwise noted.

Table 1. Electrical Characteristics

^{1 V}IL < 0.5 V, VIH > 0.7 V.

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² ΔVS1 = VS1OL - VS1T. This is the minimum difference between the output logic low level and the input logic threshold within a given component. This ensures that there is no possibility of the part latching up the bus to which it is connected.

Ambient temperature = 25°C, unless otherwise noted.

Table 6. Absolute Maximum Ratings

¹ All voltages are relative to their respective ground.

Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this

specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability.

THERMAL CHARACTERISTICS

Thermal performance is directly linked to PCB design and operating environment. Careful attention to the PCB thermal design is required.

Thermal resistance and characterization parameter values specified in Table 7 are defined and calculated based on the JEDEC JESD51 standards. For more details on their definition and usage, see JEDEC JESD51-12 and the Thermal Analysis section.

Table 7. Package Thermal Data

¹ Thermal impedance simulated values are based on JEDEC 2S2P thermal test board with no vias and still air.

Table 5.

¹ All voltages are relative to their respective ground. See the Magnetic Field Immunity section for information about immunity to external magnetic fields.

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Thermal performance is directly linked to PCB design and operating environment. Careful attention to the PCB thermal design is required.

Thermal resistance and characterization parameter values specified in Table 7 are defined and calculated based on the JEDEC JESD51 standards. For more details on their definition and usage, see JEDEC JESD51-12 and the Thermal Analysis section.

Table 7. Package Thermal Data

¹ Thermal impedance simulated values are based on JEDEC 2S2P thermal test board with no vias and still air.

Figure 9 shows a typical application circuit including the pull-up resistors required for both Side 1 and Side 2 buses. Bypass capacitors with values from 0.01 μF to 0.1 μF are required between VDD1 and GND¹ and between VDD2 and GND2. The 200 Ω resistor shown in Figure 9 is required for latch-up immunity when hot plugging if the ambient temperature is between 105°C and 125°C, and must be placed on the side being hot plugged. Use 200 Ω for 5 V VDD1 and 91 Ω for 3.3 V VDD1.

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Figure 9. Typical Isolated I2C Interface Using the ADuM1250