ISO1540

Part: ISO1540 / ISO1541 — Texas Instruments

Type: Low-Power Bidirectional I²C Digital Isolator

Description: 3–5.5 V, 1 MHz isolated bidirectional I²C isolator with open-drain outputs (3.5 mA side 1 / 35 mA side 2 sink), 2500 VRMS isolation (UL 1577) and ±50 kV/μs typical transient immunity.

Operating Conditions:

• Supply voltage (VCC1, VCC2): 3–5.5 V
• Operating temperature (ambient): -40 to 125 °C
• Operating frequency: up to 1 MHz
• Capacitive load: 40 pF max (side 1), 400 pF max (side 2)

Absolute Maximum Ratings:

• Max supply voltage (VCC1, VCC2): 6 V
• Output current: 20 mA (SDA1, SCL1); 100 mA (SDA2, SCL2)
• Max junction temperature: 150 °C
• Storage temperature: -65 to 150 °C

Key Specs:

• Supply voltage: 3–5.5 V on both sides
• Output sink current (recommended): 0.5–3.5 mA side 1, 0.5–35 mA side 2
• Input thresholds side 1: VIL1 max 0.5 V, VIH1 min 0.7 × VCC1
• Input thresholds side 2: VIL2 max 0.3 × VCC2, VIH2 min 0.7 × VCC2
• Maximum operating frequency: 1 MHz
• Thermal resistance RθJA: 114.6 °C/W (D, SOIC-8)
• ESD HBM: ±8000 V (bus pins), ±4000 V (all pins); CDM ±1500 V
• Recommended junction temperature: -40 to 136 °C; thermal shutdown 139–197 °C

Features:

• Isolated bidirectional I²C-compatible communication
• ISO1540: two bidirectional channels (SDA and SCL), suitable for multi-controller systems and clock stretching
• ISO1541: bidirectional data and unidirectional clock channel, for single-controller systems
• ±50 kV/μs typical transient immunity
• 4242 VPK isolation per DIN EN IEC 60747-17 (VDE 0884-17)
• 2500 VRMS isolation for 1 minute per UL 1577
• CSA approval per IEC 62368-1; CQC basic insulation per GB4943.1-2011

Applications:

• Isolated I²C buses
• SMBus and PMBus interfaces
• Open-drain networks
• Motor control systems
• Battery management
• I²C level shifting

Package:

• SOIC (8), D package, 4.90 mm × 3.91 mm

• Isolated bidirectional, I 2 C compatible, communication
• Supports up to 1-MHz operation
• 3-V to 5.5-V supply range
• Open-drain outputs With 3.5-mA Side 1 and 35mA Side 2 sink current capability
• -40°C to +125°C operating temperature
• ±50-kV/μs transient immunity (Typical)
• HBM ESD protection of 4 kV on all pins; 8 kV on bus pins
• Safety-related certifications:
• -4242-VPK isolation per DIN EN IEC 60747-17 (VDE 0884-17)
• -2500-VRMS isolation for 1 minute per UL 1577
• -CSA approval per IEC 62368-1 end equipment standard
• -CQC basic insulation per GB4943.1-2011

• Isolated I 2 C buses
• SMBus and PMBus interfaces
• Open-drain networks
• Motor control systems
• Battery management
• I 2 C level shifting

Figure 5-1. ISO1540 D Package 8-Pin SOIC Top View

Table 5-1. Pin Functions-ISO1540

Table 5-1. Pin Functions-ISO1540

Figure 5-2. ISO1541 D Package 8-Pin SOIC Top View

Table 5-2. Pin Functions-ISO1541

over recommended operating conditions, unless otherwise noted

over operating free-air temperature range (unless otherwise noted) (1) (2)

• (1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions . Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
• (2) All voltage values here within are with respect to the local ground pin (GND1 or GND2) and are peak voltage values.
• (3) Maximum voltage must not exceed 6 V.

In Figure 8-4, the ultra low-power microcontroller, MSP430G2132, controls the I 2 C data traffic of configuration data and conversion results for the analog inputs and outputs. Low-power data converters build the analog