LTC2946 PIN FUNCTIONSSDAI: I2C Bus Data Input. Used for shifting in address, SENSE+: Supply Voltage and Current Sense Input. Used command or data bits. This pin is driven by an open- as a supply and current sense input for internal current collector output from a master controller. An external sense amplifier. The voltage at this pin is monitored by pull-up resistor or current source is required and can be the onboard ADC with a full-scale input range of 102.4V. placed between SDAI and VDD or INTVCC. The voltage at See Figure 20 for recommended Kelvin connection. SDAI is internally clamped to 6.4V typically. Tie to SDAO SENSE–: Current Sense Input. Connect an external sense for normal I2C operation. resistor between SENSE+ and SENSE–. The differential SDAO: LTC2946 Only. I2C Bus Data Output. Open-drain voltage between SENSE+ and SENSE– is monitored by the output used for sending data back to the master control- onboard ADC with a full-scale sense voltage of 102.4mV. ler or acknowledging a write operation. An external V pull-up resistor or current source is required. Tie to SDAI DD: High Voltage Supply Input. This pin powers an in- ternal series regulator with input voltages ranging from for normal I2C operation. 4V to 100V and produces 5V at INTVCC when VDD is above SDAO: LTC2946-1 Only. Inverted I2C Bus Data Output. 8V. Connect a bypass capacitor of 0.1μF or greater from Open-drain output used for sending data back to the this pin to ground if an external load is present on the master controller or acknowledging a write operation. INTVCC pin. The onboard 12-bit ADC can be configured Data is inverted for convenience of opto-isolation. An to monitor the voltage at VDD with a full-scale input range external pull-up resistor or current source is required. The of 102.4V. LTC2946-1 cannot be used in nonisolated I2C applications without additional components. 2946fa For more information www.linear.com/LTC2946 9 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Timing Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
