LTC1623 Datasheet

• SMBus and I²C Compatible
• Built-In Charge Pumps Drive N-Channel Switches
• 16 Available Switches on the Same Bus
• 0.6V V_IL and 1.4V V_IH for DATA and CLK
• Available in 8-Lead MSOP and S0 Packages
• Low Standby Current: 14µA
• Eight Addresses from Two Three-State Address Pins
• Internal Power-On Reset Timer
• Internal Undervoltage Lockout
• No Need for External Pull-Up Resistors at Output
• No Need for Secondary Power Source

• Computer Peripheral Control
• Laptop Computer Power Plane Switching
• Portable Equipment Power Control
• Industrial Control Systems
• Handheld Equipment

The LTC1623 SMBus switch controller is a slave device that controls two high-side N-channel MOSFETs on either the SMBus or the I²C bus. The LTC1623 operates with an input voltage from 2.7V to 5.5V with a low standby current of 14µA (at 3.3V). In accordance with the SMBus specification, the LTC1623 maintains the 0.6V V_IL and 1.4V V_IH input thresholds throughout the supply voltage range.

Using the 2-wire interface, CLK and DATA, the LTC1623 monitors the bus for a start condition (DATA going from high to low while CLK is high). Once detected, the LTC1623 compares its address with the first (address) byte sent over the bus from the master. If matched, the LTC1623 will execute the second (command) byte from the master and independently control the built-in charge pumps to drive two external switches.

The LTC1623 has two three-state programmable address pins, thus allowing eight different addresses and a total of sixteen available switches on the same bus.