Datasheet LTC4332 (Analog Devices) - 6

LTC4332
PIN FUNCTIONS Logic (All Inputs and Outputs Referenced to GND MOSI (Pin 8):
Master Out Slave In. When in local mode,
and VL)
MOSI is the serial data input for each of the slave select
V
pins. MOSI data is captured on the rising edge of SCK.
CC (Pin 1):
Main Supply Voltage. 3.0V ≤ VCC ≤ 5.5V. Bypass with 4.7µF ceramic capacitor to GND. When in remote mode, MOSI is the serial data output and can be connected to remote slave devices’ SDI or MOSI
VL (Pin 2):
Logic Interface Supply Voltage. 1.62V ≤ VL ≤ pin. MOSI contains a weak bus-hold circuit which holds 5.5V. Bypass with 1µF ceramic capacitor to GND. the last driven value on the pin if undriven.
ON (Pin 3):
Enable Input. Set high for operation. Set low
MISO (Pin 9):
Master In Slave Out. When in local mode, for low power mode, in which the internal reset is held, MISO is the serial data output for each of the slave select and outputs are disabled. Connect to VL if unused. pins. MISO’s output driver is disabled when SS1-3 and
REMOTE (Pin 4):
Operating Mode Select Input. Set low SSC are high. A weak bus-hold circuit holds the last driven for local SPI slave mode. Set high for SPI master mode value to prevent the pin from floating. when used on the remote side. REMOTE is weakly pulled When in remote mode, MISO is the serial data input and to GND. can be connected to a remote slave devices’ SDO or MISO
LINK (Pin 5):
Link Status Open-Drain Output. LINK is pin. In this mode, MISO is weakly pulled to VL and can be driven low when the device establishes link communi- unconnected if not used. cation. Connect to an external pull-up to VL to monitor
INT (Pin 10):
Remote to Local Interrupt. INT is an open- status, otherwise float or connect to GND. drain output in local mode and an input in remote mode.
SSC (Pin 6):
Control Interface Select Input (Active Low). Values set on the remote side INT propagate to the local SSC enables access to the LTC4332 internal control reg- side INT pin. In addition, INT is the level-sensitive active isters. Set SSC low to initiate a SPI transfer using pins low interrupt signal for the LTC4332’s control interface. SCK, MOSI, and MISO. SSC must be set high when the Connect to an external pull-up to VL on the local side. Do SPI bus is idle. SSC is only used in local mode (REMOTE not allow INT to float on the remote side. = 0). SSC is weakly pulled to VL and can be unconnected if
SS1 (Pin 11):
Remote Slave Select 1 (Active Low). When not used. When in remote mode, leave SSC unconnected. in local mode, SS1 is an input. Set SS1 low to initiate a
SCK (Pin 7):
Serial Port Clock. When in local mode, SCK remote SPI transfer using pins SCK, MOSI, and MISO. is an input. MOSI data is captured by the LTC4332 on When in remote mode, SS1 is an output and can be con- the rising edge of SCK. MISO data from the LTC4332 is nected to a remote SPI device’s slave or chip select input. updated on the falling edge of SCK. When in remote mode SS1 must be set high when the SPI bus is idle. SS1 is SCK is an output providing the serial port clock to remote weakly pulled to VL and can be unconnected if not used. devices. After startup, the remote side SCK is driven low. The local side SCK contains a weak bus-hold circuit which holds the last driven value on the pin if undriven. Rev. A 6 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Switching Characteristics Typical Performance Characteristics Pin Functions Block Diagram Test Circuits Timing Diagram Applications Information Package Description Typical Application Related Parts