LTC5599IUFPBF View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC5599IUFPBF' PDF : 42 Pages View PDF
LTC5599
Applications Information
For VCC = 3.3V and EN = High the RF pin voltage is about
1.68V. For VCC = 3.3V and EN = Low the RF pin voltage
is about 3.1V.
Enable Interface
Figure 5 shows a simplified schematic of the EN pin
interface. The voltage necessary to turn on the LTC5599 is
1.1V. To disable (shut down) the chip, the enable voltage
must be below 0.2V.
VCC
23 EN
INTERNAL
ENABLE
CIRCUIT
5599 F05
Figure 5. Simplified Circuit Schematic of the EN interface
SERIAL PORT
The SPI-compatible serial port provides control and
monitoring functionality.
Communication Sequence
The serial bus is comprised of CSB, SCLK, SDI and
SDO. Data transfers to the part are accomplished by the
serial bus master device first taking CSB low to enable
the LTC5599’s port. Input data applied on SDI is clocked
on the rising edge of SCLK, with all transfers MSB first.
The communication burst is terminated by the serial bus
master returning CSB high. See Figure 6 for details.
Data is read from the part during a communication burst
using SDO. Readback may be multidrop (more than one
LTC5599 connected in parallel on the serial bus), as SDO
is high impedance (Hi-Z) when CSB = 1, or when data is
not being read from the part. If the LTC5599 is not used
in a multidrop configuration, or if the serial port master
is not capable of setting the SDO line level between read
sequences, it is recommended to attach a resistor between
SDO and VCC_L to ensure the line returns to VCC_L during
Hi-Z states. The resistor value should be large enough
to ensure that the SDO output current does not exceed
10mA. See Figure 7 for details.
Single Byte Transfers
The serial port is arranged as a simple memory map, with
status and control available in 9 read/write and 23 read-
only byte-wide registers. All data bursts are comprised of
at least two bytes. The 7 most significant bits of the first
byte are the register address, with an LSB of 1 indicating
a read from the part, and LSB of 0 indicating a write to the
part. The subsequent byte, or bytes, is data from/to the
MASTER–CSB
MASTER–SCLK
MASTER–SDI
tCSS
tCSS
tCKL
tCKH
tCSH
tCS
tCH
DATA
DATA
5599 F06
Figure 6. Serial Port Write Timing Diagram
MASTER–CSB
MASTER–SCLK
LTC5599–SDO
8TH CLOCK
tDO
tDO
tDO
tDO
DATA
DATA
5599 F07
Figure 7. Serial Port Read Timing Diagram
5599f
28
For more information www.linear.com/LTC5599
Share Link: 
