LTC5599IUFPBF View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC5599IUFPBF' PDF : 42 Pages View PDF
LTC5599
Pin Functions
VCTRL (Pin 1): Variable Gain Control Input. This analog
control pin sets the gain. Write a “1” to bit 6 in register
0x01 (AGCTRL = 1) to activate this pin, resulting in about
2.58mA current draw from a positive supply. Typical VCTRL
voltage range is 0.9V to 3.3V. Gain transfer function is
not linear-in-dB. Tie to VCC when not used.
GND (Pins 2, 5, 12, Exposed Pad 25): Ground. All these
pins are connected together internally. For best RF perfor-
mance all ground pins should be connected to RF ground.
LOL, LOC (Pins 3, 4): LO Inputs. This is not a differen-
tial input. Both pins are 50Ω inputs. An LC diplexer is
recommended to be used at these pins (see Figure 13).
AC-coupling capacitors are required at these pins if the
applied DC level is higher than ±100mV.
TTCK (Pin 6): Temperature Update. When the TTCK tem-
perature update mode is selected in register 0x01 (bit 7
= High, TEMPUPDT = 1), the temperature readout and
digital gain compensation vs temperature can be updated
through a logic low to logic high transition at this pin. Do
not float.
TEMP (Pin 7): Temperature Sensing Diode. This pin is
connected to the anode of a diode that may be used to
measure the die temperature, by forcing a current and
measuring the voltage. This diode is not part of the on-
chip thermometer.
BBPI, BBMI (Pins 8, 9): Baseband Inputs of the I-Channel.
The input impedance of each input is about 1kΩ. It should
be externally biased to a 1.4V common mode level, or AC-
coupled. Do not apply common mode voltage beyond 2VDC.
BBPQ, BBMQ (Pins 10, 11): Baseband Inputs of the
Q-Channel. The input impedance of each input is about
1kΩ. It should be externally biased to a 1.4V common
mode level, or AC-coupled. Do not apply common mode
voltage beyond 2VDC. Float if Q-channel is disabled.
GNDRF (Pins 13, 14, 15, 17, 18): RF Ground. These pins
are connected together internally. For best RF performance
all ground pins should be connected to RF ground.
RF (Pin 16): RF Output. The output impedance at RF
frequencies is 50Ω. Its DC output voltage is about 1.7V
if enabled. An AC-coupling capacitor should be used at
this pin with a recommended value of 10nF.
CSB (Pin 19): Serial Port Chip Select. This CMOS input
initiates a serial port transaction when driven low, ending
the transaction when driven back high. Do not float.
SCLK (Pin 20): Serial Port Clock. This CMOS input clocks
serial port input data on its rising edge. Do not float.
SDI (Pin 21): Serial Port Data Input. The serial port uses
this CMOS input for data. Do not float.
SDO (Pin 22): Serial Port Data Output. This NMOS output
presents data from the serial port during a read transaction.
Connect this pin to the digital supply voltage through a
pull-up resistor of sufficiently large value, to ensure that
the current does not exceed 10mA when pulled low.
EN (Pin 23): Enable Pin. The chip is completely turned
on when a logic high voltage is applied to this pin, and
completely turned off for a logic low voltage. Do not float.
VCC (Pin 24): Power Supply. It is recommended to use 1nF
and 4.7µF capacitors for decoupling to ground on this pin.
For more information www.linear.com/LTC5599
5599f
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