MLX71121KLQ Melexis Inc, MLX71121KLQ Datasheet - Page 6

• Manufacturer Part Number: MLX71121KLQ
• Description: RCVR FSK/FM/ASK 32-QFN
• Manufacturer: Melexis Inc

Specifications of MLX71121KLQ

• Frequency: 300MHz ~ 930MHz
• Sensitivity: -108dBm
• Data Rate - Maximum: 100 kbps
• Modulation Or Protocol: ASK, FM, FSK
• Applications: General Remote Control, Garage Opener, RKE
• Current - Receiving: 8.1mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Features: RSSI Equipped
• Voltage - Supply: 2.1 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 32-QFN
• Data Rate: 100Kbps
• Frequency Range: 300MHz To 930MHz
• Modulation Type: AM, FM, FSK
• Rf Ic Case Style: QFN
• No. Of Pins: 32
• Supply Voltage Range: 2.1V To 5.5V
• Operating Temperature Range: -40°C To
• Sensitivity Dbm: -112dBm
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: MLX71121A

1.4
The receiver offers two operating modes selectable by setting the corresponding logic level at pin ENRX.
Note: ENRX is pulled down internally.
The receiver’s start-up procedure is controlled by a sequencer circuit. It performs the sequential activation of
the different building blocks. It also initiates the pre-charging of the data filter and data slicer capacitors in
order to reduce the overall start-up time and current consumption during the start-up phase.
At ENRX = 0, the receiver is in shutdown mode and draws only a few nA. The bias system and the reference
oscillator are activated after enabling the receiver by a positive edge at pin ENRX. The crystal oscillator (RO)
is turned on first. Then the crystal oscillation amplitude builds up from noise. After reaching a certain ampli-
tude level at pin ROI, the whole IC is activated and draws the full receive mode current consumption I
This event is used to start the pre-charging of the external data path capacitors. Pre-charging is finished
after 5504 clock cycles. After that time the data output pin DTAO output is activated.
1.5
The receiver features two identical LNAs. Each LNA is a cascode amplifier with a voltage gain of approxi-
mately 18dB. The actual gain depends on the antenna matching network at the inputs and the LC tank net-
work between the LNA outputs and mixer input. LNA operation can be controlled by the LNASEL pin.
Pin LNASEL is internally pulled to VCC/2 during receive mode. Therefore both LNAs are active if LNASEL is
left floating (Hi-Z state).
39010 71121
Rev. 009
ENRX
DTAO
I
I
I
Operating Modes
LNA Selection
SDN
CC
RO
LNASEL
ENRX
Hi-Z
0
1
0
1
t
Hi-Z
on RO
Fig. 2:
t
on RX
t
SEQ
Timing diagram of start-up and shutdown behavior
Page 6 of 28
LNA1 active, LNA2 shutdown
LNA1 shutdown, LNA2 active
LNA1 and LNA2 active
Shutdown mode
Receive mode
valid data
Description
Description
FSK/FM/ASK Receiver
MLX71121
300 to 930MHz
Hi-Z
Data Sheet
Oct/10
CC
.