MICRF211AYQS Micrel Inc, MICRF211AYQS Datasheet - Page 7

• Manufacturer Part Number: MICRF211AYQS
• Description: IC RX 3V 380-450 MHZ 16-QSOP
• Manufacturer: Micrel Inc

Specifications of MICRF211AYQS

• Operating Temperature: -40°C ~ 105°C
• Frequency: 380MHz ~ 450MHz
• Sensitivity: -110dBm
• Data Rate - Maximum: 10 kbps
• Modulation Or Protocol: ASK, OOK
• Applications: ISM, Garage Door Openers, RKE
• Current - Receiving: 6mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Features: No IF Filter Required
• Voltage - Supply: 3 V ~ 3.6 V
• Package / Case: 16-QSOP
• Data Rate: 1Kbps
• Frequency Range: 380MHz To 450MHz
• Modulation Type: ASK, OOK
• Sensitivity Dbm: -110dBm
• Rf Ic Case Style: QSOP
• No. Of Pins: 16
• Supply Voltage Range: 3V To 3.6V
• Operating Frequency (max): 450000kHz
• Operating Temperature (min): -40C
• Operating Temperature (max): 105C
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Compliant
• Other names: 576-1964-5; MICRF211AYQS

March 2007
Micrel
carrier from the IF signal. Post detection, the signal
becomes base band information.
low-pass filter further enhances the base band
information.
filter BW settings: 1625Hz, 3250Hz, 6500Hz, 13000Hz
for 433.92MHz operation. Low pass filter BW will vary
with RF Operating Frequency. Filter BW values can be
easily calculated by direct scaling. See equation below
for filter BW calculation:
BW
fits the intended data rate to minimize data distortion.
Demod BW is set at 13000Hz @ 433.92MHz as default
(assuming both SEL0 and SEL1 pins are floating). The
low pass filter can be hardware set by external pins
SEL0 and SEL1.
Slicer, Slicing Level and Squelch
The signal prior to slicer is still linear demodulated AM.
Data slicer converts this signal into digital “1”s and “0”s
by comparing with the threshold voltage built up on the
CTH capacitor.
detecting the positive and negative peaks of the data
signal and storing the mean value. Slicing threshold
default is 50%. After the slicer the signal is now digital
OOK data.
During long periods of “0”s or no data period, threshold
voltage on the CTH capacitor may be very low. Large
random noise spikes during this time may cause
erroneous “1”s at DO pin. Squelch pin when pull down
low will suppress these errors.
AGC Comparator
The AGC comparator monitors the signal amplitude
from the output of the programmable low-pass filter.
It is very important to choose the filter setting that best
Operating Freq
SEL0
0
1
0
1
Table 1: Demodulation BW Selection
= BW
There are four programmable low-pass
SEL1
0
0
1
1
@433.92MHz
This threshold is determined by
Demod BW (@ 434MHz)
1625Hz
3250Hz
6500Hz
13000Hz
*
⎛
⎜
⎝
Operating
- default
The programmable
433.92
Freq
(MHz)
⎞
⎟
⎠
7
When the output signal is less than 750mV thresh-hold,
1.5µA current is sourced into the external CAGC
capacitor. When the output signal is greater than
750mV, a 15µA current sink discharges the CAGC
capacitor.
capacitor acts to adjust the gain of the mixer and the IF
amplifier to compensate for RF input signal level
variation.
Reference Control
There are 2 components in Reference and Control sub-
block: 1) Reference Oscillator and 2) Control Logic
through parallel Inputs: SEL0, SEL1, SHDN
Reference Oscillator
The reference oscillator in the MICRF211 (Figure 2)
uses a basic Colpitts crystal oscillator configuration with
MOS transconductor to provide negative resistance. All
capacitors shown in Figure 2 are integrated inside
MICRF211.
MICRF211.
oscillation crystal.
Reference oscillator crystal frequency can be calculated:
F
For 433.92 MHz, F
To operate the MICRF211 with minimum offset, crystal
frequencies should be specified with 10pF loading
capacitance.
REF OSC
= F
RF
Figure 2: Reference Oscillator Circuit
The voltage developed on the CAGC
/(32 + 1.1/12)
User only needs to connect reference
R01 and R02 are external pins of
REF OSC
= 13.52127 MHz.
[phone]
M9999-030107
MICRF211