MICRF011
QwikRadio
tm
Receiver/Data Demodulator
Preliminary Information
General Description
The MICRF011, an enhanced version of the MICRF001, is a single chip
OOK (ON-OFF Keyed) Receiver IC for remote wireless applications,
employing Micrel’s latest QwikRadio
tm
technology. This device is a true
“antenna-in, data-out” monolithic device. All RF and IF tuning is
accomplished automatically within the IC, which eliminates manual
tuning and reduces production costs. Receiver functions are completely
integrated. The result is a highly reliable yet extremely low cost solution
for high volume wireless applications. Because the MICRF011 is a true
single-chip radio receiver, it is extremely easy to apply, minimizing design
and production costs, and improving time to market.
The MICRF011 is a functional and pin equivalent upgrade to the
MICRF001, providing improved range, lower power consumption, and
higher data rate support when in FIXED mode.
The MICRF011 provides two fundamental modes of operation, FIXED
and SWP. In FIXED mode, the device functions like a conventional
superheterodyne receiver, with an (internal) local oscillator fixed at a
single frequency based on an external reference crystal or clock. As with
any conventional superheterodyne receiver, the
transmit
frequency must
be accurately controlled, generally with a crystal or SAW (Surface
Acoustic Wave) resonator.
In SWP mode, the MICRF011 sweeps the (internal) local oscillator at
rates greater than the baseband data rate. This effectively “broadens”
the RF bandwidth of the receiver to a value equivalent to conventional
super-regenerative receivers. Thus the MICRF011 can operate with less
expensive LC transmitters without additional components or tuning, even
though the receiver topology is still superheterodyne. In this mode the
reference crystal can be replaced with a less expensive
±
0.5% ceramic
resonator.
All post-detection (demodulator) data filtering is provided on the
MICRF011, so no external filters need to be designed. Any one of four
filter bandwidths may be selected externally by the user. Bandwidths
range in binary steps, from 0.625kHz to 5kHz (SWP mode) or 1.25kHz to
10kHz (FIXED mode). The user only needs to program the appropriate
filter selection based on data rate and code modulation format.
Features
•
•
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•
•
•
•
•
•
•
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•
Complete UHF receiver on a monolithic chip
Frequency range 300 to 440 MHz
Typical range over
200
meters with monopole
antenna
Data rates to
2.5kbps
(SWP),
10kbps
(FIXED)
Automatic tuning, no manual adjustment
No Filters or Inductors required
Low Operating Supply Current—2.4
mA
at 315MHz
Fully pin compatible with MICRF001
Very low RF re-radiation at the antenna
Direct CMOS logic interface to standard decoder
and microprocessor ICs
Extremely low external part count
Applications
Garage Door/Gate Openers
Security Systems
Remote Fan/Light Control
IMPORTANT: Items in bold type represent changes from
the MICRF001 specification. Differences between the
MICRF001 and -011 are identified in table 2, together with
design considerations for using the -011 in present
MICRF001 designs.
Typical Operating Circuit
385.5 MHz, 1200 bps OOK RECEIVER
Micrel Inc.
•
1849 Fortune Drive San Jose, Ca 95131
•
USA
•
tel + 1 (408) 944-0800
•
fax + 1 (408) 944-0970
•
http://www.micrel.com
MICRF011
QwikRadio
tm
Micrel
Ordering Information
Part Number
MICRF011BN
MICRF011BM
Pin Configuration (DIP and SOIC)
Temperature Range
-40°C to +85°C
-40°C to +85°C
Package
14-Pin DIP
14-Pin SOIC
Pin Description
Pin Number
1
2/3
Pin Name
SEL0
VSSRF
Pin Function
Programs desired Demodulator Filter Bandwidth. This pin in internally pulled-up to VDD. See Table 1.
This pin is the ground return for the RF section of the IC. The bypass capacitor connected from VDDRF to
VSSRF should have the shortest possible lead length. For best performance, connect VSSRF to VSSBB
at the power supply only (i.e., keep VSSBB currents from flowing through VSSRF return path).
This is the receive RF input, internally ac-coupled. Connect this pin to the receive antenna. Input
impedance is high (FET gate) with approximately 2pF of shunt (parasitic) capacitance. For applications
located in high ambient noise environments, a fixed value band-pass network may be connected between
the ANT pin and VSSRF to provide additional receive selectivity and input overload protection. (See
“Application Note 22, MICRF001 Theory of Operation”.)
This pin is the positive supply input for the RF section of the IC. VDDBB and VDDRF should be connected
directly at the IC pins. Connect a low ESL, low ESR decoupling capacitor from this pin to VSSRF, as short
as possible.
This pin is the positive supply input for the baseband section of the IC. VDDBB and VDDRF should be
connected directly at the IC pins.
This capacitor extracts the (DC) average value from the demodulated waveform, which becomes the
reference for the internal data slicing comparator. Treat this as a low-pass RC filter with source impedance
of
118kohms
(for REFOSC frequency ft=4.90MHz).
Note that variation in source resistance with filter
selection no longer exists, as it does for the MICRF001.
(See
“Application Note 22, MICRF001 Theory
of Operation”,
section 6.4). A standard
±
20% X7R ceramic capacitor is generally sufficient.
Output data pin. CMOS level compatible.
This is the ground return for the baseband section of the IC. The bypass and output capacitors connected
to VSSBB should have the shortest possible lead lengths. For best performance, connect VSSRF to
VSSBB at the power supply only (i.e., keep VSSBB currents from flowing through VSSRF return path).
Integrating capacitor for on-chip receive AGC (Automatic Gain Control). The Decay/Attack time-constant
(TC) ratio is nominally set as 10:1. Use of 0.47µF or greater is strongly recommended for best range
performance. See
“Application Note 22, MICRF001 Theory of Operation”
for further information.
Programs desired Demodulator Filter Bandwidth. This pin in internally pulled-up to VDD. See Table 1.
This is the timing reference for on-chip tuning and alignment. Connect either a ceramic resonator or crystal
(mode dependent) between this pin and VSSBB, or drive the input with an AC coupled 0.5Vpp input clock.
Use ceramic resonators without integral capacitors.
Note that if operated in FIXED mode, a crystal must be used; however in SWP mode, one may use either a
crystal or ceramic resonator. See
“Application Note 22, MICRF001 Theory of Operation”
for details on
frequency selection and accuracy.
This logic pin controls the operating mode of the MICRF011. When SWEN = HIGH, the MICRF011 is in
SWP mode. This is the normal (default) mode of the device. When SWEN = LOW, the device operates
as a conventional single-conversion superheterodyne receiver. (See
“Application Note 22, MICRF001
Theory of Operation”
for details.) This pin is internally pulled-up to VDD.
4
ANT
5
VDDRF
6
7
VDDBB
CTH
8
9/10
DO
VSSBB
11
CAGC
12
13
SEL1
REFOSC
14
SWEN
December 1998b
2
MICRF011
MICRF011
SEL0
1
0
1
0
SEL1
1
1
0
0
QwikRadio
SWP Mode
5000
2500
1250
625
tm
Micrel
FIXED Mode
10000
5000
2500
1250
Demodulator Bandwidth (Hz)
Table 1
Nominal Demodulator (Baseband) Filter Bandwidth
vs. SEL0, SEL1 and Mode
No
.
1.
Design Change
Local Oscillator sweep range
reduced 2X. Affects SWP mode
only.
Retrofit Design Action
Reconsider Tx/Rx Frequency Alignment Error Budget, per App. Note 22.
If alignment tolerances cannot be met, consider:
(1) tighten ceramic resonator tolerance,
(2) replace ceramic resonator with crystal, or
(3) not to upgrade to -011
Impacts SWP mode maximum data rate.
If data rate constraint cannot be met, consider
(1) reduce system data rate by 2X, or
(2) not to upgrade to -011
Factor this change into Tx/Rx Frequency Alignment Error Budget.
FIXED mode users of -001 must change crystal frequency.
Factor this change into Tx/Rx Frequency Alignment Error Budget.
For FIXED mode only, choose next lower filter frequency (via control pins
SEL0/1), to maintain same range performance
Recompute appropriate value of CTH capacitor, and change value on PCB
2.
Local Oscillator sweep rate reduced
2X. Affects SWP mode only.
3.
4.
5.
6.
IF Center Frequency reduced 2X.
Affects both modes SWP and
FIXED.
IF Bandwidth reduced 2X. Affects
both modes SWP and FIXED.
FIXED mode Demod Filter cutoff
frequencies increased 2X. Affects
FIXED mode only.
CTH Pin Impedance
118kΩ @ ft=4.90 MHz [see Note 4].
Affects both modes SWP and
FIXED.
Table 2
MICRF001/011 Change List and
Design Retrofit Guidelines
December 1998b
3
MICRF011
MICRF011
QwikRadio
tm
Micrel
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VDDRF, VDDBB).................................+7V
Voltage on any I/O Pin.........................VSS-0.3 to VDD+0.3
Junction Temperature..............................................+150°C
Storage Temperature Range.....................-65°C to + 150°C
Lead Temperature (soldering, 10 seconds).............+ 260°C
Operating Ratings
Supply Voltage (VDDRF, VDDBB)..................4.75V to 5.5V
Ambient Operating Temperature (TA)..........-40°C to +85°C
Package Thermal Resistance
θ
JA (14 Pin DIP)........90°C/W
Package Thermal Resistance
θ
JA (14 Pin SOIC)...120°C/W
This device is ESD sensitive: Meets Class 1ESD test
requirements (Human body Model, HBM), in
accordance with MIL-STD-883C, Method 3015. Do
not operate or store near strong electrostatic fields.
Use appropriate ESD precautions.
Electrical Characteristics
Unless otherwise stated, these specifications apply for Ta=-40°C to 85°C, 4.75<VDD<5.5V. All voltages are with respect to
Ground; Positive currents flow into device pins. CAGC = 4.7µF, CTH = .047µF, VDDRF= VDDBB = VDD. REFOSC
frequency =4.90MHz.
Note: Items in bold represent changes from the MICRF001 specification.
Parameter
Power Supply
Operating Current
RF/IF Section
Receiver Sensitivity
IF Center Frequency
IF 3dB Bandwidth
RF Input Range
Receive Modulation Duty-Cycle
Maximum Receiver Input
Spurious Reverse Isolation
AGC Attack / Decay ratio
Local Oscillator Stabilization Time
Demod Section
CTH Source Impedance
CTH Source Impedance Variation
Demod Filter Bandwidth
Demod Filter Bandwidth
Digital Section
REFOSC Input Impedance
Input Pullup Current
Input High Voltage
Input Low Voltage
Output Current
Output High Voltage
Output Low Voltage
Output Tr, Tf
Note 1:
Test Conditions
MIN
TYP
2.4
MAX
UNITS
mA
dBm
MHz
MHz
MHz
%
dBm
µVrms
msec
Ω
%
Hz
Hz
Ω
µA
V
V
µA
V
V
µsec
Note 1, 3
Note 4
Note 3, 4
300
20
Rsc = 50Ω
ANT pin, Rsc = 50Ω Note 2
T(Attack) / T(Decay)
To 1% of Final Value
Note 5
-15
SEL0 = SEL1 = SWEN = VDD, Note 4, 6
SEL0 = SEL1 = VDD, SWEN = VSS
Note 4, 6
-103
0.86
0.43
440
80
-20
30
0.1
2.5
118k
+15
4160
8320
SEL0, SEL1, SWEN = VSS
SEL0, SEL1, SWEN
SEL0, SEL1, SWEN
DO pin, Push-Pull
DO pin, Iout = -1µA
DO pin, Iout = +1µA
DO pin, Cload= 15pF
200k
8
0.8VDD
0.2VDD
10
0.9VDD
0.1VDD
10
Note 2:
Note 3:
Sensitivity is defined as the average signal level measured at the input necessary to achieve 10e-2 Bit Error Rate (BER). The
input signal is defined as a return-to-zero (RZ) waveform with 50% average duty cycle (e.g., Manchester Encoded Data) at a
data rate of 300bps. The RF input is assumed to be matched into 50Ω.
Spurious reverse isolation represents the spurious components which appear on the RF input (ANT) pin measured into 50Ω
with an input RF matching network.
Sensitivity, a commonly specified Receiver parameter, provides an indication of the Receiver’s input referred noise, generally
input thermal noise. However, it is possible for a more sensitive receiver to exhibit range performance no better than that of a
less sensitive receiver, if the “ether” noise is appreciably higher than the thermal noise. “Ether” noise refers to other interfering
“noise” sources, such as FM radio stations, pagers, etc.
A better indicator of receiver range performance is usually given by its Selectivity, often stated as Intermediate Frequency (IF)
or Radio Frequency (RF) bandwidth, depending on receiver topology. Selectivity is a measure of the rejection by the receiver
of “ether” noise. More selective receivers will almost invariably provide better range. Only when the receiver selectivity is so
high that most of the noise on the receiver input is actually thermal will the receiver demonstrate sensitivity-limited
performance.
December 1998b
4
MICRF011
MICRF011
Note 4:
QwikRadio
tm
Micrel
Note 5:
Note 6:
Parameter scales linearly with REFOSC frequency ft. For any REFOSC frequency other than 4.90MHz, compute new
parameter value as the ratio [(REFOSC FREQ (in MHz) / 4.90] * [Parameter Value @ 4.90MHz]. Example: For REFOSC
Freq. ft = 6.00MHz, [Parameter Value @ 6.00MHz] = (6.00 / 4.90) *[Parameter Value @ 4.90MHz].
Parameter scales inversely with REFOSC frequency ft. For any REFOSC frequency other than 4.90MHz, compute new
parameter value as the ratio [4.90 / (REFOSC FREQ (in MHz)] * [Parameter Value @ 4.90MHz]. Example: For REFOSC
Freq. ft = 6.00MHz, [Parameter Value @ 6.00MHz] = (4.90 / 6.00) * [Parameter Value @ 4.90MHz].
Demod filter bandwidths are related in a binary manner, so any of the (lower) nominal filter values may be derived simply by
dividing this parameter value by 2, 4, or 8 as desired.
Typical Performance Characteristics
MICRF011 I
DD
vs Frequency
(Temperature=25°C, V
DD
=5.0V, SWP Mode)
°
6.10
5.60
5.10
I
DD
(mA)
4.60
4.10
3.60
3.10
2.60
2.10
1.60
250
275
300
325
350
375
400
425
450
475
500
Frequency (MHz)
MICRF011 I
DD
vs Temperature
(Frequency=315MHz, V
DD
=5.0V, SWP Mode)
3.30
3.10
2.90
2.70
2.50
2.30
2.10
1.90
-40
-20
0
20
40
60
85
I
DD
(mA)
Temperature (C)
December 1998b
5
MICRF011
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