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
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
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
QwikRadio
tm
2
December 1998b
MICRF011
MICRF011
Micrel
Ordering Information
Part Number
Temperature Range
Package
MICRF011BN
-40
C to +85
C
14-Pin DIP
MICRF011BM
-40
C to +85
C
14-Pin SOIC
Pin Configuration (DIP and SOIC)
Pin Description
Pin Number
Pin Name
Pin Function
1
SEL0
Programs desired Demodulator Filter Bandwidth. This pin in internally pulled-up to VDD. See Table 1.
2/3
VSSRF
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).
4
ANT
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".)
5
VDDRF
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.
6
VDDBB
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.
7
CTH
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.
8
DO
Output data pin. CMOS level compatible.
9/10
VSSBB
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).
11
CAGC
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 0.47
F or greater is strongly recommended for best range
performance. See
"Application Note 22, MICRF001 Theory of Operation" for further information.
12
SEL1
Programs desired Demodulator Filter Bandwidth. This pin in internally pulled-up to VDD. See Table 1.
13
REFOSC
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.
14
SWEN
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.
QwikRadio
tm
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December 1998b
MICRF011
MICRF011
Micrel
SEL0
SEL1
Demodulator Bandwidth (Hz)
SWP Mode
FIXED Mode
1
1
5000
10000
0
1
2500
5000
1
0
1250
2500
0
0
625
1250
Table 1
Nominal Demodulator (Baseband) Filter Bandwidth
vs. SEL0, SEL1 and Mode
No
.
Design Change
Retrofit Design Action
1.
Local Oscillator sweep range
reduced 2X. Affects SWP mode
only.
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
2.
Local Oscillator sweep rate reduced
2X. Affects SWP mode only.
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
3.
IF Center Frequency reduced 2X.
Affects both modes SWP and
FIXED.
Factor this change into Tx/Rx Frequency Alignment Error Budget.
FIXED mode users of -001 must change crystal frequency.
4.
IF Bandwidth reduced 2X. Affects
both modes SWP and FIXED.
Factor this change into Tx/Rx Frequency Alignment Error Budget.
5.
FIXED mode Demod Filter cutoff
frequencies increased 2X. Affects
FIXED mode only.
For FIXED mode only, choose next lower filter frequency (via control pins
SEL0/1), to maintain same range performance
6.
CTH Pin Impedance
118k
@ ft=4.90 MHz [see Note 4].
Affects both modes SWP and
FIXED.
Recompute appropriate value of CTH capacitor, and change value on PCB
Table 2
MICRF001/011 Change List and
Design Retrofit Guidelines
QwikRadio
tm
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December 1998b
MICRF011
MICRF011
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
JA (14 Pin DIP)........90
C/W
Package Thermal Resistance
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 = 4.7F, CTH = .047F, VDDRF= VDDBB = VDD. REFOSC
frequency =4.90MHz.
Note: Items in bold represent changes from the MICRF001 specification.
Parameter
Test Conditions
MIN
TYP
MAX
UNITS
Power Supply
Operating Current
2.4
mA
RF/IF Section
Receiver Sensitivity
Note 1, 3
-103
dBm
IF Center Frequency
Note 4
0.86
MHz
IF 3dB Bandwidth
Note 3, 4
0.43
MHz
RF Input Range
300
440
MHz
Receive Modulation Duty-Cycle
20
80
%
Maximum Receiver Input
Rsc = 50
-20
dBm
Spurious Reverse Isolation
ANT pin, Rsc = 50
Note 2
30
Vrms
AGC Attack / Decay ratio
T(Attack) / T(Decay)
0.1
Local Oscillator Stabilization Time
To 1% of Final Value
2.5
msec
Demod Section
CTH Source Impedance
Note 5
118k
CTH Source Impedance Variation
-15
+15
%
Demod Filter Bandwidth
SEL0 = SEL1 = SWEN = VDD, Note 4, 6
4160
Hz
Demod Filter Bandwidth
SEL0 = SEL1 = VDD, SWEN = VSS
Note 4, 6
8320
Hz
Digital Section
REFOSC Input Impedance
200k
Input Pullup Current
SEL0, SEL1, SWEN = VSS
8
A
Input High Voltage
SEL0, SEL1, SWEN
0.8VDD
V
Input Low Voltage
SEL0, SEL1, SWEN
0.2VDD
V
Output Current
DO pin, Push-Pull
10
A
Output High Voltage
DO pin, Iout = -1A
0.9VDD
V
Output Low Voltage
DO pin, Iout = +1A
0.1VDD
V
Output Tr, Tf
DO pin, Cload= 15pF
10
sec
Note 1: 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 50
.
Note 2: Spurious reverse isolation represents the spurious components which appear on the RF input (ANT) pin measured into 50
with an input RF matching network.
Note 3: 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.
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tm
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December 1998b
MICRF011
MICRF011
Micrel
Note 4: 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].
Note 5: 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].
Note 6: 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
1.90
2.10
2.30
2.50
2.70
2.90
3.10
3.30
-40
-20
0
20
40
60
85
Temperature (C)
Frequency (MHz)
I
DD
(mA)
I
DD
(mA)
1.60
2.10
2.60
3.10
3.60
4.10
4.60
5.10
5.60
6.10
250
275
300
325
350
375
400
425
450
475
500
MICRF011 I
DD
vs Frequency
(Temperature=25
C, V
DD
=5.0V, SWP Mode)
MICRF011 I
DD
vs Temperature
(Frequency=315MHz, V
DD
=5.0V, SWP Mode)
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