RFM RX5005H

®
RX5005H
•
Designed for Short-Range Wireless Control and Data Communications
•
Supports RF Data Transmission Rates Up to 115.2 kbps
•
3 V, Low Current Operation plus Sleep Mode
•
Stable, Easy to Use, Low External Parts Count
•
Complies with Directive 2002/95/EC (RoHS)
433.42 MHz
Hybrid
Receiver
The RX5005H hybrid receiver is ideal for short-range wireless control and data applications where robust operation, small size, low power consumption and low cost are required. The RX5005H employs RFM’s amplifier-sequenced hybrid (ASH) architecture to achieve this unique blend of characteristics. All critical RF
functions are contained in the hybrid, simplifying and speeding design-in. The RX5005H is sensitive and stable. A wide dynamic range log detector, in combination with digital AGC and a compound data slicer, provide
robust performance in the presence of on-channel interference or noise. Two stages of SAW filtering provide
excellent receiver out- of-band rejection. The RX5005H generates virtually no RF emissions, facilitating compliance with ETSI I-ETS 300 220 and similar regulations.
Rating
Value
Units
Power Supply and All Input/Output Pins
-0.3 to +4.0
V
Non-Operating Case Temperature
-50 to +100
°C
260
°C
Soldering Temperature (10 seconds / 5 cycles max.)
SM-20H Case
Electrical Characteristics
Characteristic
Operating Frequency
Sym
Notes
fo
Minimum
Typical
433.22
Modulation Types
Maximum
Units
433.62
MHz
115.2
kbps
OOK & ASK
Data Rate
Receiver Performance, High Sensitivity Mode
Sensitivity, 2.4 kbps, 10-3 BER, AM Test Method
1
-109
dBm
Sensitivity, 2.4 kbps, 10-3 BER, Pulse Test Method
1
-103
dBm
Current, 2.4 kbps (RPR = 330 K)
2
3.0
mA
Sensitivity, 19.2 kbps, 10-3 BER, AM Test Method
1
-105
dBm
Sensitivity, 19.2 kbps, 10-3 BER, Pulse Test Method
1
-99
dBm
Current, 19.2 kbps (RPR = 330 K)
2
3.1
mA
Sensitivity, 115.2 kbps, 10-3 BER, AM Test Method
1
-101
dBm
Sensitivity, 115.2 kbps, 10-3 BER, Pulse Test Method
1
-95
dBm
3.8
mA
Current, 115.2 kbps
Receiver Performance, Low Current Mode
Sensitivity, 2.4 kbps, 10-3 BER, AM Test Method
1
-104
dBm
Sensitivity, 2.4 kbps, 10-3 BER, Pulse Test Method
1
-98
dBm
Current, 2.4 kbps (RPR = 1100 K)
2
1.8
mA
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 1 of 10
Electrical Characteristics (typical values given for 3.0 Vdc power supply, 25 °C)
Characteristic
Sym
Notes
Minimum
Typical
Receiver Out-of-Band Rejection, ±5% fo
R±5%
3
80
dB
Receiver Ultimate Rejection
RULT
3
100
dB
0.7
µA
IS
Sleep Mode Current
VCC
Power Supply Voltage Range
Maximum
2.2
3.7
Vdc
10
mVP-P
85
°C
Power Supply Voltage Ripple
TA
Ambient Operating Temperature
Units
-40
Notes:
1. Typical sensitivity data is based on a 10-3 bit error rate (BER), using DC-balanced data. There are two test methods commonly used to measure
OOK/ASK receiver sensitivity, the “100% AM” test method and the “Pulse” test method. Sensitivity data is given for both test methods. See Appendix 3.8 in the ASH Transceiver Designer’s Guide for the details of each test method, and for sensitivity curves for a 2.2 to 3.7 V supply voltage
range at five operating temperatures. The application/test circuit and component values are shown on the next page and in the Designer’s Guide.
2. At low data rates it is possible to adjust the ASH pulse generator to trade-off some receiver sensitivity for lower operating current. Sensitivity
data and receiver current are given at 2.4 kbps for both high sensitivity operation (RPR = 330 K) and low current operation (RPR = 1100 K).
3. Data is given with the ASH radio matched to a 50 ohm load. Matching component values are given on the next page.
4. See Table 1 on Page 8 for additional information on ASH radio event timing.
SM-20H Package Drawing
B
C
D
E
ASH Transceiver Pin Out
RFIO
GND1
1
20
2
19
GND3
AGCCAP
3
18
CNTRL0
PKDET
4
17
CNTRL1
BBOUT
5
16
VCC2
VCC1
CMPIN
6
15
PWIDTH
RXDATA
7
14
PRATE
TXMOD
8
13
THLD1
LPFADJ
9
12
THLD2
10
GND2
F
A
H
G
mm
Inches
Dimension
11
RREF
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
Min
Nom
Max
Min
Nom
Max
A
9.881
10.033
10.135
.389
.395
.400
B
6.731
6.858
6.985
.265
.270
.275
C
1.778
1.930
2.032
.070
.076
.080
D
1.651
1.778
1.905
.065
.070
.075
E
0.381
0.508
0.635
.015
.020
.025
F
0.889
1.016
1.143
.035
.040
.045
G
3.175
3.302
3.429
.125
.130
.135
H
1.397
1.524
1.651
.055
.060
.065
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 2 of 10
ASH Receiver Application Circuit
ASK Configuration
ASH Receiver Application Circuit
OOK Configuration
+3
VDC
+3
VDC
C DCB
C DCB
+
R/S
19
L AT
GND
3
R PW
17
16
VCC
2
CNT
RL1
R PR
15
14
13
P
WIDTH
P
RATE
THLD
1
12
RREF
C AT
RF
A1
PK
DET
BB
OUT
CMP
IN
2
3
4
5
6
RX
DATA
NC
LPF
ADJ
8
9
GND
3
20
R REF
L ESD
10
1
C AT
18
CNT
RL0
17
CNT
RL1
16
VCC
2
R TH1
R PR
15
14
13
12
P
WIDTH
P
RATE
THLD
1
THLD
2
RFIO
RREF
GND1
GND2
VCC
1
AGC
CAP
PK
DET
BB
OUT
CMP
IN
2
3
4
5
6
RX
DATA
7
R TH2
11
TOP VIEW
R LPF
R BBO
+3
VDC
7
L AT
11
GND2
VCC
1
19
NC
TOP VIEW
GND1
1
R PW
R/S
RFIO
20
L ESD
18
CNT
RL0
+
R TH1
NC
LPF
ADJ
8
9
R REF
10
R LPF
C BBO
C RFB1
C RFB1
C BBO
C LPF
+3
VDC
C AGC
C PKD
Data Output
Data Output
Receiver Set-Up, 3.0 Vdc, -40 to +85 °C
Item
Symbol
OOK
OOK
ASK
Units
Notes
Nominal NRZ Data Rate
DRNOM
2.4
19.2
115.2
kbps
see page 1& 2
Minimum Signal Pulse
SPMIN
416.67
52.08
8.68
µs
single bit
Maximum Signal Pulse
SPMAX
1666.68
208.32
34.72
µs
4 bits of same value
AGCCAP Capacitor
CAGC
-
-
2200
pF
±10% ceramic
PKDET Capacitor
CPKD
-
-
0.001
µF
±10% ceramic
BBOUT Capacitor
CBBO
0.1
0.015
0.0027
µF
±10% ceramic
BBOUT Resistor
RBBO
12
0
0
K
±5%
LPFAUX Capacitor
CLPF
0.0047
-
-
µF
±5%
LPFADJ Resistor
RLPF
300
100
15
K
±5%
RREF Resistor
RREF
100
100
100
K
±1%
THLD2 Resistor
RTH2
-
-
100
K
±1%, for 6 dB below peak
THLD1 Resistor
RTH1
0
0
10
K
±1%, typical values
PRATE Resistor
RPR
330
330
160
K
±5%
PWIDTH Resistor
RPW
270 to GND
270 to GND
1000 to Vcc
K
±5%
DC Bypass Capacitor
CDCB
4.7
4.7
4.7
µF
tantalum
RF Bypass Capacitor 1
CRFB1
100
100
100
pF
±5% NPO
LAT
56
56
56
nH
50 ohm antenna
Shunt Tuning/ESD Inductor
LESD
220
220
220
nH
50 ohm antenna
Antenna Tuning Capacitor
CAT
6.8
6.8
6.8
pf
±5%
Antenna Tuning Inductor
CAUTION: Electrostatic Device. Observe precautions when handling.
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 3 of 10
ASH Receiver Theory of Operation
Introduction
RFM’s RX5005H series amplifier-sequenced hybrid (ASH) receivers are
specifically designed for short-range wireless control and data communication applications. The receivers provide robust operation, very small size,
low power consumption and low implementation cost. All critical RF functions are contained in the hybrid, simplifying and speeding design-in. The
ASH receiver can be readily configured to support a wide range of data
rates and protocol requirements. The receiver features virtually no RF
emissions, making it easy to certify to short-range (unlicensed) radio regulations.
Amplifier-Sequenced Receiver Operation
The ASH receiver’s unique feature set is made possible by its system architecture. The heart of the receiver is the amplifier- sequenced receiver
section, which provides more than 100 dB of stable RF and detector gain
without any special shielding or decoupling provisions. Stability is achieved
by distributing the total RF gain over time. This is in contrast to a superheterodyne receiver, which achieves stability by distributing total RF gain over
multiple frequencies.
Figure 1 shows the basic block diagram and timing cycle for an amplifiersequenced receiver. Note that the bias to RF amplifiers RFA1 and RFA2
are independently controlled by a pulse generator, and that the two amplifiers are coupled by a surface acoustic wave (SAW) delay line, which has
a typical delay of 0.5 µs.
An incoming RF signal is first filtered by a narrow-band SAW filter, and is
then applied to RFA1. The pulse generator turns RFA1 ON for 0.5 µs. The
amplified signal from RFA1 emerges from the SAW delay line at the input
to RFA2. RFA1 is now switched OFF and RFA2 is switched ON for 0.55 µs,
amplifying the RF signal further. The ON time for RFA2 is usually set at 1.1
times the ON time for RFA1, as the filtering effect of the SAW delay line
stretches the signal pulse from RFA1 somewhat. As shown in the timing diagram, RFA1 and RFA2 are never on at the same time, assuring excellent
receiver stability. Note that the narrow-band SAW filter eliminates sampling
sideband responses outside of the receiver passband, and the SAW filter
and delay line act together to provide very high receiver ultimate rejection.
Amplifier-sequenced receiver operation has several interesting characteristics that can be exploited in system design. The RF amplifiers in an amplifier-sequenced receiver can be turned on and off almost instantly,
allowing for very quick power-down (sleep) and wake-up times. Also, both
RF amplifiers can be off between ON sequences to trade-off receiver noise
figure for lower average current consumption. The effect on noise figure
can be modeled as if RFA1 is on continuously, with an attenuator placed in
front of it with a loss equivalent to 10*log10(RFA1 duty factor), where the
duty factor is the average amount of time RFA1 is ON (up to 50%). Since
an amplifier-sequenced receiver is inherently a sampling receiver, the
overall cycle time between the start of one RFA1 ON sequence and the
start of the next RFA1 ON sequence should be set to sample the narrowest
RF data pulse at least 10 times. Otherwise, significant edge jitter will be
added to the detected data pulse.
ASH Receiver Block Diagram & Timing Cycle
Antenna
SAW Filter
SAW
Delay Line
RFA1
P1
Detector &
Low-Pass
Filter
RFA2
Data
Out
P2
Pulse
Generator
RF Input
RF Data Pulse
tPW1
tPRI
P1
tPRC
RFA1 Out
Delay Line
Out
tPW2
P2
Figure 1
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 4 of 10
RX5005H ASH Receiver Block Diagram
CN TRL1
CN TRL0
17
Power
Down
Control
Bias Control
Antenna
Log
RFIO
ESD
Choke
VCC1: Pin 2
VCC2: Pin 16
GND1: Pin 1
GND2: Pin 10
GND3: Pin 19
NC:
Pin 8
RREF: Pin 11
CMPIN: Pin 6
18
20
SAW
CR Filter
SAW
Delay Line
RFA1
RFA2
BBOUT
Low-Pass
Filter
Detector
LPFADJ
BB
9
5
C BBO
6
Peak
Detector
PKDET
4
DS2
Ref
dB Below
Peak Thld
C PKD
AND
R LPF
AGC
AGC Set
7
RXDATA
DS1
Gain Select
Ref
Pulse Generator
& RF Amp Bias
PRATE
14
AGC Reset
AGC
Control
15 PWIDTH
AGCCAP
3
Threshold
Control
THLD1
C AGC
R PR
Thld
11
13
R TH1
R PW
12
THLD2
R TH2
R REF
Figure 2
RX5000 Series ASH Receiver Block Diagram
Figure 2 is the general block diagram of the RX5005H series ASH receiver.
Please refer to Figure 2 for the following discussions.
Antenna Port
The only external RF components needed for the receiver are the antenna
and its matching components. Antennas presenting an impedance in the
range of 35 to 72 ohms resistive can be satisfactorily matched to the RFIO
pin with a series matching coil and a shunt matching/ESD protection coil.
Other antenna impedances can be matched using two or three components. For some impedances, two inductors and a capacitor will be required. A DC path from RFIO to ground is required for ESD protection.
Receiver Chain
The output of the SAW filter drives amplifier RFA1. This amplifier includes
provisions for detecting the onset of saturation (AGC Set), and for switching
between 35 dB of gain and 5 dB of gain (Gain Select). AGC Set is an input
to the AGC Control function, and Gain Select is the AGC Control function
output. ON/OFF control to RFA1 (and RFA2) is generated by the Pulse
Generator & RF Amp Bias function. The output of RFA1 drives the SAW
delay line, which has a nominal delay of 0.5 µs.
The second amplifier, RFA2, provides 51 dB of gain below saturation. The
output of RFA2 drives a full-wave detector with 19 dB of threshold gain. The
onset of saturation in each section of RFA2 is detected and summed to provide a logarithmic response. This is added to the output of the full-wave detector to produce an overall detector response that is square law for low
signal levels, and transitions into a log response for high signal levels. This
combination provides excellent threshold sensitivity and more than 70 dB
of detector dynamic range. In combination with the 30 dB of AGC range in
RFA1, more than 100 dB of receiver dynamic range is achieved.
The detector output drives a gyrator filter. The filter provides a three-pole,
0.05 degree equiripple low-pass response with excellent group delay flatness and minimal pulse ringing. The 3 dB bandwidth of the filter can be set
from 4.5 kHz to 1.8 MHz with an external resistor.
The filter is followed by a base-band amplifier which boosts the detected
signal to the BBOUT pin. When the receiver RF amplifiers are operating at
a 50%-50% duty cycle, the BBOUT signal changes about 10 mV/dB, with
a peak-to-peak signal level of up to 685 mV. For lower duty cycles, the mV/
dB slope and peak-to-peak signal level are proportionately less. The detected signal is riding on a 1.1 Vdc level that varies somewhat with supply
voltage, temperature, etc. BBOUT is coupled to the CMPIN pin or to an external data recovery process (DSP, etc.) by a series capacitor. The correct
value of the series capacitor depends on data rate, data run length, and
other factors as discussed in the ASH Transceiver Designer’s Guide.
When an external data recovery process is used with AGC, BBOUT must
be coupled to the external data recovery process and CMPIN by separate
series coupling capacitors. The AGC reset function is driven by the signal
applied to CMPIN.
When the receiver is placed in the power-down (sleep) mode, the output
impedance of BBOUT becomes very high. This feature helps preserve the
charge on the coupling capacitor to minimize data slicer stabilization time
when the receiver switches out of the sleep mode.
Data Slicers
The CMPIN pin drives two data slicers, which convert the analog signal
from BBOUT back into a digital stream. The best data slicer choice depends on the system operating parameters. Data slicer DS1 is a capacitively-coupled comparator with provisions for an adjustable threshold. DS1
provides the best performance at low signal-to-noise conditions. The
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 5 of 10
threshold, or squelch, offsets the comparator’s slicing level from 0 to 90
mV, and is set with a resistor between the RREF and THLD1 pins. This
threshold allows a trade- off between receiver sensitivity and output noise
density in the no-signal condition. For best sensitivity, the threshold is set
to 0. In this case, noise is output continuously when no signal is present.
This, in turn, requires the circuit being driven by the RXDATA pin to be able
to process noise (and signals) continuously.
In the low data rate mode, the interval between the falling edge of one
RFA1 ON pulse to the rising edge of the next RFA1 ON pulse tPRI is set by
a resistor between the PRATE pin and ground. The interval can be adjusted between 0.1 and 5 µs. In the high data rate mode (selected at the
PWIDTH pin) the receiver RF amplifiers operate at a nominal 50%-50%
duty cycle. In this case, the start-to-start period tPRC for ON pulses to RFA1
are controlled by the PRATE resistor over a range of 0.1 to 1.1 µs.
This can be a problem if RXDATA is driving a circuit that must “sleep” when
data is not present to conserve power, or when it its necessary to minimize
false interrupts to a multitasking processor. In this case, noise can be
greatly reduced by increasing the threshold level, but at the expense of
sensitivity. The best 3 dB bandwidth for the low-pass filter is also affected
by the threshold level setting of DS1. The bandwidth must be increased as
the threshold is increased to minimize data pulse-width variations with signal amplitude.
In the low data rate mode, the PWIDTH pin sets the width of the ON pulse
tPW1 to RFA1 with a resistor to ground (the ON pulse width tPW2 to RFA2
is set at 1.1 times the pulse width to RFA1 in the low data rate mode). The
ON pulse width tPW1 can be adjusted between 0.55 and 1 µs. However,
when the PWIDTH pin is connected to Vcc through a 1 M resistor, the RF
amplifiers operate at a nominal 50%-50% duty cycle, facilitating high data
rate operation. In this case, the RF amplifiers are controlled by the PRATE
resistor as described above.
Data slicer DS2 can overcome this compromise once the signal level is
high enough to enable its operation. DS2 is a “dB-below- peak” slicer. The
peak detector charges rapidly to the peak value of each data pulse, and decays slowly in between data pulses (1:1000 ratio). The slicer trip point can
be set from 0 to 120 mV below this peak value with a resistor between
RREF and THLD2. A threshold of 60 mV is the most common setting,
which equates to “6 dB below peak” when RFA1 and RFA2 are running a
50%-50% duty cycle. Slicing at the “6 dB-below-peak” point reduces the
signal amplitude to data pulse-width variation, allowing a lower 3 dB filter
bandwidth to be used for improved sensitivity.
Both receiver RF amplifiers are turned off by the Power Down Control Signal, which is invoked in the sleep mode.
DS2 is best for ASK modulation where the transmitted waveform has been
shaped to minimize signal bandwidth. However, DS2 is subject to being
temporarily “blinded” by strong noise pulses, which can cause burst data
errors. Note that DS1 is active when DS2 is used, as RXDATA is the logical
AND of the DS1 and DS2 outputs. DS2 can be disabled by leaving THLD2
disconnected. A non-zero DS1 threshold is required for proper AGC operation.
AGC Control
The output of the Peak Detector also provides an AGC Reset signal to the
AGC Control function through the AGC comparator. The purpose of the
AGC function is to extend the dynamic range of the receiver, so that the receiver can operate close to its transmitter when running ASK and/or high
data rate modulation. The onset of saturation in the output stage of RFA1
is detected and generates the AGC Set signal to the AGC Control function.
The AGC Control function then selects the 5 dB gain mode for RFA1. The
AGC Comparator will send a reset signal when the Peak Detector output
(multiplied by 0.8) falls below the threshold voltage for DS1.
A capacitor at the AGCCAP pin avoids AGC “chattering” during the time it
takes for the signal to propagate through the low-pass filter and charge the
peak detector. The AGC capacitor also allows the hold-in time to be set
longer than the peak detector decay time to avoid AGC chattering during
runs of “0” bits in the received data stream. Note that AGC operation requires the peak detector to be functioning, even if DS2 is not being used.
AGC operation can be defeated by connecting the AGCCAP pin to Vcc.
The AGC can be latched on once engaged by connecting a 150 kilohm resistor between the AGCCAP pin and ground in lieu of a capacitor.
Receiver Pulse Generator and RF Amplifier Bias
The receiver amplifier-sequence operation is controlled by the Pulse Generator & RF Amplifier Bias module, which in turn is controlled by the
PRATE and PWIDTH input pins, and the Power Down (sleep) Control Signal from the Bias Control function.
Receiver Mode Control
The receiver operating modes – receive and power-down (sleep), are controlled by the Bias Control function, and are selected with the CNTRL1 and
CNTRL0 control pins. Setting CNTRL1 and CNTRL0 both high place the
unit in the receive mode. Setting CNTRL1 and CNTRL0 both low place the
unit in the power-down (sleep) mode. CNTRL1 and CNTRL0 are CMOS
compatible inputs. These inputs must be held at a logic level; they cannot
be left unconnected.
Receiver Event Timing
Receiver event timing is summarized in Table 1. Please refer to this table
for the following discussions.
Turn-On Timing
The maximum time tPR required for the receive function to become operational at turn on is influenced by two factors. All receiver circuitry will be operational 5 ms after the supply voltage reaches 2.2 Vdc. The BBOUTCMPIN coupling-capacitor is then DC stabilized in 3 time constants
(3*tBBC). The total turn-on time to stable receiver operation for a 10 ms
power supply rise time is:
tPR = 15 ms + 3*tBBC
Sleep and Wake-Up Timing
The maximum transition time from the receive mode to the power-down
(sleep) mode tRS is 10 µs after CNTRL1 and CNTRL0 are both low (1 µs
fall time).
The maximum transition time tSR from the sleep mode to the receive mode
is 3*tBBC, where tBBC is the BBOUT-CMPIN coupling-capacitor time constant. When the operating temperature is limited to 60 oC, the time required
to switch from sleep to receive is dramatically less for short sleep times, as
less charge leaks away from the BBOUT- CMPIN coupling capacitor.
AGC Timing
The maximum AGC engage time tAGC is 5 µs after the reception of a -30
dBm RF signal with a 1 µs envelope rise time.
The minimum AGC hold-in time is set by the value of the capacitor at the
AGCCAP pin. The hold-in time tAGH = CAGC/19.1, where tAGH is in µs and
CAGC is in pF.
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 6 of 10
Peak Detector Timing
The Peak Detector attack time constant is set by the value of the capacitor
at the PKDET pin. The attack time tPKA = CPKD/4167, where
tPKA is in µs and CPKD is in pF. The Peak Detector decay time
constant tPKD = 1000*tPKA.
Pulse Generator Timing
In the low data rate mode, the interval tPRI between the falling edge of an
ON pulse to the first RF amplifier and the rising edge of the next ON pulse
to the first RF amplifier is set by a resistor RPR between the PRATE pin and
ground. The interval can be adjusted between 0.1 and 5 µs with a resistor
in the range of 51 K to 2000 K. The value of the RPR is given by:
In the low data rate mode, the PWIDTH pin sets the width of the ON pulse
to the first RF amplifier tPW1 with a resistor RPW to ground (the ON pulse
width to the second RF amplifier tPW2 is set at 1.1 times the pulse width to
the first RF amplifier in the low data rate mode). The ON pulse width tPW1
can be adjusted between 0.55 and 1 µs with a resistor value in the range
of 200 K to 390 K. The value of RPW is given by:
RPW = 404* tPW1 - 18.6, where tPW1 is in µs and RPW is in kilohms
However, when the PWIDTH pin is connected to Vcc through a 1 M resistor, the RF amplifiers operate at a nominal 50%-50% duty cycle, facilitating
high data rate operation. In this case, the RF amplifiers are controlled by
the PRATE resistor as described above.
RPR = 404* tPRI + 10.5, where tPRI is in µs, and RPR is in kilohms
LPF Group Delay
In the high data rate mode (selected at the PWIDTH pin) the receiver RF
amplifiers operate at a nominal 50%-50% duty cycle. In this case, the period tPRC from the start of an ON pulse to the first RF amplifier to the start of
the next ON pulse to the first RF amplifier is controlled by the PRATE resistor over a range of 0.1 to 1.1 µs using a resistor of 11 K to 220 K. In this
case RPR is given by:
The low-pass filter group delay is a function of the filter 3 dB bandwidth,
which is set by a resistor RLPF to ground at the LPFADJ pin. The minimum
3 dB bandwidth fLPF = 1445/RLPF, where fLPF is in kHz, and RLPF is in kilohms.
The maximum group delay tFGD = 1750/fLPF = 1.21*RLPF, where tFGD is in
µs, fLPF in kHz, and RLPF in kilohms.
RPR = 198* tPRC - 8.51, where tPRC is in µs and RPR is in kilohms
Receiver Event Timing, 3.0 Vdc, -40 to +85 °C
Event
Symbol
Time
Min/Max
Test Conditions
Notes
Turn On to Receive
tPR
3*tBBC + 15 ms
max
10 ms supply voltage rise time
time until receiver operational
Sleep to RX
tSR
3*tBBC
max
1 µs CNTRL0/CNTROL 1 rise times
time until receiver operational
RX to Sleep
tRS
10 µs
max
1 µs CNTRL0/CNTROL 1 fall times
time until receiver is in power-down mode
AGC Engage
tAGC
5 µs
max
1 µs rise time, -30 dBm signal
RFA1 switches from 35 to 5 dB gain
AGE Hold-In
tAGH
CAGC/19.1
min
CAGC in pF, tAGH in µs
user selected; longer than tPKD
PKDET Attack Time Constant
tPKA
CPKD/4167
min
CPKD in pF, tPKA in µs
user selected
PKDET Decay Time Constant
tPKD
1000*tPKA
min
tPKD and tPKA in µs
slaved to attack time
PRATE Interval
tPRI
0.1 to 5 µs
range
low data rate mode
user selected mode
PWIDTH RFA1
tPW1
0.55 to 1 µs
range
low data rate mode
user selected mode
PWIDTH RFA2
tPW2
1.1*tPW1
range
low data rate mode
user selected mode
PRATE Cycle
tPRC
0.1 to 1.1 µs
range
high data rate mode
user selected mode
PWIDTH High (RFA1 & RFA2)
tPWH
0.05 to 0.55 µs
range
high data rate mode
user selected mode
LPF Group Delay
tFGD
1750/fLPF
max
tFGD in µs, fLPF in kHz
user selected
LPF 3 dB Bandwidth
fLPF
1445/RLPF
min
fLPF in kHz, RLPF in kilohms
user selected
BBOUT-CMPIN Time Constant
tBBC
0.064*CBBO
min
tBBC in µs, CBBO in pF
user selected
Table 1
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 7 of 10
Pin Descriptions
Pin
Name
1
GND1
GND1 is the RF ground pin. GND2 and GND3 should be connected to GND1 by short, low-inductance traces.
2
VCC1
VCC1 is the positive supply voltage pin for the receiver base-band circuitry. VCC1 must be bypassed by an RF capacitor,
which may be shared with VCC2. See the description of VCC2 (Pin 16) for additional information.
AGCCAP
This pin controls the AGC reset operation. A capacitor between this pin and ground sets the minimum time the AGC will
hold-in once it is engaged. The hold-in time is set to avoid AGC chattering. For a given hold-in time tAGH, the capacitor
value CAGC is:
CAGC = 19.1* tAGH, where tAGH is in µs and CAGC is in pF
A ±10% ceramic capacitor should be used at this pin. The value of CAGC given above provides a hold-in time between tAGH
and 2.65* tAGH, depending on operating voltage, temperature, etc. The hold-in time is chosen to allow the AGC to ride
through the longest run of zero bits that can occur in a received data stream. The AGC hold-in time can be greater than the
peak detector decay time, as discussed below. However, the AGC hold-in time should not be set too long, or the receiver
will be slow in returning to full sensitivity once the AGC is engaged by noise or interference. The use of AGC is optional
when using OOK modulation with data pulses of at least 30 µs. AGC operation can be defeated by connecting this pin to
Vcc. Active or latched AGC operation is required for ASK modulation and/or for data pulses of less than 30 µs. The AGC
can be latched on once engaged by connecting a 150 K resistor between this pin and ground, instead of a capacitor. AGC
operation depends on a functioning peak detector, as discussed below. The AGC capacitor is discharged in the receiver
power-down (sleep) mode.
PKDET
This pin controls the peak detector operation. A capacitor between this pin and ground sets the peak detector attack and
decay times, which have a fixed 1:1000 ratio. For most applications, these time constants should be coordinated with the
base-band time constant. For a given base-band capacitor CBBO, the capacitor value CPKD is:
CPKD = 0.33* CBBO , where CBBO and CPKD are in pF
A ±10% ceramic capacitor should be used at this pin. This time constant will vary between tPKA and 1.5* tPKA with variations in supply voltage, temperature, etc. The capacitor is driven from a 200 ohm “attack” source, and decays through a
200 K load. The peak detector is used to drive the “dB-below-peak” data slicer and the AGC release function. The AGC
hold-in time can be extended beyond the peak detector decay time with the AGC capacitor, as discussed above. Where
low data rates and OOK modulation are used, the “dB-below-peak” data slicer and the AGC are optional. In this case, the
PKDET pin and the THLD2 pin can be left unconnected, and the AGC pin can be connected to Vcc to reduce the number
of external components needed. The peak detector capacitor is discharged in the receiver power-down (sleep) mode.
5
BBOUT
BBOUT is the receiver base-band output pin. This pin drives the CMPIN pin through a coupling capacitor CBBO for internal
data slicer operation. The time constant tBBC for this connection is:
tBBC = 0.064*CBBO , where tBBC is in µs and CBBO is in pF
A ±10% ceramic capacitor should be used between BBOUT and CMPIN. The time constant can vary between tBBC and
1.8*tBBC with variations in supply voltage, temperature, etc. The optimum time constant in a given circumstance will
depend on the data rate, data run length, and other factors as discussed in the ASH Transceiver Designer’s Guide. A common criteria is to set the time constant for no more than a 20% voltage droop during SPMAX. For this case:
CBBO = 70*SPMAX, where SPMAX is the maximum signal pulse width in µs and CBBO is in pF
The output from this pin can also be used to drive an external data recovery process (DSP, etc.). The nominal output
impedance of this pin is 1 K. When the receiver RF amplifiers are operating at a 50%-50% duty cycle, the BBOUT signal
changes about 10 mV/dB, with a peak-to-peak signal level of up to 685 mV. For lower duty cycles, the mV/dB slope and
peak-to-peak signal level are proportionately less. The signal at BBOUT is riding on a 1.1 Vdc value that varies somewhat
with supply voltage and temperature, so it should be coupled through a capacitor to an external load. A load impedance of
50 K to 500 K in parallel with no more than 10 pF is recommended. When an external data recovery process is used with
AGC, BBOUT must be coupled to the external data recovery process and CMPIN by separate series coupling capacitors.
The AGC reset function is driven by the signal applied to CMPIN. When the receiver is in power-down (sleep) mode, the
output impedance of this pin becomes very high, preserving the charge on the coupling capacitor.
6
CMPIN
This pin is the input to the internal data slicers. It is driven from BBOUT through a coupling capacitor. The input impedance
of this pin is 70 K to 100 K.
7
RXDATA
RXDATA is the receiver data output pin. This pin will drive a 10 pF, 500 K parallel load. The peak current available from
this pin increases with the receiver low-pass filter cutoff frequency. In the power-down (sleep) mode, this pin becomes high
impedance. If required, a 1000 K pull-up or pull-down resistor can be used to establish a definite logic state when this pin
is high impedance. If a pull-up resistor is used, the positive supply end should be connected to a voltage no greater than
Vcc + 200 mV.
8
NC
3
4
Description
This pin may be left unconnected or may be grounded.
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 8 of 10
Pin
Name
Description
9
LPFADJ
This pin is the receiver low-pass filter bandwidth adjust. The filter bandwidth is set by a resistor RLPF between this pin and
ground. The resistor value can range from 330 K to 820 ohms, providing a filter 3 dB bandwidth fLPF from 4.5 kHz to 1.8
MHz. The resistor value is determined by:
RLPF = 1445/ fLPF, where RLPF is in kilohms, and fLPF is in kHz
A ±5% resistor should be used to set the filter bandwidth. This will provide a 3 dB filter bandwidth between fLPF and 1.3*
fLPF with variations in supply voltage, temperature, etc. The filter provides a three-pole, 0.05 degree equiripple phase
response. The peak drive current available from RXDATA increases in proportion to the filter bandwidth setting.
10
GND2
GND2 is an IC ground pin. It should be connected to GND1 by a short, low inductance trace.
11
RREF
RREF is the external reference resistor pin. A 100 K reference resistor is connected between this pin and ground. A ±1%
resistor tolerance is recommended. It is important to keep the total capacitance between ground, Vcc and this node to less
than 5 pF to maintain current source stability. If THLD1 and/or THDL2 are connected to RREF through resistor values less
that 1.5 K, their node capacitance must be added to the RREF node capacitance and the total should not exceed 5 pF.
THLD2
THLD2 is the “dB-below-peak” data slicer (DS2) threshold adjust pin. The threshold is set by a 0 to 200 K resistor RTH2
between this pin and RREF. Increasing the value of the resistor decreases the threshold below the peak detector value
(increases difference) from 0 to 120 mV. For most applications, this threshold should be set at 6 dB below peak, or 60 mV
for a 50%-50% RF amplifier duty cycle. The value of the THLD2 resistor is given by:
RTH2 = 1.67*V, where RTH2 is in kilohms and the threshold V is in mV
A ±1% resistor tolerance is recommended for the THLD2 resistor. Leaving the THLD2 pin open disables the dB-belowpeak data slicer operation.
THLD1
The THLD1 pin sets the threshold for the standard data slicer (DS1) through a resistor RTH1 to RREF. The threshold is
increased by increasing the resistor value. Connecting this pin directly to RREF provides zero threshold. The value of the
resistor depends on whether THLD2 is used. For the case that THLD2 is not used, the acceptable range for the resistor is
0 to 100 K, providing a THLD1 range of 0 to 90 mV. The resistor value is given by:
RTH1 = 1.11*V, where RTH1 is in kilohms and the threshold V is in mV
For the case that THLD2 is used, the acceptable range for the THLD1 resistor is 0 to 200 K, again providing a THLD1
range of 0 to 90 mV. The resistor value is given by:
RTH1 = 2.22*V, where RTH1 is in kilohms and the threshold V is in mV
A ±1% resistor tolerance is recommended for the THLD1 resistor. Note that a non-zero DS1 threshold is required for
proper AGC operation.
PRATE
The interval between the falling edge of an ON pulse to the first RF amplifier and the rising edge of the next ON pulse to
the first RF amplifier tPRI is set by a resistor RPR between this pin and ground. The interval tPRI can be adjusted between
0.1 and 5 µs with a resistor in the range of 51 K to 2000 K. The value of RPR is given by:
RPR = 404* tPRI + 10.5, where tPRI is in µs, and RPR is in kilohms
A ±5% resistor value is recommended. When the PWIDTH pin is connected to Vcc through a 1 M resistor, the RF amplifiers operate at a nominal 50%-50% duty cycle, facilitating high data rate operation. In this case, the period tPRC from startto-start of ON pulses to the first RF amplifier is controlled by the PRATE resistor over a range of 0.1 to 1.1 µs using a resistor of 11 K to 220 K. In this case the value of RPR is given by:
RPR = 198* tPRC - 8.51, where tPRC is in µs and RPR is in kilohms
A ±5% resistor value should also be used in this case. Please refer to the ASH Transceiver Designer’s Guide for additional
amplifier duty cycle information. It is important to keep the total capacitance between ground, Vcc and this pin to less than
5 pF to maintain stability.
15
PWIDTH
The PWIDTH pin sets the width of the ON pulse to the first RF amplifier tPW1 with a resistor RPW to ground (the ON pulse
width to the second RF amplifier tPW2 is set at 1.1 times the pulse width to the first RF amplifier). The ON pulse width tPW1
can be adjusted between 0.55 and 1 µs with a resistor value in the range of 200 K to 390 K. The value of RPW is given by:
RPW = 404* tPW1 - 18.6, where tPW1 is in µs and RPW is in kilohms
A ±5% resistor value is recommended. When this pin is connected to Vcc through a 1 M resistor, the RF amplifiers operate
at a nominal 50%-50% duty cycle, facilitating high data rate operation. In this case, the RF amplifier ON times are controlled by the PRATE resistor as described above. It is important to keep the total capacitance between ground, Vcc and
this node to less than 5 pF to maintain stability. When using the high data rate operation with the sleep mode, connect the
1 M resistor between this pin and CNTRL1 (Pin 17), so this pin is low in the sleep mode.
16
VCC2
VCC2 is the positive supply voltage pin for the receiver RF section. This pin must be bypassed with an RF capacitor, which
may be shared with VCC1. VCC2 must also be bypassed with a 1 to 10 µF tantalum or electrolytic capacitor.
12
13
14
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 9 of 10
Description
CNTRL1
CNTRL1 and CNTRL0 select the receiver modes. CNTRL1 and CNTRL0 both high place the unit in the receive mode.
CNTRL1 and CNTRL0 both low place the unit in the power-down (sleep) mode. CNTRL1 is a high-impedance input
(CMOS compatible). An input voltage of 0 to 300 mV is interpreted as a logic low. An input voltage of Vcc - 300 mV or
greater is interpreted as a logic high. An input voltage greater than Vcc + 200 mV should not be applied to this pin. A logic
high requires a maximum source current of 40 µA. Sleep mode requires a maximum sink current of 1 µA. This pin must be
held at a logic level; it cannot be left unconnected.
18
CNTRL0
CNTRL0 is used with CNTRL1 to control the receiver modes. CNTRL0 is a high-impedance input (CMOS compatible). An
input voltage of 0 to 300 mV is interpreted as a logic low. An input voltage of Vcc - 300 mV or greater is interpreted as a
logic high. An input voltage greater than Vcc + 200 mV should not be applied to this pin. A logic high requires a maximum
source current of 40 µA. Sleep mode requires a maximum sink current of 1 µA. This pin must be held at a logic level; it cannot be left unconnected.
19
GND3
GND3 is an IC ground pin. It should be connected to GND1 by a short, low inductance trace.
RFIO
RFIO is the receiver RF input pin. This pin is connected directly to the SAW filter transducer. Antennas presenting an
impedance in the range of 35 to 72 ohms resistive can be satisfactorily matched to this pin with a series matching coil and
a shunt matching/ESD protection coil. Other antenna impedances can be matched using two or three components. For
some impedances, two inductors and a capacitor will be required. A DC path from RFIO to ground is required for ESD protection.
17
.1475
.1225
20
.1625
Name
.1875
Pin
.435
.370
.345
.305
.265
.225
.185
.145
.09
.105
0.000
.310
.220
.090
0.000
.065
Dimensions in inches.
SM-20H PCB Pad Layout
Note: Specifications subject to change without notice.
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: [email protected]
http://www.rfm.com
RX5005H-100405
Page 10 of 10