MICREL MICRF011BN, MICRF011BM Datasheet

MICRF011

QwikRadiotm 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 QwikRadiotm 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

Micrel Inc. • 1849 Fortune Drive San Jose, Ca 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com

MICRF011 Micrel

QwikRadio

tm

Ordering Information

Part Number Temperature Range Package

MICRF011BN
MICRF011BM

-40°C to +85°C

-40°C to +85°C

14-Pin DIP
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

4 ANT This is the receive RF input, internally ac-coupled. Connect this pin to the receive antenna. Input

5 VDDRF This pin is the positive supply input for the RF section of the IC. VDDBB and VDDRF should be connected

6 VDDBB This pin is the positive supply input for the baseband section of the IC. VDDBB and VDDRF should be
7 CTH This capacitor extracts the (DC) average value from the demodulated waveform, which becomes the

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

11 CAGC Integrating capacitor for on-chip receive AGC (Automatic Gain Control). The Decay/Attack time-constant

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

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).

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”.)

directly at the IC pins. Connect a low ESL, low ESR decoupling capacitor from this pin to VSSRF, as short
as possible.

connected directly at the IC pins.
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.

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).

(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.

(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

14 SWEN This logic pin controls the operating mode of the MICRF011. When SWEN = HIGH, the MICRF011 is in

December 1998b MICRF011

frequency selection and accuracy.
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.

2

MICRF011 Micrel

SEL0 SEL1 Demodulator Bandwidth (Hz)

SWP Mode FIXED Mode
1 1
0 1
1 0
0 0

1250 2500

Nominal Demodulator (Baseband) Filter Bandwidth

QwikRadio

5000 10000

2500 5000

625 1250

Table 1

vs. SEL0, SEL1 and Mode

tm

No
.

1. Local Oscillator sweep range
reduced 2X. Affects SWP mode
only.

2. Local Oscillator sweep rate reduced
2X. Affects SWP mode only.

3. IF Center Frequency reduced 2X.
Affects both modes SWP and
FIXED.

4. IF Bandwidth reduced 2X. Affects
both modes SWP and FIXED.

5. FIXED mode Demod Filter cutoff
frequencies increased 2X. Affects
FIXED mode only.

6. CTH Pin Impedance
118kΩ @ ft=4.90 MHz [see Note 4].
Affects both modes SWP and
FIXED.

Design Change 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

Table 2

MICRF001/011 Change List and

Design Retrofit Guidelines

December 1998b MICRF011

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MICRF011 Micrel

QwikRadio

tm

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 θJA (14 Pin DIP)........90°C/W

Package Thermal Resistance θJA (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 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
IF 3dB Bandwidth Note 3, 4

0.86

0.43

RF Input Range 300 440 MHz
Receive Modulation Duty-Cycle 20 80 %
Maximum Receiver Input
Spurious Reverse Isolation

Rsc = 50Ω
ANT pin, Rsc = 50Ω Note 2

-20 dBm
30

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

8320 Hz

Note 4, 6

Digital Section

REFOSC Input Impedance 200k
Input Pullup Current SEL0, SEL1, SWEN = VSS 8 µA
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 µA
Output High Voltage DO pin, Iout = -1µA 0.9VDD V
Output Low Voltage DO pin, Iout = +1µA 0.1VDD V
Output Tr, Tf DO pin, Cload= 15pF 10 µsec

MHz
MHz

µVrms

Ω

Ω

Note 1: Sensitivity is defined as the average signal level measured at the input necessary to achieve 10e-2 Bit Error Rate (BER). The

Note 2: Spurious reverse isolation represents the spurious components which appear on the RF input (ANT) pin measured into 50Ω
Note 3: Sensitivity, a commonly specified Receiver parameter, provides an indication of the Receiver’s input referred noise, generally

December 1998b MICRF011

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.

with an input RF matching network.
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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