MICREL MICRF004BM, MICRF004BN Datasheet

MICRF004/RF044 Micrel

SEL0SEL0 SWEN

VSSRF REFOSC
VSSRF SEL1
ANT CAGC

VDDRF

WAKEB

VDDBB

SHUT
CTH DO
NC VSSBB

0.047µF

4.85MHz

(ceramic resonator)

Data

Output

MICRF004

4.7µF

+5V

MICRF004

QwikRadio™ Low-Power VHF Receiver

Advance Information

General Description

The MICRF004 QwikRadio™ VHF receiver is a single-chip
OOK (on-off keyed) receiver IC for remote wireless applica­tions. This device is a true single-chip, “antenna-in, data-out”
device. All RF and IF tuning is accomplished automatically
within the IC which eliminates manual tuning production
costs and results in a highly reliable, extremely low-cost
solution for high-volume wireless applications.

The MICRF004 is extremely easy to apply, minimizing design
and production costs, and improving time to market. The
MICRF004 provides two fundamental modes of operation,
fixed and sweep.

In fixed mode, the device functions as a conventional super­heterodyne receiver with an internal local oscillator operating
at a single frequency based on an external reference crystal
or clock. Fixed mode is for use with accurately-controlled
transmitters utilizing crystal or SAW (surface acoustic wave)
resonators.

In sweep mode, the MICRF004 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 superregenerative receiv­ers. This allows the MICRF004 to 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.

The MICRF004 features a shutdown control, which may be
used for duty-cycled operation, and a wake-up output, which
provides a logical indication of an incoming RF signal. These
features make the MICRF004 ideal for low- and ultra-low­power applications, such as RKE (remote keyless entry) and
RFID (RF identification).

Since all post-detection (demodulator) data filtering is pro­vided on the MICRF004, no external filters are required. One
of the four internal filter bandwidths must be externally
selected based on data rate and code modulation format.
Bandwidths range in binary steps, from 0.55kHz to 4.4kHz
(sweep mode) or 1.1kHz to 8.8kHz (fixed mode).

Features

• Complete VHF receiver on a monolithic chip

• 140MHz to 200MHz frequency range

• >200 meters typical range with monopole antenna

• 2.5kb/s sweep- and 10kb/s fixed-mode data rates

• Automatic tuning, no manual adjustment

• No filters or inductors required

• Low 240µA operating supply current at 150MHz
(10:1 duty cycle)

• Shutdown mode for >100:1 duty-cycle operation

• Wakeup for enabling decoders and microprocessors

• Very low RF antenna reradiation

• CMOS logic interface for standard ICs

• Extremely low external part count

Applications

• Automotive remote keyless entry

• Long range RF identification

• Remote fan and light control

• Garage door and gate openers

Ordering Information

Part Number Junction Temp. Range Package

MICRF004BM –40°C to +85°C 16-Lead SOP
MICRF004BN –40°C to +85°C 16-Pin DIP

8-pin versions available. See “Custom 8-Pin Options,” following page.

T ypical Application

QwikRadio is a trademark of Micrel, Inc.

February 9, 2000 1 MICRF004/RF044

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

150MHz 1200b/s On-Off Keyed Receiver

MICRF004/RF044 Micrel

Pin Configuration

VSSRF
VSSRF

ANT
VDDRF
VDDBB

CTH

NC

1SEL0
2
3
4
5
6
7
8

16 SWEN

REFOSC

15

SEL1

14

CAGC

13

WAKEB

12

SHUT

11

DO

10

VSSBB

9

16-Pin DIP (N) or SOP (M) Packages

MICRF004 2 February 9, 2000

MICRF004/RF044 Micrel

Pin Description

Pin Number Pin Number Pin Name Pin Function

16-Pin Pkg. 8-Pin Pkg.

1 SEL0 Bandwidth Selection Bit 0 (Input): Configure with SEL1 to set the desired

demodulator filter bandwidth. See Table 1. Internally pulled-up to VDDRF.

2, 3 1 VSSRF RF [Analog] Return (Input): Ground return to the RF section power supply.

See “Application Information” for bypass capacitor details.

4 2 ANT Antenna (Input): High-impedance, internally ac coupled receiver input.

Connect this pin to the receive antenna. This FET gate input has approxi­mately 2pF of shunt (parasitic) capacitance. See “Applications Information”
for optional band-pass filter information.

5 3 VDDRF RF [Analog] Supply (Input): Positive supply input for the RF section of the

IC. VDDBB and VDDRF should be connected together directly at the IC
pins. Connect a low ESL, low ESR decoupling capacitor from this pin to
VSSRF, as short as possible.

6 VDDBB Base-Band [Digital] Supply (Input): Positive supply input for the baseband

section of the IC. VDDBB and VDDRF should be connected together at the
IC pins.

7 4 CTH [Data Slicing] Threshold Capacitor (External Component): Capacitor

extracts the dc average value from the demodulated waveform which
becomes the reference for the internal data slicing comparator. See “Appli-

cations Information” for selection.
8 NC not internally connected
9 VSSBB Base-Band [Digital] Return (Input): Ground return to the baseband section

power supply. See “Application Information” for bypass capacitor and layout

details.

10 5 DO Digital Output (Output): CMOS-level compatible data output signal.
11 6 SHUT Shutdown (Input): Shutdown-mode logic-level control input. Pull low to

enable the receiver. This input has an internal pulled-up to VDDRF.

12 WAKEB Wakeup (Output): Active-low output that indicates detection of an incoming

RF signal. Signal is determined by monitoring for data preamble. CMOS-

level compatible.

13 7 CAGC AGC Capacitor (External Component): Integrating capacitor for on-chip

AGC (automatic gain control). The decay/attack time-constant (τ) ratio is

nominally 10:1. See “Applications Information” for capacitor selection.

14 SEL1 Bandwidth Selection Bit 1 (Input): Configure with SEL0, programs to set the

desired demodulator filter bandwidth. See Table 1. Internally pulled-up to

VDDRF.

15 8 REFOSC Reference Oscillator (External Component or Input): Timing reference for

on-chip tuning and alignment. Connect either a ceramic resonator or crystal

(mode dependent, see “Application Information”). between this pin and

VSSBB, or drive the input with an ac-coupled 0.5Vpp input clock.

16 SWEN Sweep-Mode Enable (Input): Sweep- or fixed-mode operation control input.

When VSWEN is high, the MICRF004 is in sweep mode; when SWEN is

low, the receiver operates as a conventional single-conversion superhetero-

dyne receiver. This pin is internally pulled-up to VDDRF.

February 9, 2000 3 MICRF004/RF044

MICRF004/RF044 Micrel

Absolute Maximum Ratings (Note 1)

Supply Voltage (V
Reference Oscillator Input Voltage (V
Input/Output Voltage (V

Junction Temperature (TJ) ......................................+150°C

Storage Temperature Range (T

DDRF

, V

I/O

)....................................+7V

DDBB

REFOSC

)..........V

) ................. VSS–0.3 to VDD+0.3

)............ –65°C to +150°C

S

DDBB

Operating Ratings (Note 2)

Supply Voltage (V
Ambient Temperature (T
Package Thermal Resistance (θ

16-pin DIP (θJA)...................................................90°C/W

16-pin SOIC (θJA)..............................................120°C/W

DDRF

, V

)................ +4.75V to +5.5V

DDBB

)......................... –40°C to +85°C

A

)

JA

Lead Temperature (soldering, 10 sec.) ................... +260°C

ESD Rating, Note 3

Electrical Characteristics

V

= V

DDRF

values indicate –40°C ≤ TA ≤ +85°C; current flow into device pins is positive; unless noted.

Symbol Parameter Condition Min Typ Max Units

I

OP

I

STBY

RF Section, IF Section

f

IF

f

BW

f

ANT

Z

IN(ant)

Reference Oscillator

Z

REFOSC

I

REFOSC

Demodulator

Z

CTH

∆Z

CTH

I

ZCTH(leak)

= VDD where +4.75V ≤ VDD ≤ 5.5V, VSS = 0V; C

DDBB

= 4.7µF, CTH = 0.047µF; f

AGC

REFOSC

= 4.65MHz; TA = 25°C, bold

Operating Current continuous operation 2.4 mA

10:1 duty cycle 240 µA

Standby Current V

SHUT

= V

DD

0.35 µA

Receiver Sensitivity Notes 4, 6 –80 dBm
IF Center Frequency Note 7 0.86 MHz
IF 3dB Bandwidth Notes 6, 7 0.43 MHz
RF Input Range 145 200 MHz
Antenna Input Impdeance fIN = 150MHz 422 Ω
Receive Modulation Duty-Cycle 20 80 %
Maximum Receiver Input RSC = 50Ω –20 dBm
Spurious Reverse Isolation ANT pin, RSC = 50Ω, Note 5 30 µVrms
AGC Attack to Decay Ratio t

ATTACK

÷ t

DECAY

0.1

AGC Leakage Current TA = +85°C ±200 nA

Reference Oscillator extermal reference (250mV peak) 6 ms
Stabilization Time

ceramic resonator 5 ms
crystal 10 ms

Reference Oscillator 290 kΩ
Input Impedance

Reference Oscillator Note 10 0.1 2 Vp-p
Input Sensitivity

Reference Oscillator Current 4.5 µA

CTH Source Impedance Note 8 124 kΩ
CTH Source Impedance Variation ±15 %
CTH Leakage Current TA = +85°C ±200 nA
Demodulator Filter Bandwidth V
Demodulator Filter Bandwidth V

SEL0
SEL0

= V
= V

SEL1
SEL1

= V

SWEN

= VDD, V

= VDD, Notes 7, 9 3960 Hz

= VSS, 7930 Hz

SWEN

Note 7, 9

MICRF004 4 February 9, 2000

MICRF004/RF044 Micrel

Symbol Parameter Condition Min Typ Max Units
Digital/Control Section

I

IN(pu)

V

IN(high)

V

IN(low)

I

OUT

V

OUT(high)

V

OUT(low)

tR, t

F

t

WAKEB

Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside its operating rating.
Note 3. Devices are ESD sensitive. Use appropriate ESD precautions. Meets class 1 ESD test requirements, (human body model HBM), in accor-

Note 4: Sensitivity is defined as the average signal level measured at the input necessary to achieve 10

Note 5: Spurious reverse isolation represents the spurious components which appear on the RF input pin (ANT) measured into 50Ω with an input RF

Note 6: Sensitivity, a commonly specified receiver parameter, provides an indication of the receiver’s input referred noise, generally input thermal

Note 7: Parameter scales linearly with reference oscillator frequency fT. For any reference oscillator frequency other than 4.65MHz, compute new

Note 8: Parameter scales inversely with reference oscillator frequency fT. For any reference oscillator frequency other than 4.65MHz, compute new

Note 9: Demodulator filter bandwidths are related in a binary manner, so any of the (lower) nominal filter values may be derived simply by dividing this

Note 10: External signal generator used. When a crystal or ceramic resonator is used, the minimum voltage is 300mVp-p. The reference oscillator

Input Pull up Current SEL0, SEL1, SWEN, V
Input High Voltage SEL0, SEL1, SWEN 0.8V
Input Low Voltage SEL0, SEL1, SWEN 0.2V

SHUT

= V

SS

8 µA

DD

DD

V

V
Output Current DO, WAKEB pins, push-pull 10 µA
Output High Voltage DO, WAKEB pins, I
Output Low Voltage DO, WAKEB pins, I
Output Rise and Fall Times DO, WAKEB pins, C

= –1µA 0.9V

OUT

= +1µA 0.1V

OUT

= 15pF 10 µs

LOAD

DD

DD

V

V

Wakeup Output Time RFIN = TBDdBm, 4 ms

V

= V

SEL0

dance with MIL-STD-883C, method 3015. Do not operate or store near strong electrostatic fields.

defined as a return-to-zero (RZ) waveform with 50% average duty cycle (Manchester encoded data) at a data rate of 300b/s. The RF input is
assumed to be matched into 50Ω.

matching network.

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
background noise is appreciably higher than the thermal noise. Background noise refers to other interfering signals, such as FM radio
stations, pagers, etc.

A better indicator of achievable receiver range performance is usually given by its selectivity, often stated as fntermediate 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.

parameter value as the ratio:

f MHz

REFOSC

Example: For reference oscillator freqency fT = 6.00MHz:

parameter value as the ratio:

Example: For reference oscillator frequency fT = 6.00MHz:

parameter value by 2, 4, or 8 as desired.

voltage amplitude is a function of the quality of the ceramic or crystal resonator.

4.65

(parameter value at 6.00MHz)

4.65

f MHz

REFOSC

(parmeter value at 4.65MHz)

(parameter value at 4.65MHz)

×

6.00
(paramter value at 4.65MHz)=×

4.65

×

(parmeter value at 4.65MHz)

4.65
(parmeter value at 4.65MHz)=×

6.00

SEL1

= V

SWEN

= V

SHUT

= V

SS

-2

BER (bit error rate). The input signal is

February 9, 2000 5 MICRF004/RF044