BiM3G datasheet, PDF - EEWORLD Datasheet

Hartcran House, 231 Kenton Lane, Harrow, Middlesex, HA3 8RP, England

Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233, www.radiometrix.com

BiM2/BiM3G

PRELIMINARY

Issue 1, 11 November 2009

433 / 868MHz FM Data Transceiver

The BIM2/3G data radio module is a PLL

synthesiser based miniature PCB

mounting UHF radio transceiver which

enable the simple implementation of a

wireless data link at up to 128 kbps at

distances up to 75 metres in-building

and 300 metres open ground.

Features

!

Data rates up to 128 kbps

Figure 1: BIM3G-869-64-5V

Usable range up to 300 m

Versions available on 433.92MHz, 434.42MHz and 868MHz band

Fully screened

Low profile with small footprint

Designed for compliance with EN 300 220-3 (radio) and EN 301 489-3 (EMC) standards

!

Available for operation at 433.92MHz, 434.42MHz and 868MHz band in the UK and Europe, these modules

combine full screening with extensive internal filtering to ensure EMC compliance by minimising spurious

radiations and susceptibilities. The BIM2/3G module will suit one-to-one and multi-node wireless links in

applications. Because of their small size and low power requirements, the module is ideal for use in portable,

battery-powered applications such as hand-held terminals.

Applications

!

Data loggers

EPOS equipment, barcode scanners, belt clip printers

Audience response systems

In-building environmental monitoring and control

Security and fire alarms

Restaurant ordering systems

Vehicle data up/download

Technical Summary

!

Crystal-locked PLL, FM modulated at up to 128 Kbps

+10dBm on 433.92MHz and 868MHz (Dependent on version)

High efficiency, >30%, DC to RF

2nd harmonic, > -60dBc

Single conversion FM superhet receiver

SAW front end filter gives >50dB image rejection

Sensitivity: -102dBm sensitivity @ 1ppm BER, 64kbps version

-108dBm sensitivity @ 1ppm BER, 15kbps version

TBA dBm sensitivity @ 1ppm BER, 128kbps version

RSSI output with 60dB range

Extremely low LO leakage, -125dBm typical

Supply: +5V (± 10%)

Current consumption: 10mA (typ.)

Size: 33 x 23 x 5mm

!

Evaluation platforms:

Universal Evaluation Kit, NBEK + DIL carrier

Radiometrix Ltd, BIM2/3G Data Sheet

page 1

Functional overview

The transmit section of the BiM2/3G consists of a frequency modulated crystal locked PLL feeding a buffer

amplifier and RF filter. A Tx select line controls operation. The transmitter achieves full RF output typically

within 1ms of this line being pulled low. Modulation is applied at the TXD input and may be either a serial digital

stream toggling between 0V and 5V (digital drive) or a high level analogue waveform with the same peak limits

(linear drive). Modulation shaping is performed internally by a 2nd order lowpass filter, which minimises spectral

spreading. The RF output is filtered to ensure compliance with the appropriate regulations and fed via a Tx/Rx

changeover switch to the antenna pin.

The receive section is a single conversion FM superhet with an IF of 10.7MHz. A SAW bandpass filter in the

receiver front-end provides image rejection and suppression of other unwanted out-of-band signals. Like the

transmitter, the receiver is controlled by its own active low RX select line. A post-detection lowpass filter

establishes the signal bandwidth and ensures clean operation of the subsequent adaptive data slicer. The slicer

is optimised for balanced data such as bi-phase code. A received signal strength (RSSI) output with 60dB of

range is provided. A version of BiM2/3G featuring a fast acting Carrier Detect (CD) output on the same RSSI

pin is also available. The CD output will indicate the presence of any RF signals on the carrier frequency.

side view (through can)

5 mm

side view (with can)

top view (without can)

RF GND 1

Antenna 2

RF GND 3

4

5

No pin

6

7

8

0V 9

30.48 mm

33 mm

18 0V

17 Vcc

16 RX SELECT

15 TX SELECT

14 TXD

13 AF

12 RXD

11 RSSI/CD

10 0V

23 mm

recommended PCB hole size: 1.2 mm

module footprint size: 25 x 32 mm

pin pitch: 2.54 mm (0.1")

pins 4, 5, 6, 7 & 8 are not fitted

Fig. 2: Physical dimensions

Pin description

RF GND

pins 1 & 3

RF ground pins, internally connected to the module screen and to pins 9, 10 & 18 (0V). These pins should be

connected directly to the RF return path (e.g. coax braid, main PCB ground plane etc).

Antenna

pin 2

50Ω RF connection to the antenna, DC-isolated. See pages 7 & 8 for details of suitable antennas and feeds.

0V (GND)

pins 9, 10 & 18

Supply ground connection and screen.

RSSI /CD

pin 11

RSSI variant:

Received Signal Strength Indicator with 60dB range, operational when Rx is enabled. Output

voltage nominally 0.50Vdc (no signal), 1.0Vdc (maximum strength). See page.6 for typical characteristics.

Carrier Detect variant:

When the receiver is enabled, a low indicates a signal above the detection threshold is

being received. The output is high impedance and should only be used to drive a CMOS logic input.

Radiometrix Ltd, BIM2/3G Data Sheet

page 2

RXD

pin 12

Digital output from internal data slicer. The output is a squared version of the signal on pin 13 (AF) and may be

used to drive a decoder directly. The data is true data, i.e. as fed to the transmitter. Output is “open-collector”

format with internal 10kΩ pullup to Vcc (pin 17).

AF

pin 13

Buffered & filtered analogue output from FM demodulator. Standing DC bias of 1V approx. Useful for test

purposes or for driving external decoders. External load should be >10kΩ // <100pF

TXD

pin 14

This DC-coupled transmitter modulation input will accept either serial digital data or high level linear signals.

Drive signal must be limited to 0V min, 5V max. See page 7 for suggested drive methods. Input impedance

>50kΩ.

TX select

pin 15

Active-low Transmit select. 47kΩ internal pull-up to Vcc.

RX select

pin 16

Active-low Receive select. 47kΩ internal pull-up to Vcc.

Pin 15 TX

Pin 16 RX

Function

1

Power down (<10µA)

1

0

Receiver enabled

0

1

Transmitter enabled

0

Self test loop-back*

* Loop-back allows the receiver to monitor the transmitted signal. Under these conditions the Tx radiated signal

level will be reduced to approximately -10dBm).

Vcc

pin 17

+5V DC +ve supply pin. The supply should be clean, <20mVP-P ripple.

Radiometrix Ltd, BIM2/3G Data Sheet

page 3

Absolute maximum ratings

Exceeding the values below may cause permanent damage to the module.

Operating temperature

Storage temperature

Vcc (pin 17)

TX, RX select (pins 15, 16)

All other pins

Antenna (pin 2)

-20°C to +70°C

-40°C to +100°C

-0.3V to +16V(Dependant on version)

-9V to +5.5V

-0.3V to +Vcc

±50V DC, +10dBm RF

Performance specifications

Figures apply to standard version @ Vcc=5.0V, temperature +20°C, unless stated.

General

Supply voltage

Tx supply current

Rx supply current

RF centre frequency

Antenna port impedance

TX & RX select: high

(deselect)

low

(select)

Internal select pull-ups

Balanced code bit rate

Transmitter section

RF power output

TX harmonics/spurious emission

Initial centre frequency accuracy

FM deviation

Modulation bandwidth

Modulation distortion

TX spectral bandwidth @-40dBc

TXD input level: high

low

TX power up to full RF

Receiver section

RF sensitivity, 10dB S/N

RF sensitivity, 1ppm BER

RSSI range

IF bandwidth

Image rejection (f

RF

-21.4MHz)

IF rejection (10.7MHz)

Local osc. leakage, conducted

Baseband bandwidth @ -3dB

AF output signal level

DC offset on AF output

Distortion on recovered AF

Load capacitance, AF & RXD

Radiometrix Ltd, BIM2/3G Data Sheet

17

-

2

15, 16

15,16

12

2

-

2

14

2

2, 13

2, 12

2, 11

-

2

13

12, 13

min.

4.5

-

10

-

Vcc-0.5

0

-

min.

-

-10

±20

0

-

2.8

0

-

min.

-

50

100

-

0

200

1.5

-

typ.

5.0

14

11

50

max.

5.5

-

17

-

Vcc

0.5

-

128

64

15

max.

-

-40

+10

±35

65

10

250

0.2

1.5

max.

-

-110

65

50

7.8

350

2.5

5

100

units

V

mA

MHz

Ω

V

kΩ

kbps

units

dBm

kHz

%

kHz

V

ms

units

dBm

dB

kHz

dB

dBm

kHz

mV p-p

V

%

pF

notes

Note 9

Note 1

Note 9

Tx or Rx

47

-

typ.

+10

-55

0

±27

-

5

-

5

-

1

typ.

-113

-TBA

-102

-108

60

180

54

-

-125

-

250

2.0

1

-

To Vcc (pin 17)

-128 version

-64 version

-15 version

notes

Note 9

Peak

@ -3db

Note 2

worst case

Note 3

Note 4

notes

-128 version

-64 version

-15 version

-128 version

-64 version

-15 version

Note 5

Note 6

Note 7

page 4

Receiver section

Dynamic Timing

Rx power up with signal present

Power up to valid RSSI, t

PU-RSSI

Power up to stable data, t

PU-data

Power up to stable data, t

PU-data

Signal applied with Rx on

RSSI response time (rise/fall)

Signal to stable data, t

sig-data

Signal to stable data, t

sig-data

Time between data transitions

Averaged code mark:space

Note:

min.

typ.

max.

units

notes

11

12

-

0.5

2

1

10

ms

-15 version

-64 version

11

12

14

-

70

15.6

20

100

0.5

0.2

-

50

-

1

0.5

5000

1500

80

µs

ms

µs

%

-15 version

-64 version

-15 version

-64 version

Note 8

1. Increases at high RF input level (>-20dBm)

2. See page 6 for further details

3. For specified FM deviation

4. Tx select low > full RF output

5. ±30kHz FM deviation –15 and –64 versions on;y

6. Min/max at ±50kHz offset

7. Max at ±50kHz offset

8. Average, at max. data rate

9. Dependant on version

Power supply requirement

The power supply ripple/noise should be below 10mVp-p to avoid problems. If the quality of the supply is in

doubt, it is recommended that a 10µF low-ESR tantalum or similar capacitor be added between the module

supply pin (Vcc) and ground, together with a 10Ω series feed resistor between the Vcc pin and the supply rail.

The BIM2/3G incorporates a low voltage shutoff circuit, which prevents any possibility of erratic operation by

disabling the RF output of the transmitter if the supply voltage drops below 2.2V (±5%). This feature is self-

resetting, i.e. restoring the supply to greater than 2.2V will immediately restore full RF output from the module.

The standard BiM2/3G requires a regulated 5V supply with ripple content <100mVpk-pk.

Received Signal Strength Indicator (RSSI)

The BIM2/3G module incorporates a wide range RSSI which measures the strength of an incoming signal over

a range of approximately 60dB. This allows assessment of link quality and available margin and is useful when

performing range tests.

Please note that the actual RSSI voltage at any given RF input level varies somewhat between units. The RSSI

facility is intended as a relative indicator only - it is not designed to be, or suitable as, an accurate and

repeatable measure of absolute signal level or transmitter-receiver distance.

The output on pin 5 of the module has a standing DC bias in the region of 0.5V with no signal, rising to around

1V at maximum indication. The RSSI output source impedance is high (~100kΩ) and external loading should

therefore be kept to a minimum.

To ensure a fast response the RSSI has limited internal decoupling of 1nF to ground. This may result in a small

amount of ripple on the DC output at pin 5 of the module. If this is a problem further decoupling may be added

at the expense of response speed, in the form of a capacitor from pin 5 to ground. For example, adding 10nF

here will increase RSSI response time from 100µs to around 1ms. The value of this capacitor may be increased

without limit.

Radiometrix Ltd, BIM2/3G Data Sheet

page 5

BiM3G

BiM3G Overview

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