MELEXIS TH7120NE Datasheet

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 1 of 28 Data Sheet
Rev. 005 Jan. 2002

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Features

! Single chip solution with only a few external components
! Stand-alone fixed-frequency transceiver operation modes
! Programmable multi-channel transceiver operation modes
! Low current consumption in active mode and very low standby current
! PLL-stabilized RF VCO (LO) with internal varactor diode
! Lock detection in programmable channel applications
! 3wire bus serial control interface
! FSK/ASK modulation selection
! FSK for digital data and FM for analog signal reception
! RSSI allows signal strength indication and ASK detection
! Switchable LNA gain for improved dynamic range
! Automatic PA turn-on after PLL lock
! FM possible with external varactor
! ASK modulation achieved by on/off keying
! AFC option for extended input frequency acceptance range
! Surface mount package LQFP32

Ordering Information

Part No. (Engineering Samples) Temperature Code Package Code

TH7120 (TH7120-03) E (-40 °C to 85 °C) NE (LQFP32)

Application Examples

! General bi-directional half duplex digital data transmission or analog signal transmission
! Low-power telemetry
! Alarm and security systems
! Keyless car and central locking
! Domotics
! Model control

Technical Data Overview

! Frequency range: 300 MHz to 930 MHz for programmable channel applications
! 315 MHz, 433 MHz, 868 MHz or 915 MHz fixed-frequency single-channel variants
! Power supply range: 2.5 V to 5.5 V
! Temperature range: -40 °C to +85 °C
! Standby current: 50 nA
! Operating current: 6.0 mA in receive mode at low gain
! Operating current 9.0 mA in transmit mode at 0 dBm output power
! Adjustable output power range from –15 dBm to +6 dBm
! Sensitivity: -103 dBm at FSK with 150 kHz IF filter BW
! Sensitivity: -105 dBm at ASK with 150 kHz IF filter BW
! Maximum data rate for FSK and ASK: 60 kbit/s NRZ
! Maximum input level: –10 dBm at FSK and -20 dBm at ASK
! Input frequency acceptance: ± 50 kHz (with AFC option)
! Frequency deviation range: ±5 kHz to ±100 kHz
! Maximum analog modulation frequency: 20 kHz
! 3 MHz to 12 MHz crystal reference

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 2 of 28 Data Sheet
Rev. 005 Jan. 2002

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General Description

The TH7120 is a single chip FSK/FM/ASK transceiver IC. It is designed to operate in low-power multi-channel
programmable or single-channel s tand-alone, half -duplex data tr ansm ission s ystems. It c an be used for ISM,
SRD or any other application operating in the frequency ranging of 300 MHz to 930 MHz.

The TH7120 transceiver IC consists of the following building blocks:

" Low-noise amplifier (LNA) for high-sensitivity RF signal reception with switchable gain
" Mixer (MIX) for RF-to-IF down-conversion
" IF amplifier (IFA) to amplify and limit the IF signal and for RSSI generation
" Phase-coincidence demodulator with external ceramic discriminator (FSK Demodulator)
" Operational amplifier, connected to demodulator output (OA1)
" Operational amplifier, integrator circuit at FSK-AFC mode (OA2)
" Control logic with 3wire bus serial control interface (SCI)
" Reference oscillator (RO) with external crystal
" Reference divider (R counter)
" Programmable divider (N/A counter)
" Phase-frequency detector (PFD)
" Charge pump (CP)
" Voltage control oscillator (VCO) with internal varactor
" Power amplifier (PA) with adjustable output power

The transceiver can be used either as a 3wire-bus-controlled programmable or as a stand-alone fixed­frequency device. After power up, the transceiver is set to fixed-frequency mode. In this mode, pins
FS0/SDEN and FS1/LD must be connected to V

EE

or VCC in order to set the desired frequency of operation.
The logic levels at pins FS0/SDEN and FS1/LD m ust not be changed after power up in order to remain in
fixed-frequency mode.

Channel frequency 433.92 MHz 868.3 MHz 315.0 MHz 915.0 MHz

FS0/SDEN

1010

FS1/LD

0011

After the first logic level change at pin FS0/SDEN, the transceiver enters into program mable m ode while pin
FS1/LD is now a PLL lock detector output. In this mode, the user can set any PLL frequency or mode of op­eration by the SCI.

In the fixed-frequency mode, the user c an set the transceiver to Standby, Receive, Tr ansmit or Idle (only PLL
synthesizer active) mode via control pins RE/SCLK and TE/SDTA.

Operation mode Standby Receive Transmit Idle

RE/SCLK

0101

TE/SDTA

0011

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 3 of 28 Data Sheet
Rev. 005 Jan. 2002

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Block Diagram

Figure 1: TH7120 block diagram

IN_LNA

LNA

GAIN_LNA

OUT_LNA

IN_MIX

OUT_DTA

OA2

bias

IF

MIX

OUT_MIX1

IN_IFA

VEE_IF

IFA

IN_DEM

26

29

28

30 32 31 1

VCC_IF

2

3

OUT_DEM

6

OA1

8

INT1

5

INT2

4

RSSI

7

1.5pF

200k

VEE_LNA

27

MIX

DemodulatorFSK

VEE_PLL

OUT_PA

FSK

ASK

LO

IN_DTA

ASK/FSK

RE/SCLK

TE/SDTA

FS0/SDEN

25

VCC_PLL

20

PS_PA

24

FSK_SW

FS1/LD

VEE_RO

11 19 9 1716151312

RO

RO

R

counter

N

counter

RO

10

LF

21

SCLK
SDTA
SDEN

Control Logic

SCI

TNK_LO

23

VCO

22

PA

18

VEE_DIG

14

VCC_DIG

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 4 of 28 Data Sheet
Rev. 005 Jan. 2002

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Pin Definition and Descripti on

Pin No. Name I/O Type Functional Schematic Description

1 IN_IFA input

3.1k3.1k

IN_IFA

1

VCC

140µA

VEE

2.2k

IF amplifier input, approx.
2

kΩ single-ended

2 VCC_IF supply positive supply of LNA, MIX,

IFA, FSK Demodulator, PA,
OA1 and OA2

3 IN_DEM analog I/O

VCC

100µA

10µA

VEE

IN_DEM

3

77k

1.5p

IF amplifier output and de­modulator input, connection
to external ceramic discrimi­nator

4 INT2 output integrator output OA2

8 OUT_DTA output

VCC

VEE

INT2

4

8

OUT_DTA

output OA1

5 INT1 input inverting inputs OA1 and

OA2

6 OUT_DEM analog I/O

OA2

bias

VEE

VCC

INT1

5

VEE

OUT_DEM

6

VCC

120

120

VEE

VCC

120

10.5p

10.5p

520k 520k

1k

OA1

+

200k

demodulator output and non­inverting input OA1

7 RSSI output

VCC

VEE

RSSI

7

120

VEE

VCC

5µA

5µA

RSSI output

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 5 of 28 Data Sheet
Rev. 005 Jan. 2002

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Pin No. Name I/O Type Functional Schematic Description

9 VEE_RO ground ground of RO

10 RO analog I/O

40p

VEE

VCC

RO
10

2.6µA

39k

40p

RO input, base of bipolar
transistor

11 FSK_SW analog I/O

VCC

VEE

FSK_SW

11

FSK pulling pin, switch to
ground or OPEN

12 IN_DTA input ASK/FSK modulation data

input, pull down resistor
120kΩ

15 RE/SCLK input receiver enable input / clock

input for the shift register,
pull down resistor 120kΩ

16 TE/SDTA input

VEE

VCC

IN_DTA

12

RE/SCLK

15

16

TE/SDTA

120k

120

transmitter enable input /
serial data input, pull down
resistor 120kΩ

13 ASK/FSK input ASK/FSK mode select input

17 FS0/SDEN input

VEE

VCC

ASK/FSK

13

17

FS0/SDEN

120

frequency select input / se­rial data enable input

14 VCC_DIG supply positive supply of serial port

and control logic

18 VEE_DIG ground ground of serial port and

control logic

19 FS1/LD input

VEE

VCC

FS1/LD

19

120

frequency select input / lock
detector output

20 VCC_PLL supply positive supply of PLL fre-

quency synthesizer

22 VEE_PLL ground ground of PLL frequency

synthesizer

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 6 of 28 Data Sheet
Rev. 005 Jan. 2002

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Pin No. Name I/O Type Functional Schematic Description

21 LF analog I/O charge pump output, con-

nection to external loop filter

23 TNK_LO analog I/O

120

10k

6.3p

VCC

VCC

VCC

VEE

33 33

VEE

LF

21

TNK_LO

23

VCO open-collector output,
connection to external LC
tank

24 PS_PA analog I/O

VEE VEE

VCC VCC

120

PS_PA

24

power-setting input

25 OUT_PA output

VEE VEE

VCC

OUT_PA

25

power amplifier open­collector output

27 VEE_LNA ground ground of LNA and PA
28 OUT_LNA output LNA open-collector output,

connection to external LC
tank at RF

26 IN_LNA input

40p

VEE

VEE

3.8k

OUT_LNA

28

bias

37

IN_LNA

26

LNA input,
approx. 50Ω single-ended

29 GAIN_LNA input

VCC

VEE

GAIN_LNA

29

120

LNA gain control input

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 7 of 28 Data Sheet
Rev. 005 Jan. 2002

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Pin No. Name I/O Type Functional Schematic Description

30 IN_MIX input

VCC

210

bias

LO

IN_MIX

30

VEE VEE

mixer input, approx. 200Ω
single-ended

31 VEE_IF ground ground of IFA, Demodulator,

OA1 and OA2

32 OUT_MIX output

VCC

VEE

OUT_MIX

32

100

mixer output, approx. 330Ω
single-ended

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 8 of 28 Data Sheet
Rev. 005 Jan. 2002

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Stand-Alone Fixed-Frequency Operation

After power up the transceiver is set to fixed-frequency mode. In this mode, pins FS0/SDEN and FS1/LD
must be connected to V

EE

or VCC to set the desired frequency of operation. The logic levels at pins FS0/SDEN
and FS1/LD must not be changed after power up in or der to remain in fixed-f requency mode. The default
settings of the control word bits in stand-alone mode are described in the frequency selection table.

Frequency Selection

Channel frequency 433.92 MHz 868.3 MHz 315 MHz 915 MHz

FS0/SDEN

1010

FS1/LD

0011

Reference oscillator frequency

7.1505 MHz

R counter ratio in RX mode

16 16 18 30

PFD frequency in RX mode

446.91 kHz 446.91 kHz 397.25 kHz 238.35 kHz

N/A counter ratio in RX mode

947 1919 766 3794

VCO frequency in RX mode

423.22 MHz 857.60 MHz 304.30 MHz 904.30 MHz

RX frequency

433.92 MHz 868.30 MHz 315.00 MHz 915.00 MHz

R counter ratio in TX mode

16 16 18 30

PFD frequency in TX mode

446.91 kHz 446.91 kHz 397.25 kHz 238.35 kHz

N/A counter ratio in TX mode

971 1943 793 3839

VCO frequency in TX mode

433.92 MHz 868.30 MHz 315.00 MHz 915.00 MHz

TX frequency

433.92 MHz 868.30 MHz 315.00 MHz 915.00 MHz

IF frequency in RX mode

10.7 MHz 10.7 MHz 10.7 MHz 10.7 MHz

TH7120

300 to 930MHz

FSK/FM/ASK Transceiver

3901007120 Page 9 of 28 Data Sheet
Rev. 005 Jan. 2002

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Default Register Settings After Power-up

Bits

A-word

symbols

Channel

‘00’

868.3
MHz

Channel

‘01’

433.92
MHz

Channel

‘10’

915.0
MHz

Channel

‘11’

315.0
MHz

B-word

symbols

Channel

‘00’

868.3
MHz

Channel

‘01’

433.92
MHz

Channel

‘10’

915.0
MHz

Channel

‘11’

315.0
MHz

21 not used 0 not used 0
20 DI_MODE 0 not used 0
19 MODUL 0 EnDelPLL 1
18 HighCur 0 LNAHYST 1
17

LOCK_MODE

0 EnAdj 0
16 PA_AUTO 0 EnFM 0
15 Pow1 1 Max2 1
14 Pow0 1 Max1 1
13 MIXG 1 Max0 1
12 LNAG 1 Min2 0
11 TE 0 Min1 1
10 RE 0 Min0 1

9 RR9 0 0 0 0 RT9 0 0 0 0
8 RR8 0 0 0 0 RT8 0 0 0 0
7 RR7 0 0 0 0 RT7 0 0 0 0
6 RR6 0 0 0 0 RT6 0 0 0 0
5 RR5 0 0 0 0 RT5 0 0 0 0
4 RR4 1 1 1 1 RT4 1 1 1 1
3 RR3 0 0 1 0 RT3 0 0 1 0
2 RR2 0 0 1 0 RT2 0 0 1 0
1 RR1 0 0 1 1 RT1 0 0 1 1
0 RR0 0 0 0 0 RT0 0 0 0 0

Bits

C-word

symbols

Channel

‘00’

868.3
MHz

Channel

‘01’

433.92
MHz

Channel

‘10’

915.0
MHz

Channel

‘11’

315.0
MHz

B-word

symbols

Channel

‘00’

868.3
MHz

Channel

‘01’

433.92
MHz

Channel

‘10’

915.0
MHz

Channel

‘11’

315.0
MHz

21 LNAGI_E 0

MODUL_CTR

0

20 POLAR 0 LD_TM1 1
19 High2 0 0 0 0 LD_TM0 0
18 High1 1 1 1 1 ER_TM1 0
17 UP 1 0 1 0 ER_TM0 0
16 NR16 0 0 0 0 NT16 0 0 0 0
15 NR15 0 0 0 0 NT15 0 0 0 0
14 NR14 0 0 0 0 NT14 0 0 0 0
13 NR13 0 0 0 0 NT13 0 0 0 0
12 NR12 0 0 0 0 NT12 0 0 0 0
11 NR11 0 0 1 0 NT11 0 0 1 0
10 NR10 1 0 1 0 NT10 1 0 1 0

9 NR9 1 1 1 1 NT9 1 1 1 1
8 NR8 1 1 0 0 NT8 1 1 0 1
7 NR7 0 1 1 1 NT7 1 1 1 0
6 NR6 1 0 1 1 NT6 0 1 1 0
5 NR5 1 1 0 1 NT5 0 0 1 0
4 NR4 1 1 1 1 NT4 1 0 1 1
3 NR3 1 0 0 1 NT3 0 1 1 1
2 NR2 1 0 0 1 NT2 1 0 1 0
1 NR1 1 1 1 1 NT1 1 1 1 0
0 NR0 1 1 0 0 NT0 1 1 1 1