TH72036KLD Melexis Inc, TH72036KLD Datasheet - Page 3

• Manufacturer Part Number: TH72036KLD
• Description: TX, ASK/FSK W/CLOCK, 868/915MHZ, 10QFN
• Manufacturer: Melexis Inc

Specifications of TH72036KLD

• Data Rate: 40Kbps
• Frequency Range: 850MHz To 930MHz
• Modulation Type: ASK, FSK
• Rf Ic Case Style: QFN
• No. Of Pins: 10
• Supply Voltage Range: 1.95V To 5.5V
• Operating Temperature Range: -40°C To
• Output Power: 9.5dBm
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

1 Theory of Operation
1.1 General
As depicted in Fig.1, the TH72036 transmitter consists of a fully integrated voltage-controlled oscillator
(VCO), a divide-by-32 divider (div32), a phase-frequency detector (PFD) and a charge pump (CP). An inter-
nal loop filter determines the dynamic behavior of the PLL and suppresses reference spurious signals. A
Colpitts crystal oscillator (XOSC) is used as the reference oscillator of a phase-locked loop (PLL) synthe-
sizer. The VCO’s output signal feeds the power amplifier (PA). The RF signal power P
four steps from P
voltage V
or to be matched to a 50Ohm load. Bandgap biasing ensures stable operation of the IC at a power supply
range of 1.95 V to 5.5 V.
1.2 Block Diagram
2 Functional Description
2.1 Crystal Oscillator
A Colpitts crystal oscillator with integrated functional capacitors is used as the reference oscillator for the PLL
synthesizer. The equivalent input capacitance CRO offered by the crystal oscillator input pin ROI is about
18pF. The crystal oscillator is provided with an amplitude control loop in order to have a very stable fre-
quency over the specified supply voltage and temperature range in combination with a short start-up time.
3901072036
Rev. 006
CX1
XTAL
CX2
FSKSW
PS
CKOUT
ROI
at pin PSEL. The open-collector output (OUT) can be used either to directly drive a loop antenna
3
2
out
5
= –11 dBm to +9.5 dBm, either by changing the value of resistor RPS or by varying the
FSKDTA
XOSC
div 32
div 8
1
Fig. 1: Block diagram with external components
CKDIV
XBUF
7
PLL
PFD
CP
32
Page 3 of 16
VCC
VCO
10
RPS
PSEL
control
mode
PA
6
R1
9
VEE
FSK/ASK Transmitter
ASKDTA
8
4
ENTX
OUT
TH72036
out
can be adjusted in
matching
868/915MHz
antenna
network
Data Sheet
Jun/08