T5753-6AQ ATMEL [ATMEL Corporation], T5753-6AQ Datasheet - Page 3

• Manufacturer Part Number: T5753-6AQ
• Description: UHF ASK/FSK TRANSMITTER
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 3. Block Diagram
General Description
4510F–RKE–07/04
PA_ENABLE
This fully integrated PLL transmitter allows particularly simple, low-cost RF miniature
transmitters to be assembled. The VCO is locked to 32 f
crystal is needed for a 315 MHz transmitter. All other PLL and VCO peripheral elements
are integrated.
The XTO is a series resonance oscillator so that only one capacitor together with a
crystal connected in series to GND are needed as external elements.
The crystal oscillator together with the PLL needs typically < 3 ms until the PLL is locked
and the CLK output is stable. There is a wait time of
microcontroller and the PA is switched on.
The power amplifier is an open-collector output delivering a current pulse which is nearly
independent from the load impedance. The delivered output power is hence controllable
via the connected load impedance.
This output configuration enables a simple matching to any kind of antenna or to 50 . A
high power efficiency of = P
an optimized load impedance of Z
ANT2
ANT1
CLK
1
2
3
4
T5753
f
PA
4
PLL
VCO
f
Power up/down
PFD
CP
LF
32
out
/(I
Load
S,PA
= (255 + j192)
V
XTO
S
) of 40% for the power amplifier results when
ENABLE
8
GND
7
VS
6
XTAL
5
3 ms until the CLK is used for the
is used at 3 V supply voltage.
XTAL
hence a 9.8438 MHz
T5753
3