Datasheet

MAX1479
300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter
_______________________________________________________________________________________ 3
Note 1: Supply current, output power, and efficiency are greatly dependent on board layout and PAOUT match.
Note 2: 100% tested at T
A
= +125°C. Guaranteed by design and characterization over temperature.
Note 3: 50% duty cycle at 10kHz ASK data (Manchester coded).
Note 4: Guaranteed by design and characterization, not production tested.
Note 5: V
ENABLE
= V
IL
to V
ENABLE
= V
IH
. f
OFFSET
is defined as the frequency deviation from the desired carrier frequency.
Note 6: Dependent on crystal and PCB trace capacitance.
Note 7: V
ENABLE
> V
IH
, V
DATA
> V
IH
, Efficiency = P
OUT
/(V
DD
x I
DD
).
Note 8: Dependent on PCB trace capacitance.
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX UNITS
SYSTEM PERFORMANCE
Frequency Range f
RF
(Note 2)
300
450
MHz
Settle to within 50kHz
200
Turn-On Time (Note 5) t
ON
Settle to within 5kHz
350
µs
ASK mode (Manchester coded)
100
Maximum Data Rate (Note 4)
FSK mode (Manchester coded) 20
kbps
f
RF
= 315MHz 55
Maximum FSK Frequency
Deviation
DEV[2:0] = 111
(Note 6)
f
RF
= 433MHz 80
kHz
T
A
= +25°C, V
DD
= +2.7V 6.8 10
12.0
T
A
= +125°C, V
DD
= +2.1V 2.7 5.3Output Power (Note 2) P
OUT
T
A
= -40°C, V
DD
= +3.6V
12.2 16.1
dBm
f
RF
= 315MHz 35
Transmit Efficiency with CW Tone
(Note 7)
f
RF
= 433MHz 34
%
f
RF
= 315MHz 27
Transmit Efficiency at 50% Duty
Cycle
f
RF
= 433MHz 25
%
PHASE-LOCKED-LOOP PERFORMANCE
VCO Gain K
VCO
280 MHz/V
f
OFFSET
= 100kHz -75
f
RF
= 315MHz
f
OFFSET
= 1MHz -98
f
OFFSET
= 100kHz -74
Phase Noise
f
RF
= 433MHz
f
OFFSET
= 1MHz -98
dBc/Hz
f
RF
= 315MHz -50
Maximum Carrier Harmonics
f
RF
= 433MHz -45
dBc
Reference Spur -40 dBc
Loop Bandwidth BW
300
kHz
Crystal Frequency Range f
XTAL
F
RF
/ 32 MHz
Crystal Tolerance 50
ppm
Crystal Load Capacitance C
LOAD
(Note 8) 4.5 pF
Clock Output Frequency
D eter m i ned b y C LK0 and C LK1; see Tab l e 1
F
XTAL
/N
MHz
AC ELECTRICAL CHARACTERISTICS
( Typical Application Circuit , all RF inputs and outputs are referenced to 50Ω, V
DD
= +2.1V to +3.6V, V
ENABLE
= V
DD
, T
A
= -40°C to
+125°C, unless otherwise noted. Typical values are at V
DD
= +2.7V, T
A
= +25°C, unless otherwise noted.) (Note 1)