U2745B Datasheet, PDF (6/9 Pages) ATMEL Corporation – UHF ASK TRANSMITTER

Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Parameters
Symbol
Min.
Max.
Unit
Supply voltage
Power dissipation
Junction temperature
Storage temperature
Ambient temperature
V_S
P_tot
T_j
T_stg
-55
T_amb
-40
6
V
250
mW
150
°C
125
°C
85
°C
Thermal Resistance
Parameters
Junction ambient
Symbol
R_thJA
Value
180
Unit
K/W
Electrical Characteristics
All parameters are refered to GND (pin 5), V_S = 3 V, T_amb = 25°C, unless otherwise specified
The possible operating ranges refer to different circuit conditions: V_S = 2.2 V to 4.0 V at T_amb = -40°C to +85°C
Parameters
Test Conditions
Symbol
Min.
Typ.
Max.
Supply current (power down)
V_ASK, V_FSK £ 0.3 V, V_S < 3.6 V
Supply current (power up, output OFF) V_ASK = GND, V_EN = V_S, V_S = 3 V
Supply current (power up, output ON) V_ASK = V_S, V_S = 3 V, R_PWRSET = 1.2 kW
Output power
V_S = 3 V, T_amb = 25°C, f = 433.92 MHz
R_PWRSET = 1.2 kW
Output power variation for
f = 315 MHz compared to
f = 433.92 MHz
f = 315 MHz
P_out = P_Ref + DP_Ref
at P_out = 2.0 mW,
the load impedance must be selected
Maximum peak output
antenna voltage
to meet the V_out maximum
requirement, the supply current is not
dependent on the load impedance
tolerance
IS_off
IS_on
IS_transmit
P_Ref
DP_Ref
V_outmax
2
10
4.7
6.2
10
12.5
1
3
5
1.5
V_S - 0.7 V
f_o ±(n ´ f_PC) where f_PC = 6.78 MHz
Spurious emission
Load capacitance at CLK £ 3 pF
f = 230 MHz to 470 MHz
Em
-40
f < 230 MHz, f > 470 MHz
Em
-58
Oscillator frequency XTO
Crystal frequency = 13.56 MHz
f_XTO
13.56 -
30 ppm
13.56
13.56 +
30 ppm
Loop bandwidth
Phase noise PLL
Phase noise VCO
For best LO noise
Loop filter components:
C₂ = 3.9 nF, C₁ = 15 nF, R₄ = 220 W
Referring to the phase comparator
f_PC = 6.78 MHz
at 1 MHz
at 36 MHz
B_Loop
PN_PLL
PN_VCO
PN_VCO
100
-111
-105
-90
-122
Unit
µA
mA
mA
dBm
dB
V_(peak)
dBC
dBC
MHz
kHz
dBC/Hz
dBC/Hz
6 U2745B
4734A–RKE–11/03