U2741B Datasheet, PDF (7/9 Pages) ATMEL Corporation – UHF ASK/FSK TRANSMITTER

U2741B
Electrical Characteristics (Continued)
All parameters are refered to GND (pin 5). The possible operating ranges refer to different circuit conditions:
V_S = 2.0 V to 5.5 V at T_amb = -20°C to +70°C, V_S = 2.2 V to 5.5 V at T_amb = -40°C to +85°C (typically 25°C, 3 V)
Parameters
Test Conditions
Symbol Min.
Typ.
Max. Unit
Oscillator frequency XTO
M-version: at T_amb = 25°C
N-version: full temperature range
(monitoring)
Crystal frequency = 13.56 MHz
f_XTO
13.56 - 13.56 13.56 + MHz
30 ppm
30 ppm
Crystal frequency = 6.78 MHz
Load capacity of the crystal must be
selected accordingly
f_XTO
6.78 -
6.78
6.78 + MHz
30 ppm
30 ppm
Loop bandwidth
Phase noise PLL
Phase noise VCO
Frequency range of the VCO
Clock output
(CMOS microcontroller compatible)
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
f_VCO
Clk_out
100
kHz
-111
-105 dBC/Hz
-91
-123
-87
-119
dBC/Hz
300
450 MHz
f_out/128
MHz
Load capacitance at CLK
Series resonance R of the crystal
FSK modulation frequency rate
f_XTO = 13.56 MHz
f_XTO = 9.84 MHz
f_XTO = 6.78 MHz
f_XTO = 4.90 MHz
Duty cycle of the
modulation signal = 50%
C_CLK
Rs
Rs
Rs
Rs
f_modFSK
0
10
pF
80
100
150
W
225
20
kHz
ASK modulation frequency rate
Duty cycle of the
modulation signal = 50%
f_modASK
0
20
kHz
CLK output
- Output current Low
- Output current Low
- Output current High
- Output current High
ASK input
- Low level input voltage
- High level input voltage
- Input current High
FSK input
- Low level input voltage
- High level input voltage
- Input current High
V_CLK = 0.2 ´ V_S
V_CLK = 0.3 ´ V_S
V_CLK = 0.8 ´ V_S
V_CLK = 0.7 ´ V_S
I_ol
I_ol
I_oh
I_oh
V_ASKl
V_ASKh
I_ASKh
V_FSKl
V_FSKh
I_FSKh
150
200
-150
-200
1.7
1.7
µA
µA
µA
100
µA
0.3
V
V
140
µA
0.3
V
V
140
µA
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4733A–RKE–11/03