ON Semiconductor NCN49597, Manual

Page: 10 / 28

NCN49597
http://onsemi.com
10
Transmitter External Parameters: Pin TX_OUT, ALC_IN, TX_ENB
To guarantee the transmitter external specifications the TX_CLK frequency must be 12 MHz ± 100 ppm.
Table 7. TRANSMITTER EXTERNAL PARAMETERS
Parameter Test Conditions Symbol Min Typ Max Unit
Maximum peak output level f
TX_OUT
= 23 – 75 kHz
f
TX_OUT
= 95 kHz
Level control at max. output
V
TX_OUT
0.85
0.76 1.15
1.22 Vp
Second order harmonic distortion f
TX_OUT
= 95 kHz
Level control at max. output
HD2 − 54 dB
Third order harmonic distortion f
TX_OUT
= 95 kHz
Level control at max. output
HD3 − 53 dB
Frequency accuracy of the gener-
ated sine wave
(Notes 4 and 6) Df
TX_OUT
30 Hz
Capacitive output load at pin
TX_OUT
(Note 4) CL
TX_OUT
20 pF
Resistive output load at pin
TX_OUT
RL
TX_OUT
5 k W
Turn off delay of TX_ENB output (Note 5) Td
TX_ENB
0.25 0.5 ms
Automatic level control attenuation
step
ALC
step
2.9 3.1 dB
Maximum attenuation ALC
range
20.3 21.7 dB
Low threshold level on ALC_IN VTL
ALC_IN
− 0.46 − 0.36 V
High threshold level on ALC_IN VTH
ALC_IN
− 0.68 − 0.54 V
Input impedance of ALC_IN pin R
ALC_IN
111 189 k W
Power supply rejection ration of the
transmitter section
PSRR
TX_OUT
10
(Note 7)
35
(Note 8)
dB
4. This parameter will not be tested in production.
5. This delay corresponds to the internal transmit path delay and will be defined during design.
6. Taking into account the resolution of the DDS and an accuracy of 100ppm of the crystal.
7. A sinusoidal signal of 10 kHz and 100 mVpp is injected between VDDA and VSSA. The digital AD converter generates an idle pattern. The
signal level at TX_OUT is measured to determine the parameter.
8. A sinusoidal signal of 50 Hz and 100 mVpp is injected between VDDA and VSSA. The digital AD converter generates an idle pattern. The
signal level at TX_OUT is measured to determine the parameter.
The LPF amplifier must have a frequency characteristic between the limits listed below. The absolute output level
depends on the operating condition. In production the measurement will be done for relative output levels where the 0 dB
reference value is measured at 50 kHz with a signal amplitude of 100 mV.
Table 8. TRANSMITTER FREQUENCY CHARACTERISTICS
Frequency (kHz)
Attenuation
Unit
Min Max
10 − 0.5 0.5 dB
95 − 1.3 0.5 dB
130 − 4.5 − 2.0 dB
165 − 3.0 dB
330 − 18.0 dB
660 − 36.0 dB
1000 − 50 dB
2000 − 50 dB