SI4720-B20-GMR Datasheet, PDF (15/48 Pages) Silicon Laboratories – BROADCAST FM RADIO TRANSCEIVER FOR PORTABLE APPLICATIONS

Si4720/21-B20
Table 10. FM Transmitter Characteristics¹
Test conditions: V_RF = 118 dBµV, stereo, f = 68.25 kHz, fpilot = 6.75 kHz, REFCLK = 32.768 kHz, 75 µs pre-emphasis,
unless otherwise specified.
Production test conditions: V_DD = 3.3 V, V_IO = 3.3 V, T_A = 25 °C, F_RF = 98 MHz.
Characterization test conditions: V_DD = 2.7 to 5.5 V, V_IO = 1.5 to 3.6 V, T_A = –20 to 85 °C, F_RF = 76–108 MHz.
All minimum and maximum specifications are guaranteed and apply across the recommended operating conditions.
Typical values apply at V_DD = 3.3 V and 25 °C unless otherwise stated.
Parameters are tested in production unless otherwise specified.
Parameter
Transmit Frequency Range²
Transmit Frequency Accuracy and
Stability^2,3
Transmit Voltage Accuracy²
Symbol
f_RF
Transmit Voltage Accuracy
Transmit Voltage Temperature Coef-
ficient²
Test Condition
V_RF = 103–117 dBµV
V_RF = 102, 118 dBµV
Min Typ Max
76
— 108
–3.5 —
3.5
Unit
MHz
kHz
–2.5 —
2.5
dB
–2.5 —
2.5
dB
–0.075 — –0.025 dB/°C
Transmit Channel Edge Power
> ±100 kHz,
pre-emphasis off
—
—
–20
dBc
Transmit Adjacent Channel Power
> ±200 kHz,
pre-emphasis off
—
–30 –26
dBc
Transmit Alternate Channel Power
> ±400 kHz,
pre-emphasis off
—
–30 –26
dBc
Transmit Emissions
Output Capacitance Max²
Output Capacitance Min²
Pre-emphasis Time Constant²
In-band (76–108 MHz)
—
—
–30
dBc
C_TUNE
—
53
—
pF
C_TUNE
—
5
—
pF
TX_PREMPHASIS = 75 µs 70
75
80
µs
Audio SNR Mono²
TX_PREMPHASIS = 50 µs 45
50
54
µs
f = 22.5 kHz, Mono,
58
63
—
dB
limiter off
Audio SNR Stereo
f = 22.5 kHz,
53
58
—
dB
fpilot = 6.75 kHz, Stereo,
limiter off
Audio THD Mono
f = 75 kHz, Mono,
limiter off
—
0.1 0.5
%
Notes:
1. FM transmitter performance specifications are subject to adherence to Silicon Laboratories guidelines in “AN383:
Universal Antenna Selection and Layout Guidelines.” Silicon Laboratories will evaluate schematics and layouts for
qualified customers. Tested with test schematic (L = 120 nH, Q > 30) shown in Figure 10 on page 19.
2. Guaranteed by characterization.
3. No measurable fRF/V_DD at V_DD of 500 mVpk-pk at 100 Hz to 10 kHz.
Rev. 1.0
15