U2793B Datasheet, PDF (10/12 Pages) ATMEL Corporation – 300 MHZ QUADRATURE MODULATOR

Application Circuits
Bias network for AC-coupled baseband inputs (V_BA, V_BB).
R₁ = 2.5 kΩ, R₂ ≤10 kΩ for ≥ 35 dB LO suppression which is in reference to < 2 mV input
offset.
Figure 12. Application Circuit with AC-coupled Baseband Inputs
R₂
10
BB_{Ai 9}
BB_Ai
LO_i 14
Duty cycle
LO_i 15 _regenerator
Frequency
doubler
0°
90°
BB_Bi 11
BB_Bi ¹²
90° control
loop
R₁
1n
V_{Ref PU}
Power down
13
1 _{6,7 VS}
100n
Power
up
8 ^SPU
19 _LP2
LP1
20
Σ
4 RF_o
AC_GND
2
3,16,17,18
GND
5 _ACGND
Figure 13. Application Circuit with DC-coupled Baseband Inputs
100n
10k
10
BB_{Ai 9}
Baseband
processing
10k ^BBAi
100p
LO
LO_i 14
LO_i 15
Duty cycle
regenerator
10k
100n
10k
BB_BI ¹¹
BB_BI 12
Frequency
doubler
0°
90°
V_Ref
1n
PU
13
1
Power
up
Power down
6,7 ^VS
8 ^SPU
100n
90° control
loop
Σ
3,16,17,18
GND
19 _LP2 1n
LP1
20
OUT
4 RF_{o 1n}
AC_GND
1n
2
1n
5
AC_GND
10 U2793B
4651C–CELL–07/04