HFA3766 Datasheet, PDF (4/11 Pages) Intersil Corporation – 400MHz AGC Quadrature IF Modulator/Demodulator

HFA3766
Pin Descriptions
PIN
SYMBOL
DESCRIPTION
1
AGC1_BYP+ DC feedback pin for AGC amplifier 1. Requires good decoupling and minimum wire length to a solid signal
ground.
2
AGC1_IN+ Non-inverting analog input of AGC amplifier 1.
3
GND
Ground. Connect to a solid ground plane.
4
AGC_SEL This pin selects either differential or single ended input configuration for the first stage AGC. Ground this pin for
differential input configuration. Leave it floating for single ended input configuration.
5
AGC1_IN- Inverting analog input of AGC amplifier 1.
6
AGC1_BYP- DC feedback pin for AGC amplifier 1. Requires good decoupling and minimum wire length to a solid signal
ground.
7, 8
GND
Ground. Connect to a solid ground plane.
9
LPF_V_CC
Supply pin for the Low pass filter. Use high quality decoupling capacitors right at the pin.
10
2V REF
Stable 2V reference voltage output for external applications. Loading must be higher than 10kΩ. A bypass
capacitor of at least 0.1µF is required.
11
LPF_BYP
Internal reference bypass pin. This is the common voltage (V_CM) used for the LPF digital thresholds. Requires
0.1µF decoupling capacitor.
12
LPF_TXI_IN Low pass filter in phase (I) channel transmit input. Conventional or attenuated direct coupling is required for
digital inputs.
13
LPF_TXQ_IN Low pass filter quadrature (Q) channel transmit input. Conventional or attenuated direct coupling is required for
digital inputs
14
LPF_RX_I Low pass filter in phase (I) channel receive output. Requires AC coupling.
15
LPF_RX_Q Low pass filter quadrature (Q) channel receive output. Requires AC coupling.
16
LPF_SEL1 Digital control input pins. Selects four programmed cut off frequencies for the receive channel. Tuning speed from
one cutoff to another is less than 1µs.
17
LPF_SEL0
SEL1 SEL0 CUTOFF FREQUENCY
SEl1 SEl0 CUTOFF FREQUENCY
LO LO
2.2MHz
HI
LO
8.8MHz
LO HI
4.4MHz
HI
HI
17.6MHz
18
LPF_TUNE1 These two pins are used to fine tune the Low pass filter cutoff frequency. A resistor connected between the two
pins (R_TUNE) will fine tune both transmit and receive filters. Refer to the tuning equation in the LPF AC
19
LPF_TUNE0 _{specifications.}
20
TXD or TXA Selects between digital or analog signals. Tie to GND for digital. Tie to V_CC for analog.
21
LPF_RX_PE Digital input control pin to enable the LPF receive mode of operation. Enable logic level is High.
22
LPF_TX_PE Digital input control pin to enable the LPF transmit mode of operation. Enable logic level is High.
23
LPF_TXQ- Negative output of the transmit Low pass filter, quadrature channel. AC coupling is required. Normally connects
to the inverting input of the quadrature Modulator (Mod_TXQ-), pin 40.
24
LPF_TXQ+ Positive output of the transmit Low pass filter, quadrature channel. AC coupling is required. Normally connects
to the non inverting input of the quadrature Modulator (Mod_TXQ+), pin 39.
25
LPF_TXI- Negative output of the transmit Low pass filter, in phase channel. AC coupling is required. Normally connects to
the inverting input of the in phase Modulator (Mod_TXI-), pin 38.
26
LPF_TXI+ Positive output of the transmit Low pass filter, in phase channel. AC coupling is required. Normally connects to
the non inverting input of the in phase Modulator (Mod_TXI+), pin 37.
27
LPF_RXQ- Low pass filter inverting input of the receive quadrature channel. AC coupling is required. This input is normally
coupled to the negative output of the quadrature demodulator (Mod_RXQ-), pin 36.
4