Rainbow Electronics MAX2701 - Manual (Page 17)

MAX2700/MAX2701
1.8GHz to 2.5GHz Direct Downconversion
Receivers
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PIN NAME FUNCTION
1 CEXT-
Inverting Input Port of VGA2 I/Q Gain Imbalance Correction Circuitry. Connect an
external capacitor between CEXT- and CEXT+ to activate the circuit. Short CEXT- to
CEXT+ to disable.
2 CEXT+
Noninverting Input Port of VGA2 I/Q Gain Imbalance Correction Circuitry. Connect an
external capacitor between CEXT+ and CEXT- to activate the circuit. Short CEXT- to
CEXT+ to disable.
3, 12, 17, 29, 38,
48
V CC Supply Voltage. Bypass V CC to GND with capacitors as close to pin as possible.
4 X2_EN
Logic-Level Enable for Doubler Circuitry. Drive logic low to turn on the doubler
(f
LO = f RFIN/2 ). Drive logic high to bypass the doubler (f LO = f RFIN ).
5, 7, 8, 13, 15,
32, 44, 46
GND Ground. Connect to ground plane with minimal inductance.
6 LNAIN LNA Input. Connect to GND to turn the LNA off. Off-chip 50
Ω
match required.
9 GAIN_SET
LNA Gain Select Input. Drive logic high to select the high-gain mode. Drive logic low to
select low-gain mode.
10 SHDN Shutdown Control Input. Drive logic low to enable shutdown mode.
11 AGC
Automatic Gain-Control Input for AGC. Bypass this pin with a 1000pF capacitor to
GND to minimize coupling.
14 LNAOUT LNA Output. This pin requires an external pullup inductor and off-chip 50
Ω
match.
16 MIX_Q
Mixer Q-Channel Baseband Output. Connect external series capacitor to AC-couple
the output to the load.
18 QIN1+ Noninverting VGA1, Q-Channel Baseband Input
19 QIN1- Inverting VGA1, Q-Channel Baseband Input
20 DCQ1+ Noninverting Offset Correction Input for Q-Channel VGA1 Amplifier
21 DCQ1- Inverting Offset Correction Input for Q-Channel VGA1 Amplifier
22 QOUT1 Q-Channel VGA1 Amplifier Baseband Output
23 MIXTNK Inductive Common-Mode Degeneration Pin for Mixer Stages
24 QIN2+ Noninverting VGA2, Q-Channel Baseband Input
25 QIN2- Inverting VGA2, Q-Channel Baseband Input
26 DCQ2+ Noninverting Offset Correction Input for Q-Channel VGA2 Amplifier
27 DCQ2- Inverting Offset Correction Input for Q-Channel VGA2 Amplifier
28 QOUT2 Q-Channel VGA2 Amplifier Baseband Output
30 RFIN+ I/Q Mixers Inverting Input. For narrow frequency bands between 1.8GHz and 2.5GHz,
port must be matched using external matching components.
Pin Description