MAX2820ETM-T Maxim Integrated Products, MAX2820ETM-T Datasheet - Page 14

• Manufacturer Part Number: MAX2820ETM-T
• Description: RF Transceiver 2.4GHz 802.11b Zero-If Transceiver
• Manufacturer: Maxim Integrated Products

Specifications of MAX2820ETM-T

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX2820A/MAX2821A are cost-reduced versions
of the original MAX2820/MAX2821, intended as a drop-
in replacement—no changes to PC board layout, BOM,
or control software are required. Functionally, the “A”
version removes unused functions and programmability
while maintaining virtually identical performance char-
acteristics. The changes are detailed below.
The original device has the ability to program the
charge-pump source/sink current (±1mA or ±2mA); the
“A” version sets the charge-pump current at ±2mA, and
bit SYNTH:D6 (ICP) should now always be pro-
grammed to be 1.
2.4GHz 802.11b Zero-IF Transceivers
14
Exposed
Paddle
______________________________________________________________________________________
PIN
39
40
41
42
43
44
45
46
47
48
RX_BBQN
VCC_RMX
RX_BBQP
VCC_BUF
RX_BBIN
RX_BBIP
RX_AGC
RX_DET
RX_ON
TX_ON
NAME
GND
Changes in “A” Version
N.C.
Receive Positive Quadrature Baseband Output. Analog low-impedance differential buffer output.
Connect output directly to baseband ADC input. Internally biased to 1.2V common-mode voltage and
can drive loads up to 5kΩ || 5pF.
Receive Negative Quadrature Baseband Output. Analog low-impedance differential buffer output.
Connect output directly to baseband ADC input. Internally biased to 1.2V common-mode voltage and
can drive loads up to 5kΩ || 5pF.
Receive Negative In-Phase Baseband Output. Analog low-impedance differential buffer output.
Connect output directly to baseband ADC input. Internally biased to 1.2V common-mode voltage and
can drive loads up to 5kΩ || 5pF.
Receive Positive In-Phase Baseband Output. Analog low-impedance differential buffer output.
Connect output directly to baseband ADC input. Internally biased to 1.2V and can drive loads up to
5kΩ || 5pF.
Receive Level Detection Output. Digital CMOS output. Connect output directly to baseband IC input.
Used to indicate RF input level. Logic high for input levels above -49dBm (typ). Logic low for levels
below -54dBm (typ). (MAX2820 and MAX2821)
No Connection (MAX2820A/MAX2821A)
Supply Voltage for Receiver Baseband Buffer. Bypass with a capacitor as close to the pin as
possible. Do not share the bypass capacitor ground vias with other branches.
Receiver-On Control Input. Digital CMOS input. Connect to baseband IC mode control CMOS output.
Supply Voltage for Receiver Downconverter. Bypass with a capacitor as close to the pin as possible.
Do not share the bypass capacitor ground vias with other branches.
Transmitter-On Control Input. Digital CMOS input. Connect directly to baseband IC mode control
CMOS output.
Receive AGC Control. Analog high-impedance input. Connect directly to baseband IC DAC voltage
output. See the Typical Operating Characteristics for Gain vs. V
DC and AC Ground Return for IC. Connect to PC board ground plane using multiple vias.
Synthesizer
The original device has the ability to control the base-
band LPF corner; the “A” version sets the LPF corner at
8.0MHz. Register bits RECEIVE:D2–D0 are now “don’t
cares.”
The original device has a receive-level detect output (pin
43, “RX_DET”); the “A” version removes this functionality.
Pin 43 is a no-connect (N.C.) on the “A” version.
DESCRIPTION
Pin Description (continued)
Receive-Level Detector (RSSI)
RX_AGC
.
Receive Filter