MAX2839AS datasheet(21/39 Pages) MAXIM

21 / 39 page

2.3GHz to 2.7GHz MIMO Wireless

BroadbandRF Transceiver

______________________________________________________________________________________

Detailed Description

Modes of Operation

The modes of operation for the MAX2839AS are shut-

down, clock-out only, standby, receive, transmit, trans-

mitter calibration, and receiver calibration. See Table 1

for a summary of the modes of operation. When the

parts are active, various blocks can be shutdown indi-

vidually by programming different SPI registers.

Shutdown Mode

The MAX2839AS features a low-power shutdown mode.

In shutdown mode, all circuit blocks are powered down,

except the 4-wire serial bus and its internal programma-

ble registers.

Clock-Out Only

In clock-out mode, the entire transceiver is off except

the divided reference clock output on the CLKOUT pin

and the clock divider, which remain on.

Standby Mode

The standby mode is used to enable the frequency

synthesizer block while the rest of the device is pow-

ered down. In this mode, the PLL, VCO, and LO gener-

ator are on so that Tx or Rx modes can be quickly

enabled from this mode. These and other blocks can

be selectively enabled in this mode by programming

different SPI registers.

Receive (Rx) Mode

In receive mode, all Rx circuit blocks are powered on

and active. Antenna signal is applied; RF is downcon-

verted, filtered, and buffered at Rx BB I and Q outputs.

Either receiver A or both receivers can be enabled.

Receiver B cannot be enabled by itself.

Transmit (Tx) Mode

In transmit mode, all Tx circuit blocks are powered on.

The external PA is powered on after a programmable

delay using the on-chip PA bias DAC.

Transmitter (Tx) Calibration Mode

All Tx circuit blocks except PA driver and external PA

are powered on and active. The AM detector and

receiver I/Q channel buffers are also on, along with

multiplexers in the receiver side to route this AM detec-

tor’s signal to each I and Q differential outputs. When

required, the I/Q lowpass filter can be bypassed.

MODE CONTROL LOGIC INPUTS

CIRCUIT BLOCK STATES

MODE

ENABLE

TXRX

SPI

REG1

D<3>

SPI

REG16

D<1:0>

Rx PATH

Tx PATH

PLL, VCO, LO

GEN

CALIBRATION

SECTIONS ON

CLOCK

OUTPUT

Shutdown

Off

None

Off

Clock-Out Only

Off

None

Clock-Out Only

Off

None

Standby

Off

On or Off

None

Rx (1x2 MIMO)

Off

None

Rx (1x1 SISO)

On (RX_A)

Off

None

Off

None

Tx Calibration

Off

On (except

PA driver)

SPI REG7D<7> = 1

AM detector + Rx

I, Q buffers

RX_A

Calibration

(Loopback)

(except

LNA)

On (except

PA driver)

SPI REG26D<3> = 1

Loopback

RX_B

Calibration

(Loopback)

(except

LNA)

On (except

PA driver)

SPI REG26D<3> = 1

Loopback

Table 1. Operating Mode

MAX2839AS Datasheet(PDF) 21 Page - Maxim Integrated Products

MAX2839AS Datasheet(HTML) 21 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

Datasheet Download

Link URL