MAXIM MAX2837 Technical data

General Description

The MAX2837 direct-conversion zero-IF RF transceiver
is designed specifically for 2.3GHz to 2.7GHz wireless
broadband systems. The MAX2837 completely inte­grates all circuitry required to implement the RF trans­ceiver function, providing RF-to-baseband receive path;
and baseband-to-RF transmit path, VCO, frequency
synthesizer, crystal oscillator, and baseband/control
interface. The device includes a fast-settling sigma­delta RF synthesizer with smaller than 20Hz frequency
steps and a crystal oscillator, which allows the use of a
low-cost crystal in place of a TCXO. The transceiver IC
also integrates circuits for on-chip DC offset cancella­tion, I/Q error, and carrier-leakage detection circuits.
Only an RF bandpass filter (BPF), crystal, RF switch,
PA, and a small number of passive components are
needed to form a complete wireless broadband RF
radio solution.

The MAX2837 completely eliminates the need for an
external SAW filter by implementing on-chip monolithic
filters for both the receiver and transmitter. The baseband
filters along with the Rx and Tx signal paths are optimized
to meet stringent noise figure and linearity specifications.
The device supports up to 2048 FFT OFDM and imple­ments programmable channel filters for 1.75MHz to
28MHz RF channel bandwidths. The transceiver requires
only 2µs Tx-Rx switching time, which includes frequency
transient settling. The IC is available in a small, 48-pin thin
QFN package measuring only 6mm x 6mm x 0.8mm.

Applications

802.16-2004 Fixed WiMAX

Korea Wibro and 802.16e Mobile WiMAX

Dual Mode

TM

WiMAX/802.11b/g Wi-Fi

Proprietary Wireless Broadband Systems

4G/LTE Systems

Features

♦ 2.3GHz to 2.7GHz Wideband Operation

♦ Complete RF Transceiver, PA Driver, and

Crystal Oscillator

0dBm Linear OFDM Transmit Power

-70dBr Tx Spectral Emission Mask

2.3dB Rx Noise Figure

Tx/Rx I/Q Error and LO Leakage Detection

Monolithic Low-Noise VCO with -39dBc

Integrated Phase Noise

Programmable Tx I/Q Lowpass

Anti-Aliasing Filter

Sigma-Delta Fractional-N PLL with

20Hz Step Size

45dB Tx Gain-Control Range

94dB Receive Gain-Control Range

60dB Analog RSSI Instantaneous

Dynamic Range

4-Wire SPI™ Digital Interface

I/Q Analog Baseband Interface

Digitally Tuned Crystal Oscillator

On-Chip Digital Temperature Sensor Read-Out

♦ +2.7V to +3.6V Transceiver Supply

♦ Low-Power Shutdown Current

♦ Small 48-Pin Thin QFN Package

(6mm x 6mm x 0.8mm)

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

________________________________________________________________

Maxim Integrated Products

1

Ordering Information

19-0806; Rev 1; 11/08

For information on other Maxim products, visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE

PIN­PACKAGE

MAX2837ETM+TD

48 TQFN-EP*

*

EP = Exposed paddle.

+

Denotes a lead-free package.

Pin Configuration appears at end of data sheet.

Dual Mode is a trademark of Maxim Integrated Products, Inc.

SPI is a trademark of Motorola, Inc.

-40°C to +85°C

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(MAX2837 evaluation kit: V

CC_

= 2.7V to 3.6V, Rx set to the maximum gain; CS = high, RXHP = SCLK = DIN = low, RSSI and clock output

buffer are off, no signal at RF inputs, all RF inputs and outputs terminated into 50Ω, receiver baseband outputs are open; 90mV

RMS

dif-

ferential I and Q signals applied to I, Q baseband inputs of transmitter in transmit mode, f

REF

= 40MHz, registers set to recommended

settings and corresponding test mode, T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at VCC= 2.8V, fLO= 2.5GHz,

and T

A

= +25°C, unless otherwise noted.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

V

CCLNA

, V

CCTXMX

, V

CCTXPAD

, V

CCDIG

, V

CCCP

, V

CCXTAL

,

V

CCVCO

, V

CCRXVGA

, V

CCRXFL

and V

CCRXMX

to

GND...................................................................-0.3V to +3.9V

B1–B7, TXRF_, CS, SCLK, DIN, DOUT, TXBBI_, TXBBQ_, RXHP,

RXBBI_, RXBBQ_, RSSI, ENABLE, BYPASS, CPOUT_,
CLOCKOUT, XTAL1, XTAL2, RXRF_,RXENABLE, TXENABLE

to GND.......................................-0.3V to (Operating V

CC

+ 0.3V)

RXBBI_, RXBBQ_, RSSI, BYPASS, CPOUT_, DOUT, CLOCKOUT,

PABIAS Short-Circuit Duration............................................10s

RF Input Power ...............................................................+10dBm

Continuous Power Dissipation (T

A

= +70°C)

48-Pin Thin QFN (derates 37mW/°C above +70°C).......2.96W

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10s) .................................+260°C

PARAMETER CONDITIONS

Supply Voltage V

CC_

2.7 3.6 V

Shutdown mode, TA = +25°C10µA

Standby mode 35 45

Rx mode 91 110

Tx mode, TA = +25°C

170

Rx calibration mode

160

Supply Current

Tx calibration mode

135

mA

D9:D8 = 00 in A4:A0 = 00100

1.0

D9:D8 = 01 in A4:A0 = 00100 1.1

D9:D8 = 10 in A4:A0 = 00100 1.2

Rx I/Q Output Common-Mode
Voltage

D9:D8 = 11 in A4:A0 = 00100

V

Tx Baseband Input Common­Mode Voltage Operating Range

DC-coupled 0.5 1.2 V

Tx Baseband Input Bias Current Source current 10 20 µA

LOGIC INPUTS: ENABLE, TXENABLE, RXENABLE, SCLK, DIN, CS, B7:B1, RXHP

Digital Input-Voltage High, V

IH

0.4

V

Digital Input-Voltage Low, V

IL

0.4 V

Digital Input-Current High, I

IH

-1 +1 µA

Digital Input-Current Low, I

IL

-1 +1 µA

CAUTION! ESD SENSITIVE DEVICE

MIN TYP MAX UNITS

145

135

0.85

VCC -

110

1.35

1.20

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

_______________________________________________________________________________________ 3

PARAMETER CONDITIONS

LOGIC OUTPUTS: DOUT

Sourcing 100µA

V

CC

-

0.4

V

Digital Output-Voltage Low, V

OL

Sinking 100µA 0.4 V

DC ELECTRICAL CHARACTERISTICS (continued)

(MAX2837 evaluation kit: V

CC_

= 2.7V to 3.6V, Rx set to the maximum gain; CS = high, RXHP = SCLK = DIN = low, RSSI and clock output

buffer are off, no signal at RF inputs, all RF inputs and outputs terminated into 50Ω, receiver baseband outputs are open; 90mV

RMS

dif-

ferential I and Q signals applied to I, Q baseband inputs of transmitter in transmit mode, f

REF

= 40MHz, registers set to recommended

settings and corresponding test mode, T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at VCC= 2.8V, fLO= 2.5GHz,

and T

A

= +25°C, unless otherwise noted.) (Note 1)

AC ELECTRICAL CHARACTERISTICS—Rx MODE

(MAX2837 evaluation kit: VCC_ = 2.8V, fRF= 2.502GHz, fLO= 2.5GHz; receiver baseband I/Q outputs at 90mV

RMS

(-21dBV), f

REF

= 40MHz, ENABLE = RXENABLE = CS = high, TXENABLE = SCLK = DIN = low, with power matching for the differential RF

pins using the typical applications and registers set to default settings and corresponding test mode, T

A

= +25°C, unless otherwise noted.

Lowpass filter is set to 10MHz RF channel BW. Unmodulated single-tone RF input signal is used, unless otherwise indicated.) (Note 1)

PARAMETER CONDITIONS

UNITS

RECEIVER SECTION: LNA RF INPUT TO BASEBAND I/Q OUTPUTS

RF Input Frequency Range 2.3 2.7

GHz

Peak-to-Peak Gain Variation over
RF Input Frequency Range

Tested at band edges and band center 0.8 dB

RF Input Return Loss All LNA gain settings 13 dB

M axi m um g ai n, B7:B1 = 0000000 90 99

Total Voltage Gain

M i ni m um g ai n, B7:B1 = 1111111 5 13

dB

From max RF gain to max RF gain - 8dB 8

From max RF gain to max RF gain - 16dB 16

RF Gain Steps

From max RF gain to max RF gain - 32dB 32

dB

Any RF or baseband gain change; gain settling to within
±1dB of steady state; RXHP = 1

0.2

Gain Change Settling Time

Any RF or baseband gain change; gain settling to within
±0.1dB of steady state; RXHP = 1

2

µs

Baseband Gain Range

From maximum baseband gain (B5:B1 = 00000) to
minimum baseband gain (B5:B1 = 11111),
T

A

= - 40°C to + 85°C

58 62 66 dB

Baseband Gain Minimum
Step Size

2dB

Voltage gain ≥ 65dB with max RF gain (B7:B6 = 00) 2.3

Voltage gain = 50dB with max RF gain - 8dB
(B7:B6 = 01)

5.5

Voltage gain = 45dB with max RF gain - 16dB
(B7:B6 = 10)

17

DSB Noise Figure

Voltage gain = 15dB with max RF gain - 32dB
(B7:B6 = 11)

27

dB

Digital Output-Voltage High, V

MIN TYP MAX UNITS

OH

MIN TYP MAX

TA = - 40°C to + 85°C

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

4 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS—Rx MODE (continued)

MAX2837 evaluation kit: VCC_ = 2.8V, fRF= 2.502GHz, fLO= 2.5GHz; receiver baseband I/Q outputs at 90mV

RMS

(-21dBV), f

REF

= 40MHz, ENABLE = RXENABLE = CS = high, TXENABLE = SCLK = DIN = low, with power matching for the differential RF

pins using the typical applications and registers set to default settings and corresponding test mode, T

A

= +25°C, unless otherwise noted.

Lowpass filter is set to 10MHz RF channel BW. Unmodulated single-tone RF input signal is used, unless otherwise indicated.) (Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Max RF gain (B7:B6 = 00) -37

Max RF gain - 8dB (B7:B6 = 01) -29

Max RF gain - 16dB (B7:B6 = 10) -21

In-Band Input P-1dB

Max RF gain - 32dB (B7:B6 = 11) -4

dBm

Maximum Output Signal Level

Over passband frequenc y range; at any gain setting;
1dB compression point

2.5 V

P-P

Max RF gain (B7:B6 = 00), AGC set for -65dBm
wanted signal

-11

Max RF gain - 8dB (B7:B6 = 01), AGC set for -55dBm
wanted signal

-8

Max RF gain - 16dB (B7:B6 = 10), AGC set for -40dBm
wanted signal

-6

Out-of-Band Input IP3 (Note 2)

Max RF gain - 32dB (B7:B6 = 11), AGC set for -30dBm
wanted signal

+16

dBm

I/Q Phase Error 50kHz ba seband output; 1 variation 0.15 Degrees

I/Q Gain Imbalance 50kHz ba seband output; 1 variation 0.1 dB

Minimum differential resistance 10 k

Rx I/Q Output Load Impedance
(R || C)

Maximum differential capacitance 5 pF

I/Q Output DC Droop

After sw itching RXHP to 0; average over 1μ s after any
gain change, or 2μs after receive enabled with 100Hz
interval AC-coupl ing, 1 var iat ion

±1 mV/ms

I/Q Static DC Offset

No RF input signal; mea sure at 3μs after recei ve
enable; RXHP = 1 for 0 to 2μ s and set to 0 after 2μs,
1 variation

±1 mV

Loopback Gain
(for Receiver I/Q Calibration)

Transm itter I/Q input to receiver I/Q output; transmitter
B6:B1 = 000011, receiver B5:B1 = 10100 programmed
through SPI

-4.5 0 +4.5 dB

RECEIVER BASEBAND FILTERS

At 15MHz 57

At 20MHz 75

Baseband Filter Reject ion

At > 40MHz 90

dB

RXHP = 1 (used before AGC completion) 650

D5:D4 = 00 0.1

D5:D4 = 01 1

D5:D4 = 10 30

Baseband Highpass Filter
Cor ner Fr equen c y

RXHP = 0 (used after
AGC completion)
address A4:A0 = 01110

D5:D4 = 11 100

kHz

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

_______________________________________________________________________________________ 5

AC ELECTRICAL CHARACTERISTICS—Rx MODE (continued)

MAX2837 evaluation kit: VCC_ = 2.8V, fRF= 2.502GHz, fLO= 2.5GHz; receiver baseband I/Q outputs at 90mV

RMS

(-21dBV), f

REF

= 40MHz, ENABLE = RXENABLE = CS = high, TXENABLE = SCLK = DIN = low, with power matching for the differential RF

pins using the typical applications and registers set to default settings and corresponding test mode, T

A

= +25°C, unless otherwise noted.

Lowpass filter is set to 10MHz RF channel BW. Unmodulated single-tone RF input signal is used, unless otherwise indicated.) (Note 1)

PARAMETER CONDITIONS

UNITS

A4:A0 = 00010 serial bits D7:D4 = 0000

A4:A0 = 00010 serial bits D7:D4 = 0001

A4:A0 = 00010 serial bits D7:D4 = 0010 3.5

A4:A0 = 00010 serial bits D7:D4 = 0011 5.0

A4:A0 = 00010 serial bits D7:D4 = 0100 5.5

A4:A0 = 00010 serial bits D7:D4 = 0101 6.0

A4:A0 = 00010 serial bits D7:D4 = 0110 7.0

A4:A0 = 00010 serial bits D7:D4 = 0111 8.0

A4:A0 = 00010 serial bits D7:D4 = 1000 9.0

A4:A0 = 00010 serial bits D7:D4 = 1001

A4:A0 = 00010 serial bits D7:D4 = 1010

A4:A0 = 00010 serial bits D7:D4 = 1011

A4:A0 = 00010 serial bits D7:D4 = 1100

A4:A0 = 00010 serial bits D7:D4 = 1101

A4:A0 = 00010 serial bits D7:D4 = 1110

RF Channel BW Supported by
Baseband Filter

A4:A0 = 00010 serial bits D7:D4 = 1111

MHz

0 to 2.3MHz for BW = 5MHz 1.3

Baseband Gain Ripple

0 to 4.6MHz for BW = 10MHz 1.3

dB

P-P

0 to 2.3MHz for BW = 5MHz 90

Baseband Group Delay Ripple

0 to 4.6MHz for BW = 10MHz 50

ns

P-P

At 3.3MHz 7

Baseband Filter Rejection for
5MHz RF Channel BW

At > 21MHz 85

dB

At 6.7MHz 7

Baseband Filter Rejection for
10MHz RF Channel BW

At > 41.6MHz 85

dB

RSSI

RSSI Minimum Output Voltage R

LOAD

≥ 10kΩ 0.4 V

RSSI Maximum Output Voltage R

LOAD

≥ 10kΩ 2.2 V

RSSI Slope 30

mV/dB

+32dB signal step 200

RSSI Output Settling Time

To within 3dB of steady
state

-32dB signal step 800

ns

MIN TYP MAX

1.75

2.25

10.0

12.0

14.0

15.0

20.0

24.0

28.0

PARAMETER CONDITIONS MIN TYP MAX UNITS

TRANSMIT SECTION: Tx BASEBAND I/Q INPUTS TO RF OUTPUTS

RF Output Frequency Range 2.3 2.7 GHz

Peak-to-Peak Gain Variation over
RF Band

Output optimally matched over 200MHz RF BW 2.5 dB

Total Voltage Gain Max gain; at unbalanced 50 balun output 12 dB

Maximum Output Power over
Frequency for Any Given
200MHz Band

OFDM signal conforming to spectral emission mask
and -36dB EVM after I/Q imbalance calibration by
modem (Note 3)

0 dBm

RF Output Return Loss

Given 200MHz band in the 2.3GHz to 2.7GHz range,
for which the matching has been optimized

8 dB

RF Gain Control Range 45 dB

Unwanted Sideband Suppression

Without calibration by modem, and excludes modem
I/Q imbalance; P

OUT

= 0dBm

45 dBc

B1 1

B2 2

B3 4

B4 8

B5 16

RF Gain-Control Binary Weights

B6 16

dB

Carrier Leakage

Relative to 0dBm output power; without calibration by
modem

-35 dBc

Minimum differential resistance 100 k

Tx I/Q Input Impedance (R || C)

Maximum differential capacitance 0.5 pF

0 to 2.3MHz 0.2

Baseband Frequency Response
for 5MHz RF Channel BW

At > 25MHz 80

dB

0 to 4.6MHz 0.2

Baseband Frequency Response
for 10MHz RF Channel BW

At > 17MHz 80

dB

0 to 2.3MHz (BW = 5MHz) 20

Baseband Group Delay Ripple

0 to 4.6MHz (BW = 10MHz) 12

ns

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

6 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS—Tx MODE

(MAX2837 evaluation kit: V

CC_

= 2.8V, TA= +25°C, fRF= 2.502GHz, fLO= 2.5GHz; f

REF

= 40MHz, ENABLE = TXENABLE = CS = high,

and RXENABLE = SCLK = DIN = low, with power matching for the differential RF pins using the

Typical Operating Circuit

. Lowpass

fitler is set to 10MHz RF channel BW, 90mV

RMS

sine and cosine signal (or 90mV

RMS

64QAM 1024-FFT OFDMA FUSC I/Q signals

wherever OFDM is mentioned) applied to baseband I/Q inputs of transmitter (differential DC-coupled).) (Note 1)

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

_______________________________________________________________________________________ 7

AC ELECTRICAL CHARACTERISTICS—FREQUENCY SYNTHESIS

(MAX2837 evaluation kit: V

CC_

= 2.8V, fLO= 2.5GHz, f

REF

= 40MHz, ENABLE = CS = high, SCLK = DIN = low, PLL loop bandwidth =

120kHz, T

A

= +25°C, unless otherwise noted.) (Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

FREQUENCY SYNTHESIZER

RF Channel Center Frequency 2.3 2.7 GHz

Channel Center Frequency
Programming Minimum Step Size

20 Hz

Charge-Pump Comparison
Frequency

11 40 MHz

Reference Frequency Range 11 40 80 MHz

Reference Frequency Input
Level s

AC-coupled to XTAL2 p in 800 mV

P-P

Resistance (XTAL2 pin) 10 k

Reference Frequency Input
Impedance (R | | C)

Capacitance (XTAL2 pin) 1 pF

Programmable Reference Divider
Values

1 2 4

Closed-Loop Integrated Phase
Noise

Loop BW = 120kHz; integrate phase noi se from 200Hz
to 5MHz, charge-pump comparison frequency = 40MH z

-39 dBc

Charge-Pump Output Current On each differential side 1.6 mA

f

OFFSET

= 0 to 1.8MH z -40

f

OFFSET

= 1.8MH z to 7MHz -70

Close-In Spur Level

f

OFFSET

> 7MHz -80

dBc

Reference Spur Level -85 dBc

Turnaround LO Frequenc y Error

Relative to steady state; measured 35μs after Tx-Rx or
Rx-T x switching instant, and 4μs after any rece iver
gain changes

±50 Hz

Temperature Range o ver Which
VCO Maintains Lock

Relative to the ambient temperature T

A

, as long as the
VCO lock temperature range is within operating
temperature range

T

A

±40 °C

Reference Output Clock Divider
Values

1 2

Output Clock Drive Level 20MHz output, 1x drive setting 1.5 V

P-P

Resistance 10 k

Output Clock Minimum Load
Impedance (R | | C)

Capacitance 2 pF

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

8 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS—MISCELLANEOUS BLOCKS

(MAX2837 evaluation kit: V

CC_

= 2.8V, f

REF

= 40MHz, ENABLE = CS = high, SCLK = DIN = low, TA= +25°C, unless otherwise noted.)

(Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

PA BIAS DAC: CURRENT MODE

Numbers of B it s 6 Bit s

Minimum Output Sink Current D5:D0 = 000000 in A4:A0 = 11100 0 μA

Maximum Output Sink Current D5:D0 = 111111 in A4:A0 = 11100 310 μA

Compliance Voltage Range 0.8 2.0 V

Turn-On Time

Excludes programmable dela y of 0 to 7μs in steps
of 0.5μs

200 ns

DNL 1 LSB

PA BIAS DAC: VOLTAGE MODE

Output High Le ve l 10mA source current

V

CC

-

0.2

V

Output Low Leve l 10mA sink current 0.1 V

Turn-On Time

Excludes programmable dela y of 0 to 7μs in steps
of 0.5μs

200 ns

CRYSTAL OSCILLATOR

Maximum capacitance, A4:A0 = 11000,
D6:D0 =1111111

15.5

On-Chip Tuning Capacitance
Range

Minimum capacitance, A4:A0 = 11000,
D6:D0 =0000000

0.5

pF

On-Chip Tuning Capacitance
Step Size

0.12 pF

ON-CHIP T EMPERATURE S ENSOR

TA = +25°C 01111

TA = +85°C 11101

Digital Output Code

Read-out at DOUT pin through SPI
A4:A0 = 00111, D4:D0

T

A

= -40°C 00001

AC ELECTRICAL CHARACTERISTICS—TIMING

(MAX2837 evaluation kit: V

CC_

= 2.8V, fLO= 2.5GHz, f

REF

= 40MHz, ENABLE = CS = high, SCLK = DIN = low, PLL loop bandwidth =

120kHz, T

A

= +25°C, unless otherwise noted.) (Note 1)

PARAMETER

CONDITIONS

UNITS

SYSTEM TIMING

Rx to Tx 2

Turnaround Time

Measured from Tx or
Rx enable rising
edge; signal settling
to within 0.5dB of
steady state

2

µs

Tx Turn-On Time
(from Standby Mode)

M easur ed fr om Tx enab l e r i si ng ed g e; si g nal
settl i ng to w i thi n 0.5d B of stead y state

2µs

SYMBOL

Tx to Rx, RXHP = 1

MIN TYP MAX

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

_______________________________________________________________________________________ 9

AC ELECTRICAL CHARACTERISTICS—TIMING (continued)

(MAX2837 evaluation kit: V

CC_

= 2.8V, fLO= 2.5GHz, f

REF

= 40MHz, ENABLE = CS = high, SCLK = DIN = low, PLL loop bandwidth =

120kHz, T

A

= +25°C, unless otherwise noted.) (Note 1)

PARAMETER

CONDITIONS

UNITS

Tx Turn-Off Time
(to Standby Mode)

From Tx enable falling edge 0.1 µs

Rx Turn-On Time
(from Standby Mode)

Measured from Rx enable rising edge;
signal settling to within 0.5dB of steady
state

2µs

Rx Turn-Off Time
(to Standby Mode)

From Rx enable falling edge 0.1 µs

4-WIRE SERIAL-INTERFACE TIMING (See Figure 1)

SCLK Rising Edge to CS Falling
Edge Wait Time

t

CSO

6ns

Falling Edge of CS to Rising
Edge of First SCLK Time

t

CSS

6ns

DIN to SCLK Setup Time t

DS

6ns

DIN to SCLK Hold Time t

DH

6ns

SCLK Pulse-Width High t

CH

6ns

SCLK Pulse-Width Low t

CL

6ns

Last Rising Edge of SCLK to
Rising Edge of

CS or Clock to

Load Enable Setup Time

t

CSH

6ns

CS High Pulse Width t

CSW

20 ns

Time Between Rising Edge
of

CS and the Next Rising Edge

of SCLK

t

CS1

6ns

Clock Frequency f

CLK

45 MHz

Rise Time t

R

ns

Fall Time t

F

ns

SCLK Falling Edge to Valid
DOUT

t

D

ns

Note 1: Min and max limits guaranteed by test above TA= +25°C and guaranteed by design and characterization at TA= -40°C.

The power-on register settings are not production tested. Recommended register setting must be loaded after V

CC

is supplied.

Note 2: Two tones at +25MHz and +39MHz offset with -35dBm/tone. Measure IM3 at 1MHz.
Note 3: Gain adjusted over max gain and max gain - 3dB. Optimally matched over given 200MHz band.

SYMBOL

MIN TYP MAX

f

/ 10

C LK

f

/ 10

C LK

12.5

Rx CURRENT vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

CURRENT (mA)

MAX2837 toc01

2.7 3.0 3.3 3.6

85

87

89

91

93

95

97

TA = -40°C

TA = +85°C

T

A

= +25°C

NOISE FIGURE

vs. BASEBAND VGA GAIN SETTING

BASEBAND VGA CODE

NOISE FIGURE (dB)

MAX2837 toc02

0 8 16 24 32

0

5

10

15

20

25

30

35

40

LNA = MAX - 8dB

LNA = MAX

LNA = MAX - 16dB

LNA = MAX - 32dB

Rx VOLTAGE GAIN

vs. BASEBAND GAIN SETTING

BASEBAND VGA CODE

Rx VOLTAGE GAIN (dB)

MAX2837 toc03

0 8 16 24 32

0

20

40

60

80

100

LNA = MAX

LNA = MAX - 32dB

LNA = MAX - 8dB

LNA = MAX - 16dB

WiMAX EVM WITH OFDM JAMMER

vs. OFFSET FREQUENCY

P

JAMMER

(dBm)

EVM (%)

MAX2837 toc07

-65 -55 -45 -35 -25

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

f

OFFSET

= 10MHz

f

OFFSET

= 20MHz

P

IN

= -60dBm

Rx EMISSION SPECTRUM AT LNA INPUT

MAX2837 toc08

(dBm)

DC 26.5GHz

-140

-130

-120

-110

-100

-90

-80

-70

-60

-50

-150

4/3LO

2LO

8/3LO

4LO

8LO

MIN LNA GAIN
RBW = 300kHz

Rx VOLTAGE GAIN VARIATION vs. RF FREQUENCY

RF FREQUENCY (GHz)

Rx VOLTAGE GAIN VARIATION (dB)

MAX2837 toc04

2.3 2.4 2.5 2.6 2.7

-2

-1

0

1

2

LNA = MAX - 32dB

LNA = MAX

LNA = MAX - 8dB

LNA = MAX - 16dB

Rx IN-BAND OUTPUT V1dB

vs. BASEBAND GAIN SETTING

BASEBAND VGA CODE

Rx IN-BAND OUTPUT V1dB (V

RMS

)

MAX2837 toc05

0 8 16 24 32

0

0.3

0.6

0.9

1.2

1.5

Rx EVM vs. P

IN

P

IN

(dBm)

EVM (%)

MAX2837 toc06

-90 -80 -70 -60 -50 -40 -30 -20 -10 0

0

2

4

6

8

10

12

14

16

18

20

22

LNA = MAX

LNA = MAX -16dB

LNA = MAX - 32dB

LNA = MAX - 8dB

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

10 ______________________________________________________________________________________

Typical Operating Characteristics

(MAX2837 evaluation kit: V

CC_

= 2.8V, fLO= 2.5GHz, 10MHz channel 16E UL/DL WiMax signal, f

REF

= 40MHz, ENABLE =

CS = high, RXHP = SCLK = DIN = low, T

A

= +25°C, unless otherwise noted.)

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

______________________________________________________________________________________ 11

INPUT RETURN LOSS vs. RF FREQUENCY

RF FREQUENCY (GHz)

INPUT RETURN LOSS (dB)

MAX2837 toc09

2.0 2.2 2.4 2.6 2.8 3.0

-40

-30

-20

-10

0

LNA = MAX - 32dB

LNA = MAX - 8dB,
LNA = MAX - 16dB

LNA = MAX

RSSI VOLTAGE vs. INPUT POWER

INPUT POWER (dBm)

RSSI VOLTAGE (V)

MAX2837 toc10

-120 -100 -80 -60 -40 -20 0

0

0.5

1.0

1.5

2.0

2.5

3.0

LNA = MAX - 32dB

LNA = MAX - 16dB

LNA = MAX - 8dB

LNA = MAX

CW TONE

MAX2837 toc11

3V

1.45V

200ns/div

0V

0.45V

Rx RSSI STEP RESPONSE

(+40dB SIGNAL STEP)

Typical Operating Characteristics (continued)

(MAX2837 evaluation kit: V

CC_

= 2.8V, fLO= 2.5GHz, 10MHz channel 16E UL/DL WiMax signal, f

REF

= 40MHz, ENABLE =

CS = high, RXHP = SCLK = DIN = low, T

A

= +25°C, unless otherwise noted.)

Rx LPF GROUP DELAY vs. FREQUENCY

FREQUENCY (MHz)

LPF GROUP DELAY (ns)

MAX2837 toc13

0246810121416

0

50

100

150

200

250

300

350

CHANNEL BW = 5MHz

CHANNEL BW = 8MHz

CHANNEL BW = 10MHz

CHANNEL BW = 9MHz

0

26

13

52

39

65

78

HISTOGRAM: Rx STATIC DC OFFSET

MAX2837 toc14

1σ/div

MEAN: 0mV
STD: 0.977mV
SAMPLE SIZE: 1006

MAX2837 toc12

3V

1.5V

200ns/div

0V

0.45V

Rx RSSI STEP RESPONSE

(-40dB SIGNAL STEP)

Tx CURRENT vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

CURRENT (mA)

MAX2837 toc15

2.7 3.0 3.3 3.6

135

140

145

150

TA = -40°C

T

A

= +85°C

TA = +25°C

Tx OUTPUT POWER vs. RF FREQUENCY

RF FREQUENCY (GHz)

Tx POWER (dBm)

MAX2837 toc16

2.3 2.4 2.5 2.6 2.7

-3

-2

-1

1

0

VCC = 2.7V

VCC = 3V, 3.6V

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

12 ______________________________________________________________________________________

Tx TRANSMIT SPECTRUM FROM

DC TO 26.5GHz

MAX2837 toc20

(dBm)

DC 26.5GHz

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-100

RBW = 1MHz

2RF

4RF

RF

16/3RF

4/3RF

8/3RF

EVM vs. Tx OUTPUT POWER

OUTPUT POWER (dBm)

EVM (%)

MAX2837 toc21

-30 -24 -18 -12 -6 0

1.0

1.2

1.4

1.6

1.8

2.0

PHASE NOISE vs. OFFSET FREQUENCY

OFFSET FREQUENCY (MHz)

PHASE NOISE (dBc/Hz)

MAX2837 toc22

-150

-140

-130

-120

-110

-100

-90

-80

-70

-60

-50

0.001 0.01 0.1 1 10

2.5kHz

-2.5kHz

500Hz/div

0s 1ms

PLL SETTLING TIME FROM SHUTDOWN

MAX2837 toc23

CRYSTAL OFFSET FREQUENCY

vs. C

TUNE

BITS

C

TUNE

(DIGITAL BITS)

CRYSTAL OFFSET FREQUENCY (Hz)

MAX2837 toc24

0102030405060708090100

110

120

130

-800

-700

-600

-500

-400

-300

-200

-100

0

100

200

300

400

500

600

700

800

KYOCERA
(CX-3225SB)

Typical Operating Characteristics (continued)

(MAX2837 evaluation kit: V

CC_

= 2.8V, fLO= 2.5GHz, 10MHz channel 16E UL/DL WiMax signal, f

REF

= 40MHz, ENABLE =

CS = high, RXHP = SCLK = DIN = low, T

A

= +25°C, unless otherwise noted.)

Tx OUTPUT POWER vs. TEMPERATURE

TEMPERATURE (°C)

Tx POWER (dBm)

MAX2837 toc17

-40 -15 10 35 60 85

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0

Tx VGA SET TO MAX - 3dB

Tx OUTPUT SPECTRUM

MAX2837 toc18

5MHz/div

P

OUT

= -3dBm

EVM = 1.35%
f

RF

= 2.5GHz

10dB/div (dBm)

Tx P

OUT

vs. GAIN SETTING

Tx VGA GAIN CODE

Tx POWER (dBm)

MAX2837 toc19

0 8 16 24 32 40 48 56 64

-50

-40

-30

-20

-10

0

10

-40°C
+25°C

-40°C

+85°C

+85°C

+25°C

FORBIDDEN CODE

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

______________________________________________________________________________________ 13

Block Diagram/Typical Operating Circuit

B2

1

2

3

4

5

6

7

8

9

10

11

12

13 14 15 16 17 18 19 20 21 22 23 24

48 47 46 45 44 43 42 41 40 39 38 37

36

35

34

33

32

31

30

29

28

27

26

25

V

CCRXLNA

B5

GNDRXLNA

RXRF+

RXRF-

B4

V

CCTXPAD

TXRF+

TXRF-

B1

÷

÷

SERIAL

INTERFACE

SERIAL

INTERFACE

AM

DETECTOR

V

C

C

T

X

M

X

P

A

B

IA

S

S

C

L

K

C

L

O

C

K

O

U

T

X

T

A

L

2

X

T

A

L

1

V

C

C

X

T

A

L

V

C

C

D

IG

V

C

C

C

P

G

N

D

C

P

C

P

O

U

T

+

C

P

O

U

T

-

RXBBQ+

RXBBQ-

Rx Q
OUTPUTS

Rx/Tx GAIN
CONTROL

MODE
CONTROL

SERIAL
INPUTS

SERIAL
INPUTS

SERIAL
OUTPUT

SERIAL
INPUTS

B6

B7

RSSI

DIN

DOUT

CS

V

CCVCO

PLL

+

GNDVCO

BYPASS

ENABLE

R

X

E

N

A

B

L

E

T

X

E

N

A

B

L

E

V

C

C

R

X

M

X

T

X

B

B

Q

-

T

X

B

B

Q

+

T

X

B

B

I+

T

X

B

B

I-

V

C

C

R

X

F

L

R

X

H

P

V

C

C

R

X

V

G

A

R

X

B

B

I+

R

X

B

B

I-

MAX2837

M

O

D

E

C

O

N

T

R

O

L

R

x

/T

x

G

A

IN

C

O

N

T

R

O

L

P

L

L

L

O

O

P

F

IL

T

E

R

R

E

F

E

R

E

N

C

E

C

L

O

C

K

B

U

F

F

E

R

O

U

T

P

U

T

B3

Rx GAIN
CONTROL

R

x

IN

P

U

T

T

x

O

U

T

P

U

T

Rx/Tx GAIN

CONTROL

Rx/Tx GAIN

CONTROL

Rx/Tx GAIN

CONTROL

Rx/Tx GAIN

CONTROL

Tx INPUTS Rx I OUTPUTS

Rx BASEBAND
HPF CONTROL

0°

90°

RSSI
MUX

RSSI

SCLK

TEMP SENSOR

CRYSTAL

OSCILLATOR/

BUFFER

RSSITORSSI

MUX

QMUX

IMUX QMUX

IMUX

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

14 ______________________________________________________________________________________

Pin Description

PIN NAME FUNCTION

1 V

CCRXLNA

LNA Supply Voltage. Bypass with a capacitor as close as possible to the pin.
2 GNDRXLNA LNA Ground
3 B5 Receiver and Transmitter Gain-Control Logic Input Bit 5

4 RXRF+

5 RXRF-

LNA Differential Inputs. Inputs are internally DC-coup led. An external shunt inductor and series
capacitors match the inputs to 100 differentia l.

6 B4 Receiver and Transmitter Gain-Control Logic Input Bit 4

7 V

CCTXPAD

Supply Voltage for Power-Amplifier Driver. Bypass with a capacitor as close as possible to the pin.
8 B3 Receiver and Transmitter Gain-Control Logic Input Bit 3
9 B2 Receiver and Transmitter Gain-Control Logic Input Bit 2

10 TXRF+
11 TXRF-

Power-Amplifier Dri ver Differential Output. PA driver output is internal ly matched to a 100
differential. The pins have internal DC-blocking capacitors.

12 B1 Receiver and Transmitter Gain-Control Logic Input Bit 1
13 V

CCTXM X

Transmitter Upconverter Supply Voltage. Bypass with a capacitor as close as po ssible to the pin.
14 PABIAS Transmit PA B ia s DAC Output

15 SCLK Serial-Clock Logic Input of 4-Wire Serial Interface (See Figure 1)
16 CLOCKOUT Reference Clock Buffer Output
17 XTAL2 Crystal or Reference Cloc k Input. AC-couple a cr ystal or a reference cloc k to this ana log input.

18 XTAL1

Connection for Crystal-Oscillator Off-Chip Capacitors. When using an external reference clock
input, leave XTAL1 unconnected.

19 V

CCXTAL

Crystal-Oscillator Supply Voltage. Bypass with a capacitor as close as possible to the pin.
20 V

CCDIG

Digital Circuit Supply Voltage. Bypass with a capacitor as close as possible to the pin.

21 V

CCCP

PLL Charge-Pump Supply Voltage. Bypass w ith a capacitor as clo se as possible to the pin.
22 GNDCP Charge-Pump Circuit Ground

23 CPOUT+

24 CPOUT-

Differential Charge-Pump Output. Connect the frequenc y synthe sizer’ s loop filter between CPOUT+
and CPOUT-. (See the Typical Operating Circuit.)

25 ENABLE Operation Mode Logic Input. See Table 1 for operating modes.
26 GNDVCO VCO Ground

27 BYPASS

On-Chip VCO Regulator Output Bypass. Bypass with a 1μF capacitor to GND. Do not connect other
circuitry to this point.

28 V

CCVCO

VCO Supply Voltage. Bypass with a capacitor as close as possible to the pin.

29 DOUT Data Logic Output of 4-Wire Serial Interface (See Figure 1)
30 CS Chip-Select Logic Input of 4-Wire Serial Interface (See Figure 1)
31 DIN Data Logic Input of 4-Wire Serial Interface (See Figure 1)

32 RSSI RSSI or Temperature Sensor Mult iplexed Analog Output
33 B7 Receiver Gain-Control Logic Input Bit 7
34 B6 Receiver and Transmitter Gain-Control Logic Input Bit 6

35 RXBBQ-

36 RXBBQ+

Receiver Baseband Q-Channel Differential Outputs. In Tx calibration mode, these pins are the
LO leakage and s ideband detector outputs.

37 RXBBI-

38 RXBBI+

Receiver Baseband I-Channel Differential Outputs. In Tx calibration mode, these pins are the
LO leakage and s ideband detector outputs.

39 V

CCRX VGA

Receiver VGA Supply Voltage

40 RXHP Receiver Baseband AC-Coupling Highpass Corner Frequency Control Logic Input

41 V

CCRXFL

Receiver Baseband Filter Supply Voltage

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

______________________________________________________________________________________ 15

Detailed Description

Modes of Operation

The modes of operation for the MAX2837 are clock-out,
shutdown, transmit, receive, transmitter calibration, and
receiver calibration. See Table 1 for a summary of the
modes of operation. The logic input pins—ENABLE (pin

25), TXENABLE (pin 47), and RXENABLE (pin 48)—con­trol the various modes. When the parts are active, vari­ous blocks can be shut down individually through SPI.

Shutdown Mode

The MAX2837 features a low-power shutdown mode.
Current drain is the minimum possible with the supply
voltages applied. In shutdown mode, all circuit blocks
are powered down, except the 4-wire serial bus and its
internal programmable registers. If the supply voltage is
applied, the registers are loaded and retained.

Standby Mode

The standby mode is used to enable the frequency syn­thesizer block while the rest of the device is powered
down. In this mode, PLL, VCO, and LO generator 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.

Receive (Rx) Mode

In receive mode, all Rx circuit blocks are powered on and
active. Antenna signal is applied; RF is downconverted,
filtered, and buffered at Rx BB I and Q outputs. The slow­charging Tx circuits are in a precharged “idle-off” state
for fast Rx-to-Tx turnaround time.

Transmit (Tx) Mode

In transmit mode, all Tx circuit blocks are powered on.
The external PA is powered on after a programmable

Pin Description (continued)

PIN NAME FUNCTION

42 TXBBI-

43 TXBBI+

Transm itter Baseband I-Channel D ifferential Inputs

44 TXBBQ+

45 TXBBQ-

Transm itter Baseband Q-Channel Differential Input s

46 V

CCRXM X

Receiver Downconverters Supply Voltage. Bypass with a capacitor as close as possible to the pin.

47 TXENABLE Tx Mode Control Logic Input. See Table 1 for operating modes.

48 RXENABLE Rx Mode Control Logic Input. See Table 1 for operating modes.

EP EP

Exposed Paddle. Connect to the ground plane with multiple v ia s for proper operation and heat
dis sipat ion. Do not share with any other pin grounds and bypass capac itors’ ground.

LOGIC

PINS

REGISTER

SETTING

CIRCUIT

BLOCK STATES

MODE

ENABLE RXENABLE TXENABLE

D1:D0

A4:A0 = 10000

Rx

PATH

Tx

PATH

PLL, VCO,

LO GEN

CALIBRATION

SECTIONS

ON

CLOCK

OUT

Cloc k-Out 1 0 0 0 0 Off Off Off None On

Shutdown 0 0 0 0 X Off Off Off None Off

Standby 1 0 0 0 1 Off* Off* On None On

Rx 1 1 0 0 1 On Off On None On
Tx 1 0 1 0 1 Off On On None On

Rx

Calibration

1 1 0 1 1

On

(Except

LNA)

Off (Except

Upconverters)

On

Tx Baseband

Buffer

On

Tx

Calibration

1 0 1 1 1 Off

On

(Except PA

Dri ver)

On

AM Detector,

Rx I/Q Buffers

On

Table 1. Operating Mode Table

*

Blocks of the transceiver can be selectively enabled through SPI.

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

16 ______________________________________________________________________________________

delay using the on-chip PA bias DAC. The slow-charg­ing Rx circuits are in a precharged “idle-off” state for
fast Tx-to-Rx turnaround time.

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 remains on.

Programmable Registers

and 4-Wire SPI Interface

The MAX2837 includes 32 programmable 16-bit regis­ters. The most significant bit (MSB) is the read/write
selection bit. The next 5 bits are register address. The
10 least significant bits (LSBs) are register data.
Register data is loaded through the 4-wire
SPI/MICROWIRE™-compatible serial interface. Data at
DIN is shifted in MSB first and is framed by CS. When

CS is low, the clock is active, and input data is shifted
at the rising edge of the clock. During the read mode,
register data selected by address bits is shifted out to
DOUT at the falling edges of the clock. At the CS rising
edge, the 10-bit data bits are latched into the register
selected by address bits. See Figure 1. The register
values are preserved in shutdown mode as long as the
power-supply voltage is maintained. However, every
time the power-supply voltage is turned on, the regis­ters are reset to the default values. Note that default
register states are not guaranteed, and the user should
always reprogram all registers after power-up.

MICROWIRE is a trademark of National Semiconductor Corp.

BIT 6

SPI REGISTER WRITE

DON'T CARE

BIT 2BIT 1 BIT 14BIT 13BIT 5

t

CH

DIN

DOUT

t

CSS

SCLK

t

CSO

t

DS

t

DH

t

CL

t

CSW

t

CSH

t

C

S

1

CS

SPI REGISTER READ

DON'T CARE

DON'T CARE

BIT 2BIT 1 BIT 5

DIN

DOUT

SCLK

t

D

CS

BIT 6 BIT 14BIT 13

Figure 1. 4-Wire SPI Serial-Interface Timing Diagram

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

______________________________________________________________________________________ 17

Chip Information

PROCESS: SiGe BiCMOS

Pin Configuration

TOP VIEW

MAX2837

THIN QFN

6mm x 6mm

13

14

15

16

17

18

19

20

21

22

23

24

ENABLE

GNDVCO

BYPASS

V

CCVCO

DOUT

CS

SCLK

DIN

RSSI

B7

B6

RXBBQ-

RXBBQ+

RXBBI-

RXBBI+

V

CCRXVGA

RXHP

V

CCRXFL

TXBBI-

TXBBI+

TXBBQ+

TXBBQ-

V

CCRXMX

TXENABLE

RXENABLE

48

+

47

46

45

44

43

42

41

40

39

38

37

1

2

345678 910

11

12

B1

TXRF-

TXRF+

B2

B3

V

CCTXPAD

B4

RXRF-

RXRF+

B5

GNDRXLNA

V

CCRXLNA

V

CCTXMX

V

CCXTAL

V

CCDIG

V

CCCP

36

35

34 33 32 31 30 29 28 27

26

25

CLOCKOUT

GNDCP

CPOUT+

CPOUT-

XTAL2

XTAL1

PABIAS

Package Information

For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages

.

PACKAGE TYPE PACKAGE CODE DOCUMENT NO.

48 TQFN-EP T4866-2

21-0141

MAX2837

2.3GHz to 2.7GHz Wireless
Broadband RF Transceiver

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

18

____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

Revision History

REVISION

NUMBER

DATE

DESCRIPTION

PAGES

CHANGED

0 5/07 Initial release —

1 11/08

Corrected SPI description in Programmable Registers and 4-Wire SPI-
Interface section

16

REVISION