MAX2242EBC+T - Maxim Integrated Products, Inc.

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

General Description

The MAX2242 low-voltage linear power amplifier (PA) is

designed for 2.4GHz ISM-band wireless LAN applica-

tions. It delivers +22.5dBm of linear output power with

an adjacent-channel power ratio (ACPR) of <-33dBc

1st-side lobe and <-55dBc 2nd-side lobe, compliant

with the IEEE 802.11b 11MB/s WLAN standard with at

least 3dB margin. The PA is packaged in the tiny 3x4

chip-scale package (UCSP™), measuring only 1.5mm x

2.0mm, ideal for radios built in small PC card and com-

pact flash card form factors.

The MAX2242 PA consists of a three-stage PA, power

detector, and power management circuitry. The power

detector provides over 20dB of dynamic range with

±0.8dB accuracy at the highest output power level. An

accurate automatic level control (ALC) function can be

easily implemented using this detector circuit.

The PA also features an external bias control pin.

Through the use of an external DAC, the current can be

throttled back at lower output power levels while main-

taining sufficient ACPR performance. As a result, the

highest possible efficiency is maintained at all power

levels. The device operates over a single +2.7V to

+3.6V power-supply range. An on-chip shutdown fea-

ture reduces operating current to 0.5µA, eliminating the

need for an external supply switch.

________________________Applications

IEEE 802.11b DSSS Radios

Wireless LANs

HomeRF

2.4GHz Cordless Phones

2.4GHz ISM Radios

Features

♦2.4GHz to 2.5GHz Operating Range

♦+22.5dBm Linear Output Power (ACPR of <-33dBc

1st-Side Lobe and <-55dbc 2nd-Side Lobe)

♦28.5dB Power Gain

♦On-Chip Power Detector

♦External Bias Control for Current Throttleback

♦+2.7V to +3.6V Single-Supply Operation

♦0.5µA Shutdown Mode

♦Tiny Chip-Scale Package (1.5mm ✕2.0mm)

MAX2242

2.4GHz to 2.5GHz Linear Power Amplifier

________________________________________________________________ Maxim Integrated Products 1

B4C4

GND

VCC1

VCC2

GNDRF_IN

BIAS

CIRCUIT

B1C1

GND

RF_OUTBIAS

PD_OUT

DET

SHDN

VCCB

3✕4 UCSP

Pin Configuration

19-1912; Rev 3; 11/03

EVALUATION KIT

AVAILABLE

Ordering Information

PART TEMP RANGE

PIN-

PACKAGE

TOP

MARK

MAX2242EBC-T -40°C to +85°C3

✕ 4 UCSP AAE

Typical Application Circuit appears at end of data sheet.

Actual Size

1.5mm ✕2.0mm

UCSP is a trademark of Maxim Integrated Products, Inc.

MAX2242

2.4GHz to 2.5GHz

Linear Power Amplifier

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC = +2.7V to +3.6V, fIN = 2.4GHz to 2.5GHz, V SHDN = VCC, RF_IN = RF_OUT = connected to 50Ωload, TA= -40°C to +85°C.

Typical values are measured at VCC = +3.3V, fIN = 2.45GHz, TA= +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.

VCC1, VCC2 to GND (no RF signal applied) ..........-0.3V to +5.5V

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

SHDN, BIAS, PD_OUT, RF_OUT................-0.3V to (VCC + 0.3V)

DC Input Current at RF_IN Port.............................-1mA to +1mA

Maximum VSWR Without Damage ........................................10:1

Maximum VSWR for Stable Operation.....................................5:1

Continuous Power Dissipation (TA = +85°C)

3✕4 UCSP (derate 80mW/°C above +85°C) ..................1.6W

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

Thermal Resistance .........................................................25°C/W

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

Storage Temperature Range .............................-65°C to +125°C

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

Continuous Operating Lifetime.....................10yrs ×0.92(TA- 60°C)

(For Operating Temperature, TA≥+60°C)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Supply Voltage 2.7 3.6 V

POUT = +22dBm, VCC = +3.3V, idle current = 280mA 300 335

POUT = +13dBm, idle current = 55mA 90

Supply Current

(Notes 2, 3, 6)

POUT = +5dBm, idle current = 25mA 50

Shutdown Supply Current V SHDN = 0, no RF input 0.5 10 µA

Logic Input Voltage High 2.0 V

Logic Input Voltage Low 0.8 V

Logic Input Current High -1 5 µA

Logic Input Current Low -1 1 µA

CAUTION! ESD SENSITIVE DEVICE

MAX2242

2.4GHz to 2.5GHz

Linear Power Amplifier

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS

(MAX2242 Evaluation Kit, VCC = +3.3V, V SHDN = VCC, 50Ωsource and load impedance, fIN = 2.45GHz, TA= +25°C, unless other-

wise noted.) (Note 6)

Note 1: Specifications over TA= -40°C to +85°C are guaranteed by design. Production tests are performed at TA= +25°C.

Note 2: Idle current is controlled by external DAC for best efficiency over the entire output power range.

Note 3: Parameter measured with RF modulation based on IEEE 802.11b standard.

Note 4: Power gain is guaranteed over this frequency range. Operation outside this range is possible, but is not guaranteed.

Note 5: Output two-tone third-order intercept point (OIP3) is production tested at TA= +25°C. The OIP3 is tested with two signals at

f1 = 2.450GHz and f2 = 2.451GHz with fixed PIN.

Note 6: Min/max limits are guaranteed by design and characterization.

Note 7: The total turn-on and turn-off times required for PA output power to settle to within 0.5dB of the final value.

Note 8: Excludes PC board loss of approximately 0.15dB.

Note 9: See Typical Operating Characteristics for statistical variation.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Frequency Range (Notes 3, 4) 2.4 2.5 GHz

TA = +25°C 26.5 28.5

Power Gain (Notes 1, 3) TA = -40°C to +85°C 25.5 dB

Gain Variation Over Temperature

(Note 3) TA = -40°C to +85°C±1.2 dB

Gain Variation Over VCC (±10%)

(Note 3) VCC = +3.0V to +3.6V ±0.3 dB

Output Power (Notes 3, 5, 8)

ACPR,

1st-side lobe < -33dBc,

2nd-side lobe < -55dBc 21.5 22.5 dBm

Saturated Output Power PIN = +5dBm 26.5 dBm

Harmonic Output (2f, 3f, 4f) -40 dBc

Input VSWR Over full PIN range 1.5:1

Output VSWR Over full POUT range 2.5:1

Power Ramp Turn-On Time

(Note 7) SHDN from low to high 1 1.5 µs

Power Ramp Turn-Off Time

(Note 7) SHDN from high to low 1 1.5 µs

RF Output Detector Response

TIme 2.5 5 µs

Po = +22dBm (Note 9) 1.8

Po = +13dBm (Note 9) 0.9

RF Output Detector Voltage

Po = +5dBm (Note 9) 0.55

MAX2242

2.4GHz to 2.5GHz

Linear Power Amplifier

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VCC = +3.3V, fIN = 2.45MHz, RF modulation = IEEE 802.11b, V SHDN = VCC, TA= +25°C, unless otherwise noted.)

GAIN vs. SUPPLY VOLTAGE

MAX2242 toc01

SUPPLY VOLTAGE (V)

GAIN (dB)

2.7 3.33.0 3.6

PO = +22dBm

TA = +25°C

TA = +85°C

TA = -40°C

240

220

280

260

300

320

2.7 3.0 3.3 3.6

ICC vs. SUPPLY VOLTAGE

MAX2242 toc02

SUPPLY VOLTAGE (V)

ICC (mA)

= +22dBm

= +25°C

= -40°C

= +85°C

IDLE CURRENT SET TO 280mA

AT V

= +3.3V, T

= +25°C

OUTPUT POWER vs. INPUT POWER

MAX2242 toc03

INPUT POWER (dBm)

OUTPUT POWER (dBm)

-15 -11 -7 -3 1 5-13 -9 -5 -1 3

120

150

180

210

240

270

300

330

ICC vs. OUTPUT POWER

MAX2242 toc04

OUTPUT POWER (dBm)

ICC (mA)

0462 8 10 12 14 16 18 20 22

= +25°C

= -40°C

= +85°C

IDLE CURRENT ADJUSTED TO

KEEP ACPR/ALT = -33/-55dBc

-40

-32

-33

-34

-36

-37

-38

-39

-30

-31

-28

-29

-27

-25

-26

-24

ACPR vs. OUTPUT POWER

MAX2242 toc05

OUTPUT POWER (dBm)

ACPR (dBc)

-35

16 19 2017 18 21 22 23 24 25

IDLE CURRENT = 280mA

= +25°C

= -40°C

= +85°C

2400 24502425 2475 2500

ACPR vs. FREQUENCY

MAX2242 toc06

FREQUENCY (MHz)

ACPR (dBc)

-35

-34

-33

-32

OUT

= +22 dBm

280

285

290

295

300

305

310

315

320

2400 2425 2450 2475 2500

ICC vs. FREQUENCY

MAX2242 toc07

FREQUENCY (MHz)

ICC (mA)

= +22dBm

= +25°C

= -40°C

= +85°C

0.4

0.6

1.8

0.8

1.2

1.4

1.6

0 468210121816 2014 22

POWER DETECTOR VOLTAGE

vs. OUTPUT POWER

MAX2242 toc08

OUTPUT POWER (dBm)

POWER DETECTOR VOLTAGE (V)

= +2.7V, T

= +25°C

= +3.3V, T

= -40°C

= +3.3V, T

= +25°C

= +3.3V, T

= +85°C

= +3.6V, T

= +25°C

= +3.0V, T

= +25°C

OUTPUT POWER HISTOGRAM AT FIXED

1.6V POWER DETECTOR VOLTAGE

MAX2242 toc09

OUTPUT POWER (dBm)

OCCURENCES

21.6 21.8 22 22.2 22.4

SIGMA = 0.14dBm

BASED ON

100 PARTS

MAX2242

p2.4GHz to 2.5GHz

Linear Power Amplifier

_______________________________________________________________________________________ 5

Typical Operating Characteristics (continued)

(VCC = +3.3V, fIN = 2.45MHz, RF modulation = IEEE 802.11b, V SHDN = VCC, TA= +25°C, unless otherwise noted.)

OUTPUT POWER HISTOGRAM AT FIXED

0.8V POWER DETECTOR VOLTAGE

MAX2242 toc10

OUTPUT POWER (dBm)

OCCURRENCES

12.1 12.3 12.5 12.7 12.9 13.1 13.3 13.5 13.7

SIGMA = 0.25dBm

BASED ON 100 PARTS

2.2 3.4 4.6 5.82.8 4.0 5.2 6.4 7.0

OUTPUT POWER HISTOGRAM AT FIXED

0.5V POWER DETECTOR VOLTAGE

MAX2242 toc11

OUTPUT POWER (dBm)

OCCURRENCES

SIGMA = 0.75dBm

BASED ON 100 PARTS

-13

-15

-11

-5

-3

-7

-9

-1

2400 2420 2440 2460 2480 2500

S11, S22, vs. FREQUENCY

MAX2242 toc12

FREQUENCY (MHz)

S11, S22 (dB)

= -15dBm

S22

S11

2400 24402420 2460 2480 2500

MAX2242

S21 vs. FREQUENCY

MAX2242 toc13

FREQUENCY (MHz)

S21 (dB)

= -15dBm

Detailed Description

The MAX2242 is a linear PA intended for 2.4GHz ISM-

band wireless LAN applications. The PA is fully charac-

terized in the 2.4GHz to 2.5GHz ISM band. The PA

consists of two driver stages and an output stage. The

MAX2242 also features an integrated power detector

and power shutdown control mode.

Dynamic Power Control

The MAX2242 is designed to provide optimum power-

added efficiency (PAE) in both high and low power

applications. For a +3.3V supply at high output power

level, the output power is typically +22.5dBm with an

idle current of 280mA. At low output-power levels, the

DC current can be reduced by an external DAC to

increase PAE while still maintaining sufficient ACPR

performance. This is achieved by using external resis-

tors connected to the BIAS pin to set the bias currents

of the driver and output stages. The resistors are typi-

cally 8kΩ. Typically, a DAC voltage of 1.0V will give a

280mA bias current. Increasing the DAC voltage will

decrease the idle current. Similarly, decreasing the

DAC voltage will increase the idle current.

The BIAS pin is maintained at a constant voltage of

1.0V, allowing the user to set the desired idle current

using only two off-chip 1% resistors: a shunt resistor,

R2, from BIAS to ground; and a series resistor, R1, to

the DAC voltage, as shown in the Typical Application

Circuit. Resistor values R1 and R2 are determined as

follows:

VMAX = 1.0 + (1.0 ✕R1) / R2;

(ICC = 0, VDAC = VMAX) (1)

IMAX = (1.0 ✕1867) ✕(R1 + R2) / (R1 ✕R2);

(ICC = IMAX = max value, VDAC = 0) (2)

IDAC = (VDAC - 1.0) / R1 (3)

IMID = (1.0 ✕1867) / R2;

(VDAC = 1.0V or floating) (4)

ICC = 1867 ✕IBIAS (5)

where

VMAX = is the maximum DAC voltage

IMAX = is the maximum idle current

IMID = is the idle current with VDAC = 1.0V or not

connected

VDAC = is the DAC voltage

IDAC = is the DAC current

If no DAC is used and a constant idle current is

desired, use equation 4 to determine the resistor values

for a given total bias current. Only R2 is required.

MAX2242

2.4GHz to 2.5GHz

Linear Power Amplifier

6 _______________________________________________________________________________________

Pin Description

PIN NAME FUNCTION

A1 GND 3rd Stage Ground. Refer to Application Information section for detailed PC-board layout information.

A2 VCC2 2nd Stage Supply Voltage. Bypass to ground using configuration in the typical operating circuit.

A3 GND 3rd Stage Ground. Refer to Application Information section for detailed PC-board layout information.

A4 VCC1 1st Stage Supply Voltage. Bypass to ground using configuration in the typical operating circuit.

B1 RF_OUT RF Output. Requires external matching.

B2 PD_OUT Power Detector Output. This output is a DC voltage indicating the PA output power. Connect a

47kΩ resistor to GND.

B4 GND 1st Stage and Bias Control Circuit Ground

C1 BIAS Bias Control. Connect one 8kΩ resistor from BIAS to GND and one 8kΩ resistor from BIAS to DAC

block to set the idle current.

C2 SHDN Shutdown Input. Drive logic low to place the device in shutdown mode. Drive logic high for normal

operation.

C3 VCCB Bias Circuit DC Supply Voltage. Bypass to ground using configuration in the typical operating

circuit.

C4 RF_IN RF Input. Requires external matching.

MAX2242

2.4GHz to 2.5GHz

Linear Power Amplifier

_______________________________________________________________________________________ 7

For a DAC capable of both sourcing and sinking cur-

rents, the full voltage range of the DAC (typically from 0

to +3V) can be used. By substituting the desired values

of VMAX and IMAX into equations 1 and 2, R1 and R2

can be easily calculated.

For a DAC capable of sourcing current only, use equa-

tion 4 to determine the value of resistor R2 for the

desired maximum current. Use equation 1 to determine

the value of resistor R1 for the desired minimum current.

For a DAC capable of sinking current only, set resistors

R1 and R2 to 0 and connect the DAC directly to the

BIAS pin. Use equation 5 to determine the DAC current

required for a given ICC.

Shutdown Mode

Apply logic low to SHDN (pin C2) to place the

MAX2242 into shutdown mode. In this mode, all gain

stages are disabled and supply current typically drops

to 0.5µA. Note that the shutdown current is lowest when

VSHDN = 0.

Power Detector

The power detector generates a voltage proportional to

the output power by monitoring the output power using

an internal coupler. It is fully temperature compensated

and allows the user to set the bandwidth with an exter-

nal capacitor. For maximum bandwidth, connect a

47kΩresistor from PD_OUT to GND and do not use any

external capacitor.

Applications Information

Interstage Matching and Bypassing

VCC1 and VCC2 provide bias to the first and second

stage amplifiers, and are also part of the interstage

matching networks required to optimize performance

between the three amplifier stages. See the Typical

Application Circuit for the lumped and discrete compo-

nent values used on the MAX2242 EV kit for optimum

interstage matching and RF bypassing. In addition to

RF bypass capacitors on each bias line, a global

bypass capacitor of 22µF is necessary to filter any

noise on the supply line. Route separate VCC bias

paths from the global bypass capacitor (star topology)

to avoid coupling between PA stages. Use the

MAX2242 EV kit PC board layout as a guide.

External Matching

The RFIN port requires a matching network. The RFIN

port impedance is 16–j30 at 2.45GHz. See the Typical

Application Circuit for recommended component values.

The RFOUT port is an open-collector output that must

be pulled to VCC through a 10nH RF choke for proper

biasing. A shunt 33pF capacitor to ground is required

at the supply side of the inductor. In addition, a match-

ing network is required for optimum gain, efficiency,

ACPR, and output power. The load impedance seen at

the RFOUT port of the MAX2242 on the EV kit is

approximately 8 + j5Ω. This should serve as a good

starting point for your layout. However, optimum perfor-

mance is layout dependent and some component opti-

mization may be required. See the Typical Application

Circuit for the lumped and discrete component values

used on the MAX2242 EV kit to achieve this impedance.

Ground Vias

Placement and type of ground vias are important to

achieve optimum gain and output power and ACPR

performance. Each ground pin requires its own through-

hole via (via diameter = 10mils) placed as near to the

device pin as possible to reduce ground inductance

and feedback between stages. Use the MAX2242 EV

kit PC board layout as a guide.

Layout and Thermal Management Issues

The MAX2242 EV kit serves as a layout guide. Use con-

trolled-impedance lines on all high-frequency inputs

and outputs. The GND pins also serve as heat sinks.

Connect all GND pins directly to the topside RF ground.

On boards where the ground plane is not on the com-

ponent side, connect all GND pins to the ground plane

with plated multiple throughholes close to the package.

PC board traces connecting the GND pins also serve

as heat sinks. Make sure that the traces are sufficiently

wide.

UCSP Reliability

UCSP represents a unique packaging form factor that

may not perform equally to a packaged product

through traditional mechanical reliability tests. UCSP

reliability is integrally linked to the user’s assembly

methods, circuit-board material, and usage environ-

ment. The user should closely review these areas when

considering use of a UCSP. Performance through the

operating-life test and moisture resistance remains

uncompromised as it is primarily determined by the

wafer-fabrication process. Mechanical stress perfor-

mance is a greater consideration for a UCSP. UCSPs

are attached through direct solder contact to the user’s

PC board, foregoing the inherent stress relief of a pack-

aged-product lead frame. Solder joint contact integrity

must be considered. Testing done to characterize the

MAX2242

UCSP reliability performance shows that it is capable of

performing reliably through environmental stresses.

Users should also be aware that as with any intercon-

nect system there are electromigration-based current

limits that, in this case, apply to the maximum allowable

current in the bumps. Reliability is a function of this cur-

rent, the duty cycle, lifetime, and bump temperature.

See the Absolute Maximum Ratings section for any

specific limitations listed under Continuous Operating

Lifetime.Results of environmental stress tests and addi-

tional usage data and recommendations are detailed in

the UCSP application note, which can be found on

Maxim’s website at www.maxim-ic.com.

Chip Information

TRANSISTOR COUNT: 486

2.4GHz to 2.5GHz

Linear Power Amplifier

8 _______________________________________________________________________________________

GND

NOTE: REFER TO MAX2242 EV KIT DATA SHEET FOR DETAILED LAYOUT INFORMATION.

GND GND

BIAS

CIRCUIT DETECTOR

DET

OUT

6pF

1.8pF

100pF

10nH

33pF

0.1µF

33pF

0.1µF

RF_IN

VCC1

VCC2

VCC

VCCB

BIAS

DAC

PD_OUT

47kΩ

8kΩ

0.1µF

2.2nH

SHDN

RF_OUT

50Ω

VCC

Typical Application Circuit

BOTTOM VIEW

CHIP-SCALE PACKAGE (ALL DIMENSIONS IN mm)

SIDE VIEW

NOT

USED

0.75

MAX

1.5

0.5

2.0

0.5

Package Diagram

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.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 9

12L, UCSP 4x3.EPS

21-0104

PACKAGE OUTLINE, 4x3 UCSP

2.4GHz to 2.5GHz

Linear Power Amplifier

Note: MAX2242 does not use bump B3.

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information

go to www.maxim-ic.com/packages.)