Rainbow Electronics MAX2374 User Manual

General Description

The MAX2374 silicon-germanium (SiGe), switchable­gain, variable-linearity, low-noise amplifier (LNA) is
designed for cellular-band, code-division multiple­access (CDMA). It can be used for applications such
as TDMA and PDC or wherever high dynamic range
and low noise are required. This LNA provides a high
intermodulation intercept point (IIP3), which is
adjustable to meet specific system requirements by
selecting an appropriate external resistor. To achieve
high gain and low noise, the LNA is packaged in a tiny
ultra-chip-scale package (UCSP) with six solder
bumps. The LNA operates from a +2.7V to +5.5V single
supply and consumes just 8.5mA while achieving a
+6.2dBm input IIP3. Supply current reduces to less
than 1µA in shutdown mode.

The MAX2374 provides two gain modes. High-gain
mode optimizes system sensitivity, while low-gain mode
optimizes system linearity.

Applications

CDMA Phones

TDMA Phones

Wireless Local Loop (WLL)

GSM Handsets

Land Mobile Radio

Wireless Data

Features

♦ +2.7V to +5.5V Single Supply

♦ Low Operating Current

8.5mA for High Linearity

4.5mA for Paging

4.1mA in Low-Gain, High-Linearity Mode

♦ Low Noise Figure: 1.5dB Cellular

♦ Adjustable IIP3

♦ Two Gain Settings

♦ < 1µA Shutdown Mode

♦ Ultra-Small 6-Bump UCSP (1mm x 1.5mm)

MAX2374

SiGe, Variable IIP3, Low-Noise Amplifier

in UCSP Package

________________________________________________________________ Maxim Integrated Products 1

19-1614; Rev 0; 6/00

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

Ordering Information

*UCSP reliability is integrally linked to the user’s assembly
methods, circuit board material, and environment. Refer to the
UCSP Reliability Notice in the UCSP Reliability section of this
data sheet for more information.

For free samples and the latest literature, visit www.maxim-ic.com or phone [phone].
For small orders, phone [phone].

Pin Configuration appears at end of data sheet.

Typical Application Circuit

PART

MAX2374EBT

TEMP. RANGE

-40°C to +85°C

PIN­PACKAGE

6 UCSP*

TOP

MARK

AAB

+ 2.75V

V

CC =

100pF

A3

GND

5pF

LNA INPUT LNA OUTPUT

6.8nH

0.01µF

GAIN-CONTROL
LOGIC OUTPUT

MAX2374

A2

LNAIN

A1

GAIN

LNAOUT

V

BIAS

B3

CC

8.2nH

B2

B1

R

BIAS

2pF

V

CC

MAX2374

SiGe, Variable IIP3, Low-Noise Amplifier
in UCSP Package

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= +2.7V to +5.5V, R

BIAS

= 20kΩ, V

GAIN

= high, LNAOUT = VCC, no input signals at LNAIN, TA= -40°C to +85°C. Typical values

are at V

CC

= +2.75V, 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.

VCCto GND...........................................................-0.3V to +6.0V

GAIN, BIAS Voltage to GND...................-0.3V to (V

CC

+ 0.3V)

GAIN, BIAS Current ......................................................±10mA

RF Input Power

LNAIN .........................................................................+10dBm

LNAOUT to GND ....................................-0.3V to (V

CC

+ 0.6V)

Continuous Power Dissipation (T

A

= +85°C) ...................540mW

Operating Temperature Range

MAX2374 .........................................................-40°C to +85°C

Storage Temperature.........................................-65°C to +150°C

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

VCC= 2.75V

GAIN = 0.6V, VCC= 2.75V

BIAS = open circuit

VCC= 5.5V

R

BIAS

= 10kΩ

R

BIAS

= 43kΩ

CONDITIONS

V

VCC-

1.16

BIAS Pin Voltage (Note 2)

µA-5 5Input Current

V0.6Input Logic Voltage Low

V1.5Input Logic Voltage High

µA0.1 1Shutdown Supply Current

8.5 10.5

V2.7 5.5Supply Voltage

mA

4.5 5.5

Supply Current

10.5

15

4.5

UNITSMIN TYP MAXPARAMETER

AC ELECTRICAL CHARACTERISTICS

(Typical Application Circuit, VCC= +2.7V to +5.5V, P

LNAIN

= -30dBm, V

GAIN

= high, f

LNAIN

= 881MHz, R

BIAS

= 20kΩ, TA= +25°C.

Typical values are at V

CC

= +2.75V, unless otherwise noted.) (Note 2)

VCC= 2.75V

All modes, f ≤ 6.5GHz

Input and output ports externally matched to 50Ω

V

GAIN

= high

CONDITIONS

10:1Maximum Stable Load VSWR

MHz750 1000

Recommended Operating Frequency
Range (Note 3)

dBm

-3.5

Output 1dB Compression

dB14Input and Output Return Loss

-20

6

UNITSMIN TYP MAXPARAMETER

V

GAIN

= high

V

GAIN

= low

V

GAIN

= low

dB

-9

Reverse Isolation

SUPPLY

GAIN CONTROL INPUT

TA= -40°C to +85°C

MAX2374

SiGe, Variable IIP3, Low-Noise Amplifier

in UCSP Package

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS (continued)

(Typical Application Circuit, VCC= +2.7V to +5.5V, P

LNAIN

= -30dBm, V

GAIN

= high, f

LNAIN

= 881MHz, R

BIAS

= 18kΩ, TA= +25°C.

Typical values are at V

CC

= +2.75V, unless otherwise noted.) (Note 2)

VCC= 2.75V

CONDITIONS

dB1.5 1.7Noise Figure

dB

12.5 17

Gain

13.8 15 15.6

UNITSMIN TYP MAXPARAMETER

Note 1: Production tested at TA= +25°C. Maximum and minimum limits are guaranteed by design and characterization.
Note 2: Guaranteed by design and characterization.
Note 3: Operation over this frequency range is possible with a matching network tuned to the desired operating frequency.
Note 4: Measured with two-tone test with P

LNAIN

= -25dBm per tone, f1 = 881MHz, f2 = 881.9MHz.

0.4 1.2 2

Gain TA= -40°C to +85°C

-1 3.5

dB

Noise Figure 3 3.5 dB

TA= +25°C

TA= +25°C

TA= -40°C to +85°C

7.2

4.5 6.2

MAX2374 dBm

4.2

Input Third-Order Intercept Point (Note 4)

R

BIAS

= 10kΩ

R

BIAS

= 20kΩ

R

BIAS

= 43kΩ

10.5

5.8 7.2

Input Third-Order Intercept Point (Note 4) MAX2374

1

dBm

HIGH-GAIN MODE (GAIN = VCC)

LOW-GAIN MODE (GAIN = GND)

R

BIAS

= 10kΩ

R

BIAS

= 20kΩ

R

BIAS

= 43kΩ

12

10

8

6

4

2.5 4.03.0 3.5 4.5 5.0 5.5

ICC vs. V

CC

AND TEMPERATURE

MAX2374-01

VCC (V)

I

CC

(mA)

TA = -40°C

TA = +25°C

TA = +85°C

TA = +85°C

TA = +25°C

TA = -40°C

GAIN = V

CC

GAIN = GND

R

BIAS

= 20kΩ

-30

-20

0

-10

10

20

750 850800 900 950 1000

MAX2374-03

FREQUENCY (MHz)

MAGNITUDE (dB)

S21, S11, S22, S12 vs. FREQUENCY

S21

S11

S22

S12

V

CC

= GAIN = 2.75V

-20

-15

-5

-10

0

5

750 850800 900 950 1000

S21, S11, S22, S12 vs. FREQUENCY

MAX2374-04

FREQUENCY (MHz)

MAGNITUDE (dB)

S21

S12

S11

S22

V

CC

= 2.75V

GAIN = GND

TA= -40°C to +85°C

Typical Operating Characteristics

(Typical Application Circuit, VCC= +2.7V to +5.5V, P

LNAIN

= -30dBm, f

LNAIN

= 881MHz, R

BIAS

= 20kΩ, TA= +25°C, unless other-

wise noted.)

MAX2374

SiGe, Variable IIP3, Low-Noise Amplifier
in UCSP Package

4 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(Typical Application Circuit, VCC= +2.7V to +5.5V, P

LNAIN

= -30dBm, f

LNAIN

= 881MHz, R

BIAS

= 20kΩ, TA= +25°C, unless other-

wise noted.)

LNA Output Port. This port requires an external pullup inductor, which may be used as part of the matching
network.

LNAOUTB2

Supply Voltage Input. Bypass with a 100pF capacitor to GND.V

CC

B3

LNA Bias Setting Pin. For nominal bias, connect 20kΩ resistor to VCC. Adjust the resistor value to alter the
linearity of the LNA.

BIASB1

Gain-Control Logic Input. Drive high for high-gain mode. Drive low for low-gain mode.GAINA1

PIN

LNA Input Port. Blocking capacitor is required, which may be used as part of the matching network.LNAINA2

Ground GNDA3

FUNCTIONNAME

20

0

52515 35 45

GAIN vs. R

BIAS

AND TEMPERATURE

MAX2374-05

R

BIAS

(kΩ)

GAIN (dB)

15

10

5

TA = +85°C

TA = -40°C

TA = -40°C

TA = +25°C

TA = +85°C

TA = +25°C

GAIN = V

CC

GAIN = GND

V

CC

= 2.75V

0204060

IIP3 vs. R

BIAS

AND TEMPERATURE

MAX2374-06

R

BIAS

(kΩ)

IIP3 (dBm)

0

5

15

10

20

V

CC

= 2.75V,

f = 881MHz, 882MHz

= V

GAIN

= GND

A

= V

GAIN

= V

CC

B

TA = +25°C

TA = +85°C

TA = -40°C

TA = +85°C

A

B

B

TA = +25°C

TA = -40°C

Pin Description

4.5

4.0

3.5

3.0

2.5

NOISE FIGURE (dB)

2.0

1.5

1.0
750 850800 900 950 1000

NOISE FIGURE vs. FREQUENCY

V

= 2.75V

CC

GAIN = V

FREQUENCY (MHz)

CURRENT vs. VOLTAGE AND R

20

R

= 10kΩ, GAIN = V

MAX2374-07

(mA)

CC

I

CC

BIAS

15

R

= 20kΩ, GAIN = V

BIAS

10

5

0

2.5 4.03.0 3.5 4.5 5.0 5.5

R

BIAS

CC

R

= 43kΩ, GAIN = V

BIAS

R

= 20kΩ, GAIN = GND

BIAS

R

= 43kΩ, GAIN = GND

BIAS

VCC (V)

CC

= 10kΩ, GAIN = GND

BIAS

MAX2374-08

CC

MAX2374

SiGe, Variable IIP3, Low-Noise Amplifier

in UCSP Package

_______________________________________________________________________________________ 5

Table 1a. S-Parameters (VCC= V

GAIN

= 2.75V)

2250

2500

158.7

146.5

-20.2

78.8

-54.8

S22

0.626

3000

0.689

FREQ (MHz)

0.842

0.908

0.728

2750

250

128

MAGNITUDE

0.68

50

0.671

0.68

0.704

0.732

0.697

-12.9

-45.4

ANGLE

69

123.5

47.6

S12

0.693

500

ANGLE

33.3

21

11.19

5.042

15

17

1100.686

0.161

0.1

-81

0.026

0.007

-33.3

0.041

-370.078

MAGNITUDE

0.053

0.06

0.063

0.057

0.061

0.094

-60.5

750

-77

-105

122.73

-151.3

79.42

S21

0.074

ANGLE

49.35

24.18

1

-19.2

-35

-51

1.01

0.892

-128

9.83

12.84

6.19

-91.7

1000

0.781

MAGNITUDE

4.21

1250

3.12

2.38

1.771500

1.46

1.07

149

1750

139

-150

-49

2000

-11.89

-77.5

S11

125

ANGLE

-101

-123.7

-145.2

-165

176

163

0.664

0.691

-171

0.728

0.929

0.571

0.716

162

MAGNITUDE

0.524

0.529

0.568

0.612

0.639

0.652

-1040.662111.50.72

2250

2500

140

126.35

1.23

85.8

-42

S22

0.534

3000

0.623

FREQ (MHz)

0.471

0.374

0.596

2750

250

103.2

MAGNITUDE

0.659

50

0.689

0.694

0.695

0.681

0.629

-47

-77.2

ANGLE

85.7

127

52.2

S12

0.6

500

ANGLE

19.6

-9.33

-30.7

-47

-53.4

-42.5

85.80.566

0.175

0.123

-82

0.06

0.01

-62.8

0.14

-63.30.082

MAGNITUDE

0.189

0.2

0.184

0.146

0.117

0.096

-62

750

-89

-117.3

128.8

-148.7

72.4

S21

0.103

ANGLE

28.18

-6.87

-34.5

-54

-66

-66

0.196

0.156

-147.5

1.21

1.25

1

-83

1000

0.096

MAGNITUDE

0.772

1250

0.583

0.429

0.3011500

0.228

0.148

126.3

1750

112

-173

-42.4

2000

-8.93

-77

S11

92.4

ANGLE

-106

-132.7

-158

180

159.5

141.5

0.739

0.745

164.6

0.916

0.987

0.8

0.701

141.7

MAGNITUDE

0.75

0.754

0.782

0.803

0.811

0.797

-73.480.112730.591

Table 1b. S-Parameters (VCC= 2.75V, V

GAIN

= GND)

MAX2374

SiGe, Variable IIP3, Low-Noise Amplifier
in UCSP Package

6 _______________________________________________________________________________________

Detailed Description

The MAX2374 SiGe LNA is packaged in a UCSP pack­age in order to deliver high gain, high linearity, and low
noise in the smallest package possible. The special
feature of this LNA is that its linearity is adjusted by an
external resistor, R

BIAS

. The LNA has two digitally con­trollable gain modes to increase system dynamic
range. Digital high at GAIN selects the high-gain mode,
and digital low selects the low-gain mode.

Adjust the LNA bias current to control the amplifier’s lin­earity. The resistor R

BIAS

connected between BIAS and
VCCcontrols the LNA current. The amplifier’s linearity is
directly related to the operating current. Increasing the
bias current of the LNA increases the IIP3. V

BIAS

is
approximately constant at VCC- 1.16V. Connecting a
resistor from BIAS to VCCresults in a supply current
that can be calculated as follows:

VCC= (High Gain)

~

–

(150 - 1.16V) / R

BIAS

I

BIAS

can be set by a fixed resistor to VCCas described

above, or it can be generated with a switched network.

To operate the LNA in high-gain/high-linearity mode,
set R

BIAS

= 20kΩ and drive GAIN high. Do this in the
presence of a transmit signal to minimize cross-modu­lation. To operate the LNA in low-gain/low-linearity
mode, set R

BIAS

= 43kΩ and drive GAIN high. This
mode draws less current and should be used in the
absence of a transmit signal (paging mode). Shutdown
of the IC is accomplished by switching R

BIAS

to open

circuit.

Layout Issues

Design the layout for the IC to be as compact as possi­ble to minimize the parasitics. The chip-scale IC pack­age uses a bump pitch of 0.5mm (19.7mil) and bump
diameter of 0.3mm (~12mil). Therefore, lay out the sol­der-pad spacing on 0.5mm (19.7mil) centers, using a

pad size of 0.25mm (~10mil) and a solder mask open­ing of 0.33mm (13mil). Round or square pads are per­missible. Connect multiple vias from the ground plane
as close to the ground pins as possible.

Install capacitors as close as possible to the IC supply
voltage pin and supply end of the series inductor.
Place the ground end of these capacitors near the IC
GND pins to provide a low-impedance return path for
the signal current.

Prototype Chip Installation

Alignment keys on the PC board around the area where
the chip is located will be helpful in the prototype
assembly process. It is better to align the chip on the
board before any other components are placed, and
then place the board on a hot plate or hot surface until
the solder starts melting. Remove the board from the
hot plate without disturbing the position of the chip, and
let it cool down to room temperature before processing
the board further.

UCSP Reliability

The ultra-chip-scale package (UCSP) represents a
unique packaging form factor that may not perform
equally well as a packaged product through traditional
mechanical reliability tests. UCSP reliability is integrally
linked to the user’s assembly methods, circuit board
material, and usage environment. The user should
closely review these areas when considering use of a
UCSP package.

Performance through operating-life test and moisture
resistance remains uncompromised as it is primarily
determined by the wafer-fabrication process.
Mechanical stress performance is a greater considera­tion for UCSP packages. UCSPs are attached through
direct solder contact to the user’s PC board, foregoing
the inherent stress relief of a packaged product lead
frame. Solder joint contact integrity must be consid­ered. Comprehensive reliability tests have been per­formed and are available upon request. In conclusion,
the UCSP performs reliably through environmental
stresses.

Marking Information

Pin Configuration

TRANSISTOR COUNT: 296

Chip Information

TOP VIEW
(BUMPS ON BOTTOM)

LNAIN

GAIN

MAX2374

A3GND

A2

A1

UCSP

V

B3

CC

LNAOUT

B2

B1

BIAS

ORIENTATION

A A A
A A A

PRODUCT ID CODE
LOT CODE

MAX2374

SiGe, Variable IIP3, Low-Noise Amplifier

in UCSP Package

_______________________________________________________________________________________ 7

Package Information

6L,UCSP.EPS

MAX2374

SiGe, Variable IIP3, Low-Noise Amplifier
in UCSP Package

8 _______________________________________________________________________________________

NOTES