Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsMAX2055EUP+D

General Description

The MAX2055 high-performance, digitally controlled,

variable-gain, differential analog-to-digital converter

(ADC) driver/amplifier (DVGA) is designed for use from

30MHz to 300MHz in base station receivers.

The device integrates a digitally controlled attenuator

and a high-linearity single-ended-to-differential output

amplifier, which can either eliminate an external trans-

former, or can improve the even-order distortion perfor-

mance of a transformer-coupled circuit, thus relaxing

the requirements of the anti-alias filter preceding an

ADC. Targeted for ADC driver applications to adjust

gain either dynamically or as a one-time channel gain

setting, the MAX2055 is ideal for applications requiring

high performance. The attenuator provides 23dB of

attenuation range with ±0.2dB accuracy.

The MAX2055 is available in a thermally enhanced 20-

pin TSSOP-EP package and operates over the -40°C to

+85°C temperature range.

Applications

Cellular Base Stations

PHS/PAS Infrastructure

Receiver Gain Control

Broadband Systems

Automatic Test Equipment

Terrestrial Links

High-Performance ADC Drivers

Features

♦ 30MHz to 300MHz Frequency Range

♦ Single-Ended-to-Differential Conversion

♦ -3dB to +20dB Variable Gain

♦ 40dBm Output IP3 (at All Gain States and 70MHz)

♦ 2nd Harmonic -76dBc

♦ 3rd Harmonic -69dBc

♦ Noise Figure: 5.8dB at Maximum Gain

♦ Digitally Controlled Gain with 1dB Resolution and

±0.2dB Accuracy

♦ Adjustable Bias Current

MAX2055

Digitally Controlled, Variable-Gain, Differential

ADC Driver/Amplifier

________________________________________________________________

Maxim Integrated Products

Ordering Information

GND

ATTN

OUT

GND

SET

GND

RF_IN

AMP

BIAS

RF_OUT+

RF_OUT-

ATTENUATION

LOGIC

CONTROL

TSSOP

MAX2055

TOP VIEW

19-2799; Rev 0; 4/03

EVALUATION KIT

AVAILABLE

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.

PART TEMP RANGE PIN-PACKAGE

MAX2055EUP-T -40°C to +85°C 20 TSSOP-EP*

EP = Exposed paddle.

Pin Configuration/

Functional Diagram

Summary of content (13 pages)

PAGE 1
KIT ATION EVALU E L B AVAILA 19-2799; Rev 0; 4/03 Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier The MAX2055 high-performance, digitally controlled, variable-gain, differential analog-to-digital converter (ADC) driver/amplifier (DVGA) is designed for use from 30MHz to 300MHz in base station receivers.
PAGE 2
MAX2055 Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier ABSOLUTE MAXIMUM RATINGS All Pins to GND. .....................................-0.3V to +(VCC + 0.25V) Input Signal (RF_IN)............................…………………….20dBm Output Power (RF_OUT) ...................................................24dBm Continuous Power Dissipation (TA = +70°C) 20-Pin TSSOP (derate 21.7mW/°C above +70°C) ...........2.1W Operating Temperature Range ...........................
PAGE 3
Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier (Circuit of Figure 1; VCC = +4.75V to +5.25V, GND = 0V, max gain (B0 = B1 = B2 = B3 = B4 = 0), R1 = 1.13kΩ, POUT = 5dBm, fIN = 70MHz, 50Ω system impedance. Typical values are at VCC = +5V and TA = +25°C, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Gain Flatness Over 50MHz Bandwidth Peak-to-peak for all settings 0.
PAGE 4
Typical Operating Characteristics (continued) (Circuit of Figure 1, VCC = 5.0V, R1 = 1.13kΩ, max gain (B0 = B1 = B2 = B3 = B4 = 0), POUT = 5dBm, TA = +25°C, unless otherwise noted.) 0.8 0.2 0 -0.2 -0.4 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.6 -0.8 -0.8 -1.0 90 120 150 180 210 240 270 300 30 60 FREQUENCY (MHz) 90 120 150 180 210 240 270 300 OUTPUT P-1dB vs. FREQUENCY OUTPUT P-1dB vs. FREQUENCY 27 MAX2055 toc10 26 OUTPUT P-1dB (dBm) 7.5 NOISE FIGURE (dB) 60 FREQUENCY (MHz) TA = +85°C 6.5 6.
PAGE 5
Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier 2ND HARMONIC vs. FREQUENCY -60 MAX2055 toc17 MAX2055 toc16 TA = -40°C -60 3RD HARMONIC vs. FREQUENCY -55 -60 TA = +85°C TA = -40°C -65 MAX2055 toc18 3RD HARMONIC vs. FREQUENCY -55 TA = +25°C TA = +85°C -75 -80 -65 -70 VCC = +5V VCC = +4.75V -75 90 120 150 180 210 240 270 300 60 30 FREQUENCY (MHz) TA = +25°C VCC = +4.75V 80 VCC = +5.0 75 VCC = +4.
PAGE 6
Typical Operating Characteristics (continued) (Circuit of Figure 2, VCC = 5.0V, R1 = 909Ω, max gain, (B0 = B1 = B2 = B3 = B4 = 0), POUT = 5dBm, TA = +25°C, unless otherwise noted.) 240 230 VCC = 4.75V 30 40 -15 10 35 60 30 85 60 GAIN vs. RF FREQUENCY (ALL STATES) 22 TA = -40°C GAIN vs. RF FREQUENCY 24 22 5 VCC = 4.75V 20 GAIN (dB) 10 90 120 150 180 210 240 270 300 FREQUENCY (MHz) 20 GAIN (dB) 15 GAIN (dB) 60 GAIN vs.
PAGE 7
Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier 6.5 6.0 5.5 TA = +25°C TA = +85°C 25 24 TA = +25°C TA = -40°C 26 23 MAX2055 toc35 26 OUTPUT P-1dB (dBm) NOISE FIGURE (dB) 7.0 27 MAX2055 toc34 MAX2055 toc33 TA = +85°C 7.5 OUTPUT P-1dB vs. FREQUENCY OUTPUT P-1dB vs. FREQUENCY 27 OUTPUT P-1dB (dBm) NOISE FIGURE vs. FREQUENCY 8.0 VCC = +5.25V 25 24 VCC = +5V VCC = +4.75V 23 5.0 22 22 4.
PAGE 8
Typical Operating Characteristics (continued) (Circuit of Figure 2, VCC = 5.0V, R1 = 909Ω, max gain, (B0 = B1 = B2 = B3 = B4 = 0), POUT = 5dBm, TA = +25°C, unless otherwise noted.) TA = +85°C 80 -60 75 75 -70 -75 VCC = +5V 70 65 TA = +25°C VCC = +4.75V 60 -90 90 120 150 180 210 240 270 300 60 60 30 90 120 150 180 210 240 270 300 60 90 120 150 180 210 240 270 300 FREQUENCY (MHz) FREQUENCY (MHz) OUTPUT-PORT PHASE UNBALANCE vs. FREQUENCY 0.15 0.10 0.05 MAX2055 toc46 3.
PAGE 9
Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier PIN NAME FUNCTION 1, 9 VCC 2 RF_IN Signal Input. Internally matched to 50Ω over the operating frequency. See the typical application circuit for recommended component values. 3, 18, 20, EP GND Ground. Use low-inductance layout techniques on the PC board. Solder the exposed paddle to the board ground plane. 4–8 B4–B0 10 RF_OUT- Inverted Differential Signal Output.
PAGE 10
MAX2055 Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier VCC C3 C2 C4 1 20 GND ATTNOUT 19 VCC 2 RF_IN RF_IN 3 C1 5 B3 6 B2 7 B1 ATTENUATION LOGIC CONTROL C12 C5 LE 14 1 L2 L1 CBP 13 9 V CC VCC R1 16 CC AMPIN 15 8 B0 R7 T1 18 GND ISET 17 GND 4 B4 CONTROL INPUTS C6 MAX2055 IBIAS 12 11 C11 L3 RF_OUT+ 10 RF_OUTVCC L5 L4 C10 C8 C9 1 T2 RF_OUT Figure 1.
PAGE 11
Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier MAX2055 VCC C3 C2 1 V CC GND 20 ATTNOUT 19 2 RF_IN RF_IN 3 C1 GND 18 GND 5 B3 CONTROL INPUTS 6 B2 7 B1 AMPIN 15 LE 14 C12 L2 CBP 13 9 V CC VCC MAX2055 IBIAS L1 12 C7 11 C11 C4 C5 CC 16 ATTENUATION LOGIC CONTROL 8 B0 R7 R1 ISET 17 4 B4 10 RF_OUT- L3 RF_OUT+ VCC L5 L4 C10 C8 C9 1 T2 RF_OUT Figure 2. Low-Cost Application Circuit feedback topology.
PAGE 12
MAX2055 Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier package. This pad should be connected to the ground plane of the board by using multiple vias under the device to provide the best RF/thermal conduction path. Solder the exposed pad on the bottom of the device package to a PC board exposed pad. The MAX2055 Evaluation Kit can be used as a reference for board layout. Gerber files are available upon request at www.maxim-ic.com.
PAGE 13
Digitally Controlled, Variable-Gain, Differential ADC Driver/Amplifier TSSOP4.40mm.EPS PACKAGE OUTLINE, TSSOP 4.40mm BODY 21-0066 I 1 1 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.