For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
ATTENUATORS - DIGITAL - SMT
8
8 - 1
1 dB LSB GaAs MMIC 5-BIT SERIAL
CONTROL DIGITAL ATTENUATOR, 0.7 - 3.7 GHz
General Description
Features
Functional Diagram
1 dB LSB Steps to 31 dB
CMOS Compatible Serial Data Interface
SPI Compatible Serial Output
±0.4 dB Typical Bit Error
24 Lead 4x4mm QFN Package: 16mm
Included in the HMC-DK004 Designer’s Kit
Electrical Specications, TA = +25° C, Vcc = +3V to +5V
Typical Applications
The HMC271ALP4(E) is a broadband 5-bit positive
control GaAs IC digital attenuator with CMOS com-
patible serial-to-parallel drivers in a low cost lead-
less QFN 4x4 mm SMT package. Covering 0.7 to
3.7 GHz, the insertion loss is typically less than 2.5
dB. The attenuator bit values are 1 (LSB), 2, 4, 8,
and 16 dB for a total attenuation of 31 dB. Accuracy
is excellent at ± 0.4 dB typical with an IIP3 of up to
+48 dBm. Five bit CMOS compatible serial control
words are used to select each attenuation state. A
single Vcc bias of +3V to +5V applied through an
external 5 kOhm resistor is required.
The HMC271ALP4(E) is ideal for:
• Cellular/3G Infrastructure
• Fixed Wireless, WiMax & WiBro
• Test Instrumentation
Parameter Frequency Min. Typical Max. Units
Insertion Loss
0.7 - 1.4 GHz
1.4 - 2.3 GHz
2.3 - 2.7 GHz
2.7 - 3.7 GHz
1.9
2.3
2.6
2.8
2.4
2.8
3.1
3.3
dB
dB
dB
dB
Attenuation Range 0.7 - 3.7 GHz 31 dB
Return Loss (RF1 & RF2, All Atten. States)
0.7 - 1.4 GHz
1.4 - 2.7 GHz
2.7 - 3.7 GHz
12
15
16
dB
dB
dB
Attenuation Accuracy: (Referenced to Insertion Loss)
All Attenuation States 0.7 - 0.9 GHz
0.9 - 2.2 GHz
2.2 - 3.7 GHz
± (0.4 + 5% of Atten. Setting) Max
± (0.4 + 4% of Atten. Setting) Max
± (0.4 + 6% of Atten. Setting) Max
dB
dB
dB
Input Power for 0.1 dB Compression Vcc = 5V
Vcc = 3V 0.7 - 3.7 GHz 24
22
dBm
dBm
Input Third Order Intercept Point
(Two-tone Input Power = 0 dBm Each Tone)
Vcc = 5V
Vcc = 3V 0.7 - 3.7 GHz 48
46
dBm
dBm
Switching Characteristics
tRISE, tFALL (10/90% RF)
tON, tOFF (Latch Enable to 10/90% RF) 0.7 - 3.7 GHz 750
830
ns
ns
HMC271ALP4 / 271ALP4E
v01.0510
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
ATTENUATORS - DIGITAL - SMT
8
8 - 2
Bit Error
vs. Attenuation State
Return Loss RF1, RF2
(Only Major States are Shown)
Insertion Loss
Normalized Attenuation
(Only Major States are Shown)
Note: All Data Typical Over Voltage (+3V to +5V) & Temperature (-40°C to +85°C).
Bit Error vs. Frequency
(Only Major States are Shown)
Relative Phase vs. Frequency
(Only Major States are Shown)
-4
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5 1 1.5 2 2.5 3 3.5 4
+25C
+85C
-40C
INSERTION LOSS (dB)
FREQUENCY (GHz)
-30
-25
-20
-15
-10
-5
0
0.5 1 1.5 2 2.5 3 3.5 4
RETURN LOSS (dB)
FREQUENCY (GHz)
1 dB
16 dB 31 dB
2 dB
8 dB4 dB
I.L.
-35
-30
-25
-20
-15
-10
-5
0
0.5 1 1.5 2 2.5 3 3.5 4
NORMALIZED ATTENUATION (dB)
FREQUENCY (GHz)
-1
-0.5
0
0.5
1
1.5
2
0 4 8 12 16 20 24 28 32
BIT ERROR (dB)
ATTENUATION STATE (dB)
2.4 GHz
0.9 GHz 1.9 GHz
3.5 GHz
-1
0
1
2
3
4
0.5 1 1.5 2 2.5 3 3.5 4
BIT ERROR (dB)
FREQUENCY (GHz)
16 dB
31 dB
1, 2, 4 dB8 dB
-100
-75
-50
-25
0
25
50
75
100
0 0.5 1 1.5 2 2.5 3 3.5 4
RELATIVE PHASE (deg.)
FREQUENCY (GHz)
31 dB 16 dB
1, 2, 4, 8 dB
HMC271ALP4 / 271ALP4E
v01.0510
1 dB LSB GaAs MMIC 5-BIT SERIAL
CONTROL DIGITAL ATTENUATOR, 0.7 - 3.7 GHz
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
ATTENUATORS - DIGITAL - SMT
8
8 - 3
Digital Control Voltages
Truth Table
Serial Data Input Attenuation
Setting
RF1 - RF2
C1 C2 C4 C8 C16
High High High High High Reference
I.L.
Low High High High High 1 dB
High Low High High High 2 dB
High High Low High High 4 dB
High High High Low High 8 dB
High High High High Low 16 dB
Low Low Low Low Low 31 dB
Max. Atten.
Any combination of the above states will provide an attenuation
approximately equal to the sum of the bits selected.
State Vcc = +5V Vcc = +3V
Low 0 to 1.3V 0 to 0.7V
High 3.5 to 5V 2.3 to 3V
-1.2
-0.8
-0.4
0
0.4
0.8
1.2
0.5 1 1.5 2 2.5 3 3.5 4
STEP ERROR (dB)
FREQUENCY (GHz)
Worst Case Step Error
Between Successive Attenuation States
Timing Diagram
Serial Input Truth Table
Latch
Enable
Shift
Clock Reset Function
X X L Shift register cleared
XáH Shift register clocked
áX H
Contents of shift register
transferred to Digital
Attenuator
Parameter Symbol Vcc = +5V Vcc = +3V Units
Min. Max. Min. Max.
Serial Input Setup
Time ts 20 - 100 - ns
Hold time from Serial
Input to Shift Clock th 0 - 5 - ns
Setup time from
Shift Clock to Latch
Enable
tlsup 40 - 100 - ns
Propagation delay,
Latch Enable to C1
through C16
tpd - 30 - 70 ns
Setup time from
Reset to Shift Clock - 20 - 50 - ns
Clock Frequency
(1/tclk) fclk - 30 - 10 MHz
Timing
HMC271ALP4 / 271ALP4E
v01.0510
1 dB LSB GaAs MMIC 5-BIT SERIAL
CONTROL DIGITAL ATTENUATOR, 0.7 - 3.7 GHz
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
ATTENUATORS - DIGITAL - SMT
8
8 - 4
Logic / Functional Diagram
Programming Example to Select 1 dB Attenuation State
HMC271ALP4 / 271ALP4E
v01.0510
1 dB LSB GaAs MMIC 5-BIT SERIAL
CONTROL DIGITAL ATTENUATOR, 0.7 - 3.7 GHz
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
ATTENUATORS - DIGITAL - SMT
8
8 - 5
Pin Number Function Description Interface Schematic
1, 3, 4, 6, 10, 12, 13,
15, 16, 18 N/C
These pins are not connected internally. However, all data
shown herein was measured with these pins connected
to RF/DC Ground.
2, 17 RF1, RF2
This pin is DC coupled and matched to 50 Ohms
Blocking capacitors are required. Select value based on
lowest frequency of operation.
5 Serial Output Serial data output. Serial input data
delayed by 8 clock cycles.
7Reset
See truth table, control voltage table and timing diagram.
8 Shift Clock
9 Latch Enable
11 Serial Input
14 Vcc Supply Voltage.
19 - 24 GND Package bottom has an exposed metal paddle that must also
be connected to RF/DC Ground.
Pin Descriptions
HMC271ALP4 / 271ALP4E
v01.0510
1 dB LSB GaAs MMIC 5-BIT SERIAL
CONTROL DIGITAL ATTENUATOR, 0.7 - 3.7 GHz
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
ATTENUATORS - DIGITAL - SMT
8
8 - 6
Application Circuit
DC blocking capacitors C1 & C2 are required on RF1 & RF2. Choose C1 = C2 = 100 ~ 300 pF to allow lowest customer specic
frequency to pass with minimal loss. R1 = 5 kOhm is required to supply voltage to the circuit through either PIN 2 or PIN 17.
HMC271ALP4 / 271ALP4E
v01.0510
1 dB LSB GaAs MMIC 5-BIT SERIAL
CONTROL DIGITAL ATTENUATOR, 0.7 - 3.7 GHz
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
ATTENUATORS - DIGITAL - SMT
8
8 - 7
Absolute Maximum Ratings
Outline Drawing
ELECTROSTATIC SENSITIVE DEVICE
OBSERVE HANDLING PRECAUTIONS
Package Information
NOTES:
1. LEADFRAME MATERIAL: COPPER ALLOY
2. DIMENSIONS ARE IN INCHES [MILLIMETERS]
3. LEAD SPACING TOLERANCE IS NON-CUMULATIVE
4. PAD BURR LENGTH SHALL BE 0.15mm MAXIMUM.
PAD BURR HEIGHT SHALL BE 0.05mm MAXIMUM.
5. PACKAGE WARP SHALL NOT EXCEED 0.05mm.
6. ALL GROUND LEADS AND GROUND PADDLE MUST BE
SOLDERED TO PCB RF GROUND.
7. REFER TO HITTITE APPLICATION NOTE FOR SUGGESTED
LAND PATTERN.
Digital Inputs (Reset, Shift Clock,
Latch Enable & Serial Input) -0.5 to (Vcc + 0.5) V
Digital Outputs (Serial Output) -0.5 to (Vcc + 0.5) V
DC Current on Serial Output ±35 mA
Bias Voltage (Vcc) +5.6 V
Storage Temperature -65 to +150 °C
Operating Temperature -40 to +85 °C
RF Input Power (0.7 - 3.7 GHz) +26 dBm
ESD Sensitivity (HBM) Class 1A
HMC271ALP4 / 271ALP4E
v01.0510
1 dB LSB GaAs MMIC 5-BIT SERIAL
CONTROL DIGITAL ATTENUATOR, 0.7 - 3.7 GHz
Part Number Package Body Material Lead Finish MSL Rating Package Marking [3]
HMC271ALP4 Low Stress Injection Molded Plastic Sn/Pb Solder MSL1 [1] H271A
XXXX
HMC271ALP4E RoHS-compliant Low Stress Injection Molded Plastic 100% matte Sn MSL1 [2] H271A
XXXX
[1] Max peak reow temperature of 235 °C
[2] Max peak reow temperature of 260 °C
[3] 4-Digit lot number XXXX
For price, delivery and to place orders: Hittite Microwave Corporation, 20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
ATTENUATORS - DIGITAL - SMT
8
8 - 8
Evaluation Circuit Board
The circuit board used in the application should
use RF circuit design techniques. Signal lines sho-
uld have 50 Ohm impedance while the package
ground leads and exposed ground paddle should
be connected directly to the ground plane similar to
that shown below. A sufficient number of via holes
should be used to connect the top and bottom
ground planes. The evaluation circuit board as
shown is available from Hittite Microwave Corpora-
tion upon request.
Item Description
J1 - J2 PCB Mount SMA Connector
J3 18 Pin DC Connector
J6, J7 DC Pin
C1, C2 100 pF Capacitor, 0402 Pkg.
C3 0.01 µF Capacitor, 0402 Pkg.
R1 5 kOhm Resistor, 0402 Pkg.
U1 HMC271ALP4(E) Digital Attenuator
PCB [2] 108780 Evaluation PCB
[1] Reference this number when ordering complete evaluation PCB
[2] Circuit Board Material: Rogers 4350
List of Materials for Evaluation PCB 108782 [1]
HMC271ALP4 / 271ALP4E
v01.0510
1 dB LSB GaAs MMIC 5-BIT SERIAL
CONTROL DIGITAL ATTENUATOR, 0.7 - 3.7 GHz