12 - 1
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
HMC681LP5 / 681LP5E
v03.1010
Functional Diagram
Electrical Specications, TA = +25° C, Vdd = Vs= P/S= +5V
The HMC681LP5(E) is ideal for:
• IF & RF Applications
• Cellular/3G Infrastructure
• WiBro / WiMAX / 4G
• Microwave Radio & VSAT
• Test Equipment and Sensors
+13.5 dB to +45 dB Gain Control in 0.5 dB Steps
High Output IP3: +36 dBm
±0.25 dB Typical Gain Step Error
Single +5V Supply
32 Lead 5x5mm SMT Package: 25mm2
The HMC681LP5(E) is a digitally controlled variable
gain amplier which operates from DC to 1 GHz,
and can be programmed to provide anywhere from
13.5 dB, to 45 dB of gain, in 0.5 dB steps. The
HMC681LP5(E) delivers noise gure of 2.8 dB in its
maximum gain state, with output IP3 of up to +36
dBm in any state. This serially controlled digital VGA
incorporates off chip AC ground capacitors for near
DC operation, making it suitable for a wide variety of
RF and IF applications. The HMC681LP5(E) is housed
in a RoHS compliant 5x5 mm QFN leadless package,
and provides the user with a highly integrated solution.
This functionality is also available with parallel control
as the HMC626LP5(E).
Parameter Min. Typ. Max. Min. Typ. Max. Units
50 - 350 350 - 1000 MHz
Gain (Maximum Gain State) 40 45 30 40 dB
Gain Control Range 31.5 31.5 dB
Input Return Loss 25 30 dB
Output Return Loss 20 17 dB
Gain Setting Accuracy:
(Referenced to Maximum Gain State)
All Gain States
± (0.15 + 3% of Relative Gain Setting) Max. ± (0.15 + 3% of Relative Gain Setting) Max. dB
Output Power for 1 dB Compression 20 19 dBm
Output Third Order Intercept Point
(Two-Tone Output Power= 5 dBm Each Tone) 38 36 dBm
Noise Figure 2.7 2.8 dB
Switching Characteristics
tRISE, tFALL (10/90% RF)
tON, tOFF (50% CTL to 10/90% RF)
60
120
60
120
ns
ns
Total Supply Current 176 225 176 225 mA
Typical Applications Features
General Description
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE GAIN
AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
12 - 2
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Relative Gain Setting
(Referenced to Maximum Gain State)
(Only Major States are Shown)
Gain vs. Frequency
Input Return Loss
(Only Major States are Shown)
Output Return Loss
(Only Major States are Shown)
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
0
5
10
15
20
25
30
35
40
45
50
0.05 0.1 0.15 0.2 0.25 0.3 0.35
+25C
+85C
-40C
GAIN (dB)
FREQUENCY (GHz)
-40
-35
-30
-25
-20
-15
-10
-5
0
0.05 0.1 0.15 0.2 0.25 0.3 0.35
RETURN LOSS (dB)
FREQUENCY (GHz)
31.5dB
2dB
-40
-35
-30
-25
-20
-15
-10
-5
0
0.05 0.1 0.15 0.2 0.25 0.3 0.35
RETURN LOSS (dB)
FREQUENCY (GHz)
31.5dB
I.L
-35
-30
-25
-20
-15
-10
-5
0
0.05 0.1 0.15 0.2 0.25 0.3 0.35
RELATIVE GAIN (dB)
FREQUENCY (GHz)
31.5 dB
16 dB
8 dB
Bit Error vs. Frequency
(Only Major States are Shown) Bit Error vs. Relative Gain Setting
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 4 8 12 16 20 24 28 32
BIT ERROR (dB)
RELATIVE GAIN SETITING (dB)
350MHz
150, 200MHz
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
0.05 0.1 0.15 0.2 0.25 0.3 0.35
BIT ERROR (dB)
FREQUENCY (GHz)
0.5dB
16dB
31.5dB
50 to 350 MHz Tuning
12 - 3
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Step Error vs. Frequency
(Only Major States are Shown)
Relative Phase vs. Frequency
(Only Major States are Shown)
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
0.05 0.1 0.15 0.2 0.25 0.3 0.35
STEP ERROR (dB)
FREQUENCY (GHz)
16 dB
1 dB
-40
-20
0
20
40
60
0.05 0.1 0.15 0.2 0.25 0.3 0.35
RELATIVE PHASE (deg)
FREQUENCY (GHz)
31.5 dB
16 dB
0.5 - 16 dB
31.5 dB
8 dB
Output P1dB
(Major States shown are IL through 16 dB))
Output IP3 @ 5 dBm Output Power per
Tone (Major States shown are IL through 16 dB)
35
37
39
41
43
45
0.05 0.1 0.15 0.2 0.25 0.3 0.35
IP3 (dBm)
FREQUENCY (GHz)
16 dB
I.L.
16
18
20
22
24
0.05 0.1 0.15 0.2 0.25 0.3 0.35
P1dB (dBm)
FREQUENCY (GHz)
I.L.
16 dB
50 to 350 MHz Tuning
12 - 4
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Relative Gain Setting
(Referenced to Maximum Gain State)
(Only Major States are Shown)
Gain vs. Frequency
Input Return Loss
(Only Major States are Shown)
Output Return Loss
(Only Major States are Shown)
0
5
10
15
20
25
30
35
40
45
50
0.2 0.4 0.6 0.8 1
+25 C
+85 C
-40 C
GAIN (dB)
FREQUENCY (GHz)
-50
-40
-30
-20
-10
0
0.2 0.4 0.6 0.8 1
RETURN LOSS (dB)
FREQUENCY (GHz)
31.5 dB
I.L
-40
-35
-30
-25
-20
-15
-10
-5
0
0.2 0.4 0.6 0.8 1
RETURN LOSS (dB)
FREQUENCY (GHz)
31.5 dB
I.L
-35
-30
-25
-20
-15
-10
-5
0
0.2 0.4 0.6 0.8 1
RELATIVE GAIN (dB)
FREQUENCY (GHz)
31.5 dB
16 dB
8 dB
Bit Error vs. Frequency
(Only Major States are Shown) Bit Error vs. Relative Gain Setting
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 4 8 12 16 20 24 28 32
BIT ERROR (dB)
RELATIVE GAIN SETTING (dB)
350 MHz
1000 MHz
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
0.2 0.4 0.6 0.8 1
BIT ERROR (dB)
FREQUENCY (GHz)
31.5 dB
16 dB
8 dB
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
350 to 1000 MHz Tuning
12 - 5
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Step Error vs. Frequency
(Only Major States are Shown)
Relative Phase vs. Frequency
(Only Major States are Shown)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
0.2 0.4 0.6 0.8 1
STEP ERROR (dB)
FREQUENCY (GHz)
4, 8 dB
32 dB16 dB
-40
-20
0
20
40
60
0.2 0.4 0.6 0.8 1
RELATIVE PHASE (deg)
FREQUENCY (GHz)
31.5 dB
16 dB
8 dB
0.5 - 4 dB
PUP Truth Table
LE PUP1 PUP2 Relative Gain Setting
0 0 0 -31.5
0 1 0 -24
0 0 1 -16
0 1 1 Insertion Loss
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
Output P1dB
(Major States shown are IL through 16 dB)
Output IP3 @ 5 dBm Output Power per
Tone (Major States shown are IL through 16 dB)
10
20
30
40
50
0.2 0.4 0.6 0.8 1
IP3 (dBm)
FREQUENCY (GHz)
16 dB
I.L.
16
18
20
22
24
0.2 0.4 0.6 0.8 1
P1dB (dBm)
FREQUENCY (GHz)
16 dB
I.L.
350 to 1000 MHz Tuning
Power-Up States
If LE is set to logic LOW at power-up, the logic state
of PUP1 and PUP2 determines the power-up state of
the part per PUP truth table. The attenuator latches
in the desired power-up state approximately 200 ms
after power-up.
Power-On Sequence
The ideal power-up sequence is: GND, Vdd, digital
inputs, RF inputs. The relative order of the digital
inputs are not important as long as they are powered
after Vdd / GND
12 - 6
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Serial Control Interface
The HMC681LP5(E) contains a 3-wire SPI compatible digital interface (SERIN, CLK, LE). It is activated when P/S
is kept high. The 6-bit serial word must be loaded MSB rst. The positive-edge sensitive CLK and LE requires
clean transitions. If mechanical switches were used, sufficient debouncing should be provided. When LE is high,
6-bit data in the serial input register is transferred to the attenuator. When LE is high CLK is masked to prevent data
transition during output loading.
For all modes of operations, gain will remain constant while LE is kept low.
Serial Word Relative
Gain
Setting
B5
16 dB
B4
8dB
B3
4 dB
B2
2 dB
B1
1 dB
B0
0.5 dB
High High High High High High Reference
0 dB
High High High High High Low -0.5 dB
High High High High Low High -1 dB
High High High Low High High -2 dB
High High Low High High High -4 dB
High Low High High High High -8 dB
Low High High High High High -16 dB
Low Low Low Low Low Low -31.5 dB
Any combination of the above states will provide a relative gain
setting approximately equal to the sum of the bits selected.
Truth Table
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
Parameter Typ.
Min. serial period, tSCK 100 ns
Control set-up time, tCS 20 ns
Control hold-time, tCH 20 ns
LE setup-time, tLN 10 ns
Min. LE pulse width, tLEW 10 ns
Min LE pulse spacing, tLES 630 ns
Serial clock hold-time from LE, tCKN 10 ns
Hold Time, tPH. 0 ns
Latch Enable Minimum Width, tLEN 10 ns
Setup Time, tPS 2 ns
12 - 7
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Outline Drawing
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.
Part Number Package Body Material Lead Finish MSL Rating Package Marking [3]
HMC681LP5 Low Stress Injection Molded Plastic Sn/Pb Solder MSL1 [1] H681
XXXX
HMC681LP5E RoHS-compliant Low Stress Injection Molded Plastic 100% matte Sn MSL1 [2] H681
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
Package Information
Absolute Maximum Ratings
ELECTROSTATIC SENSITIVE DEVICE
OBSERVE HANDLING PRECAUTIONS
Bias Voltage
Vdd (V) Idd (Typ.) (mA)
+5 5
Vs (V) Is1 (mA) Is2 (mA)
+5 88 88
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
RF Input Power [1] (At Max Gain
Setting) -10.5 dBm (T = +85 °C)
Digital Inputs (Reset, Shift Clock,
Latch Enable & Serial Input) -0.5 to Vdd +0.5V
Bias Voltage (Vdd) 5.5V
Collector Bias Voltage (Vcc) 5.5V
Channel/Junction Temperature 150 °C
Continuous Pdiss (T = 85 °C)
(derate 19.8 mW/°C above 85 °C) [1] 1.29 W
Thermal Resistance 50.8 °C/W
Storage Temperature -65 to +150 °C
Operating Temperature -40 to +85 °C
[1] The Max RF Input Power Rating will increase by 0.5 dB for
every 0.5 dB reduction in gain to a maximum RF Input Power of
10 dBm.
Control Voltage Table
State Vdd = +3V Vdd = +5V
Low 0 to 0.5V @ <1 µA 0 to 0.8V @ <1 µA
High 2 to 3V @ <1 µA 2 to 5V @ <1 µA
12 - 8
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Pin Descriptions
Pin Number Function Description Interface Schematic
1, 5, 9, 14,
16, 23, 28 N/C
The pins are not connected internally; however, all data shown
herein was measured with these pins connected to RF/DC
ground externally.
2, 20 RFin1,RFin2 This pin is DC coupled. An off chip DC blocking capacitor is
required.
4, 22 RFout1, RFout2
RF output and DC bias (Vcc) for the output stage of the
ampliers. Amplier bias provided via external bias tee as
shown in application circuit.
3, 7, 18, 21 GND These pins and package bottom
must be connected to RF/DC ground.
6, 19 ATTin, ATTout
These pins are DC coupled and matched to 50 Ohms.
Blocking capacitors are required. Select value based
on lowest frequency of operation.
8, 10,
11, 12,
13, 15,
17
ACG1, ACG2,
ACG3, ACG4,
ACG5, ACG6, ACG7
External capacitors to ground is required. Select value for
lowest frequency of operation. Place capacitor as close to
pins as possible.
24 SEROUT Serial input data delayed by 6 clock cycles.
25, 26 PUP2, PUP1
Refer to truth tables and serial control interface diagram.
30 CLK
31 SERIN
32 LE
29 P/S Apply +5V for normal operation.
27 Vdd Supply voltage
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
12 - 9
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Application Circuit
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz
Tuned Frequency 50 - 350 MHz 350 - 1000 MHz
Evaluation PCB 119171 123115
C1, C2, C9, C10 3300 pF 100 pF
C6 - C8 330 pF 100 pF
L1, L2 560 nH 270 nH
Components for Selected Frequencies
12 - 10
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
VARIABLE GAIN AMPLIFIERS - DIGITAL - SMT
12
Evaluation PCB
The circuit board used in the application should use
RF circuit design techniques. Signal lines should
have 50 Ohm impedance while the package ground
leads and exposed paddle should be connected
directly to the ground plane similar to that shown.
A sufficient number of via holes should be used to
connect the top and bottom ground planes. The
evaluation circuit board shown is available from
Hittite upon request. Refer to “Components for
Selected Frequencies” table for part number.
List of Materials for Evaluation PCB [1]
Item Description
J1 - J2 PCB Mount SMA Connector
J3 18 Pin DC Connector
J4 - J7, J9 DC Pin
C1, C2, C9, C10 Capacitor, 0402 Pkg. [1]
C3 - C5 100 pF Capacitor, 0402 Pkg.
C6 - C8 Capacitor, 0402 Pkg. [1]
C11 - C13 1000 pF Capacitor, 0402 Pkg.
C14, C15 2.2 µF Capacitor, CASE A Pkg.
R1, R2 1.8 Ohm Resistor, 0603 Pkg.
L1, L2 Inductor, 0603 Pkg. [1]
U1 HMC681LP5(E) Variable Gain Amplier
PCB [2] 119169 Evaluation PCB
[1] Please reference “Components for Selected Frequencies” table.
[2] Circuit Board Material: Arlon 25FR
HMC681LP5 / 681LP5E
v03.1010
0.5 dB LSB GaAs MMIC 6-BIT DIGITAL VARIABLE
GAIN AMPLIFIER w/ SERIAL CONTROL, DC - 1 GHz