REV. 0
Wideband, 37 dB Isolation at 1 GHz, CMOS
1.65 V to 2.75 V, 2:1 Mux/SPDT Switches
ADG918/ADG919
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may result from its use. No license is granted by implication or otherwise
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Tel: 781/329-4700 www.analog.com
Fax: 781/326-8703 © 2003 Analog Devices, Inc. All rights reserved.
FUNCTIONAL BLOCK DIAGRAMS
RF2
RF1
CTRL
ADG918
RFC 50
50
ADG919
RF2
RF1
CTRL
RFC
FEATURES
Wideband Switch: –3 dB @ 4 GHz
Absorptive/Reflective Switches
High Off Isolation (37 dB @ 1 GHz)
Low Insertion Loss (0.8 dB @1 GHz)
Single 1.65 V to 2.75 V Power Supply
CMOS/LVTTL Control Logic
8-Lead MSOP and Tiny 3 mm 3 mm LFCSP Packages
Low Power Consumption (<1 A)
APPLICATIONS
Wireless Communications
General-Purpose RF Switching
Dual-Band Applications
High Speed Filter Selection
Digital Transceiver Front End Switch
IF Switching
Tuner Modules
Antenna Diversity Switching
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
–100
–90
–70
–60
–50
–40
–30
–80
–20
–10
0
ISOLATION (dB)
S21
VDD = 2.5V
TA = 25C
S12
Figure 1. Off Isolation vs. Frequency
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
–3.2
–2.8
–2.6
–2.4
–2.2
–1.8
–1.6
–1.4
–1.2
–1.0
–2.0
–3.0
–0.8
–0.6
–0.4
INSERTION LOSS (dB)
VDD = 2.5V
TA = 25C
Figure 2. Insertion Loss vs. Frequency
GENERAL DESCRIPTION
The ADG918/ADG919 are wideband switches using a CMOS
process to provide high isolation and low insertion loss to 1 GHz.
The ADG918 is an absorptive (matched) switch having 50 Ω
terminated shunt legs, while the ADG919 is a reflective switch.
These devices are designed such that the isolation is high over
the dc to 1 GHz frequency range. They have on-board CMOS
control logic, thus eliminating the need for external controlling
circuitry. The control inputs are both CMOS and LVTTL
compatible. The low power consumption of these CMOS devices
makes them ideally suited to wireless applications and general-
purpose high frequency switching.
PRODUCT HIGHLIGHTS
1. –37 dB Off Isolation @ 1 GHz
2. 0.8 dB Insertion Loss @ 1 GHz
3. Tiny 8-Lead MSOP/LFCSP Packages
REV. 0–2–
ADG918/ADG919–SPECIFICATIONS
1
B Version
Parameter Symbol Conditions Min Typ
2
Max Unit
AC ELECTRICAL CHARACTERISTICS
Operating Frequency
3
DC 2 GHz
–3 dB Frequency
4
4GHz
Input Power
4
0 V dc Bias 7 dBm
0.5 V dc Bias 16 dBm
Insertion Loss S
21
, S
12
DC to 100 MHz; V
DD
= 2.5 V ± 10% 0.4 0.7 dB
500 MHz; V
DD
= 2.5 V ± 10% 0.5 0.8 dB
1000 MHz; V
DD
= 2.5 V ± 10% 0.8 1.25 dB
Isolation—RFC to RF1/RF2 S
21
, S
12
100 MHz 55 60 dB
500 MHz 43 47 dB
1000 MHz 34 37 dB
Isolation—RF1 to RF2 S
21
, S
12
100 MHz 54 57 dB
(Crosstalk) 500 MHz 39 42 dB
1000 MHz 31 33 dB
Return Loss (On Channel)
4
S
11
, S
22
DC to 100 MHz 21 27 dB
500 MHz 22 27 dB
1000 MHz 22 26 dB
Return Loss (Off Channel)
4
S
11
, S
22
DC to 100 MHz 18 23 dB
ADG918 500 MHz 17 21 dB
1000 MHz 16 20 dB
On Switching Time
4
t
ON
50% CTRL to 90% RF 6.6 10 ns
Off Switching Time
4
t
OFF
50% CTRL to 10% RF 6.5 9.5 ns
Rise Time
4
t
RISE
10% to 90% RF 6.1 9 ns
Fall Time
4
t
FALL
90% to 10% RF 6.1 9 ns
1 dB Compression
4
P
–1 dB
1000 MHz 17 dBm
Third Order Intermodulation Intercept IP
3
900 MHz/901 MHz, 4 dBm 30 36 dBm
Video Feedthrough
5
2.5 mV p-p
DC ELECTRICAL CHARACTERISTICS
Input High Voltage V
INH
V
DD
= 2.25 V to 2.75 V 1.7 V
V
INH
V
DD
= 1.65 V to 1.95 V 0.65 V
CC
V
Input Low Voltage V
INL
V
DD
= 2.25 V to 2.75 V 0.7 V
V
INL
V
DD
= 1.65 V to 1.95 V 0.35 V
CC
V
Input Leakage Current I
I
0 ≤ V
IN
≤ 2.75 V ±0.1 ±1µA
CAPACITANCE
4
RF1/RF2, RF Port On Capacitance C
RF
ON f = 1 MHz 1.6 pF
CTRL Input Capacitance C
CTRL
f = 1 MHz 2 pF
POWER REQUIREMENTS
V
DD
1.65 2.75 V
Quiescent Power Supply Current I
DD
Digital inputs = 0 V or V
DD
0.1 1 µA
NOTES
1
Temperature range B Version: –40°C to +85°C.
2
Typical values are at V
DD
= 2.5 V and 25°C, unless otherwise stated.
3
Point at which insertion loss degrades by 1 dB.
4
Guaranteed by design, not subject to production test.
5
The dc transience at the output of any port of the switch when the control voltage is switched from high to low or low to high in a 50 Ω test setup, measured with 1 ns
rise time pulses and 500 MHz bandwidth.
Specifications subject to change without notice.
(VDD = 1.65 V to 2.75 V, GND = 0 V, input power = 0 dBm,
all specifications TMIN to TMAX, unless otherwise noted.)
REV. 0
ADG918/ADG919
–3–
ABSOLUTE MAXIMUM RATINGS
1
(T
A
= 25°C, unless otherwise noted.)
V
DD
to GND . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to +4 V
Inputs to GND . . . . . . . . . . . . . . . . . . –0.5 V to V
DD
+ 0.3 V
2
Continuous Current . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 mA
Input Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 dBm
Operating Temperature Range
Industrial (B Version) . . . . . . . . . . . . . . . . –40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C
MSOP Package
␪
JA
Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 206°C/W
PIN CONFIGURATION
8-Lead MSOP (RM-8)
8-Lead 3 mm 3 mm LFCSP (CP-8)
TOP VIEW
(Not to Scale)
8
7
6
5
1
2
3
4
V
DD
CTRL
GND
RFC
RF1
GND
GND
RF2
ADG918/
ADG919
Table I. Truth Table
CTRL Signal Path
0RF2 to RFC
1RF1 to RFC
LFCSP Package
␪
JA
Thermal Impedance (2-layer board) . . . . . . . . . . 84°C/W
␪
JA
Thermal Impedance (4-layer board) . . . . . . . . . . 48°C/W
Lead Temperature, Soldering (10 sec) . . . . . . . . . . . . . 300°C
IR Reflow, Peak Temperature (<20 sec) . . . . . . . . . . . . 235°C
ESD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 kV
NOTES
1
Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only and functional operation of
the device at these or any other conditions above those listed in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability. Only one absolute
maximum rating may be applied at any one time.
2
RF1/RF2 Off Port Inputs to Ground .............................. –0.5 V to V
DD
– 0.5 V
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
ADG918/ADG919 features proprietary ESD protection circuitry, permanent damage may occur on
devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.
PIN FUNCTION DESCRIPTIONS
Pin No. Mnemonic Function
1V
DD
Power Supply Input. These parts can
be operated from 1.65 V to 2.75 V,
and V
DD
should be decoupled to GND.
2CTRL CMOS or TTL Logic Level;
0
➞
RF2 to RFC
1
➞
RF1 to RFC
3, 6, 7 GND Ground Reference Point for All
Circuitry on the Part
4RFC COMMON RF Port for Switch
5RF2 RF2 Port
8RF1 RF1 Port
ORDERING GUIDE
Model Temperature Range Package Description Package Option Branding
ADG918BRM –40°C to +85°CMini Small Outline Package (MSOP) RM-8 W4B
ADG918BRM-REEL7 –40°C to +85°CMini Small Outline Package (MSOP) RM-8 W4B
ADG918BCP –40°C to +85°CLead Frame Chip Scale Package (LFCSP) CP-8*W4B
ADG918BCP-REEL7 –40°C to +85°CLead Frame Chip Scale Package (LFCSP) CP-8*W4B
ADG919BRM –40°C to +85°CMini Small Outline Package (MSOP) RM-8 W5B
ADG919BRM-REEL7 –40°C to +85°CMini Small Outline Package (MSOP) RM-8 W5B
ADG919BCP –40°C to +85°CLead Frame Chip Scale Package (LFCSP) CP-8*W5B
ADG919BCP-REEL7 –40°C to +85°CLead Frame Chip Scale Package (LFCSP) CP-8*W5B
*Contact factory for availability.
REV. 0–4–
ADG918/ADG919
TERMINOLOGY
Parameter Description
V
DD
Most positive power supply potential
I
DD
Positive supply current
GND Ground (0 V) reference
CTRL Logic control input
V
INL
Maximum input voltage for Logic 0
V
INH
Minimum input voltage for Logic 1
I
INL
(I
INH
)Input current of the digital input
C
IN
Digital input capacitance
t
ON
Delay between applying the digital control input and the output switching on.
t
OFF
Delay between applying the digital control input and the output switching off.
t
RISE
Rise time. Time for the RF signal to rise from 10% to 90% of the ON level.
t
FALL
Fall time. Time for the RF signal to fall from 90% to 10% of the ON level.
Off Isolation The attenuation between input and output ports of the switch when the switch control voltage is in the
OFF condition.
Insertion Loss The attenuation between input and output ports of the switch when the switch control voltage is in the
ON condition.
P
–1 dB
1 dB compression point. The RF input power level at which the switch insertion loss increases by 1 dB over its
low level value. It is a measure of how much power the ON switch can handle before the insertion loss increases
by 1 dB.
IP
3
Third order intermodulation intercept. This is a measure of the power in false tones that occur when closely spaced
tones are passed through a switch, whereby the nonlinearity of the switch causes these false tones to be generated.
Return Loss The amount of reflected power relative to the incident power at a port. Large return loss indicates good matching.
By measuring Return Loss the VSWR can be calculated from conversion charts. VSWR (voltage standing wave ratio)
indicates degree of matching present at a switch RF port.
Video Feedthrough Spurious signals present at the RF ports of the switch when the control voltage is switched from high to low
or low to high without an RF signal present.
REV. 0
Typical Performance Characteristics–ADG918/ADG919
–5–
V
DD
= 2.5V
V
DD
= 2.25V
V
DD
= 2.75V
T
A
= 25C
INSERTION LOSS (dB)
–3.2
–2.8
–2.6
–2.4
–2.2
–1.8
–1.6
–1.4
–1.2
–1.0
–2.0
–3.0
–0.8
–0.6
–0.4
–0.2
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 1. Insertion Loss vs. Frequency
over Supplies (RF1/RF2, S12, and S21)
+85C
VDD = 2.5V
–40C
+25C
–3.2
–2.8
–2.6
–2.4
–2.2
–1.8
–1.6
–1.4
–1.2
–1.0
–2.0
–3.0
–0.8
–0.6
–0.4
–0.2
INSERTION LOSS (dB)
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 4. Insertion Loss vs. Frequency
over Temperature (RF1/RF2, S12,
and S21)
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
V
DD
= 2.5V
S12 (+85C)
S12 (+25C)
S12 (–40C)
–90
–70
–60
–50
–40
–30
–80
–20
–10
ISOLATION (dB)
–100
–90
–70
–60
–50
–40
–30
–80
–20
–10
ISOLATION (dB)
–100
S21
(–40C, +25C, +85C)
TPC 7. Isolation vs. Frequency over
Temperature (RF1/RF2, ADG919)
T
A
= 25C
V
DD
= 2.75V
V
DD
= 2.5V
V
DD
= 2.25V
–0.75
–0.65
–0.60
–0.55
–0.50
–0.45
–0.70
–0.40
–0.35
–0.30
INSERTION (dB)
–0.80
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 2. Insertion Loss vs. Frequency
over Supplies (RF1/RF2, S12, and
S21) (Zoomed TPC 1 Plot)
S12
S21
V
DD
= 1.65V TO 2.75V
T
A
= 25C
–90
–70
–60
–50
–40
–30
–80
–
20
–10
0
ISOLATION (dB)
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 5. Isolation vs. Frequency
over Supplies (RF1/RF2, ADG918)
TA = 25C
VDD = 2.5V
OFF SWITCH (ADG918)
ON SWITCH
–35
–40
–30
–25
–20
–15
–10
–5
0
RETURN LOSS (dB)
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 8. Return Loss vs. Frequency
(RF1/RF2, S11)
–3.2
–2.8
–2.6
–2.4
–2.2
–1.8
–1.6
–1.4
–1.2
–1.0
–2.0
–3.0
–0.8
–0.6
–0.4
–0.2
V
DD
= 1.65V
V
DD
= 1.95V
T
A
= 25C
V
DD
= 1.8V
INSERTION LOSS (dB)
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 3. Insertion Loss vs. Frequency
over Supplies (RF1/RF2, S12, and S21)
S12
S21
VDD = 1.65V TO 2.75V
TA = 25C
–90
–70
–60
–50
–40
–30
–80
–
20
–10
0
ISOLATION (dB)
–100
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 6. Isolation vs. Frequency
over Supplies (RF1/RF2, ADG919)
T
A
= 25C
V
DD
= 2.5V
–35
–30
–25
–20
–55
–50
–45
–40
–15
–10
X–TALK (dB)
–70
–60
–65
–75
–80
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 9. Crosstalk vs. Frequency
(RF1/RF2, S12, S21)
REV. 0–6–
ADG918/ADG919
CH1 = CTRL = 1V/DIV T
RISE
= 6.1ns
CH2 = RF1 = 100mV/DIV T
FALL
= 6.1ns
CH3 = RF2 = 100mV/DIV
CH2/3
CH1
TPC 10. Switch Timing
20
0 250 500 750 1000 1250
FREQUENCY (MHz)
1500
P–1dB (dBm)
2
4
6
8
10
12
14
16
18
0
VDD = 2.5V
TA = 25C
TPC 13. P
–1dB
vs. Frequency
CH1 500mV CH2 1mV m 10.0ns
CTRL
RFC
CH2 p-p
2.002mV
TPC 11. Video Feedthrough
40
35
250 350 450 550
FREQUENCY (MHz)
650 750 850
30
IP
3
(dBm)
25
20
15
10
5
0
V
DD
= 2.5V
T
A
= 25C
TPC 12. IP
3
vs. Frequency
REV. 0
ADG918/ADG919
–7–
Test Circuits
*
t
ON
50% 50%
90% 10%
V
CTRL
V
OUT
t
OFF
V
DD
V
DD
0.1F
V
S
CTRL
RFx
RFC
GND
R
L
50
V
OUT
Test Circuit 1. Switching Timing: t
ON
, t
OFF
VCTRL
VOUT
50% 50%
90% 90% 10%
10%
t
FAL L
t
RISE
VDD
VDD
0.1F
VSCTRL
RFx
RFC
GND
RL
50
VOUT
Test Circuit 2. Switch Timing: t
RISE
, t
FALL
V
S
NETWORK
ANALYZER
V
CTRL
OFF ISOLATION = 20log V
OUT
V
S
V
DD
0.1F
V
DD
50
V
OUT
R
L
50
ADG919
RF2
RF1
CTRL
RFC
GND
50
Test Circuit 3. Off Isolation
V
S
NETWORK
ANALYZER
V
CTRL
INSERTION LOSS = 20log V
OUT
V
S
V
DD
0.1F
V
DD
50
V
OUT
R
L
50
ADG919
RF2
RF1
CTRL
RFC
GND
50
Test Circuit 4. Insertion Loss
V
S
NETWORK
ANALYZER
V
CTRL
CROSSTALK = 20log V
OUT
V
S
V
DD
0.1F
V
DD
50
V
OUT
R
L
50
ADG919
RF2
RF1
CTRL
RFC
GND
50
Test Circuit 5. Crosstalk
V
CTRL
V
DD
0.1F
V
DD
ADG919
RF2
RF1
CTRL
RFC
GND
NC
NC
OSCILLOSCOPE
Test Circuit 6. Video Feedthrough
*Similar setups for ADG918.
REV. 0–8–
ADG918/ADG919
SPECTRUM
ANALYZER
V
CTRL
V
DD
0.1F
V
DD
ADG919
RF2
RF1
CTRL
RFC
GND
50
COMBINER
RF
SOURCE
RF
SOURCE
Test Circuit 7. IP
3
SPECTRUM
ANALYZER
V
CTRL
V
DD
0.1F
V
DD
ADG919
RF2
RF1
CTRL
RFC
GND
50
RF
SOURCE
V
S
Test Circuit 8. P
–1dB
REV. 0
ADG918/ADG919
–9–
APPLICATIONS
The ADG918/ADG919 are ideal solutions for low power, high
frequency applications. The low insertion loss, high isolation
between ports, low distortion, and low current consumption of
these parts make them excellent solutions for many high frequency
switching applications. The most obvious application is in a
transmit/receive block, as shown in the wireless metering block
diagram in Figure 3.
Other applications include switching between high frequency
filters, ASK generator, FSK generator, and antenna diversity
switch in many tuner modules.
Absorptive vs. Reflective
The ADG918 is an absorptive (matched) switch with 50 Ω termi-
nated shunt legs, and the ADG919 is a reflective switch with 0 Ω
terminated shunts to ground. The ADG918 absorptive switch
has a good VSWR on each port, regardless of the switch mode.
An absorptive switch should be used when there is a need for a
good VSWR that is looking into the port but not passing the
through signal to the common port. The ADG918 is therefore
ideal for applications that require minimum reflections back to
the RF source. It also ensures that the maximum power is trans-
ferred to the load.
The ADG919 reflective switch is suitable for applications where
high off port VSWR does not matter and the switch has some
other desired performance feature. It can be used in many appli-
cations, including high speed filter selection. In most cases, an
absorptive switch can be used instead of a reflective switch, but
not vice versa.
Wireless Metering
The ADG918 can be used in wireless metering applications. It
can be used in conjunction with the ADF7020 transceiver IC for
a utility metering transceiver application, providing the required
isolation between the transmit and receive signals.
The SPDT configuration isolates the high frequency receive signal
from the high frequency transmit.
LNA
ANTENNA
TX/RX SWITCH PA
ADG918
Figure 3. Wireless Metering
Tuner Modules
The ADG918 can be used in a tuner module to switch between
the cable TV input and the off-air antenna.
This part is also ideal for use as an antenna diversity switch,
switching different antenna to the tuner.
VGA
ANTENNA
CABLE
ADG918/
ADG919 TUNER
Figure 4. Tuner Modules
Filter Selection
The ADG919 can be used as a 2:1 demultiplex to switch high
frequency signals between different filters and also to multiplex
the signal to the output.
ADG919ADG919 RF1
RF2
RF1
RF2 RFC
RF
OUT
RFIN RFC
Figure 5. Filter Selection
ADG9xx EVALUATION BOARD
The ADG9xx evaluation board allows designers to evaluate the
high performance wideband switches with a minimum of effort.
To prove that these devices meet the user’s requirements, the
user only requires a power supply and a network analyzer along
with the evaluation board. An application note is available with
the evaluation board and gives complete information on operating
the evaluation board.
The RFC port (see Figure 6) is connected through a 50 Ω trans-
mission line to the top left SMA connector J1. RF1 and RF2 are
connected through 50 Ω transmission lines to the top two SMA
connectors J2 and J3, respectively. A through transmission line
connects J4 and J5 and this transmission line is used to estimate
the loss of the PCB over the environmental conditions being
evaluated.
The board is constructed of a 4-layer, FR4 material with a dielec-
tric constant of 4.3 and an overall thickness of 0.062 inches. Two
ground layers with grounded planes provide ground for the RF
transmission lines. The transmission lines were designed using a
coplanar waveguide with ground plane model using a trace width
of 0.052 inches, clearance to ground plane of 0.030 inches,
dielectric thickness of 0.029 inches, and a metal thickness of
0.0014 inches.
Figure 6. ADG9xx Evaluation Board Top View
REV. 0–10–
ADG918/ADG919
OUTLINE DIMENSIONS
8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
0.80
0.60
0.40
8
0
85
4
1
4.90
BSC
PIN 1
0.65 BSC
3.00
BSC
SEATING
PLANE
0.15
0.00
0.38
0.22
1.10 MAX
3.00
BSC
COPLANARITY
0.10
0.23
0.08
COMPLIANT TO JEDEC STANDARDS MO-187AA
8-Lead Lead Frame Chip Scale Package [LFCSP]
3 mm 3 mm Body
(CP-8)
Dimensions shown in millimeters
1
BOTTOM
VIEW
0.50
BSC
0.60 MAX
PIN 1 INDICATOR
1.50
REF
0.50
0.40
0.30
0.25
MIN
0.45
2.75
BSC SQ
TOP
VIEW
12MAX 0.80 MAX
0.65 TYP
SEATING
PLANE
PIN 1
INDICATOR
0.90
0.85
0.80
0.30
0.23
0.18
0.05 MAX
0.02 NOM
0.20 REF
1.90
1.75
1.60
4
1.60
1.45
1.30
3.00
BSC SQ
5
8
–11–
C03335–0–8/03(0)
–12–