REV. 0
Wideband, 37 dB Isolation at 1 GHz, CMOS
1.65 V to 2.75 V, SPST Switches
ADG901/ADG902
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 www.analog.com
Fax: 781/326-8703 © 2003 Analog Devices, Inc. All rights reserved.
FUNCTIONAL BLOCK DIAGRAMS
RF2
CTRL
ADG901
RF1
50
50
RF2
CTRL
ADG902
RF1
50
FEATURES
Wideband Switch: –3 dB @ 4.5 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)
TA = 25C
VDD = 2.5 V
VDD = 1.8 V
Figure 1. Off Isolation vs. Frequency
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
–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)
V
DD
= 2.5V
T
A
= 25C
Figure 2. Insertion Loss vs. Frequency
GENERAL DESCRIPTION
The ADG901/ADG902 are wideband switches using a CMOS
process to provide high isolation and low insertion loss to 1 GHz.
The ADG901 is an absorptive (matched) switch having 50 W
terminated shunt legs, while the ADG902 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–
ADG901/ADG902–SPECIFICATIONS
1
B Version
Parameter Symbol Conditions Min Typ
2
Max Unit
AC ELECTRICAL CHARACTERISTICS
Operating Frequency
3
DC 2.5 GHz
–3 dB Frequency
4
4.5 GHz
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—RF1 to RF2 S
21
, S
12
100 MHz 51 60 dB
500 MHz 37.5 47 dB
1000 MHz 31 37 dB
Return Loss (On Channel)
4
S
11
, S
22
DC to 100 MHz 20 28 dB
500 MHz 23 29 dB
1000 MHz 25 28 dB
Return Loss (Off Channel)
4
S
11
, S
22
DC to 100 MHz 18 23 dB
500 MHz 17 21 dB
1000 MHz 15 19 dB
On Switching Time
4
t
ON
50% CTRL to 90% RF 3.6 6 ns
Off Switching Time
4
t
OFF
50% CTRL to 10% RF 5.8 9.5 ns
Rise Time
4
t
RISE
10% to 90% RF 3.1 5.5 ns
Fall Time
4
t
FALL
90% to 10% RF 6.0 8.5 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 1.2 pF
CTRL Input Capacitance C
CTRL
f = 1 MHz 2.1 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
1ns 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
ADG901/ADG902
–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)
1
V
DD
CTRL GND
RF1
ADG901/
ADG902
GND
GND
RF2
GND
2
3
4
8
7
6
5
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
RF1/2 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
ADG901/ADG902 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.
ORDERING GUIDE
Model Temperature Range Package Description Package Option Branding
ADG901BRM –40∞C to +85∞CMini Small Outline Package (MSOP) RM-8 W6B
ADG901BRM-REEL7 –40∞C to +85∞CMini Small Outline Package (MSOP) RM-8 W6B
ADG901BCP –40∞C to +85∞CLead Frame Chip Scale Package (LFCSP) CP-8*W6B
ADG901BCP-REEL7 –40∞C to +85∞CLead Frame Chip Scale Package (LFCSP) CP-8*W6B
ADG902BRM –40∞C to +85∞CMini Small Outline Package (MSOP) RM-8 W7B
ADG902BRM-REEL7 –40∞C to +85∞CMini Small Outline Package (MSOP) RM-8 W7B
ADG902BCP –40∞C to +85∞CLead Frame Chip Scale Package (LFCSP) CP-8*W7B
ADG902BCP-REEL7 –40∞C to +85∞CLead Frame Chip Scale Package (LFCSP) CP-8*W7B
*Contact factory for availability.
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
➞
RF1 Isolated from RF2
1
➞
RF1 to RF2
3, 5, 6, 7 GND Ground Reference Point for All
Circuitry on the Part.
4RF1 RF1 Port.
8RF2 RF2 Port.
Table I. Truth Table
CTRL Signal Path
0RF1 isolated from RF2
1RF1 to RF2
REV. 0–4–
ADG901/ADG902
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–ADG901/ADG902
–5–
–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
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
INSERTION LOSS (dB)
V
DD
= 2.25V
V
DD
= 2.75V
T
A
= 25C
V
DD
= 2.5V
TPC 1. Insertion Loss vs. Frequency
over Supplies (S12 and S21)
+85C
V
DD
= 2.5V
–40C
+25C
–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)
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 4. Insertion Loss vs. Frequency
over Temperature (S12 and S21)
T
A
= 25C
V
DD
=
2.5V
OFF SWITCH
ON SWITCH
–35
–30
–25
–20
–15
–10
–5
0
RETURN LOSS (dB)
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 7. Return Loss vs. Frequency
(S11)
–0.95
–0.90
–0.85
–0.75
–0.70
–0.65
–0.60
–0.55
–0.80
–1.00
–0.50
–0.45
–0.40
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
INSERTION LOSS (dB)
T
A
= 25C
V
DD
= 2.75V
V
DD
= 2.5V
V
DD
= 2.25V
TPC 2. Insertion Loss vs. Frequency
over Supplies (S12 and S21)
(Zoomed TPC 1 Plot)
VDD = 2.5V
VDD = 1.8V
TA = 25C
–90
–70
–60
–50
–40
–30
–80
–20
–10
–5
–15
–25
–35
–45
–55
–65
–75
–85
–95
0
ISOLATION (dB)
–100
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 5. OFF Isolation vs. Frequency
over Supplies (S12 and S21)
CH1 = CTRL = 1V/DIV T
RISE
= 2.8ns
CH2 = RFx = 100mV/DIV T
FALL
= 5.1ns
CH2
CH1
TPC 8. Switch Timing
–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)
V
DD
= 1.65V
T
A
= 25C
V
DD
= 1.95V
V
DD
= 1.8V
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 3. Insertion Loss vs. Frequency
over Supplies (S12 and S21)
V
DD
= 2.5V
+85C
+25C
–40C
–70
–60
–50
–40
–30
–80
–20
–10
–5
–15
–25
–35
–45
–55
–65
–75
–85
0
ISOLATION (dB)
–90
FREQUENCY (Hz)
10k 100k 1M 10M 100M 1G 10G
TPC 6. OFF Isolation vs. Frequency
over Temperature (S12 and S21)
CH1 500mV CH2 1mV 10.0ns
CTRL
RFx
CH2 pk-pk
2.016mV
TPC 9. Video Feedthrough
REV. 0–6–
ADG901/ADG902
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 10. IP
3
vs. Frequency
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 11. P
–1dB
vs. Frequency
REV. 0
ADG901/ADG902
–7–
Test Circuits*
V
DD
V
DD
0.1mF
V
S
CTRL
RF2
RF1
GND
R
L
50W
V
OUT
V
CTRL
50% 50%
V
OUT
t
ON
t
OFF
90% 10%
Test Circuit 1. Switching Timing: t
ON
, t
OFF
V
DD
V
DD
0.1mF
V
S
CTRL
RF2
RF1
GND
R
L
50W
V
OUT
V
CTRL
50% 50%
V
OUT
tRISE tFALL
90% 10%
90%
10%
Test Circuit 2. Switch Timing: t
RISE
, t
FALL
OFF ISOLATION = 20 LOG OUT
VS
V
VS
50
NETWORK
ANALYZER
VOUT
RL
50
0.1F
VCTRL
GND
RF2
CTRL
ADG901
RF1
50
50
VDD
VDD
Test Circuit 3. Off Isolation
INSERTION LOSS
=
20
LOG OUT
VS
V
VS
50
NETWORK
ANALYZER
VOUT
RL
50
0.1F
VDD
VCTRL
GND
RF2
CTRL
ADG901
RF1
50
50
VDD
Test Circuit 4. Insertion Loss
OSCILLOSCOPE
0.1F
V
DD
V
CTRL
NC
RF2
CTRL
RF1
GND
ADG901
50
50
V
DD
Test Circuit 5. Video Feedthrough
*Similiar setups for ADG902.
REV. 0–8–
ADG901/ADG902
COMBINER
RF
SOURCE
RF
SOURCE
SPECTRUM
ANALYZER
0.1F
V
DD
V
CTRL
GND
RF2
CTRL
ADG901
RF1
50
50
V
DD
Test Circuit 6. IP
3
RF
SOURCE
VS
SPECTRUM
ANALYZER
0.1F
VDD
VCTRL
GND
RF2
CTRL
ADG901
RF1
50
50
VDD
Test Circuit 7. P
–1dB
REV. 0
ADG901/ADG902
–9–
APPLICATIONS
The ADG901/ADG902 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.
Applications include switching between high frequency filters,
ASK generator, and FSK generator.
Absorptive vs. Reflective Switches
The ADG901 is an absorptive (matched) switch with 50 W termi-
nated shunt legs, and the ADG902 is a reflective switch with 0 W
terminated shunts to ground. The ADG901 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 ADG901 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 ADG902 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.
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 user requirements, the user
requires only a power supply and a network analyzer along with
the evaluation board. An application note is available with the
evaluation board and provides complete information on operating
the evaluation board.
The RF1 port (see Figure 6) is connected through a 50 W trans-
mission line to the top left SMA connector J1. RF2 is connected
through a 50 W transmission line to the top SMA connector J2.
J3 is connected to GND. 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 3. ADG9xx Evaluation Board Top View
REV. 0–10–
ADG901/ADG902
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–
C03336–0–8/03(0)
–12–