AD ADG749

a
CMOS Low Voltage
2.5 SPDT Switch In SC70 Package
ADG749
FEATURES
1.8 V to 5.5 V Single Supply
5 (Max) On Resistance
0.75 (Typ) On-Resistance Flatness
–3 dB Bandwidth >200 MHz
Rail-to-Rail Operation
6-Lead SC70 Package
Fast Switching Times
t ON 20 ns
t OFF 6 ns
Typical Power Consumption (<0.01 W)
TTL/CMOS-Compatible
APPLICATIONS
Battery-Powered Systems
Communication Systems
Sample Hold Systems
Audio Signal Routing
Video Switching
Mechanical Reed Relay Replacement
GENERAL DESCRIPTION
The ADG749 is a monolithic CMOS SPDT switch. This switch
is designed on a submicron process that provides low power
dissipation yet gives high switching speed, low on resistance and
low leakage currents.
FUNCTIONAL BLOCK DIAGRAM
ADG749
S2
D
S1
IN
SWITCHES SHOWN FOR
A LOGIC "1" INPUT
PRODUCT HIGHLIGHTS
1. 1.8 V to 5.5 V Single Supply Operation. The ADG749
offers high performance, including low on resistance and
fast switching times, and is fully specified and guaranteed
with 3 V and 5 V supply rails.
2. Very Low RON (5 Ω max at 5 V, 10 Ω max at 3 V). At 1.8 V
operation, RON is typically 40 Ω over the temperature range.
3. On-Resistance Flatness (RFLAT(ON)) (0.75 Ω typ).
4. –3 dB Bandwidth >200 MHz.
The ADG749 can operate from a single supply range of 1.8 V to
5.5 V, making it ideal for use in battery-powered instruments and
with the new generation of DACs and ADCs from Analog Devices.
5. Low Power Dissipation. CMOS construction ensures low
power dissipation.
Each switch of the ADG749 conducts equally well in both
directions when on. The ADG749 exhibits break-before-make
switching action.
7. Tiny 6-lead SC70 package.
6. Fast tON /tOFF.
Because of the advanced submicron process, –3 dB bandwidths
of greater than 200 MHz can be achieved.
The ADG749 is available in a 6-lead SC70 package.
REV. 0
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2000
ADG749–SPECIFICATIONS1 (Vnoted.)= 5 V 10%, GND = 0 V. All specifications –40C to +85C, unless otherwise
DD
Parameter
ANALOG SWITCH
Analog Signal Range
On Resistance (RON)
B Version
–40C to
25C
+85C
0 V to VDD
2 .5
5
On Resistance Match Between
Channels (∆RON)
On-Resistance Flatness (RFLAT(ON))
6
0.75
Channel ON Leakage ID, IS (ON)
± 0.01
± 0.25
± 0.01
± 0.25
DIGITAL INPUTS
Input High Voltage, VINH
Input Low Voltage, VINL
Input Current
IINL or IINH
0.005
DYNAMIC CHARACTERISTICS2
tON
14
Test Conditions/Comments
V
Ω typ
Ω max
VS = 0 V to VDD, IS = –10 mA
Test Circuit 1
Ω typ
Ω max
Ω typ
Ω max
0.1
0.8
1.2
LEAKAGE CURRENTS2
Source OFF Leakage IS (OFF)
Unit
VS = 0 V to VDD, IS = –10 mA
VDD = 5.5 V
VS = 4.5 V/1 V, VD = 1 V/4.5 V
Test Circuit 2
VS = VD = 1 V, or VS = VD = 4.5 V
Test Circuit 3
± 0.35
nA typ
nA max
nA typ
nA max
2.4
0.8
V min
V max
± 0.1
µA typ
µA max
VIN = VINL or VINH
RL = 300 Ω, CL = 35 pF
VS = 3 V, Test Circuit 4
RL = 300 Ω, CL = 35 pF
VS = 3 V, Test Circuit 4
RL = 300 Ω, CL = 35 pF,
VS1 = VS2 = 3 V, Test Circuit 5
RL = 50 Ω, CL = 5 pF, f = 10 MHz
RL = 50 Ω, CL = 5 pF, f = 1 MHz,
Test Circuit 6
RL = 50 Ω, CL = 5 pF, f = 10 MHz
RL = 50 Ω, CL = 5 pF, f = 1 MHz,
Test Circuit 7
RL = 50 Ω, CL = 5 pF, Test Circuit 8
± 0.35
tOFF
3
Break-Before-Make Time Delay, tD
8
Off Isolation
–67
–87
ns typ
ns max
ns typ
ns max
ns typ
ns min
dB typ
dB typ
Channel-to-Channel Crosstalk
–62
–82
dB typ
dB typ
Bandwidth –3 dB
CS (OFF)
CD, CS (ON)
200
7
27
MHz typ
pF typ
pF typ
20
6
1
VDD = 5.5 V
Digital Inputs = 0 V or 5 V
POWER REQUIREMENTS
IDD
VS = 0 V to VDD, IS = –10 mA
µA typ
µA max
0.001
1.0
NOTES
1
Temperature ranges are as follows: B Version, –40°C to +85°C.
2
Guaranteed by design, not subject to production test.
Specifications subject to change without notice.
–2–
REV. 0
ADG749
1
SPECIFICATIONS (V
DD
= 3 V 10%, GND = 0 V. All specifications –40C to +85C, unless otherwise noted.)
Parameter
B Version
–40C to
25C
+85C
ANALOG SWITCH
Analog Signal Range
On Resistance (RON)
6
On Resistance Match Between
Channels (∆RON)
On-Resistance Flatness (RFLAT(ON))
Unit
Test Conditions/Comments
0 V to VDD
7
10
V
Ω typ
Ω max
VS = 0 V to VDD, IS = –10 mA,
Test Circuit 1
0.1
0.8
2.5
Ω typ
Ω max
Ω typ
2
LEAKAGE CURRENTS
Source OFF Leakage IS (OFF)
Channel ON Leakage ID, IS (ON)
± 0.01
± 0.25
± 0.01
± 0.25
DIGITAL INPUTS
Input High Voltage, VINH
Input Low Voltage, VINL
Input Current
IINL or IINH
0.005
DYNAMIC CHARACTERISTICS2
tON
16
VDD = 3.3 V
VS = 3 V/1 V, VD = 1 V/3 V,
Test Circuit 2
VS = VD = 1 V, or VS = VD = 3 V,
Test Circuit 3
± 0.35
2.0
0.4
V min
V max
± 0.1
µA typ
µA max
VIN = VINL or VINH
RL = 300 Ω, CL = 35 pF
VS = 2 V, Test Circuit 4
RL = 300 Ω, CL = 35 pF
VS = 2 V, Test Circuit 4
RL = 300 Ω, CL = 35 pF
VS1 = VS2 = 2 V, Test Circuit 5
RL = 50 Ω, CL = 5 pF, f = 10 MHz
RL = 50 Ω, CL = 5 pF, f = 1 MHz,
Test Circuit 6
RL = 50 Ω, CL = 5 pF, f = 10 MHz
RL = 50 Ω, CL = 5 pF, f = 1 MHz,
Test Circuit 7
RL = 50 Ω, CL = 5 pF, Test Circuit 8
± 0.35
tOFF
4
Break-Before-Make Time Delay, tD
8
Off Isolation
–67
–87
ns typ
ns max
ns typ
ns max
ns typ
ns min
dB typ
dB typ
Channel-to-Channel Crosstalk
–62
–82
dB typ
dB typ
Bandwidth –3 dB
CS (OFF)
CD, CS (ON)
200
7
27
MHz typ
pF typ
pF typ
7
1
VDD = 3.3 V
Digital Inputs = 0 V or 3 V
POWER REQUIREMENTS
µA typ
µA max
0.001
1.0
NOTES
1
Temperature ranges are as follows: B Version, –40°C to +85°C.
2
Guaranteed by design, not subject to production test.
Specifications subject to change without notice.
REV. 0
VS = 0 V to VDD, IS = –10 mA
nA typ
nA max
nA typ
nA max
24
IDD
VS = 0 V to VDD, IS = –10 mA
–3–
ADG749
ABSOLUTE MAXIMUM RATINGS 1
TERMINOLOGY
(TA = 25°C unless otherwise noted)
VDD
GND
S
D
IN
RON
∆RON
Most Positive Power Supply Potential.
Ground (0 V) Reference.
Source Terminal. May be an input or output.
Drain Terminal. May be an input or output.
Logic Control Input.
Ohmic resistance between D and S.
On resistance match between any two channels
i.e., RON max – RON min.
RFLAT(ON)
Flatness is defined as the difference between the
maximum and minimum value of on resistance as
measured over the specified analog signal range.
Source Leakage Current with the switch “OFF.”
IS (OFF)
ID, IS (ON) Channel Leakage Current with the switch “ON.”
VD (VS)
Analog Voltage on Terminals D, S.
CS (OFF)
“OFF” Switch Source Capacitance.
CD (OFF)
“OFF” Switch Drain Capacitance.
CD, CS (ON) “ON” Switch Capacitance.
tON
Delay between applying the digital control input
and the output switching on.
tOFF
Delay between applying the digital control input
and the output switching off.
tD
“OFF” time or “ON” time measured between the
90% points of both switches, when switching
from one address state to another.
Crosstalk
A measure of unwanted signal that is coupled
through from one channel to another as a result
of parasitic capacitance.
Off Isolation A measure of unwanted signal coupling through
an “OFF” switch.
Bandwidth The frequency at which the output is attenuated
by –3 dBs.
On Response The frequency response of the “ON” switch.
On Loss
The voltage drop across the “ON” switch seen on
the On Response vs. Frequency plot as how many
dBs the signal is away from 0 dB at very low
frequencies.
VDD to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V
Analog, Digital Inputs2 . . . . . . . . . . –0.3 V to VDD + 0.3 V or
30 mA, Whichever Occurs First
Peak Current, S or D . . . . . . . . . . . . . . . . . . . . . . . . . . 100 mA
(Pulsed at 1 ms, 10% Duty Cycle max)
Continuous Current, S or D . . . . . . . . . . . . . . . . . . . . . 30 mA
Operating Temperature Range
Industrial (B Version) . . . . . . . . . . . . . . . . . –40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . . –65°C to +150°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C
SC70 Package, Power Dissipation . . . . . . . . . . . . . . . . 315 mW
θJA Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 332°C/W
θJC Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 120°C/W
Lead Temperature, Soldering
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . . 215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
ESD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 kV
NOTES
1
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; 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
Overvoltages at IN, S or D will be clamped by internal diodes. Current should be
limited to the maximum ratings given.
Table I. Truth Table
ADG749 IN
Switch S1
Switch S2
0
1
ON
OFF
OFF
ON
PIN CONFIGURATION
6-Lead SC70
IN 1
VDD 2
GND 3
ADG749
TOP VIEW
(Not to Scale)
6
S2
5
D
4
S1
ORDERING GUIDE
Model
Temperature Range
Package Description
Package Option
Branding Information*
ADG749BKS
–40°C to +85°C
SC70 (Plastic Surface Mount)
KS-6
SHB
*Brand = Brand on these packages is limited to three characters due to space constraints.
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 ADG749 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.
–4–
WARNING!
ESD SENSITIVE DEVICE
REV. 0
Typical Performance Characteristics– ADG749
6.0
10m
5.5
VDD = 5V
VDD = 2.7V
TA = 25C
5.0
1m
4.5
100
VDD = 4.5V
VDD = 3.0V
3.5
I SUPPLY – A
RON – 4.0
3.0
2.5
VDD = 5.0V
2.0
10
1
100n
1.5
1.0
10n
0.5
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
1n
5.0
10
1
100
VD OR VS – DRAIN OR SOURCE VOLTAGE – V
TPC 1. On Resistance as a Function of VD (VS) Single
Supplies
1M
10M
100M
TPC 4. Supply Current vs. Input Switching Frequency
6.0
–30
VDD = 5V, 3V
VDD = 3V
5.5
5.0
–40
+85C
4.5
–50
OFF ISOLATION – dB
+25C
4.0
–40C
RON – 1k
10k
100k
FREQUENCY – Hz
3.5
3.0
2.5
2.0
–60
–70
–80
–90
–100
1.5
–110
1.0
–120
0.5
0
0
0.5
1.0
1.5
2.0
2.5
VD OR VS – DRAIN OR SOURCE VOLTAGE – V
–130
10k
3.0
TPC 2. On Resistance as a Function of VD (VS) for
Different Temperatures VDD = 3 V
100k
100M 0
1M
10M
FREQUENCY – Hz
TPC 5. Off Isolation vs. Frequency
6.0
–30
5.5
VDD = 5V, 3V
VDD = 5V
–40
5.0
–50
4.5
3.5
CROSSTALK – dB
RON – 4.0
+85C
3.0
2.5
+25C
2.0
–40C
–80
–90
–110
1.0
–120
0.5
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
–130
10k
5.0
VD OR VS – DRAIN OR SOURCE VOLTAGE – V
TPC 3. On Resistance as a Function of VD (VS) for
Different Temperatures VDD = 5 V
REV. 0
–70
–100
1.5
0
–60
100k
1M
FREQUENCY – Hz
10M
TPC 6. Crosstalk vs. Frequency
–5–
100M 0
ADG749
0
ON RESPONSE – dB
VDD = 5V
–2
–4
–6
10k
100k
1M
10M
FREQUENCY – Hz
100M
TPC 7. On Response vs. Frequency
Test Circuits
IDS
V1
S
IS (OFF)
D
A
VS
ID (OFF)
S
D
ID (ON)
S
A
VD
VS
RON = V1/I DS
Test Circuit 1. On Resistance
D
A
VS
Test Circuit 2. Off Leakage
VD
Test Circuit 3. On Leakage
VDD
0.1F
VIN
50%
50%
VDD
S
D
RL
300
IN
VS
GND
90%
90%
VOUT
VOUT
CL
35pF
tOFF
tON
Test Circuit 4. Switching Times
VDD
0.1F
VIN
VDD
S1
VS1
D
D2
S2
VS2
RL2
300
IN
CL2
35pF
VOUT
VOUT
50%
0V
50%
50%
0V
tD
GND
VIN
50%
tD
Test Circuit 5. Break-Before-Make Time Delay, tD
VDD
0.1F
VDD
VDD
0.1F
0.1F
S1
VDD
VS
VIN
VDD
D
S2
D
S2
S1
VOUT
VOUT
RL
50
IN
GND
Test Circuit 6. Off Isolation
VS
S1
RL
50
D
S2
IN
GND
CHANNEL-TO-CHANNEL
CROSSTALK = 20 LOG |VS/VOUT|
Test Circuit 7. Channel-to-Channel
Crosstalk
–6–
VDD
VS
VIN
VOUT
RL
50
IN
GND
Test Circuit 8. Bandwidth
REV. 0
ADG749
APPLICATIONS INFORMATION
The signal transfer characteristic is dependent on the switch
channel capacitance, CDS. This capacitance creates a frequency
zero in the numerator of the transfer function A(s). Because the
switch on resistance is small, this zero usually occurs at high
frequencies. The bandwidth is a function of the switch output
capacitance combined with CDS and the load capacitance. The
frequency pole corresponding to these capacitances appears in
the denominator of A(s).
The ADG749 belongs to Analog Devices’ new family of
CMOS switches. This series of general purpose switches have
improved switching times, lower on resistance, higher bandwidths, low power consumption and low leakage currents.
ADG749 Supply Voltages
Functionality of the ADG749 extends from 1.8 V to 5.5 V single
supply, which makes it ideal for battery powered instruments,
where important design parameters are power efficiency and
performance.
The dominant effect of the output capacitance, CD, causes the
pole breakpoint frequency to occur first. Therefore, in order to
maximize bandwidth a switch must have a low input and output
capacitance and low on resistance. The On Response vs. Frequency plot for the ADG749 can be seen in TPC 7.
It is important to note that the supply voltage effects the input
signal range, the on resistance and the switching times of the
part. By taking a look at the typical performance characteristics
and the specifications, the effects of the power supplies can be
clearly seen.
Off Isolation
Off isolation is a measure of the input signal coupled through an
off switch to the switch output. The capacitance, CDS, couples
the input signal to the output load, when the switch is off as
shown in Figure 2.
For VDD = 1.8 V operation, RON is typically 40 Ω over the temperature range.
On Response vs. Frequency
Figure 1 illustrates the parasitic components that affect the ac
performance of CMOS switches (the switch is shown surrounded
by a box). Additional external capacitances will further degrade
some performance. These capacitances affect feedthrough,
crosstalk and system bandwidth.
CDS
D
S
VOUT
VIN
CD
CLOAD
RLOAD
CDS
Figure 2. Off Isolation Is Affected by External Load Resistance and Capacitance
D
S
RON
VIN
VOUT
CD
CLOAD
The larger the value of CDS, larger values of feedthrough will be
produced. The typical performance characteristic graph of TPC
5 illustrates the drop in off isolation as a function of frequency.
From dc to roughly 200 kHz, the switch shows better than
–95 dB isolation. Up to frequencies of 10 MHz, the off isolation
remains better than –67 dB. As the frequency increases, more and
more of the input signal is coupled through to the output. Off
isolation can be maximized by choosing a switch with the smallest CDS as possible. The values of load resistance and capacitance
affect off isolation also, as they contribute to the coefficients of the
poles and zeros in the transfer function of the switch when open.
RLOAD
Figure 1. Switch Represented by Equivalent Parasitic
Components
The transfer function that describes the equivalent diagram of
the switch (Figure 1) is of the form (A)s shown below.
 s(RON CDS ) + 1 
A(s) = RT 

 s(RT RON CT ) + 1 
where:
RT = RLOAD/(RLOAD + RON)
CT = CLOAD + CD + CDS
REV. 0


s(RLOAD CDS )
A(s) = 

 s(RLOAD ) (CLOAD + CD + CDS ) + 1 
–7–
ADG749
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
C02075–2.5–10/00 (rev. 0)
6-Lead Plastic Surface Mount Package (SC70)
(KS-6)
0.087 (2.20)
0.071 (1.80)
0.053 (1.35)
0.045 (1.15)
6
1
5
4
2
3
0.094 (2.40)
0.071 (1.80)
PIN 1
0.026 (0.65) BSC
0.051 (1.30)
BSC
0.004 (0.10)
0.000 (0.00)
0.043 (1.10)
0.031 (0.80)
0.012 (0.30) SEATING
0.006 (0.15) PLANE
8
0.007 (0.18) 0
0.004 (0.10)
0.012 (0.30)
0.004 (0.10)
PRINTED IN U.S.A.
0.039 (1.00)
0.031 (0.80)
–8–
REV. 0