TEMIC DG540DN Wideband/video t switch Datasheet

DG540/541/542
Wideband/Video “T” Switches
Features
Benefits
Applications
Wide Bandwidth: 500 MHz
Low Crosstalk: –85 dB
High Off-Isolation: –80 dB @ 5 MHz
“T” Switch Configuration
TTL Logic Compatible
Fast Switching—tON: 45 ns
Low rDS(on): 30 Flat Frequency Response
High Color Fidelity
Low Insertion Loss
Improved System Performance
Reduced Board Space
Reduced Power Consumption
Improved Data Throughput
RF and Video Switching
RGB Switching
Local and Wide Area Networks
Video Routing
Fast Data Acquisition
ATE
Radar/FLR Systems
Video Multiplexing
Description
The DG540/541/542 are high performance monolithic
wideband/video switches designed for switching RF, video
and digital signals. By utilizing a “T” switch configuration
on each channel, these devices achieve exceptionally low
crosstalk and high off-isolation. The crosstalk and
off-isolation of the DG540 are further improved by the
introduction of extra GND pins between signal pins.
To achieve TTL compatibility, low channel capacitances
and fast switching times, the DG540 family is built on the
Siliconix proprietary D/CMOS process. Each switch
conducts equally well in both directions when on.
Functional Block Diagrams and Pin Configurations
DG540
DG540
Dual-In-Line
D2
GND
GND
S1
S2
V–
V+
GND
GND
S4
S3
GND
GND
D4
D3
IN3
IN4
Truth Table
GND
V–
GND
S4
GND
Switch
S2
0
OFF
V+
1
ON
GND
S3
Logic “0” 0.8 V
Logic “1”
1 2V
Logic
S1
D1
IN2
PLCC
IN1
Updates to this data sheet may be obtained via facsimile by calling Siliconix FaxBack, 1-408-970-5600. Please request FaxBack document #70055.
Siliconix
S-53694—Rev. E, 28-May-97
1
DG540/541/542
Functional Block Diagrams and Pin Configurations (Cont’d)
DG541
DG542
Dual-In-Line and SOIC
IN1
IN2
IN1
IN2
D1
D2
D1
D2
S1
S2
GND
GND
V–
V+
S1
S2
GND
GND
V–
V+
S4
S3
S4
S3
D3
GND
GND
D4
IN4
D4
IN3
D3
0
OFF
0
OFF
ON
1
ON
1
ON
OFF
Logic “0” 0.8 V
Logic “1” 2 V
Logic “0” 0.8 V
Logic “1” 2 V
Ordering Information
Temp Range
Package
Part Number
DG540
–40toto85
_C
–40
85_C
–55 to 125_C
20-Pin Plastic DIP
DG540DJ
20-Pin PLCC
DG540DN
20-Pin Sidebraze
DG540AP
DG540AP/883
DG541
–40 to 85_C
–55 to 125_C
16-Pin Plastic DIP
DG541DJ
16-Pin Narrow SOIC
DG541DY
16-Pin Sidebraze
DG541AP
DG541AP/883
DG542
–40 to 85_C
–55 to 125_C
2
16-Pin Plastic DIP
DG542DJ
16-Pin Narrow SOIC
DG542DY
16-Pin Sidebraze
DG542AP
DG542AP/883
Siliconix
S-53694—Rev. E, 28-May-97
DG540/541/542
Absolute Maximum Ratings
V+ to V– . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to 21 V
V+ to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to 21 V
V– to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –19 V to +0.3 V
Digital Inputs . . . . . . . . . . . . . . . . . . . . . . . . (V–) –0.3 V to (V+) +0.3 V
or 20 mA, whichever occurs first
VS, VD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (V–) –0.3 V to (V–) +14 V
or 20 mA, whichever occurs first
Continuous Current (Any Terminal) . . . . . . . . . . . . . . . . . . . . . . 20 mA
Current, S or D (Pulsed 1 ms, 10% duty cycle max) . . . . . . . . . . 40 mA
Storage Temperature
(AP Suffix) . . . . . . . . . . . . . . –65 to 150_C
(DJ, DN, DY Suffixes) . . . . . –65 to 125_C
Power Dissipation (Package)a
16-Pin Plastic DIPb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20-Pin Plastic DIPc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16-Pin Narrow Body SOICd . . . . . . . . . . . . . . . . . . . . . . . . . . .
20-Pin PLCCd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16-, 20-Pin Sidebraze DIPe . . . . . . . . . . . . . . . . . . . . . . . . . . . .
470 mW
800 mW
640 mW
800 mW
900 mW
Notes:
a. All leads welded or soldered to PC Board.
b. Derate 6.5 mW/_C above 25_C
c. Derate 7 mW/_C above 25_C
d. Derate 10 mW/_C above 75_C
e. Derate 12 mW/_C above 75_C
Schematic Diagram (Typical Channel)
V+
GND
VREF
S
IN
–
+
D
V–
Figure 1.
Siliconix
S-53694—Rev. E, 28-May-97
3
DG540/541/542
Specificationsa
Test Conditions
Unless Specified
Parameter
Symbol
V V–
V = –33 V
V+ = 15 V,
VINH = 2 V, VINL = 0.8 Vf
VANALOG
V– = –5 V, V+ = 12 V
Tempb
Typc
A Suffix
D Suffixes
–55 to 125_C
–40 to 85_C
Mind
Maxd Mind Maxd Unit
Analog Switch
Analog Signal Range
Drain-Source
On-Resistance
rDS(on)
rDS(on) Match
DrDS(on)
IS = –10 mA,, VD = 0 V
Full
–5
5
–5
5
Room
Full
30
60
100
60
75
Room
2
6
6
Source Off
Leakage Current
IS(off)
VS = 0 V, VD = 10 V
Room
Full
–0.05
–10
–500
10
500
–10
–100
10
100
Drain Off
Leakage Current
ID(off)
VS = 10 V, VD = 0 V
Room
Full
–0.05
–10
–500
10
500
–10
–100
10
100
Channel On
Leakage Current
ID(on)
VS = VD = 0 V
Room
Full
–0.05
–10
–1000
10
1000
–10
–100
10
100
V
W
nA
Digital Control
Input Voltage High
VINH
Full
Input Voltage Low
VINL
Full
2
2
0.8
IIN
VIN = GND or V+
Room
Full
0.05
On State Input Capacitancee
CS(on)
VS = VD = 0 V
Room
14
20
20
Off State Input Capacitancee
CS(off)
VS = 0 V
Room
2
4
4
CD(off)
VD = 0 V
Room
2
4
4
BW
RL = 50 W , See Figure 5
Room
500
DG540
DG541
Room
Full
45
70
130
70
130
DG542
Room
Full
55
100
160
100
160
DG540
DG541
Room
Full
20
50
85
50
85
DG542
Room
Full
25
60
85
60
85
Room
–25
DG540
Room
–80
DG541
Room
–60
DG542
Room
–75
Room
–85
Room
Full
3.5
Room
Full
–3.2
Input Current
–1
–20
1
20
V
0.8
–1
–20
1
20
mA
Dynamic Characteristics
Off State Output
Capacitancee
Bandwidth
Turn On Time
Turn Off Time
Charge Injection
Off Isolation
All Hostile Crosstalk
tON
RL = 1 kW
W
CL = 35 pF
p
50% to 90%
See Figure 2
tOFF
Q
OIRR
XTALK(AH)
CL = 1000 pF, VS = 0 V
See Figure 3
RIN = 75 W
RL = 75 W
f = 5 MHz
See Figure 4
RIN = 10 W , RL = 75 W
f = 5 MHz, See Figure 6
pF
MHz
ns
pC
dB
Power Supplies
Positive Supply Current
I+
Negative Supply Current
I–
All Channels On or Off
6
9
–6
–9
6
9
–6
–9
Notes:
a. Refer to PROCESS OPTION FLOWCHART.
b. Room = 25_C, Full = as determined by the operating temperature suffix.
c. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing.
d. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum, is used in this data sheet.
e. Guaranteed by design, not subject to production test.
f. VIN = input voltage to perform proper function.
4
Siliconix
S-53694—Rev. E, 28-May-97
mA
DG540/541/542
Typical Characteristics
Supply Curent vs. Temperature
6
ID(off), IS(off) vs. Temperature
100 nA
5
10 nA
4
3
I S(off) , I D(off) – Leakage
I+
I (mA)
2
1
IGND
0
–1
–2
I–
–3
1 nA
100 pA
10 pA
1 pA
–4
0.1 pA
–5
–55 –35 –15
25 45 65
Temperature (_C)
85
105 125
125_C
100
80
25_C
60
–55_C
40
25
50
75
Temperature (_C)
V+ Constant
20
V– Constant
40
40
38
38
V– = –5 V
36
V+ = 12 V
34
34
32
32
V+ = 15 V
30
1
3
5
7
9
20
20
VD – Drain Voltage (V)
0
10 11 12 13 14 15 16
V– – Negative Supply (V)
V+ – Positive Supply (V)
On Capacitance
22
V– = –1 V
18
–5 –4 –3 –2 –1
11
V– = –3 V
30
18
–1
Off Isolation
–110
–100
20
–90
18
–80
ISO (dB)
16
C (pF)
125
42
36
0
–3
100
V+ = 10 V
rDS(on) – Drain-Source On-Resistance ( 120
0
42
V+ = 15 V
V– = –3 V
140
–25
–55
rDS(on) vs. Drain Voltage
160
rDS(on) – Drain-Source On-Resistance ( 5
14
12
DG540
–70
DG542
–60
–50
DG541
–40
10
–30
8
–20
–10
6
0
2
4
6
8
10
VD – Drain Voltage (V)
Siliconix
S-53694—Rev. E, 28-May-97
12
14
1
10
100
f – Frequency (MHz)
5
DG540/541/542
Typical Characteristics (Cont’d)
Off Isolation vs. Frequency and Load Resistance
(DG540)
All Hostile Crosstalk
–100
–90
–110
–100
RL = 75 –80
–80
1 k
XTALK (dB)
OIRR (dB)
–70
–60
10 k
–50
–40
DG542
–70
–60
DG541
–50
–30
–40
–20
–30
–10
–20
–10
0
1
10
40
100
10
1
100
f – Frequency (MHz)
f – Frequency (MHz)
Charge Injection vs. VS
Switching Times vs. Temperature
(DG540/541)
90
80
30
70
20
60
Time (ns)
10
Q (pC)
DG540
–90
180 0
–10
tON
50
40
30
–20
tOFF
20
CL = 1000 pF
–30
10
0
–40
–3 –2 –1
0
1
2
3
4
5
6
7
8
–55
–25
VS – Source Voltage (V)
0
25
50
75
100
125
Temperature (_C)
Switching and Break-Before-Make Time
vs. Temperature (DG542)
Operating Supply Voltage Range
20
90
80
18
V+ – Positive Supply (V)
tON
70
Time (ns)
60
tBBM
50
40
tOFF
30
20
16
Operating
Voltage
Area
14
12
10
0
10
–55
–25
0
25
50
Temperature (_C)
6
75
100
125
0
–1
–2
–3
–4
–5
–6
V– – Negative Supply (V)
Siliconix
S-53694—Rev. E, 28-May-97
DG540/541/542
Test Circuits
+15 V
D
S
Logic
Input
VO
IN
GND
tr <20 ns
tf <20 ns
3V
V+
CL
35 pF
RL
1 kW
V–
Switch
Input
50%
VS
90%
Switch
Output
–3 V
0
tON
tOFF
CL (includes fixture and stray capacitance)
RL
VO = VS
RL + rDS(on)
Figure 2. Switching Time
DVO
+15 V
Rg
V+
S
VO
D
VO
IN
Vg
CL
1000 pF
3V
GND
V–
INX ON
OFF
ON
DVO = measured voltage error due to charge injection
The charge injection in coulombs is DQ = CL x DVO
–3 V
Figure 3. Charge Injection
+15 V
+15 V
C
C
V+
S
VS
VO
D
Rg = 75 W
RL
75 W
IN
0 V, 2.4 V
GND
V–
–3 V
Off Isolation = 20 log
C = RF Bypass
C
V+
S
VS
VO
D
Rg = 50 W
0 V, 2.4 V
RL
50 W
IN
GND
V–
C
–3 V
VS
VO
Figure 4. Off Isolation
Siliconix
S-53694—Rev. E, 28-May-97
Figure 5. Bandwidth
7
DG540/541/542
Test Circuits (Cont’d)
C
+15 V
V+
S1
10 W
2.4 V
D1
VO
RL
75 W
INX
S2
D2
S3
D3
S4
D4
GND
RL
RL
V–
RL
C
–15 V
V OUT
X TALK(AH) 20 log 10 V
IN
Figure 6. All Hostile Crosstalk
Applications
Device Description
The DG540/541/542 family of wideband switches offers
true bidirectional switching of high frequency analog or
digital signals with minimum signal crosstalk, low insertion
loss, and negligible non-linearity distortion and group
delay.
Built on the Siliconix D/CMOS process, these “T” switches
provide excellent off-isolation with a bandwidth of around
500 MHz (350 MHz for DG541). Silicon-gate D/CMOS
processing also yields fast switching speeds.
An on-chip regulator circuit maintains TTL input
compatibility over the whole operating supply voltage
range, easing control logic interfacing.
Circuit layout is facilitated by the interchangeability of
source and drain terminals.
Frequency Response
A single switch on-channel exhibits both resistance
[rDS(on)] and capacitance [CS(on)]. This RC combination has
8
an attenuation effect on the analog signal – which is
frequency dependent (like an RC low-pass filter). The
–3-dB bandwidth of the DG540 is typically 500 MHz (into
50 W). This measured figure of 500 MHz illustrates that
the switch channel can not be represented by a two stage RC
combination. The on capacitance of the channel is
distributed along the on-resistance, and hence becomes a
more complex multi stage network of R’s and C’s making
up the total rDS(on) and CS(on). See Application Note AN502
for more details.
Off-Isolation and Crosstalk
Off-isolation and crosstalk are affected by the load
resistance and parasitic inter-electrode capacitances.
Higher off-isolation is achieved with lower values of RL.
However, low values of RL increase insertion loss requiring
gain adjustments down the line. Stray capacitances, even a
fraction of 1 pF, can cause a large crosstalk increase. Good
layout and ground shielding techniques can considerably
improve your ac circuit performance.
Siliconix
S-53694—Rev. E, 28-May-97
DG540/541/542
Applications (Cont’d)
Power Supplies
3.
A useful feature of the DG54X family is its power supply
flexibility. It can be operated from a single positive supply
(V+) if required (V– connected to ground).
Capacitors should have good high frequency
characteristics - tantalum bead and/or monolithic
ceramic types are adequate.
Suitable decoupling capacitors are 1Ć to 10ĆmF
tantalum bead, plus 10Ć to 100ĆnF ceramic.
Note that the analog signal must not exceed V– by more
than –0.3 V to prevent forward biasing the substrate p-n
junction. The use of a V– supply has a number of
advantages:
1.
2.
+15 V
+
It allows flexibility in analog signal handling, i.e.,
with V- = -5 V and V+ = 12 V; up to 5ĆV ac
signals can be controlled.
The value of on capacitance [CS(on)] may be
reduced. A property known as `the bodyĆeffect' on
the DMOS
switch devices causes various
parametric effects to occur. One of these effects is
the reduction in CS(on) for an increasing V
body-source. Note, however, that to increase Vnormally requires V+ to be reduced (since V+ to
V- = 21 V max.). Reduction in V+ causes an
increase in rDS(on), hence a compromise has to be
achieved. It is also useful to note that optimum
video linearity performance (e.g., differential phase
and gain) occurs when V- is around -3 V.
C1
C2
V+
S1
D1
S2
D2
DG540
S3
D3
S4
D4
GNDs
V–
C1 = 10 mF Tantalum
C2 = 0.1 mF Ceramic
C1
C2
+
–3 V
3.
V- eliminates the need to bias the analog signal
using potential dividers and large coupling
capacitors.
Figure 7. Supply Decoupling
Decoupling
Board Layout
It is an established RF design practice to incorporate
sufficient bypass capacitors in the circuit to decouple the
power supplies to all active devices in the circuit. The
dynamic performance of the DG54X is adversely affected
by poor decoupling of power supply pins. Also, of even
more significance, since the substrate of the device is
connected to the negative supply, adequate decoupling of
this pin is essential.
PCB layout rules for good high frequency performance
must be observed to achieve the performance boasted by the
DG540. Some tips for minimizing stray effects are:
Rules:
1.
Decoupling capacitors should be incorporated on
all power supply pins (V+, V-). (See Figure 7.)
2.
They should be mounted as close as possible to the
device pins.
Siliconix
S-53694—Rev. E, 28-May-97
1.
Use extensive ground planes on double sided PCB,
separating adjacent signal paths. Multilayer PCB is
even better.
2.
Keep signal paths as short as practically possible,
with all channel paths of near equal length.
3.
Careful arrangement of ground connections is also
very important. Star connected system grounds
eliminate signal current flowing through ground
path parasitic resistance from coupling between
channels.
9
DG540/541/542
Applications (Cont’d)
Figure 8 shows a 4-channel video multiplexer using a DG540.
+15 V
V+
CH1
CH2
75 Si582
75 +
A=2
CH3
75 CH4
–
75 DIS
250 DG540
V–
75 250 –3 V
TTL Channel Select
Figure 8. 4 by 1 Video Multiplexing Using the DG540
Figure 9 shows an RGB selector switch using two DG542s.
+15 V
V+
R1
75 Red Out
R2
75 G1
75 Green Out
G2
75 DG542
V–
–3 V
+15 V
Si584
V+
B1
75 Blue Out
B2
75 Sync 1
75 Sync Out
Sync 2
75 DG542
RGB Source Select
V–
–3 V
Figure 9. RGB Selector Using Two DG542s
10
Siliconix
S-53694—Rev. E, 28-May-97