ETC DG221

DG221
Quad SPST CMOS Analog Switch with Latches
Features
Benefits
Applications
Compatible with Most P Buses
Allows Wide Power Supply Tolerance
Without Affecting TTL Compatibility
Reduced Power Consumption
Allows Flexibility of Design
Accepts 150-ns Write Pulse Width
5-V On-Chip Regulator
Built on PLUS-40 Process
Latches Are Transparent with WR Low
Low On-Resistance: 60 P Based Systems
Automatic Test Equipment
Communication Systems
Data Acquisition Systems
Medical Instrumentation
Factory Automation
Description
The DG221 is a monolithic quad single-pole, single-throw
analog switch designed for precision switching applications in
communication, instrumentation and process control systems.
Featuring independent onboard latches and a common WR
pin, each DG221 can be memory mapped, and addressed as
a single data byte for simultaneous switching.
Designed on the Siliconix PLUS-40 CMOS process, the
DG221 combines low power and low on-resistance (60 typical) while handling continuous currents up to 20 mA.
An epitaxial layer prevents latchup.
The device features true bidirectional performance in the on
condition. These switches guarantee a rail-to-rail blocking
capability (44 V max), in the off condition.
Functional Block Diagram and Pin Configuration
Four Latchable SPST Switches per Package
Dual-In-Line and SOIC
1
16
IN2
D1
2
15
D2
S1
3
14
S2
13
V+
12
WR
Input Latch
IN1
V–
4
GND
5
S4
6
11
S3
D4
7
10
D3
IN4
8
IN3
Top View
0
0
ON
1
0
OFF
Control data latched-in,
switches on or off as selected
by last INX
X
X
1
Maintains previous state
Logic “0” 0.8 V
Logic “1” 2.4 V
Ordering Information
Temp Range
Package
0C to 70C
16-Pin Plastic DIP
DG221CJ
–40C to 85C
16-Pin Narrow SOIC
DG221DY
–55C to 125C
16-Pin CerDIP
Part Number
DG221AK/883
Updates to this data sheet may be obtained via facsimile by calling Siliconix FaxBack, 1-408-970-5600. Please request FaxBack document #70041.
Siliconix
S-52881—Rev. C, 28-Apr-97
1
DG221
Absolute Maximum Ratings
Voltages Referenced to V–
V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 V
GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 V
Digital Inputsa, VS, VD . . . . . . . . . . . . . . . . . . . (V–) –2 V to (V+) +2 V
or 20 mA, whichever occurs first
Continuous Current (Any Terminal) . . . . . . . . . . . . . . . . . . . . . . 30 mA
Continuous Current, S or D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA
Peak Current, S or D (Pulsed 1 ms, 10% duty cycle) . . . . . . . . . . 70 mA
Storage Temperature:
(AK Suffix) . . . . . . . . . . . . . . –65 to 150C
(CJ and DY Suffix) . . . . . . . . –65 to 125C
Power Dissipation (Package)b
16-Pin CerDIPc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900 mW
16-Pin Plastic DIPd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470 mW
16-Pin SOICe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 mW
Notes:
a. Signals on SX, DX, or INX exceeding V+ or V– will be clamped by
internal diodes. Limit forward diode current to maximum current
ratings.
b. All leads welded or soldered to PC Board.
c. Derate 12 mW/C above 75C
d. Derate 6.5 mW/C above 25C
e. Derate 7.7 mW/C above 75C
Schematic Diagram (Typical Channel)
V+
5V
Reg
S
GND
INX
V–
–
+
Latch
V–
V+
WR
Level
Shift/
Drive
V+
–
+
D
V–
Figure 1.
2
Siliconix
S-52881—Rev. C, 28-Apr-97
DG221
Specificationsa
Test Conditions
Unless Otherwise Specified
Parameter
Symbol
V = 15 V,
V V–
V = –15
15 V
V+
VIN = 2.4 V, 0.8f V, WR = 0
Tempb
Typc
A Suffix
D Suffix
–55 to 125C
–40 to 85C
Mind Maxd Mind Maxd
Unit
Analog Switch
Analog Signal Rangee
VANALOG
Drain-Source
On-Resistance
rDS(on)
Source Off
Leakage Current
IS(off)
Drain Off
Leakage Current
ID(off)
Drain On
Leakage Current
ID(on)
IINL , IINH
Full
–15
15
–15
V
90
135
Room
Full
60
Room
Full
"0.01
–1
–100
1
100
–5
–100
5
100
Room
Full
"0.02
–1
–100
1
100
–5
–100
5
100
VS = VD = "14 V
Room
Full
"0.01
–1
–200
1
200
–5
–200
5
200
VIN = 0 V or = 2.4 V
Room
Full
–0.0004
–1
–10
1
10
–1
–10
1
10
IS = –10 mA, VD = "10 V
VS = "14 V
V, VD = #14 V
90
135
15
nA
Digital Control
Input Current
A
Dynamic Characteristics
Turn-On Time
Room
550
550
Room
340
340
Room
550
550
tOFF, WR
Room
340
340
Write Pulse Width
tW
Room
120
150
150
Input Setup Time
tS
Room
130
180
180
Input Hold Time
tH
Full
0
20
20
Charge Injection
Q
Room
20
Room
8
Room
9
Room
29
VS = 1 Vp-p
p p, f = 100 kHz
CL = 15 pF,
F RL = 1 k
Room
70
Room
90
All Channels On or Off
VIN = 0 V or 22.4
4V
Full
0.8
Room
–0.4
Turn-Off Time
Turn-On Time Write
Turn-Off Time Write
tON
tOFF
tON, WR
Source-Off Capacitance
CS(off)
Drain-Off Capacitance
CD(off)
Channel-On Capacitance
CD(on)
Off Isolation
OIRR
Interchannel Crosstalk
XTALK
See Figure 2
See Figure 3
See Figure 4
CL = 1000 pF
VGEN = 0 V, RGEN = 0 f = 1 MHz, VS, VD = 0 V
ns
pC
pF
dB
Power Supplies
Positive Supply Current
I+
Negative Supply Current
I–
1.5
–1
1.5
mA
–1
Notes:
a. Refer to PROCESS OPTION FLOWCHART.
b. Room = 25C, 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.
Siliconix
S-52881—Rev. C, 28-Apr-97
3
DG221
Test Circuits
+15 V
V+
2V
S
D
IN
GND
WR
V–
VO
RL
1 k
3V
Logic
Input
50%
Switch
Input
CL
35 pF
tr < 10 ns
tf < 10 ns
0V
VS
90%
Switch
Output
VO
tON
–15 V
tOFF
CL (includes fixture and stray capacitance)
VO = VS
RL
RL + rDS(on)
Figure 2. Switching Time
+15 V
3V
0V
2V
WR
S
WR
V+
D
IN
GND
V–
IN
VO
RL
1 k
50%
0V
3V
tr < 10 ns
tf < 10 ns
0V
CL
35 pF
VS
VOUT
–15 V
tON, WR
CL (includes fixture and stray capacitance)
VO = VS
90%
VO
tOFF , WR
RL
RL + rDS(on)
Figure 3. WR Switching Time
3V
50%
IN
tS
tH
tS
tH
3V
50%
WR
tW
tH = Hold Time
tS = Setup Time
tW = WR Pulse Width
VOUT
The latches are level sensitive. When WR is held low the latches are transparent and the switches
respond to the digital inputs. The digital inputs are latched on the rising edge of WR.
Figure 4. WR Setup Conditions
4
Siliconix
S-52881—Rev. C, 28-Apr-97
DG221
Test Circuits (Cont’d)
+15 V
DVO
V+
Rg
S
Vg
VO
D
VO
CL
1000 pF
IN
3V
WR
INX OFF
V–
ON
OFF
DVO = measured voltage error due to charge injection
The charge injection in coulombs is Q = CL x DVO
–15 V
Figure 5. Charge Injection
+15 V
+15 V
C
C
V+
V+
S
VS
S1
VS
VO
D
Rg = 50 W
Rg = 50 W
2.4 V
NC
GND WR
V–
50 W
IN1
0V
RL
IN
D1
C
0V
S2
D2
VO
RL
IN2
GND WR
V–
C
–15 V
Off Isolation = 20 log
–15 V
VS
VO
C = RF bypass
XTALK Isolation = 20 log
C = RF bypass
VS
VO
Figure 7. Channel-to-Channel Crosstalk
Figure 6. Off Isolation
Application Hintsa
WR
(V)
VIN
Logic Input
Voltage
VINH(min)/VINL(max)
(V)
VS or VD
Analog Voltage
Range
(V)
0
2.4/0.8
2.4/0.8
–15 to 15
–20
0
2.4/0.8
2.4/0.8
–20 to 20
–10
0
2.4/0.8
2.4/0.8
–10 to 10
–5
0
2.4/0.8
2.4/0.8
–5 to 10
V+
Positive Supply
Voltage
(V)
V–
Negative Supply
Voltage
(V)
GND
(V)
15
–15
20
10
10
Notes:
a. Application Hints are for DESIGN AID ONLY, not guaranteed and not subject to production testing.
Siliconix
S-52881—Rev. C, 28-Apr-97
5
DG221
Applications
VIN
+15 V
V+
9 M
DG221
IN1
D
C
S1
Q
900 k
D1
S2
IN2
D
C
Q
90 k
D2
Data Bus
S3
IN3
D
C
Q
9 k
D3
S4
IN4
D
C
WR
Q
1 k
D4
WR
GND
V–
CS
Address
Decoder
Address Bus
+
TL081
–
–15 V
The TL081 is used as an output buffer while
the voltage divider provides attenuation.
VO
Figure 8. P-Controlled Analog Signal Attenuator
Truth Table
Output Attenuation for Figure 8
IN1
IN2
IN3
IN4
WRa
0
0
0
0
0
1
1
1
1
0
1
1
1
1
0
1
1
1
1
1
On
Switch
WR
IN1
IN2
IN3
IN4
Gain
All
0
0
1
1
1
0.1
0
None
0
1
0
1
1
0.01
0
1
0
1
1
0
1
0.001
1
0
2
0
1
1
1
0
0.0001
0
1
0
3
1
0
0
4
Notes:
a. WR may be held at “0” for temporary operation similar to DG201A/DG201B. With WR at “0” SW1 will remain on as long as IN1 is held at “0”.
6
Siliconix
S-52881—Rev. C, 28-Apr-97