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19-0220; Rev 2; 7/96
Serial Controlled, 8-Channel SPST Switch
_______________General Description
The MAX335 analog switch with serial digital interface offers eight separately controlled single-pole-singlethrow (SPST) switches. All switches conduct equally in either direction, and on-resistance (100) is constant over the analog signal range. These CMOS switches can operate continuously with power supplies ranging from ±4.5V to ±20V and handle rail-to-rail analog signals. Upon power-up, all switches are off, and the internal serial and parallel shift registers are reset to zero. The MAX335 is equivalent to two DG211 quad switches but controlled by a serial interface. The interface is compatible with the Motorola SPI interface standard. Functioning as a shift register, this serial interface allows data (at DIN) to be locked in synchronous with the rising edge of clock (SCLK). The shift register's output (DOUT) enables several MAX335s to be daisy chained.
____________________________Features
o 8 Separately Controlled SPST Switches o SPI-Compatible Serial Interface o Accepts ±15V Analog Swings o Multiple Devices Can Be Daisy Chained
MAX335
______________Ordering Information
PART MAX335CNG MAX335CWG MAX335C/D MAX335ENG MAX335EWG MAX335MRG TEMP. RANGE 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -55°C to +125°C PIN-PACKAGE 24 Narrow Plastic DIP 24 Wide SO Dice* 24 Narrow Plastic DIP 24 Wide SO 24 Narrow CERDIP**
________________________Applications
Serial Data Acquisition and Process Control Avionics Signal Routing Networking
* Contact factory for dice specifications. ** Contact factory for availability and processing to MIL-STD-883.
__________________Pin Configuration ________________Functional Diagram
NO0 NO7
TOP VIEW
SCLK V+ DIN
1 2 3 4 5 6 7 8 9
24 CS 23 VL 22 DOUT
COM0
COM7
GND NO0
MAX335
21 V20 NO7 19 COM7 18 NO6 17 COM6 16 NO5 15 COM5 14 NO4 13 COM4
PARALLEL REGISTER AND TRANSLATOR
COM0 NO1 DOUT
DIN
8-BIT SHIFT REGISTER
COM1 NO2
VL
+5V TRANSLATOR
COM2 10
MAX335
SCLK CLOCK TRANSLATOR LATCH CS CS TRANSLATOR
NO3 11 COM3 12
DIP/SO
SPI is a trademark of Motorola Corp.
________________________________________________________________ Maxim Integrated Products 1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
Serial Controlled, 8-Channel SPST Switch MAX335
ABSOLUTE MAXIMUM RATINGS
Voltages Referenced to VV+........................................................................................44V GND ....................................................................................25V VL ..................................................(GND - 0.3V) to (V+ + 0.3V) SCLK, CS, DIN, DOUT, NO_, COM_ ..............V- -2V to V+ +2V or 30mA, whichever occurs first Continuous Current (any terminal) ......................................30mA Peak Current, NO or COM (pulsed at 1ms, 10% duty cycle MAX)..........................100mA Note 1: All leads are soldered or welded to PC boards.
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Continuous Power Dissipation (TA = +70°C) (Note 1) Narrow Plastic DIP (derate 13.33mW/°C above +70°C)..1067mW Wide SO (derate 11.76mW/°C above +70°C) ....................941mW Narrow CERDIP (derate 12.50mW/°C above +70°C) ......1000mW Operating Temperature Ranges MAX335C_ _ .......................................................0°C to +70°C MAX335E_ _ ....................................................-40°C to +85°C MAX335MRG .................................................-55°C to +125°C Storage Temperature Range .............................-65°C to +160°C Lead Temperature (soldering, 10sec) .............................+300°C
ELECTRICAL CHARACTERISTICS
(VL = +5V ±10%, V+ = 15V, V- = -15V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SWITCH Analog Signal Range On-Resistance VANALOG RON TA = TMIN to TMAX VCOM = ±10V, INO = 1mA VCOM = -14V, VNO = +14V VCOM = -14V, VNO = +14V VCOM = -14V, VNO = +14V VCOM = -14V, VNO = +14V VCOM = VNO = +14V COM On-Leakage Current ICOM(ON) VCOM = VNO = -14V DIGITAL I/O DIN, SCLK, CS Input Logic Threshold High DIN, SCLK, CS Input Logic Threshold Low DIN, SCLK, CS Input Current Logic High DIN, SCLK, CS Input Current Logic Low DOUT Output Voltage Logic High VIH VIL IINH IINL VDOUT VL = +5V VL = +15V VL = +5V VL = +15V VDIN, VSCLK, VCS = 2.4V
-- VL = +15V, VDIN, VSCLK, V S = 11V C
SYMBOL
CONDITIONS
MIN -15
TYP
MAX 15
UNITS V
TA = +25°C TA = +25°C TA = +25°C TA = +25°C TA = +25°C TA = +25°C TA = +25°C -1 -20 -1 -20 -1 -20 -1 -20 -2 -40 -2 -40 2.4 11
100 0.002 0.002 0.002 0.002 0.01 0.01
150 200 1 20 1 20 1 20 1 20 2 40 2 40
NO Off-Leakage Current
INO(OFF)
nA
COM Off-Leakage Current
ICOM(OFF)
nA
nA
V 0.8 3 V µA µA V
-1 -1 -1 -1 3.5
0.03 0.03 0.03 0.03
1 1 1 1 VL
VDIN, VSCLK, VCS = 0.8V
-- VL = +15V, VDIN, VSCLK, V CS = 3V
IDOUT = 0.8mA
2
_______________________________________________________________________________________
Serial Controlled, 8-Channel SPST Switch
ELECTRICAL CHARACTERISTICS (continued)
(VL = +5V ±10%, V+ = 15V, V- = -15V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER DIGITAL I/O DOUT Output Voltage Logic Low VL RESET Voltage VL RESET Voltage SCLK Input Hysteresis SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX335
VDOUT VLL VLH SCLKHYST
IDOUT = -1.6mA (Note 2) TA = +25°C TA = +25°C From rising edge of CS From rising edge of CS VS = GND, f = 1MHz TA = +25°C TA = +25°C TA = +25°C TA = +25°C TA = +25°C TA = +25°C TA = +25°C 25 DLOAD = SLOAD = 75, measured at S and D TA = +25°C 100 200 90 2 2 8 90 100 15 0.8
0.4
V V
2.4
V mV
SWITCH DYNAMIC CHARACTERISTICS Turn-On Time Turn-Off Time NO Off-Capacitance COM Off-Capacitance Channel On-Capacitance Off Isolation Channel-to-Channel Crosstalk Break-Before-Make Delay Clock Feedthrough at S, D (Note 3) POWER SUPPLIES Power-Supply Voltage Range VL Power-Supply Voltage Range V+ Supply Current V- Supply Current VL Supply Current V+/VVL I+ IIL DIN = CS = SCLK = 0V/5V DIN = CS = SCLK = 0V/5V DIN = CS = SCLK = 0V/5V TA = +25°C TA = +25°C TA = +25°C ±4.5 4.5 150 0.01 50 ±20 V+ 300 500 10 10 100 200 V V µA µA µA tON tOFF CNO(OFF) 400 500 400 500 ns ns pF pF pF dB dB ns 100 nV-sec
CCOM(OFF) VD = GND, f = 1MHz VD = VS = GND, CCOM(ON) f = 1MHz OIRR CCRR TBBM ESCLK RL = 100, CL = 15pF, VS = 1VRMS, f = 100kHz RL = 50, CL = 15pF, VS = 1VRMS, f = 100kHz
Note 2: When VL falls below this voltage, all switches are set off and the internal shift register is cleared (all zero). Note 3: Guaranteed, not production tested.
_______________________________________________________________________________________
3
Serial Controlled, 8-Channel SPST Switch MAX335
TIMING CHARACTERISTICS OF SERIAL DIGITAL INTERFACE (Figure 1)
(VL = +5V ±10%, V+ = +15V, V- = -15V, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER SCLK Maximum Frequency Cycle Time CS Lead Time CS Lag Time SCLK High Time SCLK Low Time Data-Setup Time Data-Hold Time DOUT Data Valid After Falling SCLK DOUT Data-Hold Time After Rising SCLK (Note 4) Rise Time of DOUT (Note 3) Allowable Rise Time at DIN, SCLK, CS (Note 3) Fall Time of DOUT (Note 3) Allowable Fall Time at DIN, SCLK, CS (Note 3) SYMBOL fSCLK tCH + tCL tCSS tCSH2 tCH tCL tDS tDH tDO 50% of SCLK to 10% of DOUT CL = 10pF CL = 10pF 20% VL to 70% VL, CL = 10pF 20% VL to 70% VL, CL = 10pF 70% VL to 20% VL, CL = 10pF 70% VL to 20% VL, CL = 10pF TA = +25°C CONDITIONS MIN 2.1 480 240 240 190 190 200 0 240 ns 400 0 100 2 100 2 ns ns µs ns µs TYP MAX UNITS MHz ns ns ns ns ns ns ns
Note 4: This specification guarantees that data at DOUT never appears before SCLK's falling edge.
4
_______________________________________________________________________________________
Serial Controlled, 8-Channel SPST Switch
__________________________________________Typical Operating Characteristics
(V+ = +15V, V- = -15V, VL= 5V, TA = +25°C, unless otherwise noted.)
RON vs. VCOM AND TEMPERATURE
MAX335-02
MAX335
RON vs. VCOM AND POWER-SUPPLY VOLTAGE
MAX335-01
tON, tOFF vs. VCOM
MAX335-03
300 250 200 RON () A: B: C: D: ±5V ±10V ±15V ±20V A
300 250 200 RON () C 150 100 D 50 0 B A A: TA = +25°C B: TA = +85°C C: TA = +125°C
600 500 400 300 200 100 0 tON tOFF
150 100 50 0 -20 -10 0 VCOM (V)
B C
10
20
-20
-10
0 VCOM (V)
10
20
tON, tOFF (ns)
0
5
10 VCOM (V)
15
20
DATA-HOLD TIME vs. POWER-SUPPLY VOLTAGE
MAX335-04
DATA-SETUP TIME vs. POWER SUPPLY
MAX335-05
40 DATA-HOLD TIME (ns) 20 0 -20 -40 -60 ±5 ±10 ±15 ±20 SUPPLY VOLTAGE (V) DATA-SETUP TIME (ns)
50 40 30 20 10 0 ±5 ±10 ±15 ±20 SUPPLY VOLTAGE (V) ON-LEAKAGE (pA)
20 ON 2 0.2 0.02 OFF
0.002 0.0002 -55 +25 TEMPERATURE (°C) +125
CHARGE INJECTION vs. VCOM
MAX335-07
SUPPLY vs. TEMPERATURE
MAX335-08
MINIMUM SCLK PULSE WIDTH vs. POWER SUPPLY
MAX335-09
105 70 35 Q (pC) 0 -35 B -70 -105 -20 -15 -10 -5 0 VCOM (V) 5 10 15 A: ±5V B: ±15V A
1000 I+ 100 IL I+, I-, IL (µA) 10 1 0.1 0.01 I0.001
60 50 40 SCLK (ns) 30 20 10 0
20
-55
+25 TEMPERATURE (°C)
+125
±5
±10
±15
±20
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
5
MAX335-06
60
LEAKAGE CURRENT vs. TEMPERATURE
200
60
Serial Controlled, 8-Channel SPST Switch MAX335
_____________________Pin Description
PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 NAME SCLK V+ DIN GND NOØ COMØ NO1 COM1 NO2 COM2 NO3 COM3 COM4 NO4 COM5 NO5 COM6 NO6 COM7 NO7 VDOUT VL -- CS FUNCTION Serial Clock Input Positive Supply Voltage Serial Data Input Ground Switch 0 Switch 0 Switch 1 Switch 1 Switch 2 Switch 2 Switch 3 Switch 3 Switch 4 Switch 4 Switch 5 Switch 5 Switch 6 Switch 6 Switch 7 Switch 7 Negative Supply Voltage Serial Data Output Logic Supply/Reset Chip Select
updates the new switch configuration and inhibits further data from entering the shift register. Transitions at DIN and SCLK have no effect when CS is high, and DOUT holds the last bit in the shift register. The MAX335 three-wire serial interface is compatible with the SPITM and MicrowireTM standards. If interfacing with a Motorola processor serial interface, set CPOL = 0. The MAX335 is considered a slave device (Figures 2 and 3). Upon power-up, the shift register contains all zeros, and all switches are off. The latch that drives the analog switch is only updated on the rising edge of CS when SCLK is low. If SCLK is high when CS rises, the latch will not be updated until SCLK goes low. The CPOL = 1, CPHA = 1 SPI configuration does not update the latch correctly.
Daisy Chaining For a simple interface using several MAX335s, "daisy chain" the shift registers as shown in Figure 5. The CS pins of all devices are connected together, and a stream of data is shifted through the MAX335s in series. When CS is brought high, all switches are updated simultaneously. Additional shift registers may be included anywhere in series with the MAX335 data chain. Addressable Serial Interface When several serial devices are configured as slaves, addressable by the processor, DIN pins of each MAX335 are connected together (Figure 6). Address decode logic individually controls CS of each slave device. When a slave is selected, its CS is brought low, data is shifted in, and CS is brought high to latch the data. Typically, only one slave is addressed at a time. DOUT is not used. Digital Feedthrough Digital feedthrough energy measures 100nV-sec, which means that with no filtering at the signal channel, feedthrough from a sharply rising clock edge into an unfiltered switch channel can be measured at 1Vp-p for 100ns. However, even 100pF capacitance in the switch channel, when combined with the switch resistance, yields a filter that reduces this transient to 10mVp-p typical. To reduce digital feedthrough, hysteresis (150mV typ) was added to the SCLK input so triangle or sine waves may be used.
______________Detailed Description
Serial Digital Interface
Basic Operation Refer to Figure 2. The MAX335 interface can be thought of as an 8-bit shift register controlled by CS. While CS is low, input data appearing at DIN is clocked into the shift register synchronous with SCLK's rising edge. The data is an 8-bit word, each bit controlling one of eight switches in the MAX335 (Table 1). DOUT is the output of the shift register, with data appearing synchronous with SCLK's falling edge. Data at DOUT is simply the input data delayed by eight clock cycles. When shifting the input data, D7 is the first bit in and out of the shift register. While shifting data, the switches remain in their original configuration. When the 8 bits of data have been shifted in, CS is brought high. This
6
_______________________________________________________________________________________
Serial Controlled, 8-Channel SPST Switch MAX335
tCLL CS
···
tCSH2
tCSS tCSH0
tCH
···
tOFF
SCLK tDS tDH
···
tCL
tCSH1
DIN tDO
···
DOUT
···
Figure 1. Timing Diagram
SWITCHES UPDATED CS
SCLK DATA CLOCKED IN DIN D7 MSB INPUT DATA BITS DATA CLOCKED OUT DOUT D7 D6 D5 D4 D3 D2 D1 D0 DATA BITS FROM PREVIOUS DATA INPUT DOUT POWER-UP DEFAULT: D7D0 = 0 D7 D6 D5 D4 D3 D2 D1 D0 LSB
Figure 2. Three-Wire Interface Timing
_______________________________________________________________________________________
7
Serial Controlled, 8-Channel SPST Switch MAX335
Table 1. Serial-Interface Switch Programming
DATA BITS FUNCTION D7 0 1 X X X X X X X X X X X X X X D6 X X 0 1 X X X X X X X X X X X X D5 X X X X 0 1 X X X X X X X X X X D4 X X X X X X 0 1 X X X X X X X X D3 X X X X X X X X 0 1 X X X X X X D2 X X X X X X X X X X 0 1 X X X X D1 X X X X X X X X X X X X 0 1 X X D0 X X X X X X X X X X X X X X 0 1 Switch 7 open (off) Switch 7 closed (on) Switch 6 open Switch 6 closed Switch 5 open Switch 5 closed Switch 4 open Switch 4 closed Switch 3 open Switch 3 closed Switch 2 open Switch 2 closed Switch 1 open Switch 1 closed Switch 0 open Switch 0 closed
X = Don't care
SCLK
SK SO SI I/0 MICROWIRE PORT
DOUT
MISO MOSI SCK I/0
MAX335 DIN
DOUT CS
MAX335 DIN
SCLK CS
SPI PORT
THE DOUT-SI CONNECTION IS NOT REQUIRED FOR WRITING TO THE MAX335, BUT MAY BE USED FOR DATA-ECHO PURPOSES.
CPOL = 0, CPHA = 0 THE DOUT-MISO CONNECTION IS NOT REQUIRED FOR WRITING TO THE MAX335, BUT MAY BE USED FOR DATA-ECHO PURPOSES.
Figure 3. Connections for Microwire
Figure 4. Connections for SPI
8
_______________________________________________________________________________________
Serial Controlled, 8-Channel SPST Switch MAX335
SCLK
SCLK
SCLK
SCLK
MAX335
DIN DIN DOUT DIN
MAX335
DOUT DIN
MAX335
DOUT
CS
CS
CS
CS TO OTHER SERIAL DEVICES
Figure 5. Daisy-Chained Connection
DIN SCLK CS1 CS2 CS3 TO OTHER SERIAL DEVICES
CS
CS
CS
MAX335
SCLK SCLK
MAX335
SCLK
MAX335
DIN
DIN
DIN
Figure 6. Addressable Serial Interface
_______________________________________________________________________________________
9
Serial Controlled, 8-Channel SPST Switch MAX335
__________Applications Information
8 x 1 Multiplexer
To use the MAX335 as an 8 x 1 multiplexer, tie all drains together (COM0 to COM7); the mux inputs now source each switch (NO0 to NO7). Input a single 0V to +3V pulse at DIN. As this is clocked through the register by SCLK, each switch will sequence on one at a time.
Reset Function
Pulsing VL below +0.8V initiates the power-up reset function. The switches are set to the off position, and the serial shift register is reset to all zeros.
Power-Supply Operation
The MAX335 operates with V = ±4.5V to ±20V and VL = +5V. With V- tied to ground, the part operates with V+ = +10V to +30V. The VL supply sets TTL input compatibility at a 1.6V switching threshold. As V L is raised, the switching threshold is raised, so the part is no longer TTL compatible. The MAX335 also operates with a single power supply: VL = V+ and V- = 0V. With VL tied to V+, the VL supply cannot be used as a reset function.
4-2 Differential Multiplexer
To use the MAX335 as a 4-2 differential multiplexer, tie COM0 through COM3 together and COM4 through COM7 together. Differential inputs will be the source inputs as follows: (NO0, NO4), (NO1, NO5), (NO2, NO6), (NO3, NO7). Figure 7 shows the serial input control at DIN required to turn on two switches making a differential multiplexer.
D4 SCLK SW4 DIN 4 CLOCK PULSES SWØ DØ
___________________Chip Topography
V+ SCLK CS VL
DOUT DIN
Figure 7. Differential Multiplexer Input Control
GND
CS is held low for four clock pulses; the first pulse is clocked into the fifth switch position as the second pulse is clocked into the first switch position. CS is pulled high to update switches; then CS is pulled low, and SCLK advances pulses to S1 and S5 positions, where CS is pulled high to update, etc.
VNO7
NO0 COM0
COM7 NO6 NO1 0.156" (3.96mm)
SPDT Switches
Tie COM0 to NO1 so that NO0 and COM1 are now inputs and COM0/NO1 is the common output. SP is common output. Up to four SPDT switches can be made from each MAX335. Multiples of four or more can be made by daisy chaining devices. In Figure 8, DIN is a pulse train. Again, CS is held low to clock in pulses and CS is pulled high to update; CS is held low to shift pulses, then pulled high to update, etc.
COM6 COM1 NO5 NO2
COM2
COM5 NO3 COM3 0.099" (2.51mm) COM4 NO4
DIN 1 CLOCK PULSE
TRANSISTOR COUNT: 387 SUBSTRATE CONNECTED TO V+.
Figure 8. Serial-Input Control for SPDT Switch
10 ______________________________________________________________________________________
Serial Controlled, 8-Channel SPST Switch
________________________________________________________Package Information
DIM INCHES MAX MIN 0.200 0.015 0.150 0.125 0.080 0.055 0.022 0.016 0.065 0.050 0.012 0.008 1.265 1.235 0.080 0.050 0.325 0.300 0.280 0.240 0.100 BSC 0.300 BSC 0.400 0.150 0.115 15° 0° MILLIMETERS MIN MAX 5.08 0.38 3.18 3.81 1.40 2.03 0.41 0.56 1.27 1.65 0.20 0.30 31.37 32.13 1.27 2.03 7.62 8.26 6.10 7.11 2.54 BSC 7.62 BSC 10.16 2.92 3.81 0° 15°
21-337A
MAX335
D1
E E1 A A2 D A3
A A1 A2 A3 B B1 C D D1 E E1 e eA eB L
A1 L e B B1
C eA eB
24-PIN PLASTIC DUAL-IN-LINE (NARROW) PACKAGE
INCHES MAX MIN 0.104 0.093 0.012 0.004 0.019 0.014 0.013 0.009 0.614 0.598 0.299 0.291 0.050 BSC 0.419 0.394 0.030 0.010 0.050 0.016 8° 0° MILLIMETERS MIN MAX 2.35 2.65 0.10 0.30 0.35 0.49 0.23 0.32 15.20 15.60 7.40 7.60 1.27 BSC 10.00 10.65 0.25 0.75 0.40 1.27 0° 8°
21-338A
DIM A A1 B C D E e H h L
E
H
D A
0.127mm 0.004in.
h x 45°
e
B
A1
C
L
24-PIN PLASTIC SMALL-OUTLINE PACKAGE
______________________________________________________________________________________
11
Serial Controlled, 8-Channel SPST Switch MAX335
___________________________________________Package Information (continued)
DIM A B B1 C D E E1 e L L1 Q S S1 INCHES MAX MIN 0.200 0.023 0.014 0.065 0.038 0.015 0.008 1.280 0.310 0.220 0.320 0.290 0.100 BSC 0.200 0.125 0.150 0.060 0.015 0.098 0.005 15° 0° MILLIMETERS MIN MAX 5.08 0.36 0.58 0.97 1.65 0.20 0.38 32.51 5.59 7.87 7.37 8.13 2.54 BSC 3.18 5.08 3.81 0.38 1.52 2.49 0.13 0° 15°
21-340C
S1
S
E1 A D E
Q L e B B1 L1
C
24-PIN CERAMIC DUAL-IN-LINE (NARROW) PACKAGE
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.