Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsInterface ICsInterface IC - analogue switches PDIP 24

_______________General Description

The MAX395 8-channel, serially controlled, single-pole/sin-

gle-throw (SPST) analog switch offers eight separately

controlled switches. The switches conduct equally well in

either direction. On-resistance (100Ω max) is matched

between switches to 5Ω max and is flat (10Ω max) over

the specified signal range.

These CMOS devices can operate continuously with

dual power supplies ranging from ±2.7V to ±8V or a

single supply between +2.7V and +16V. Each switch

can handle rail-to-rail analog signals. The off leakage

current is only 0.1nA at +25°C or 5nA at +85°C.

Upon power-up, all switches are off, and the internal shift

registers are reset to zero. The MAX395 is electrically

equivalent to two MAX391 quad switches controlled by a

serial interface, and is pin compatible with the MAX335.

The serial interface is compatible with SPI™/QSPI™ and

Microwire™. Functioning as a shift register, it allows data

(at DIN) to be clocked in synchronously with the rising

edge of clock (SCLK). The shift register’s output (DOUT)

enables several MAX395s to be daisy chained.

All digital inputs have 0.8V to 2.4V logic thresholds, ensur-

ing both TTL- and CMOS-logic compatibility when using

±5V supplies or a single +5V supply.

________________________Applications

Serial Data-Acquisition Industrial and Process-

Systems Control Systems

Avionics ATE Equipment

Audio Signal Routing Networking

____________________________Features

♦ SPI™/QSPI™, Microwire™-Compatible Serial

Interface

♦ 8 Separately Controlled SPST Switches

♦ 100Ω Signal Paths with ±5V Supplies

♦ Rail-to-Rail Signal Handling

♦ Asynchronous RESET

Input

♦ Pin Compatible with Industry-Standard MAX335

♦ ±2.7V to ±8V Dual Supplies

+2.7V to +16V Single Supply

♦ >2kV ESD Protection per Method 3015.7

♦ TTL/CMOS-Compatible Inputs (with +5V or

±5V Supplies)

MAX395

Serially Controlled, Low-Voltage,

8-Channel SPST Switch

________________________________________________________________

Maxim Integrated Products

LATCH

NO0

COM0

8-BIT SHIFT REGISTER

CLOCK TRANSLATOR

CS TRANSLATOR



DIN

RESET

SCLK

NO7

COM7

PARALLEL REGISTER AND TRANSLATOR

DOUT

MAX395

________________Functional Diagram

SCLK

V+

DIN

GND

NO0

COM0

NO1

COM1

NO2

COM2

NO3

COM3

DIP/SO

TOP VIEW

MAX395

1

2

3

4

5

6

7

8

9

10

11

24

23

22

21

20

19

18

17

16

15

14

CS

RESET

DOUT

V-

NO7

COM7

NO6

COM6

NO5

COM5

NO4

COM4

LOGIC

__________________Pin Configuration

Call toll free 1-800-998-8800 for free samples or literature.

19-0448; Rev 0; 11/95

PART

MAX395CNG

MAX395CWG

MAX395C/D 0°C to +70°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

24 Narrow Plastic DIP

24 Wide SO

Dice*

______________Ordering Information

* Contact factory for dice specifications.

** Contact factory for availability.

MAX395ENG

MAX395EWG

MAX395MRG -55°C to +125°C

-40°C to +85°C

-40°C to +85°C 24 Narrow Plastic DIP

24 Wide SO

24 Narrow CERDIP**

SPI and QSPI are trademarks of Motorola, Inc. Microwire is a trademark of National Semiconductor Corp.

Summary of content (16 pages)

PAGE 1
9-0448; Rev 0; 11/95 Serially Controlled, Low-Voltage, 8-Channel SPST Switch ________________________Applications Serial Data-Acquisition Systems Avionics Audio Signal Routing Industrial and ProcessControl Systems ATE Equipment Networking __________________Pin Configuration ____________________________Features ♦ SPI™/QSPI™, Microwire™-Compatible Serial Interface ♦ 8 Separately Controlled SPST Switches ♦ 100Ω Signal Paths with ±5V Supplies ♦ Rail-to-Rail Signal Handling ♦ Asynchronous RESET Input ♦ Pin
PAGE 2
MAX395 Serially Controlled, Low-Voltage, 8-Channel SPST Switch ABSOLUTE MAXIMUM RATINGS Voltages Referenced to GND V+ ...........................................................................-0.3V, +17V V- ............................................................................-17V, +0.3V V+ to V-...................................................................-0.3V, +17V SCLK, CS, DIN, DOUT, RESET .................-0.3V to (V+ + 0.3V) NO, COM .................................................
PAGE 3
Serially Controlled, Low-Voltage, 8-Channel SPST Switch (V+ = +4.5V to +5.5V, V- = -4.5V to -5.5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
MAX395 Serially Controlled, Low-Voltage, 8-Channel SPST Switch TIMING CHARACTERISTICS—Dual Supplies (Figure 1) (V+ = +4.5V to +5.5V, V- = -4.5V to -5.5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 5
Serially Controlled, Low-Voltage, 8-Channel SPST Switch (V+ = +4.5V to +5.5V, V- = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL MIN CONDITIONS TYP (Note 2) MAX V+ V 125 175 Ω UNITS ANALOG SWITCH Analog Signal Range COM, NO On-Resistance NO Off Leakage Current (Notes 4, 5) COM Off Leakage Current (Notes 4, 5) COM On Leakage Current (Notes 4, 5) VCOM, VNO RON INO(OFF) ICOM(OFF) ICOM(ON) C, E, M V- TA = +25°C V+ = 5V, VCOM = 3.
PAGE 6
MAX395 Serially Controlled, Low-Voltage, 8-Channel SPST Switch TIMING CHARACTERISTICS—Single +5V Supply (Figure 1) (V+ = +4.5V to +5.5V, V- = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 7
Serially Controlled, Low-Voltage, 8-Channel SPST Switch (V+ = +3.0V to +3.6V, V- = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL MIN CONDITIONS TYP (Note 2) MAX V+ V 270 500 Ω UNITS ANALOG SWITCH Analog Signal Range COM, NO On-Resistance NO Off Leakage Current (Notes 4, 5) COM Off Leakage Current (Notes 4, 5) COM On Leakage Current (Notes 4, 5) VCOM, VNO RON INO(OFF) ICOM(OFF) ICOM(ON) C, E, M V- V+ = 3.0V, VCOM = 1.
PAGE 8
MAX395 Serially Controlled, Low-Voltage, 8-Channel SPST Switch TIMING CHARACTERISTICS—Single +3V Supply (Figure 1) (V+ = +3.0V to +3.6V, V- = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 9
Serially Controlled, Low-Voltage, 8-Channel SPST Switch ON-RESISTANCE vs. VCOM AND TEMPERATURE (DUAL SUPPLIES) 110 V± = ±2.5V V± = ±5.5V 100 80 60 V± = ±5V 40 TA = +125°C 70 TA = +85°C 60 TA = +25°C TA = -55°C 0 30 1 2 3 4 V+ = 5V V+ = 9V 50 V+ = 12V 0 5 -5 -4 -3 -2 -1 0 1 2 3 4 0 5 4 2 6 8 VCOM (V) VCOM (V) ON-RESISTANCE vs. VCOM AND TEMPERATURE (SINGLE SUPPLY) OFF-LEAKAGE vs. TEMPERATURE ON-LEAKAGE vs. TEMPERATURE TA = +125°C V± = ±5.
PAGE 10
____________________________Typical Operating Characteristics (continued) (V+ = +5V, V- = -5V, GND = 0V, TA = +25°C, unless otherwise noted.) POWER-SUPPLY CURRENT vs. TEMPERATURE 90 80 35 MAX395 TOC11 100 MAX395 TOC10 100 MINIMUM SCLK PULSE WIDTH vs. POSITIVE SUPPLY VOLTAGE V± = ±5.5V 10 MAX395 TOC12 DATA SETUP TIME vs. POSITIVE SUPPLY VOLTAGE 30 I+ 60 50 40 SCLK (ns) 70 I+, I-, (µA) DATA SETUP TIME (ns) 1 0.1 25 20 30 I- 0.01 20 15 10 0.
PAGE 11
Serially Controlled, Low-Voltage, 8-Channel SPST Switch Basic Operation The MAX395’s interface can be thought of as an 8-bit shift register controlled by CS (Figure 2). While CS is low, input data appearing at DIN is clocked into the shift register synchronously with SCLK’s rising edge. The data is an 8-bit word, each bit controlling one of eight switches in the MAX395 (Table 1). DOUT is the shift register’s output, with data appearing synchronously with SCLK’s falling edge.
PAGE 12
MAX395 Serially Controlled, Low-Voltage, 8-Channel SPST Switch Addressable Serial Interface When several serial devices are configured as slaves, addressable by the processor, DIN pins of each decode logic individually control CS of each slave device. When a slave is selected, its CS pin is driven low, data is shifted in, and CS is driven high to latch the data. Typically, only one slave is addressed at a time. DOUT is not used.
PAGE 13
Serially Controlled, Low-Voltage, 8-Channel SPST Switch Dual, Differential 4-Channel Multiplexer To use the MAX395 as a dual (4x2) mux, connect COM0–COM3 together and connect COM4–COM7 together, forming the two outputs. The mux input pairs become NO0/NO4, NO1/NO5, NO2/NO6, and NO3/NO7. The mux can be programmed normally, with only one differential channel selected for every eight clock pulses, or it can be programmed in a fast mode, where channel changing occurs on each clock pulse.
PAGE 14
MAX395 Serially Controlled, Low-Voltage, 8-Channel SPST Switch DIN SCLK CS1 CS2 TO OTHER SERIAL DEVICES CS3 CS CS CS MAX395 MAX395 MAX395 SCLK SCLK SCLK DIN DIN DIN Figure 6. Addressable Serial Interface Reset Function D4 D0 SCLK SW4 SW0 DIN FOUR CLOCK PULSES Figure 7. Differential Multiplexer Input Control SCLK, each switch sequences one differential channel at a time, starting with channel 7/0.
PAGE 15
Serially Controlled, Low-Voltage, 8-Channel SPST Switch DATA BITS RESET FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 X X X X X X X X All switches open, D7–D0 = 0 1 0 1 X X X X X X Switch 7 off and 6 on 1 1 0 X X X X X X Switch 6 off and 7 on 1 X X 0 1 X X X X Switch 5 off and 4 on 1 X X 1 0 X X X X Switch 4 off and 5 on 1 X X X X 0 1 X X Switch 3 off and 2 on 1 X X X X 1 0 X X Switch 2 off and 3 on 1 X X X X X X 0 1 Switch 1 off a
PAGE 16
MAX395 Serially Controlled, Low-Voltage, 8-Channel SPST Switch ___________________Chip Topography COM5 NO5 NO3 NO2 COM4 COM3 COM2 NO4 COM1 COM6 NO6 NO1 0.120" COM0 (3.05mm) COM7 NO7 NO0 GND V- DOUT RESET CS V+ SCLK DIN 0.100" (2.54mm) TRANSISTOR COUNT: 500 SUBSTRATE CONNECTED TO V+. Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.