MAXIM MAX4744, MAX4744H, MAX4745, MAX4745H, MAX4746H User Manual

General Description

The MAX4744/MAX4744H/MAX4745/MAX4745H/
MAX4746H dual SPDT (single-pole/double-throw) audio
switches feature negative signal capability that allows
signals as low as V

CC

- 5.5V to pass through without
distortion. These analog switches have a low on-resis­tance and low supply current, and operate from a single
+1.8V to +5.5V supply.

The MAX4744/MAX4744H have internal shunt resistors
that automatically discharge the capacitance at the nor­mally open (NO) and normally closed (NC) terminals
when they are not connected. The MAX4746H features
internal shunt resistors on NC_ terminals. This reduces
click-and-pop sounds that occur when switching audio
signals between precharged points. A break-before­make feature further reduces popping. The MAX4744/
MAX4745 control the switches with two control bits CB1
and CB2. The MAX4744H/MAX4745H/MAX4746H have
one control bit to switch both switches and an enable
input EN to put the switches in a high-impedance mode.
The MAX4744H/MAX4745H/MAX4746H also have an
internal protection network against voltages applied to
COM_ when VCC= 0V.

These devices are available in a space-saving 10-pin
µDFN (2mm x 2mm) package and operate over the

-40°C to +85°C extended temperature range.

Applications

Speaker Switching

Power Routing

Cellular Phones

MP3 Players

PDAs and Other Handheld Devices

Notebook Computers

Features

 Distortion-Free Negative Signal Throughput Down

to V

CC

- 5.5V

 Internal Shunt Resistor Reduces Click/Pop

(MAX4744/MAX4744H)

 0.6Ω (typ) Low On-Resistance

 0.1Ω (max) Channel-to-Channel Matching

 0.55Ω (max) On-Resistance Flatness

 +1.8V to +5.5V Single-Supply Voltage

 0.01% (typ) Total Harmonic Distortion

 -75dB (typ) Crosstalk (100kHz)

 -68dB (typ) Off-Isolation (100kHz)

 Available in 10-Pin µDFN Package (2mm x 2mm)

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless

Switches with Negative Rail Capability

________________________________________________________________

Maxim Integrated Products

1

19-0563; Rev 1; 11/06

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

123

10 9 8

45

76

COM1 V

CC

COM2NC1

CB1 CB2GNDNO1

MAX4744
MAX4745

μDFN

(2mm x 2mm)

TOP VIEW

NC2

NO2

123

10 9 8

45

76

COM1 V

CC

COM2NC1

EN CB0GNDNO1

MAX4744H
MAX4745H
MAX4746H

μDFN

(2mm x 2mm)

NC2

NO2

+

+

Pin Configurations

Ordering Information/Selector Guide

Note: All devices are specified over the -40°C to +85°C operating temperature range.

+

Denotes a lead-free package.

PART

MAX4744ELB+T 10 µDFN-10 +AAF Yes No L1022-1

MAX4744HELB+T 10 µDFN-10 +AAG Yes Yes L1022-1

MAX4745ELB+T 10 µDFN-10 +AAH No No L1022-1

MAX4745HELB+T 10 µDFN-10 +AAI No Yes L1022-1

MAX4746HELB+T 10 µDFN-10 +AAM Yes, on NC_ Yes L1022-1

PACKAGE

PIN-

TOP

MARK

CLICKLESS COM PROTECTION PKG CODE

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless
Switches with Negative Rail Capability

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

(All voltages referenced to GND.)
V

CC

, CB_, EN ........................................................-0.3V to +6.0V

NC_, NO_ ...........................................(V

CC

- 6V) to (VCC+ 0.3V)

COM_ (MAX4744/MAX4745).............(V

CC

- 6V) to (VCC+ 0.3V)

COM_ (MAX4744H/MAX4745H/MAX4746H) ..................(Note 1)

Continuous Current NO_, NC_, COM_. ..........................±300mA

Peak Current NO_, NC_, COM_ (pulsed at 1ms, 50%

duty cycle) ...................................................................±400mA

Peak Current NO_, NC_, COM_ (pulsed at 1ms, 10%

duty cycle) ...................................................................±500mA

ESD Protection per Method 3015.7
NO_, NC_, COM_, V

CC

, GND, CB_, EN...............................±2kV

Continuous Power Dissipation (T

A

= +70°C)

10-Pin µDFN (derate 5mW/°C above +70°C) ...............403mW

Operating Temperature Range ...........................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

ELECTRICAL CHARACTERISTICS

(VCC= +2.7V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VCC= 3.3V, TA= +25°C.) (Note 2)

)

)

Note 1: If VCC> 0.5V, limits are (VCC- 6V) to (VCC+ 0.3V). If VCC< 0.5V, limits are (VCC- 6.0V) to +6.0V.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER SUPPLY

Supply-Voltage Range V

Supply Current I

ANALOG SWITCH

Analog Signal Range

On-Resistance (Note 4) R

On-Resistance Match Between
Channels (Notes 4 and 5)

On-Resistance Flatness (Note 6) R

Shunt Switch Resistance R

NC_, NO_ Off-Leakage Current
(Note 3)

COM_ On-Leakage Current
(Note 3)

CC

CC

_,

V

NC

V

_,

NO

V

COM

ON

ΔR

ON

FLAT

SH

I

NO_(OFF),

I

NC_(OFF

I

COM_(ON

VCC = 5.5V, VCB_ = 0V or V

VCC = 5.5V, VCB_ = 0.5V or 1.4V 8

VCC = 2.7V, VCB_ = 0.5V or 1.4V 4

(Note 3)

_

VCC = +2.7V; V

- 5.5V, -1V, 0V, 1V,

= V

CC

2V, V

; I

CC

COM_

V

= 2.7V , V

C C

0V , I

V

C C

V

C C

V

C C

= 100m A

C OM _

= + 2.7V , V

- 5.5V , - 1V , 0V , 1V , 2V ,
; I

C OM _

MAX4744/MAX4744H/MAX4746H only,

= 2.7V

V

CC

V

= + 2.7V sw i tch op en;

C C

or V

V

N C _

N O

( M AX 4745/M AX 4745H onl y)
( M AX 4746H - I

V

= 2.7V sw i tch cl osed ;

C C

or V

V

N C _

V

N O

_ = - 2.5V , + 2.5V

C OM

1.8 5.5 V

CC

V

CC

0.3 1

- 5.5V

or VNO_

NC_

= 100mA

TA = +25°C 0.6 0.95

= T

MIN

to

T
T

A

MAX

TA = +25°C 0.1

_ or V

N C

N C

= 100m A

_ or V

N O

_ =

T

= T

= T

MIN

MIN

to

to

A

T

MAX

TA = +25°C 0.55

_ =

N O

T

A

T

MAX

25kΩ

TA = +25°C -15 +15

_ = - 2.5V , + 2.5V

) onl y)

N O_ ( OFF

T
T

= T

A

MAX

MIN

to

-50 +50

TA = +25°C -15 +15

_ = - 2.5V , + 2.5V ;

T
T

= T

A

MAX

MIN

to

-100 +100

V

CC

1.0

0.1

0.6

µA

V

Ω

Ω

Ω

nA

nA

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless

Switches with Negative Rail Capability

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +2.7V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VCC= 3.3V, TA= +25°C.) (Note 2)

)

)

)

COM_ Leakage Under Protection
Conditions

DYNAMIC CHARACTERISTICS

Turn-On Time t

Turn-Off Time t

Break-Before-Make Delay Time t

Power-Supply Rejection Ratio PSRR

Charge Injection Q V

Off-Isolation V

Crosstalk V

Total Harmonic Distortion THD

NO_, NC_ Off-Capacitance

COM On-Capacitance C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

I

L(PROT

ON

OFF

D

ISO

CT

C

NO_(OFF),

C

NC_(OFF

COM_(ON

VCC = 0V; V
V

_ and VNO_ are

NC

unconnected or connected to
GND; V

CB

(MAX4744H/MAX4745H/
MAX4746H only)

V

= 2.7V ,

C C

= 32Ω ,

R

L

C

= 35p F, Fi g ur e 2

L

VCC = 2.7V, RL =

= 35pF,

32Ω, C

L

Figure 2

VCC = 2.7V, VNC_ = V
V

_ = VCC to 0V; for NC_, VCB_ = 0V to

CB

; RL = 32Ω; CL = 35pF; Figure 3

V

CC

f = 100kHz, V
C

= 5pF

L

_ = 0V; R

GEN

CL = 5pF; RL = 50Ω; f = 100kHz;
V

_ = 1V

COM

CL = 5pF; RL = 50Ω;
f = 100kHz; V

f = 20Hz to 20kHz, V
R

= 50Ω

L

f = 1MHz, Figure 6 90 pF

f = 1MHz, Figure 6 300 pF

_ = +5.5V;

COM

_ = 0V

_ = 1V

COM

= 0Ω, CL = 1nF, Figure 4 450 pC

GEN

; Figure 5 (Note 7)

RMS

_ = 1V

COM

For N O_, V

= 0V to V

V

C B_

For N C _, V
V

= V

C B_

For N O_, V

= V

V

C B_

For N C _, V

= 0V to V

V

C B_

= 1.5V; for NO_,

NO_

, RL = 50Ω,

RMS

; Figure 5

RMS

= 0.5V

COM_

TA = +25°C 30

T

= T

MIN

= 1.5V ,

C C

= 1.5V ,

= 1.5V ,

= 1.5V ,

C C

,

to

C C

C C

A

T

MAX

N O_

N C _

to 0V

N O_

to 0V

N C _

P-P

500

55

560

540

36

20 ns

52 dB

-68 dB

-75 dB

0.01 %

nA

ns

ns

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless
Switches with Negative Rail Capability

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +2.7V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VCC= 3.3V, TA= +25°C.) (Note 2)

Note 2: All parameters are production tested at TA= +25°C and guaranteed by design over the specified temperature range.
Note 3: Signals on COM_, NO_, or NC_ exceeding V

CC

are clamped by internal diodes. Limit forward-diode current to maximum

current ratings.

Note 4: Guaranteed by design; not production tested.
Note 5: ΔR

ON

= R

ON(MAX)

- R

ON(MIN)

.

Note 6: Flatness is defined as the difference between the maximum and minimum value of on-resistance as measured over the

specified analog signal ranges.

Note 7: Off-isolation = 20log

10[VCOM_

/ V

NO_

], V

COM_

= output, V

NO_

= input to off switch.

Typical Operating Characteristics

(VCC= +3.3V, TA = +25°C, unless otherwise noted.)

0

0.6

1.2

1.8

2.4

3.0

-4 -1 0-3-2 12345

ON-RESISTANCE

vs. COM VOLTAGE

MAX4744 toc01

COM VOLTAGE (V)

ON-RESISTANCE (Ω)

VCC = +1.8V

VCC = +3V

VCC = +5V

0.1

0.2

0.4

0.3

0.5

0.6

-2.5 -0.3-1.4 0.8 1.9 3.0

ON-RESISTANCE

vs. COM VOLTAGE

MAX4744 toc02

COM VOLTAGE (V)

ON-RESISTANCE (Ω)

TA = +85°C

TA = +25°C

TA = -40°C

VCC = 3V

0

0.1

0.3

0.2

0.4

0.5

-0.5 1.70.6 2.8 3.9 5.0

ON-RESISTANCE

vs. COM VOLTAGE

MAX4744 toc03

COM VOLTAGE (V)

ON-RESISTANCE (Ω)

TA = +85°C

TA = +25°C

TA = -40°C

VCC = 5V

DIGITAL INPUTS (CB_, EN)

Input-Logic High V

Input-Logic Low V

Input Leakage Current I

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

IH

IL

LEAK

VCB_ or VEN = 0V or V

CC

1.4 V

0.5 V

-1 +1 µA

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless

Switches with Negative Rail Capability

_______________________________________________________________________________________

5

300

400

600

500

700

800

NC_ TURN-ON/NO_ TURN-OFF TIME

vs. SUPPLY VOLTAGE

MAX4744 toc04

SUPPLY VOLTAGE (V)

TIME (ns)

1.8 3.82.8 4.8

NC_ TURN-ON TIME

NO_ TURN-OFF TIME

5.5

20

40

60

80

100

120

140

1.8 2.82.3 3.3 3.8 4.3 4.8 5.3

NO_ TURN-ON/NC_ TURN-OFF TIME

vs. SUPPLY VOLTAGE

MAX4744 toc05

SUPPLY VOLTAGE (V)

TIME (ns)

NO_ TURN-ON TIME

NC_ TURN-OFF TIME

0

40

80

120

160

200

240

-40 -10-25 5 20 35 50 65 80

NO_ TURN-ON/NC_ TURN-OFF TIME

vs. TEMPERATURE

MAX4744 toc06

TEMPERATURE (°C)

TURN-ON/TURN-OFF TIME (ns)

NO_ t

ON

NC_ t

OFF

400

500

600

700

800

900

-40 -10-25 5 20 35 50 65 80

NO_ TURN-ON/NC_ TURN-OFF TIME

vs. TEMPERATURE

MAX4744 toc07

TEMPERATURE (°C)

TURN-ON/TURN-OFF TIME (ns)

NC_ t

ON

NO_ t

OFF

0

0.4

1.2

0.8

1.6

2.0

1.8 3.42.6 4.2 5.0

LOGIC THRESHOLD

vs. SUPPLY VOLTAGE

MAX4744 toc08

SUPPLY VOLTAGE (V)

LOGIC THRESHOLD (V)

V

CB_

RISING

V

CB_

FALLING

5.5

0

0.3

0.9

0.6

1.2

1.5

SUPPLY CURRENT

vs. LOGIC-INPUT VOLTAGE

MAX4744 toc09

DIGITAL INPUT VOLTAGE (V)

SUPPLY CURRENT (μA)

0 2.01.0 3.0

0.5

1.4

0

200

600

400

800

1000

00.20.1 0.3 0.4 0.5

COM PROTECTION LEAKAGE CURRENT

vs. SUPPLY VOLTAGE

MAX4744 toc10

SUPPLY VOLTAGE (V)

COM PROTECTION LEAKAGE CURRENT (nA)

TA = +85°C

TA = +25°C

TA = -40°C

200

400

300

600

500

700

800

1.8

3.8

2.8

4.8

CHARGE INJECTION

vs. SUPPLY VOLTAGE

MAX4744 toc11

SUPPLY VOLTAGE (V)

CHARGE INJECTION (pC)

5.5

Typical Operating Characteristics

(VCC= +3.3V, TA = +25°C, unless otherwise noted.)

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless
Switches with Negative Rail Capability

6 _______________________________________________________________________________________

-40

-80

-50

-60

-70

0.001 0.01 10 100

OFF-ISOLATION vs. FREQUENCY

MAX4744 toc14

FREQUENCY (MHz)

OFF-ISOLATION (dB)

0.1 1

0

-100

-20

-40

-60

-80

0.001 0.01 10 100

CROSSTALK vs. FREQUENCY

MAX4744 toc15

FREQUENCY (MHz)

CROSSTALK (dB)

0.1 1

0.01 10.1 10 100

TOTAL HARMONIC DISTORTION

vs. FREQUENCY

MAX4744 toc16

FREQUENCY (kHz)

THD (%)

1

0.001

0.1

0.01

80

0

60

40

20

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

MAX4744 toc17

FREQUENCY (MHz)

PSRR (dB)

0.001 0.1 10.01

Typical Operating Characteristics (continued)

(VCC= +3.3V, TA = +25°C, unless otherwise noted.)

1000

100

10

1.0

0.1

-40 10-15 35 60 85

LEAKAGE CURRENT

vs. TEMPERATURE

MAX4744 toc12

TEMPERATURE (°C)

LEAKAGE CURRENT (nA)

ON

OFF

0

-6

0.001 1 100.10.01 100

FREQUENCY RESPONSE

MAX4744 toc13

FREQUENCY (MHz)

ON-LOSS (dB)

-5

-4

-3

-2

-1

Detailed Description

The MAX4744/MAX4744H/MAX4745/MAX4745H/
MAX4746H are low on-resistance, low-voltage, dual­SPDT analog switches that operate from a +1.8V to
+5.5V single supply. These devices feature a negative
signal capability that allows signals as low as V

CC

-

5.5V to pass through without distortion.

The MAX4744/MAX4745 feature two digital control bits
to control each switch independently (see Table 1). The
MAX4744H/MAX4745H/MAX4746H have one control bit
to switch both switches and an enable input EN to put
the switches in a high-impedance mode. Driving EN
low takes the switches out of high impedance and CB0
controls both switches (see Table 2).

The MAX4744/MAX4744H have internal shunt resistors
on all NO and NC terminals, and the MAX4746H has
internal shunt resistors on NC terminals to suppress
click-and-pop sounds that can occur when switching
audio signals between precharged points.

Applications Information

Digital Control Inputs

The MAX4744/MAX4744H/MAX4745/MAX4745H/
MAX4746H logic inputs accept up to +5.5V, regardless
of supply voltage. For example, with a +3.3V supply,
CB0, CB1, CB2, and EN can be driven low to GND and

high to +5.5V, allowing for mixed logic levels in a sys­tem. Driving CB0, CB1, CB2, and EN rail-to-rail mini­mizes power consumption.

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless

Switches with Negative Rail Capability

_______________________________________________________________________________________ 7

Pin Description

Table 1. MAX4744/MAX4745 Truth Table

Table 2. MAX4744H/MAX4745H/MAX4746H
Truth Table

X = Don’t Care

PIN

MAX4744/

MAX4745

1 — CB1 Digital Control Input for Analog Switch 1

—1EN

2 2 NO1 Analog Switch 1—Normally Open Terminal

3 3 GND Ground

4 4 NO2 Analog Switch 2—Normally Open Terminal

5 — CB2 Digital Control Input for Analog Switch 2

— 5 CB0 Digital Control Input for Analog Switches 1 and 2

6 6 COM2 Analog Switch 2—Common Terminal

7 7 NC2 Analog Switch 2—Normally Closed Terminal

88V

9 9 NC1 Analog Switch 1—Normally Closed Terminal

10 10 COM1 Analog Switch 1—Common Terminal

MAX4744H/
MAX4745H/

MAX4746H

NAME FUNCTION

Enable Input. Driving EN high causes all switches to be high impedance. Pull EN low for
normal operation.

Positive Supply Voltage from +1.8V to +5.5V

CC

CONTROL SWITCH STATE

CB1 CB2 Switch 1 Switch 2

0 0 Connected to NC1 Connected to NC2

0 1 Connected to NC1 Connected to NO2

1 0 Connected to NO1 Connected to NC2

1 1 Connected to NO1 Connected to NO2

CONTROL SWITCH STATE

EN CB0 Switch 1 Switch 2

0 0 Connected to NC1 Connected to NC2

0 1 Connected to NO1 Connected to NO2

1 X High Impedance High Impedance

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless
Switches with Negative Rail Capability

8 _______________________________________________________________________________________

Figure 1. Functional Diagram

NC1

NO1

SHUNT

SWITCH

NC2

NO2

NC1

NO1

MAX4744

SWITCH 1

SWITCH 2

SWITCH 1

GND

V

CC

COM1

CB1
CB2

COM2

V

CC

COM1

CB1
CB2

NC1

NO1

SHUNT

SWITCH

NC2

NO2

NC1

NO1

HIGH-Z

HIGH-Z

HIGH-Z

MAX4744H

CONTROL

MAX4745HMAX4745

CONTROL

SWITCH 1

LOGIC

SWITCH 2

SWITCH 1

LOGIC

GND

V

CC

COM1

EN
CB0

COM2

V

CC

COM1

EN
CB0

SWITCH 1

CONTROL

LOGIC

SWITCH 2

NC2

NO2

GND

HIGH-Z

V

CC

COM1

EN
CB0

COM2

SWITCH 2

COM2

GND

NC2

NO2

SWITCH 2

NO1

NC1

SHUNT

SWITCH

NC2

NO2

COM2

GND

MAX4746H

HIGH-Z

HIGH-Z

Analog Signal Levels

These devices pass signals from VCCto as low as
VCC- 5.5V, including signals below ground with minimal
distortion and very little change in on-resistance (see the

Typical Operating Characteristics

). The switches are bidi­rectional, so the NO_, NC_, and COM_ terminals can be
used as either inputs or outputs.

COM_ Protection with VCC= 0V

(MAX4744H/MAX4745H/MAX4746H)

This feature prevents any damage to the device due to
improper power-supply sequencing. The protection
applies if a signal is applied on COM_ when VCCis less
than 0.5V. The switch is not protected if VCCgoes
above 0.5V due to parasitic capacitive coupling or any

leakage between COM_ and VCC. The signal at COM_
ranges between (V

CC

- 6.0V) to 6.0V under protection

conditions.

Click-and-Pop Suppression

The MAX4744/MAX4744H have a shunt resistor on all
their NO and NC terminals to automatically discharge
any capacitance when they are not connected to COM.
The shunt resistor reduces audible click-and-pop
sounds that occur when switching between audio
sources. Audible clicks and pops are caused when a
step DC voltage is switched into the speaker. The DC
step transients can be reduced by automatically dis­charging the side that is not connected to the COM ter­minal, reducing any residual DC voltage and reducing
clicks and pops.

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless

Switches with Negative Rail Capability

_______________________________________________________________________________________ 9

Figure 2. Switching Time

Figure 3. Break-Before-Make Interval

Test Circuits/Timing Diagrams

MAX4744/MAX4745/

MAX4744H/MAX4745H/

MAX4746H

V

OR V

NC_

NO_

LOGIC
INPUT

MAX4744/MAX4745/

MAX4744H/MAX4745H/

MAX4746H

V

= V

NC_

NO_

LOGIC
INPUT

V

CC

V

CC

GND

COM_

L

)

ON

V

CC

V

CC

COM_

R

NO_
OR NC_

CB_

GND

C

INCLUDES FIXTURE AND STRAY CAPACITANCE

L

V
RL + R

R

= V

OUT

N_ (

NC_

NO_

CB_

C

INCLUDES FIXTURE AND STRAY CAPACITANCE

L

V

CC

LOGIC
INPUT

LOGIC

INPUT

V

OUT

0V

0V

V

CC

0V

V

OUT

R

L

L

C

L

SWITCH

OUTPUT

V

OUT

C

L

50%

V

OUT

0.8 x V

0UT

t

ON

IN DEPENDS ON SWITCH CONFIGURATION;
INPUT POLARITY DETERMINED BY SENSE OF SWITCH.

50%

t

BBM

tr < 5ns
tf < 5ns

t

OFF

0.2 x V

OUT

0.9 x V

OUT

Break-Before-Make Switching

All devices feature break-before-make switching, which
is configured to break (open) the first set of contacts
before engaging (closing) the new contacts. This pre­vents the momentary connection of the old and new sig­nal paths to the output, reducing click-and-pop sounds.

Power-Supply Sequencing and

Overvoltage Protection

Caution: Do not exceed the Absolute Maximum
Ratings since stresses beyond the listed ratings
may cause permanent damage to the device.

Proper power-supply sequencing is recommended for
all CMOS devices. Improper supply sequencing can
force the switch into latch-up, causing it to draw exces­sive supply current. The only way out of latch-up is to
recycle the power and reapply properly. Connect all
ground pins first, then apply power to VCC, and finally
apply signals to NO_, NC_, and COM_. Follow the
reverse order upon power-down.

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless
Switches with Negative Rail Capability

10 ______________________________________________________________________________________

Figure 4. Charge Injection

Figure 5. Off-Isolation, On-Loss, and Crosstalk

Test Circuits/Timing Diagrams

V

MAX4744/MAX4745/

MAX4744H/MAX4745H/

MAX4746H

0V OR

V

CC

CB_

NC_

COM_

GND

MAX4744H
MAX4746H

V

CC

V

CC

MAX4744

GND

10nF

CB_

V

COM_

NO_

V

OR NO_

TO V

IL

CC

CC

NC_

IH

V

OUT

C

L

V

IN

V

OUT

MEAS REF

V

OUT

CB_

CB_

NETWORK
ANALYZER

50Ω 50Ω

50Ω 50Ω

OFF

OFF

LOGIC INPUT WAVEFORMS INVERTED FOR SWITCHES
THAT HAVE THE OPPOSITE LOGIC SENSE.

ON

ON

Q = (ΔV

OUT

OFF-ISOLATION = 20log

OFF-LOSS = 20log

CROSSTALK = 20log

ΔV

)(CL)

OUT

OFF

OFF

V

V

V

V

V

OUT

V

OUT

OUT

IN

IN

IN

MEASUREMENTS ARE STANDARDIZED AGAINST SHORT AND OPEN AT SOCKET TERMINALS.
OFF-ISOLATION IS MEASURED BETWEEN COM_ AND OFF NO_ OR NC_ TERMINALS.
ON-LOSS IS MEASURED BETWEEN COM_ AND ON NO_ OR NC_ TERMINAL ON EACH SWITCH.
CROSSTALK IS MEASURED FROM ONE CHANNEL TO THE OTHER CHANNEL.
SIGNAL DIRECTION THROUGH SWITCH IS REVERSED; WORST VALUES ARE RECORDED.

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746HMAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

______________________________________________________________________________________ 11

Figure 6. Channel Off-/On-Capacitance

Typical Operating Circuit

Chip Information

PROCESS: BiCMOS

Low-Voltage, Dual SPDT, Audio Clickless

Switches with Negative Rail Capability

______________________________________________________________________________________ 11

V

CC

10nF

COM_

CAPACITANCE

ANALYZER

f = 1MHz

NC_ OR
NO_

MAX4744

MAX4744H

MAX4745
MAX4745H
MAX4746H

GND

CB_

MAX4744

NC2

NO2

NC1

NO1

SHUNT
SWITCH

COM1

CB1

CB2

COM2

MAXIM

DirectDrive™

AUDIO AMP

OR V

V

IL

IH

AUDIO

MAX4744/MAX4744H/MAX4745/MAX4745H/MAX4746H

Low-Voltage, Dual SPDT, Audio Clickless
Switches with Negative Rail Capability

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

© 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages

.)

CARDENAS

XXXX
XXXX
XXXX

PIN 1
INDEX AREA

-DRAWING NOT TO SCALE-

COMMON DIMENSIONS

SYMBOL MIN. NOM.

A

A1

A2

D 1.95 2.00

E

L

L1

D

SAMPLE
MARKING

7

A1

0.70 0.75

0.15 0.20 0.25

0.020 0.025 0.035

1.95 2.00

0.30 0.40

-

0.10 REF.

A

E

A

MAX.

0.80

2.05

2.05

0.50

b

A2

L

L

e

C
L

e

EVEN TERMINAL

b

A A

(N/2 -1) x e)

PACKAGE OUTLINE,
6, 8, 10L uDFN, 2x2x0.80 mm

21-0164

N

1

C

L

e

ODD TERMINAL

SOLDER
MASK
COVERAGE

PIN 1

0.10x45∞

L1

L

1

A

2

6, 8, 10L UDFN.EPS

PACKAGE VARIATIONS

PKG. CODE N e b

6L622-1 0.65 BSC 0.30±0.05

-DRAWING NOT TO SCALE-

(N/2 -1) x e

1.30 REF.

0.25±0.050.50 BSC8L822-1

1.50 REF.

0.20±0.030.40 BSC10L1022-1

1.60 REF.

PACKAGE OUTLINE,
6, 8, 10L uDFN, 2x2x0.80 mm

21-0164

2

A

2