19-0563; Rev 0; 5/06
Low-Voltage, Dual SPDT, Audio Clickless
Switches With Negative Rail Capability
General Description
The MAX4744/MAX4744H/MAX4745/MAX4745H 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 ana-
log switches have a low on-resistance, low supply cur-
rent, 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 nor-
mally open (NO) and normally closed (NC) terminals
when they are not connected. This reduces click-and-pop
sounds that occur when switching audio signals between
pre-charged points. A break-before-make feature further
reduces popping. The MAX4744/MAX4745 control the
switches with two control bits CB1 and CB2. The
MAX4744H/MAX4745H 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
also have an internal protection network against voltages
applied to COM_ when V
CC
= 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.
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
Pin Configurations
TOP VIEW
COM1 NC1 V
CC
NC2 COM2
10
9
8
7
6
COM1 NC1 V
CC
10
9
8
NC2 COM2
7
6
Applications
Speaker Switching
Power Routing
Cellular Phones
MP3 Players
PDAs and other Handheld Devices
Notebook Computers
MAX4744
MAX4745
+
+
MAX4744H
MAX4745H
1
2
3
4
5
1
EN
2
3
4
5
CB1 NO1 GND NO2 CB2
NO1 GND NO2 CB0
μDFN
(2mm x 2mm)
μDFN
(2mm x 2mm)
Ordering Information
PART
MAX4744ELB+T
MAX4744HELB+T
MAX4745ELB+T
MAX4745HELB+T
PIN-
PACKAGE
10 µDFN-10
10 µDFN-10
10 µDFN-10
10 µDFN-10
TOP
MARK
+AAF
+AAG
+AAH
+AAI
CLICKLESS
Yes
Yes
No
No
COM PROTECTION
No
Yes
No
Yes
PKG CODE
L1022-1
L1022-1
L1022-1
L1022-1
Note:
All devices are specified over the -40°C to +85°C operating temperature range.
+Denotes
lead-free package.
________________________________________________________________
Maxim Integrated Products
1
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.
Low-Voltage, Dual SPDT, Audio Clickless
Switches With Negative Rail Capability
MAX4744/MAX4744H/MAX4745/MAX4745H
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
V
CC
, CB_,
EN
........................................................-0.3V to +6.0V
NC_, NO_ ...........................................(V
CC
- 6V) to (V
CC
+ 0.3V)
COM_ (MAX4744/MAX4745).............(V
CC
- 6V) to (V
CC
+ 0.3V)
COM_ (MAX4744H/MAX4745H)......................................(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
Note 1:
If V
CC
> 0.5V, limits are (V
CC
- 6V) to (V
CC
+ 0.3V). If V
CC
< 0.5V, limits are (V
CC
- 6.0V) to +6.0V.
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.
ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
CC
= 3.3V, T
A
= +25°C.) (Note 2)
PARAMETER
POWER SUPPLY
Supply-Voltage Range
Supply Current
ANALOG SWITCH
Analog Signal Range (Note 3)
V
NC
_,
V
NO
_,
V
COM
_,
V
CC
= 2.7V; V
NC_
or V
NO
_
= V
CC
- 5.5V, -1V, 0V, 1V,
2V, V
CC
; I
COM_
= 100mA
V
CC
= 2.7V, V
NC
_ or V
NO
_ =
0V, I
COM_
= 100mA
V
CC
= 2.7V, V
NC
_ or V
NO
_ =
V
CC
- 5.5V, - 1V, 0V, 1V, 2V,
V
CC
; I
COM_
= 100mA
T
A
= +25°C
T
A
= T
MIN
to
T
MAX
T
A
= +25°C
T
A
= T
MIN
to
T
MAX
T
A
= +25°C
T
A
= T
MIN
to
T
MAX
2
-15
-50
-15
-100
T
A
= +25°C
T
A
= T
MIN
to
T
MAX
V
CC
- 5.5V
0.6
V
CC
0.95
1.0
0.1
0.1
0.55
0.6
5
+15
+50
+15
+100
nA
nA
Ω
kΩ
Ω
Ω
V
V
CC
V
CC
= 5.5V, V
CB
_ = 0V or V
CC
I
CC
V
CC
= 5.5V, V
CB
_ = 0.5V or 1.4V
V
CC
= 2.7V, V
CB
_ = 0.5V or 1.4V
1.8
0.3
5.5
1
8
4
µA
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
On-Resistance (Note 4)
R
ON
On-Resistance Match Between
Channels (Notes 4 and 5)
ΔR
ON
On-Resistance Flatness (Note 6)
Shunt Switch Resistance
NC_, NO_ Off-Leakage Current
(Note 3)
R
FLAT
R
SH
I
NO_(OFF),
I
NC_(OFF)
MAX4744/MAX4744H only, V
CC
= 2.7V
V
CC
= 2.7V switch open;
V
NC_
or V
NO
_ = -2.5, +2.5V
(MAX4745/MAX4745H only)
COM_ On-Leakage Current
(Note 3)
I
COM_(ON)
T
A
= +25°C
V
CC
= 2.7V switch closed;
V
NC_
or V
NO
_ = -2.5, +2.5V; T
A
= T
MIN
to
V
COM
_ = -2.5, +2.5V
T
MAX
2
_______________________________________________________________________________________
Low-Voltage, Dual SPDT, Audio Clickless
Switches With Negative Rail Capability
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
CC
= 3.3V, T
A
= +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
V
CC
= 0V; V
COM
_ = +5.5V;
V
NC
_ and V
NO
_ are
unconnected or connected to
GND; V
CB
_ = 0V
(MAX4744H/MAX4745H only)
T
A
= +25°C
T
A
= T
MIN
to
T
MAX
MIN
TYP
30
nA
500
MAX
UNITS
MAX4744/MAX4744H/MAX4745/MAX4745H
COM_ Leakage Under Protection
Conditions
I
L(PROT)
DYNAMIC CHARACTERISTICS
V
CC
= 2.7V,
R
L
= 32Ω,
C
L
= 35pF, Figure 2
For NO_, V
NO_
= 1.5V,
V
CB_
= 0V to V
CC
For NC_, V
NC_
= 1.5V,
V
CB_
= V
CC
to 0V
For NO_, V
NO_
= 1.5V,
V
CB_
= V
CC
to 0V
For NC_, V
NC_
= 1.5V,
V
CB_
= 0V to V
CC
55
ns
560
540
ns
36
Turn-On Time
t
ON
Turn-Off Time
t
OFF
V
CC
= 2.7V, R
L
=
32Ω, C
L
= 35pF,
Figure 2
Break-Before-Make Delay Time
t
D
V
CC
= 2.7V, V
NC
_ = V
NO_
= 1.5V; for NO_,
V
CB
_ = V
CC
to 0V; for NC_, V
CB
_ = 0V to
V
CC
; R
L
= 32Ω; C
L
= 35pF; Figure 3
f = 100kHz, V
COM
_ = 1V
RMS
, R
L
= 50Ω,
C
L
= 5pF
V
GEN
_ = 0V; R
GEN
= 0Ω, C
L
= 1nF, Figure 4
C
L
= 5pF; R
L
= 50Ω;
f = 100kHz; V
COM
_ = 1V
RMS
; Figure 5
C
L
= 5pF; R
L
= 50Ω;
f = 100kHz; V
COM
_ = 1V
RMS
; Figure 5
f = 20Hz to 20kHz, V
COM_
= 0.5V
P-P
,
R
L
= 50Ω
20
ns
Power-Supply Rejection Ratio
Charge Injection
Off-Isolation (Note 7)
Crosstalk
Total Harmonic Distortion
NO_, NC_ Off-Capacitance
COM On-Capacitance
PSRR
Q
V
ISO
V
CT
THD
52
450
-68
-75
0.01
90
300
dB
pC
dB
dB
%
pF
pF
C
NO_(OFF),
f = 1MHz, Figure 6
C
NC_(OFF)
C
COM_(ON)
f = 1MHz, Figure 6
_______________________________________________________________________________________
3
Low-Voltage, Dual SPDT, Audio Clickless
Switches With Negative Rail Capability
MAX4744/MAX4744H/MAX4745/MAX4745H
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
CC
= 3.3V, T
A
= +25°C.) (Note 2)
PARAMETER
DIGITAL INPUTS (CB_,
EN)
Input-Logic High
Input-Logic Low
Input Leakage Current
V
IH
V
IL
I
LEAK
V
CB
_ or V
EN
= 0V or V
CC
-1
1.4
0.5
+1
V
V
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Note 2:
All parameters are production tested at T
A
= +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
[VC
OM_
/V
NO_
], V
COM_
= output, V
NO_
= input to off switch.
Typical Operating Characteristics
(V
CC
= +3.3V, T
A
= +25°C, unless otherwise noted.)
ON-RESISTANCE
vs. COM VOLTAGE
MAX4744 toc01
ON-RESISTANCE
vs. COM VOLTAGE
MAX4744 toc02
ON-RESISTANCE
vs. COM VOLTAGE
V
CC
= 5V
T
A
= +25°C
0.4
ON-RESISTANCE (Ω)
T
A
= +85°C
MAX4744 toc03
3.0
0.6
V
CC
= 3V
T
A
= +25°C
0.5
2.4
ON-RESISTANCE (Ω)
0.5
ON-RESISTANCE (Ω)
T
A
= +85°C
1.8
0.4
0.3
1.2
V
CC
= +1.8V
0.6
V
CC
= +3V
V
CC
= +5V
0.3
T
A
= -40°C
0.2
T
A
= -40°C
0.2
0.1
0
-4
-3
-2
-1
0
1
2
3
4
5
COM VOLTAGE (V)
0.1
-2.5
-1.4
-0.3
0.8
1.9
3.0
COM VOLTAGE (V)
0
-0.5
0.6
1.7
2.8
3.9
5.0
COM VOLTAGE (V)
4
_______________________________________________________________________________________
Low-Voltage, Dual SPDT, Audio Clickless
Switches With Negative Rail Capability
Typical Operating Characteristics
(V
CC
= +3.3V, T
A
= +25°C, unless otherwise noted.)
NC_ TURN-ON/NO_ TURN-OFF TIME
vs. SUPPLY VOLTAGE
MAX4744 toc04
MAX4744/MAX4744H/MAX4745/MAX4745H
NO_ TURN-ON/NC_ TURN-OFF TIME
vs. SUPPLY VOLTAGE
MAX4744 toc05
NO_ TURN-ON/NC_ TURN-OFF TIME
vs. TEMPERATURE
NO_ t
ON
TURN-ON/TURN-OFF TIME (ns)
200
160
120
80
40
0
MAX4744 toc06
800
140
120
100
240
700
TIME (ns)
NC_ TURN-ON TIME
500
TIME (ns)
600
80
NO_ TURN-ON TIME
60
NC_ TURN-OFF TIME
40
NC_ t
OFF
400
NO_ TURN-OFF TIME
300
1.8
2.8
3.8
4.8
5.5
SUPPLY VOLTAGE (V)
20
1.8
2.3
2.8
3.3
3.8
4.3
4.8
5.3
SUPPLY VOLTAGE (V)
-40
-25 -10
5
20
35
50
65
80
TEMPERATURE (°C)
NO_ TURN-ON/NC_ TURN-OFF TIME
vs. TEMPERATURE
MAX4744 toc07
LOGIC THRESHOLD
vs. SUPPLY VOLTAGE
MAX4744 toc08
SUPPLY CURRENT
vs. LOGIC-INPUT VOLTAGE
MAX4744 toc09
900
NC_ t
ON
2.0
1.5
TURN-ON/TURN-OFF TIME (ns)
800
1.6
LOGIC THRESHOLD (V)
V
CB_
RISING
1.2
1.2
SUPPLY CURRENT (μA)
700
0.9
600
0.8
V
CB_
FALLING
0.6
500
NO_ t
OFF
0.4
0.3
400
-40
-25 -10
5
20
35
50
65
80
TEMPERATURE (°C)
0
1.8
2.6
3.4
4.2
5.0
5.5
SUPPLY VOLTAGE (V)
0
0
0.5
1.0
1.4
2.0
3.0
DIGITAL INPUT VOLTAGE (V)
COM PROTECTION LEAKAGE CURRENT
vs. SUPPLY VOLTAGE
MAX4744 toc10
CHARGE INJECTION
vs. SUPPLY VOLTAGE
MAX4744 toc11
1000
COM PROTECTION LEAKAGE CURRENT (nA)
800
700
CHARGE INJECTION (pC)
600
500
400
300
200
1.8
2.8
3.8
SUPPLY VOLTAGE (V)
4.8
800
600
T
A
= +85°C
T
A
= -40°C
400
200
T
A
= +25°C
0
0
0.1
0.2
0.3
0.4
0.5
SUPPLY VOLTAGE (V)
5.5
_______________________________________________________________________________________
5
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