General Description
The MAX4855 dual, single-pole/double-throw (SPDT)
switch operates from a single +2V to +5.5V supply and
features rail-to-rail signal handling. The MAX4855 has
low on-resistance (0.75Ω) with a +3V supply making it
ideal for audio switching applications in portable
devices. The device also integrates two internal com-
parators that can be used for headphone detection or
mute/send key functions.
The MAX4855 is available in the space-saving (3mm x
3mm), 16-pin thin QFN package and operates over the
extended temperature range of -40°C to +85°C.
Applications
Speaker Headset Switching
Audio-Signal Routing
Cellular Phones
Notebook Computers
PDAs and Other Handheld Devices
Features
♦Audio Signal Routing
♦0.75ΩOn-Resistance
♦0.18ΩOn-Resistance Flatness
♦0.07ΩChannel-to-Channel Matching
♦Rail-to-Rail Signal Handling
♦2 Integrated Comparators
♦1.8V Logic Compatible
♦2V to 5.5V Supply Range
♦Available in a Space-Saving (3mm x 3mm),
16-Pin TQFN Package
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
________________________________________________________________ Maxim Integrated Products 1
TOP VIEW
16
1
2
3
4
12
11
10
9
15 14 13
5678
NC1
IN1
VCC
COUT2
NO2
COUT1
COM2
IN2
CIN1
CIN2
COM1
NO1
GND
NC2
N.C.
N.C.
MAX4855
THIN QFN
CONNECT EXPOSED PADDLE TO GROUND.
Pin Configuration
Ordering Information
VCC
3
MAX4855
NC1
NO1
0.75Ω
0.75Ω
NC2
NO2
COUT2
COM1
IN1
IN2
COM2
CIN2
VCC
3
COUT1 CIN1
MAX4855
IN_ NO_ NC_
0 OFF ON
1 ON OFF
SWITCHES SHOWN FOR
LOGIC 0 INPUT
Block Diagram/Truth Table
19-3377; Rev 0; 7/04
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.
*EP = Exposed paddle.
PART
TEMP RANGE
PIN-
PACKAGE TOP
MARK
MAX4855ETE
-40°C to +85°C 16 TQFN-EP*
ABY
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
2 _______________________________________________________________________________________
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.
Note 1: Signals on NO, NC, or COM exceeding VCC or GND are clamped by internal diodes. Signals on IN exceeding GND are
clamped by an internal diode. Limit forward-diode current to maximum current rating.
ELECTRICAL CHARACTERISTICS
(VCC = +2.7V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.0V, TA= +25°C, unless other-
wise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
Supply Voltage VCC 2 5.5 V
Supply Current ICC VCC = 5.5V, VIN_ = 0V or VCC 510µA
ANALOG SWITCH
Analog Signal Range VNO_,
VNC_,
VCOM_ 0
VCC
V
TA = +25°C
0.75
1
On-Resistance (Note 3) RON VCC = 2.7V, ICOM_ =
100mA, VNC_ or VNO_ = 0V
to VCC TA = -40°C to +85°C 1.1 Ω
TA = +25°C
0.075 0.120
On-Resistance Match
Between Channels
(Notes 3, 4) ∆RON VCC = 2.7V, ICOM = 100mA,
VNC_ or VNO_ = 1.5V TA = -40°C to +85°C
0.135
Ω
TA = +25°C
0.18 0.275
On-Resistance Flatness
(Note 5) RFLAT VCC = 2.7V, ICOM_ =
100mA, VNC_ or VNO_ =
0.75V, 1.5V, 1.75V TA = -40°C to +85°C 0.3 Ω
TA = +25°C -2 +2
NO_/NC_ Off-Leakage
Current (Note 2) IOFF VCC = 5.5V, VNC_ or VNO_ =
1V or 4.5V, VCOM_ = 4.5V or
1V TA = -40°C to +85°C -10
+10
nA
TA = +25°C -2 +2
COM_ On-Leakage
Current (Note 2) ION VCC = 5.5V; VNC_ or VNO_ =
1V, 4.5V, or floating; VCOM_
= 1V, 4.5V, or floating TA = -40°C to +85°C -15
+15
nA
DYNAMIC CHARACTERISTICS
TA = +25°C 40 60
Turn-On Time tON VCC = 2.7V, VNO_ or VNC_ =
1.5V, RL = 300Ω, CL = 50pF
(Figure 1) TA = -40°C to +85°C 100 ns
ABSOLUTE MAXIMUM RATINGS
VCC, IN_, CIN_ to GND ..............................................-0.3V to +6.0V
NO_, NC_, COM_, COUT_ (Note 1) ...............-0.3V to (VCC + 0.3V)
COUT_ Continuous Current...................................................±20mA
Closed Switch Continuous Current COM_, NO_, NC_.......±300mA
Peak Current COM_, NO_, NC_
(pulsed at 1ms, 50% duty cycle) ....................................±400mA
Peak Current COM_, NO_, NC_
(pulsed at 1ms, 10% duty cycle) ....................................±500mA
Continuous Power Dissipation (TA= +70°C)
16-Pin Thin QFN (derate 20.8mW/°C above +70°C).....1667mW
Operating Temperature Range................................-40°C to +85°C
Junction Temperature...........................................................+150°C
Storage Temperature Range .................................-65°C to +150°C
Lead Temperature (soldering, 10s)......................................+300°C
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +2.7V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +3.0V, TA= +25°C, unless other-
wise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
TA = +25°C 30 40
Turn-Off Time tOFF VCC = 2.7V, VNO_ or VNC_ =
1.5V, RL = 300Ω, CL = 50pF
(Figure 1) TA = -40°C to +85°C 60 ns
TA = +25°C 15
Break-Before-Make Time
Delay (Note 3) tDVCC = 2.7V, VNO_ or VNC_ =
1.5V, RL = 50Ω, CL = 50pF
(Figure 2) TA = -40°C to +85°C 2 ns
Charge Injection Q VCOM_ = 1.5V, RS = 0Ω, CL = 1.0nF (Figure 3)
170
pC
Off-Isolation (Note 6) f = 100kHz, VCOM_= 1VRMS, RL = 50Ω, CL = 5pF
(Figure 4) -75 dB
Crosstalk VCT f = 100kHz, VCOM_= 1VRMS, RL = 50Ω, CL = 5pF
(Figure 4) -93 dB
-3dB Bandwidth BW Signal = 0dBm, RL = 50Ω, CL = 5pF (Figure 4) 38
MHz
Total Harmonic Distortion
THD f = 20Hz to 20kHz, VCOM_ = 1V + 2VP-P, RL = 32Ω
0.07
%
NO_/NC_ Off-
Capacitance COFF f = 1MHz (Figure 5) 50 pF
COM On-Capacitance CON f = 1MHz (Figure 5)
150
pF
DIGITAL I/O (IN_) VCC = 2V to 3.6V 1.4
Input-Logic High Voltage
VIH VCC = 3.6V to 5.5V 1.8 V
VCC = 2V to 3.6V 0.5
Input-Logic Low Voltage
VIL VCC = 3.6V to 5.5V 0.8 V
Input Leakage Current IIN VIN_ = 0 or 5.5V
-0.5 +0.5
µA
COMPARATOR
Comparator Range 0 5.5 V
Comparator Threshold VCC = 2V to 5.5V, falling input 0.3 x
VCC
0.33 x
VCC
0.36 x
VCC
V
Comparator Hysteresis VCC = 2V to 5.5V 50 mV
Comparator Output High
Voltage ISOURCE = 1mA VCC -
0.4V
V
Comparator Output Low
Voltage ISINK = 1mA 0.4 V
Rising input (Figure 6) 2.5
Comparator Switching
Time Falling input (Figure 6) 0.5 µs
Note 2: Specifications are 100% tested at TA= +85°C only, and guaranteed by design and characterization over the specified
temperature range.
Note 3: Guaranteed by design and characterization; not production tested.
Note 4: ∆RON = RON(MAX) - RON(MIN).
Note 5: Flatness is defined as the difference between the maximum and minimum value of on-resistance as measured over the
specified analog signal ranges.
Note 6: Off-Isolation = 20log10 (VCOM_ / VNO_), VCOM_ = output, VNO_ = input to off switch.
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VCC = 3.0V, TA = +25°C, unless otherwise noted.)
ON-RESISTANCE vs. COM VOLTAGE
MAX4855 toc01
COM VOLTAGE (V)
ON-RESISTANCE (Ω)
42
006
VCC = 5.0V
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0
VCC = 3.0V
VCC = 2.5V
VCC = 2.3V
VCC = 1.8V
VCC = 2.0V
ON-RESISTANCE vs. COM VOLTAGE
MAX4855 toc02
COM VOLTAGE (V)
ON-RESISTANCE (Ω)
VCC = 3.0V
TA = +85°CTA = +25°C
TA = -40°C
2.52.01.51.00.5
0.2
0.4
0.6
0.8
1.0
00 3.0
4321
0.2
0.4
0.6
0.8
1.0
005
ON-RESISTANCE vs. COM VOLTAGE
MAX4855 toc03
COM VOLTAGE (V)
ON-RESISTANCE (Ω)
VCC = 5.0V
TA = +85°CTA = +25°C
TA = -40°C
MAX4855 toc04
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
4.53.52.51.5 5.5
TA = -40°C
TA = +85°C
TA = +25°C
3
4
5
6
2
TURN-ON/TURN-OFF TIME
vs. SUPPLY VOLTAGE
MAX4855 toc05
SUPPLY VOLTAGE (V)
TURN-ON/TURN-OFF TIME (ns)
4.53.52.51.5 5.5
tON
tOFF
10
20
30
40
50
60
70
0
TURN-ON/TURN-OFF TIME
vs. TEMPERATURE
MAX4855 toc06
TEMPERATURE (°C)
TURN-ON/TURN-OFF TIME (ns)
603510-15-40 85
tOFF
tON
24
26
28
30
32
34
36
38
22
LOGIC THRESHOLD vs. SUPPLY VOLTAGE
MAX4855 toc07
SUPPLY VOLTAGE (V)
LOGIC THRESHOLD (V)
4.53.52.5
0.8
1.0
1.2
1.4
1.6
0.6 1.5 5.5
VIN RISING
VIN FALLING
CHARGE INJECTION vs. COM VOLTAGE
MAX4855 toc08
COM VOLTAGE (V)
CHARGE INJECTION (pC)
432105
VCC = 3V
20
40
60
80
100
120
140
160
180
200
0
VCC = 5V
LEAKAGE CURRENT vs. TEMPERATURE
MAX4855 toc09
TEMPERATURE (°C)
LEAKAGE CURRENT (nA)
603510-15-40 85
COM ON-LEAKAGE
COM OFF-LEAKAGE
0.2
0.4
0.6
0.8
0
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
_______________________________________________________________________________________ 5
FREQUENCY RESPONSE
MAX4855 toc10
FREQUENCY (MHz)
FREQUENCY RESPONSE (dB)
-80
-60
-40
-20
0
20
-100 1011000.1
OFF-RESPONSE
ON-RESPONSE
CROSSTALK
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
MAX4855 toc11
FREQUENCY (Hz)
THD (%)
10k1k100
0.1
10 100k
1
0.01
RL = 32Ω
RL = 600Ω
COMPARATOR THRESHOLD
vs. TEMPERATURE
MAX4855 toc12
TEMPERATURE (°C)
COMPARATOR THRESHOLD (V)
603510-15
1.02
1.04
1.06
1.08
1.10
1.00 -40 85
VCMPI_ RISING
VCMPI_ FALLING
VCC = 3.0V
COMPARATOR THRESHOLD
vs. TEMPERATURE
MAX4855 toc13
TEMPERATURE (°C)
COMPARATOR THRESHOLD (V)
603510-15
1.625
1.650
1.675
1.700
1.725
1.750
1.600 -40 85
VCMPI_ RISING
VCMPI_ FALLING
VCC = 5.0V
Typical Operating Characteristics (continued)
(VCC = 3.0V, TA = +25°C, unless otherwise noted.)
MAX4855
Detailed Description
The MAX4855 dual SPDT, low on-resistance, low-voltage,
analog switch operates from a +2V to +5.5V supply and
can handle signals up to the power rails. In addition, the
MAX4855 integrates two internal comparators that can
be used for headphone or mute detection. The compara-
tor threshold is internally generated to be approximately
1/3 of VCC.Applications Information
Digital Control Inputs
The logic inputs (IN_) accept up to +5.5V even if the
supply voltages are below this level. For example, with
a +3.3V VCC supply, IN_ can be driven low to GND and
high to +5.5V allowing for mixing of logic levels in a
system. Driving IN_ rail-to-rail minimizes power con-
sumption. For a +2V supply voltage, the logic thresholds
are 0.5V (low) and 1.4V (high); for a +5V supply voltage,
the logic thresholds are 0.8V (low) and 1.8V (high).
Analog Signal Levels
The on-resistance of these switches changes very little
for analog input signals across the entire supply voltage
range (see the Typical Operating Characteristics). The
switches are bidirectional, so the NO_, NC_, and COM_
pins can be either inputs or outputs.
Comparator
The positive terminal of the comparator is internally set to
VCC/3. When the negative terminal (CIN_) is below the
threshold (VCC/3), the comparator output (COUT_) is
high. When CIN_ rises above VCC/3, COUT_ is low.
The comparator threshold allows for detection of head-
phones since headphone audio signals are typically
biased to VCC/2.
Power-Supply Sequencing
Caution: Do not exceed the absolute maximum rat-
ings because stresses beyond the listed ratings
may cause permanent damage to the device.
Proper power-supply sequencing is recommended for
all CMOS devices. Always apply VCC before applying
analog signals, especially if the analog signal is not
current-limited.
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
6 _______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1, 8 N.C. No Connection. Not internally connected.
2 CIN1 Inverting Input for Comparator 1
3 CIN2 Inverting Input for Comparator 2
4 COM1 Common Terminal for Analog Switch 1
5 NO1 Normally Open Terminal for Analog Switch 1
6 GND Ground
7 NC2 Normally Closed Terminal for Analog Switch 2
9 IN2 Digital Control Input for Analog Switch 2. A logic LOW on IN2 connects COM2 to NC2 and a logic
HIGH connects COM2 to NO2.
10 COM2 Common Terminal for Analog Switch 2
11 COUT1 Output for Comparator 1
12 NO2 Normally Open Terminal for Analog Switch 2
13 COUT2 Output for Comparator 2
14 VCC Supply Voltage. Bypass to GND with a 0.01µF capacitor as close to the pin as possible.
15 IN1 Digital Control Input for Analog Switch 1. A logic LOW on IN1 connects COM1 to NC1 and a logic
HIGH connects COM1 to NO1.
16 NC1 Normally Closed Terminal for Analog Switch 1
EP — Exposed Paddle. Connect to PC board ground plane.
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
_______________________________________________________________________________________ 7
Test Circuits/Timing Diagrams
tR < 20ns
tF < 20ns
50%
LOGIC
INPUT
RL
COM_
GND
IN_
CL INCLUDES FIXTURE AND STRAY CAPACITANCE.
VOUT = VNO ( RL )
RL + RON
VNO
tOFF
0V
NO_
0.9 x V0UT 0.9 x VOUT
tON
VOUT
SWITCH
OUTPUT
LOGIC
INPUT
VCC
CL
VCC
VOUT
MAX4855
VCC
0V
Figure 1. Switching Time
50%
VCC
0V
LOGIC
INPUT
VOUT 0.9 x VOUT
tBBM
LOGIC
INPUT
RL
GND
CL INCLUDES FIXTURE AND STRAY CAPACITANCE.
NO_
IN_
NC_ VOUT
VCC
VCC
CL
VN_ COM_
MAX4855
Figure 2. Break-Before-Make Interval
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
8 _______________________________________________________________________________________
VGEN GND
COM_
CL
VOUT
VCC VOUT
IN OFF ON OFF
∆VOUT
Q = (∆VOUT)(CL)
NC_
LOGIC-INPUT WAVEFORMS INVERTED FOR SWITCHES
THAT HAVE THE OPPOSITE LOGIC SENSE.
OFF ON OFF
IN
VIL TO VIH
VCC
RGEN
IN_
MAX4855
OR NO_
Figure 3. Charge Injection
MEASUREMENTS ARE STANDARDIZED AGAINST SHORTS AT IC TERMINALS.
OFF-ISOLATION IS MEASURED BETWEEN COM_ AND "OFF", NO_ OR NC_ TERMINAL ON EACH SWITCH.
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.
+5V
VOUT
VCC
IN_
NC1
COM1
NO1*
VIN
MAX4855
OFF-ISOLATION = 20log VOUT
VIN
ON-LOSS = 20log VOUT
VIN
CROSSTALK = 20log VOUT
VIN
NETWORK
ANALYZER
50Ω
50Ω50Ω
50Ω
MEAS REF
10nF
0V OR VCC
50ΩGND
*FOR CROSSTALK THIS PIN IS NO2.
NC2 AND COM2 ARE OPEN.
Figure 4. On-Loss, Off-Isolation, and Crosstalk
CAPACITANCE
METER NC_ OR
NO_
COM_
GND
IN VIL OR VIH
10nF VCC
f = 1MHz
VCC MAX4855
Figure 5. Channel Off-/On-Capacitance
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
_______________________________________________________________________________________ 9
MAX4855
VCC
3
VTH + 100mV
VTH - 100mV
VOUT
0V
tCOMP tCOMP
50%
50%
50%
50%
tR < 20ns
tF < 20ns
VCC
VCC
GND
VCOUT_
CIN_ COUT_
VCIN_
NO_
VTH = VCC/3
COMPARATOR
INPUT (VCIN_)
COMPARATOR
OUTPUT (VCOUT_)
Figure 6. Comparator Switching Time
Chip Information
TRANSISTOR COUNT: 735
PROCESS: CMOS
AUDIO
SOURCE 1
AUDIO
SOURCE 2 VCC
3
MUTE
BUTTON
VCC
MAX4855
OUT+
OUT-
OUT+
OUT-
NC1
NO1
NC2
NO2
COUT
COM1
IN1
IN2
COM2
CIN
8Ω
SPEAKER
INPUT
SELECT
MUTE
Typical Operating Circuit
MAX4855
0.75Ω, Dual SPDT Audio Switch with
Integrated Comparators
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.
10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
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.)
12x16L QFN THIN.EPS
0.10 C0.08 C
0.10 M C A B
D
D/2
E/2
E
A1
A2
A
E2
E2/2
L
k
e
(ND - 1) X e
(NE - 1) X e
D2
D2/2
b
L
e
L
C
L
e
C
L
L
C
L
C
E12
21-0136
PACKAGE OUTLINE
12, 16L, THIN QFN, 3x3x0.8mm
1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994.
EXPOSED PAD VARIATIONS
2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES.
3. N IS THE TOTAL NUMBER OF TERMINALS.
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO
JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED
WITHIN THE ZONE INDICATED. THE TERMINAL #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE.
5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.20 mm AND 0.25 mm
FROM TERMINAL TIP.
6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY.
7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION.
8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS.
9. DRAWING CONFORMS TO JEDEC MO220 REVISION C.
NOTES:
E
22
21-0136
PACKAGE OUTLINE
12, 16L, THIN QFN, 3x3x0.8mm
DOWN
BONDS
ALLOWED
