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.
General Description
The MAX4529 is a low-voltage T-switch designed for
switching RF and video signals from DC to 300MHz in
50Ωand 75Ωsystems. This switch is constructed in a
“T” configuration, ensuring excellent high-frequency off
isolation of -80dB at 10MHz.
The MAX4529 can handle Rail-to-Rail®analog signals
in either direction. On-resistance (70Ωmax) is flat (0.5Ω
max) over the specified signal range, using ±5V sup-
plies. The off leakage current is less than 1nA at +25°C
and 20nA at +85°C.
This CMOS switch can operate with dual power sup-
plies ranging from ±2.7V to ±6V or a single supply
between +2.7V and +12V. All digital inputs have
0.8V/2.4V logic thresholds, ensuring both TTL- and
CMOS-logic compatibility when using ±5V or a single
+5V supply.
________________________Applications
RF Switching
Video Signal Routing
High-Speed Data Acquisition
Test Equipment
ATE Equipment
Networking
____________________________Features
♦High 50ΩOff Isolation: -80dB at 10MHz
♦DC to 300MHz -3dB Signal Bandwidth
♦70ΩSignal Paths with ±5V Supplies
♦10ΩSignal-Path Flatness with ±5V Supplies
♦±2.7V to ±6V Dual Supplies
+2.7V to +12V Single Supply
♦Low Power Consumption: <1µW
♦Rail-to-Rail Bidirectional Signal Handling
♦>2kV ESD Protection per Method 3015.7
♦TTL/CMOS-Compatible Inputs with
Single +5V or ±5V
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
________________________________________________________________ Maxim Integrated Products 1
8
7
6
5
1
2
3
4
MAX4529
DIP/SO/µMAX
V+
COM
N.C.
V-IN
GND
NC
N.C.
N.C. = NOT INTERNALLY CONNECTED
LOGIC SWITCH
0
1
ON
OFF
6
5
4
1
2
3
MAX4529
SOT23-6
COM
GND
INV-
V+
NC
_______________________Pin Configurations/Functional Diagrams/Truth Table
19-1262; Rev 1; 5/01
Ordering Information
*Contact factory for dice specifications.
Rail-to-Rail is a registered trademark of Nippon Motorola Ltd.
PART
MAX4529CPA
MAX4529CSA 0°C to +70°C
0°C to +70°C
TEMP. RANGE PIN-
PACKAGE
8 Plastic DIP
8 Narrow SO
SOT
TOP MARK
—
—
MAX4529CUA
MAX4529
CUT-T
—
0°C to +70°C
0°C to +70°C 8 µMAX
6 SOT23-6 AAAQ
MAX4529C/D
MAX4529EPA
—
-40°C to +85°C
0°C to +70°C Dice*
8 Plastic DIP —
MAX4529ESA
MAX4529EUA
—
-40°C to +85°C
-40°C to +85°C 8 Narrow SO
8 µMAX —
MAX4529
EUT-T
-40°C to +85°C 6 SOT23-6 AAAQ
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS—Dual Supplies
(V+ = +4.5V to +5.5V, V- = -4.5V to -5.5V, VINL = 0.8V, VINH = 2.4V, VGND = 0V, TA= TMIN to TMAX, unless otherwise noted. Typical
values are at TA= +25°C.)
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.
(Voltages referenced to GND)
V+ ...........................................................................-0.3V, +13.0V
V- ............................................................................-13.0V, +0.3V
V+ to V-...................................................................-0.3V, +13.0V
All Other Pins (Note 1) ..........................(V- - 0.3V) to (V+ + 0.3V)
Continuous Current into Any Terminal..............................±10mA
Peak Current into Any Terminal
(pulsed at 1ms, 10% duty cycle)..................................±50mA
ESD per Method 3015.7 ..................................................>2000V
Continuous Power Dissipation (TA= +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ...727mW
8-Pin SO (derate 5.88mW/°C above +70°C)............... 471mW
8-Pin µMAX (derate 4.1mW/°C above +70°C)............. 330mW
6-Pin SOT23-6 (derate 7.1mW/°C above +70°C) ........571mW
Operating Temperature Ranges
MAX4529C_ E.....................................................0°C to +70°C
MAX4529E_ E ..................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: Voltages on all other pins exceeding V+ or V- are clamped by internal diodes. Limit forward diode current to maximum
current rating.
V+ = 5V, V- = -5V,
VCOM = ±3V, ICOM = 1mA
(Note 3)
V+ = 5.5V, V- = -5.5V,
VCOM = ±4.5V
V+ = 5V; V- = -5V; VCOM = 3V,
0V, -3V; ICOM = 1mA
V+ = 5.5V, V- = -5.5V,
VCOM = ±4.5V, VNC = 4.5V
V+ = 5.5V, V- = -5.5V,
VCOM = ±4.5V, VNC = 4.5V
VIN = 0.8V or 2.4V
CONDITIONS
µA-1 0.03 1IINH, IINL
IN Input Current Logic High or
Low
Ω
45 70
RON
Signal-Path On-Resistance
VV- V+VCOM, VNC
Analog Signal Range
V0.8 1.5VINL
IN Input Logic Threshold Low
V1.5 2.4VINH
IN Input Logic Threshold High
nA
-2 0.02 2
ICOM(ON)
COM On Leakage Current
(Notes 5, 6)
Ω510RFLAT(ON)
Signal-Path On-Resistance
Flatness (Note 4)
nA
-1 0.02 1
INC(OFF)
NC Off Leakage Current
(Notes 5, 6)
nA
-1 0.02 1
ICOM(OFF)
COM Off Leakage Current
(Notes 5, 6)
UNITS
MIN TYP MAX
(Note 2)
SYMBOLPARAMETER
+25°C
C, E
C, E
C, E
+25°C
+25°C
+25°C
+25°C
C, E
TA
C, E
C, E
C, E -20 20
-20 20
-40 40
C, E 100
±
ANALOG SWITCH
LOGIC INPUT
±
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
_______________________________________________________________________________________ 3
VIN = 5Vp-p, f < 20kHz,
600Ωin and out
RL= 50Ω, Figure 4
VNC = GND, f = 1MHz, Figure 5
CL= 1.0nF, VNC = 0V, RS= 0Ω,
Figure 3
VCOM = ±3V, V+ = 5V, V- = -5V,
Figure 2
VCOM = ±3V, V+ = 5V, V- = -5V,
Figure 2
CONDITIONS
%0.004THD+NDistortion
MHz300BW-3dB Bandwidth
11.5
pF6CNC(OFF)
NC Off Capacitance
pC510QCharge Injection (Note 3)
ns
37 75
tOFF
Turn-Off Time
ns
45 75
tON
Turn-On Time
UNITS
MIN TYP MAX
(Note 2)
SYMBOLPARAMETER
V+ = 5.5V, VIN = 0V or V+,
V- = -5.5V
µA
-1 0.05 1
I-V - Supply Current
µA
-1 0.05 1
I+V+ Supply Current
V±2.7 ±6V+, V-Power-Supply Range
+25°C
+25°C
+25°C
+25°C
+25°C
+25°C
TA
+25°C
+25°C
C, E
VCOM = VNC = 0V, f = 1MHz,
Figure 5 pFCCOM(ON)
COM_ On Capacitance +25°C
C, E -10 10
C, E -10 10
C, E 100
C, E 100
ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)
(V+ = +4.5V to +5.5V, V- = -4.5V to -5.5V, VINL = 0.8V, VINH = 2.4V, VGND = 0V, TA= TMIN to TMAX, unless otherwise noted. Typical
values are at TA= +25°C.)
VCOM = 0V, f = 1MHz, Figure 5 pF6CCOM(OFF)
COM_ Off Capacitance +25°C
-80
RL= 50Ω, VCOM = 1VRMS,
f = 10MHz, Figure 4 dBVISO
Off Isolation (Note 7) +25°C
V+ = 5.5V, VIN = 0V or V+,
V- = -5.5V
SWITCH DYNAMIC CHARACTERISTICS
POWER SUPPLY
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
4 _______________________________________________________________________________________
CL= 1.0nF, VNC = 2.5V,
RS= 0Ω, Figure 3
V+ = 5V, VCOM = 3V,
ICOM = 1mA
VCOM = 3V, V+ = 5V,
Figure 2
(Note 3)
VCOM = 3V, V+ = 5V,
Figure 2
VIN = 0.8V or 2.4V
V+ = 5.5V; VCOM = 1V, 4.5V
V+ = 5.5V, VCOM = 1V,
VNC = 4.5V
V+ = 5.5V, VCOM = 1V,
VNC = 4.5V
CONDITIONS
pC1.5 10QCharge Injection (Note 3)
ns
110
43 90
tOFF
Turn-Off Time (Note 3)
ns
120
65 100
tON
Turn-On Time (Note 3)
µA-1 0.03 1IINH, IINL
IN Input Current Logic High or
Low
V0.8 1.5VINL
IN Input Logic Threshold Low
V1.5 2.4VINH
IN Input Logic Threshold High
nA
-40 40
70 120
RON
Signal-Path On-Resistance
V0V+VCOM, VNC
Analog Signal Range
-2 0.02 2
ICOM(ON)
COM On Leakage Current
(Notes 5, 6, 8)
nA
-20 20
-1 0.02 1
ICOM(OFF)
COM Off Leakage Current
(Notes 5, 6, 8)
nA
-20 20
Ω
150
-1 0.02 1
INC(OFF)
NC Off Leakage Current
(Notes 5, 6, 8)
UNITS
MIN TYP MAX
(Note 2)
SYMBOLPARAMETER
+25°C
+25°C
C, E
+25°C
+25°C
C, E
+25°C
C, E
+25°C
C, E
C, E
C, E
+25°C
C, E
C, E
+25°C
C, E
TA
ELECTRICAL CHARACTERISTICS—Single +5V Supply
(V+ = +4.5V to +5.5V, V- = 0V, VINL = 0.8V, VINH = 2.4V, VGND = 0V, TA= TMIN to TMAX, unless otherwise noted. Typical values are
at TA= +25°C.)
V+ = 5.5V, VIN = 0V or V+ -1 0.05 1
I+V+ Supply Current µA
-10 10
+25°C
C, E
RL= 50Ω, VCOM = 1VRMS,
f = 10MHz, Figure 4 dB-75VISO
Off-Isolation (Note 7) +25°C
V- = 0V 2.7 12.0V+Power-Supply Range VC, E
POWER SUPPLY
SWITCH DYNAMIC CHARACTERISTICS
LOGIC INPUT
ANALOG SWITCH
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS—Single +3V Supply
(V+ = +2.7V to +3.6V, V- = 0V, VINL = 0.4V, VINH = 2.4V, VGND = 0V, TA= TMIN to TMAX, unless otherwise noted. Typical values are
at TA= +25°C.)
V+ = 2.7V, VCOM = 1.5V,
ICOM = 0.1mA
(Note 3)
V+ = 3.6V, VIN = 0V or V+
VCOM = 1.5V, V+ = 2.7V,
Figure 2 (Note 3)
VIN = 0.4V or 2.4V (Note 3)
(Note 3)
(Note 3)
VCOM = 1.5V, V+ = 2.7V,
Figure 2 (Note 3)
CONDITIONS
µA
-1 0.05 1
I+V+ Supply Current
ns
200
70 150
tOFF
Turn-Off Time
175 400
RON
Signal-Path On-Resistance
V0V+VCOM, VNC
Analog Signal Range
ns
400
150 300
tON
Turn-On Time
µA-1 1IINH, IINL
IN Input Current Logic High or Low
Ω
500
V1.0 2.4VINH
IN Input Logic Threshold High
V0.4 1.0VINL
IN Input Logic Threshold Low
UNITS
MIN TYP MAX
(Note 2)
SYMBOLPARAMETER
+25°C
+25°C
+25°C
C, E
+25°C
C, E
C, E
C, E
C, E
C, E
+25°C
TA
-10 10C, E
Note 2: The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column.
Note 3: Guaranteed by design.
Note 4: Resistance flatness is defined as the difference between the maximum and the minimum value of on-resistance as
measured over the specified analog signal range.
Note 5: Leakage parameters are 100% tested at the maximum rated hot temperature and guaranteed by correlation at +25°C.
Note 6: Guaranteed by design, not subject to production testing in SOT package.
Note 7: Off isolation = 20log10 (VCOM / VNC), VCOM = output, VNC = input to off switch.
Note 8: Leakage testing for single-supply operation is guaranteed by testing with dual supplies.
ANALOG SWITCH
LOGIC INPUT
SWITCH DYNAMIC CHARACTERISTICS
POWER SUPPLY
__________________________________________Typical Operating Characteristics
(V+ = +5V, V- = -5V, GND = 0V, TA= +25°C, packages are surface mount, unless otherwise noted.)
1000
10
-5 -3 1 5
ON-RESISTANCE vs. VCOM
(DUAL SUPPLIES)
100
MAX4529-01
VCOM (V)
ON-RESISTANCE (Ω)
-1 3-4 -2 204
V+ = 2.0V
V- = -2.0V
V+ = 5.0V
V- = -5.0V
V+ = 3.3V
V- = -3.3V
V+ = 1.2V
V- = -1.2V
V+ = 2.7V
V- = -2.7V
0
20
10
40
30
60
50
70
-5 -3 -2-4 -1012345
ON-RESISTANCE vs. VCOM AND
TEMPERATURE (DUAL SUPPLIES)
MAX4529-03
VCOM (V)
ON-RESISTANCE (Ω)
V+ = 5V
V- = -5V
+125°C
+85°C
+70°C +25°C
0°C
-40°C
-55°C
1000
10
02 6 10
ON-RESISTANCE vs. VCOM
(SINGLE SUPPLY)
100
MAX4529-02
VCOM (V)
ON-RESISTANCE (Ω)
4813 759
V- = 0V
V+ = 1.2V
V+ = 2.0V
V+ = 2.7V
V+ = 3.3V
V+ = 5.0V
V+ = 7.5V
V+ = 10.0V
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
6 _______________________________________________________________________________________
0
20
10
40
30
60
50
70
0 1.0 1.50.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
ON-RESISTANCE vs. VCOM AND
TEMPERATURE (SINGLE SUPPLY)
MAX4529-04
VCOM (V)
ON-RESISTANCE (Ω)
V+ = 5V
V- = -5V
+125°C
+85°C
+70°C+25°C
0°C
-40°C
-55°C
0
40
20
100
80
60
140
160
120
180
-55 5 25-35 -15 45 65 85 105 125
ON-TIME vs. TEMPERATURE
MAX4529-07
TEMPERATURE (°C)
tON (ns)
V+ = 5V
V- = -5V
V+ = 5V
V- = 0V
V+ = 3V
V- = 0V
0.01
1
0.1
1000
100
10
100,000
10,000
1,000,000
-55 5 25-35 -15 45 65 85 105 125
SUPPLY, COM, AND NC
LEAKAGE CURRENTS vs. TEMPERATURE
MAX4529-05
TEMPERATURE (°C)
CURRENT (pA)
V+ = 5V
V- = -5V
I+, I-
ION
IOFF
0
3
6
9
12
15
-5 -1 0-3 -2-4 12345
CHARGE INJECTION vs. VCOM
MAX4529-06
VCOM (V)
Q (pC)
V+ = 5V
V- = -5V
V+ = 5V
V- = 0V
V+ = 3V
V- = 0V
0
20
10
50
40
30
70
60
80
-55 5 25-35 -15 45 65 85 105 125
OFF-TIME vs. TEMPERATURE
MAX4529-08
TEMPERATURE (°C)
tOFF (ns)
V+ = 5V
V- = -5V
V+ = 5V
V- = 0V
V+ = 3V
V- = 0V
0
1.0
0.5
2.0
1.5
2.5
3.0
0 234157689101112
LOGIC-LEVEL THRESHOLD
vs. SUPPLY VOLTAGE
MAX4529-09
V+ (V)
LOGIC-LEVEL THRESHOLD (V)
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
0.1 10 10001100
FREQUENCY RESPONSE
MAX4529-10
FREQUENCY (MHz)
LOSS (dB)
ON PHASE (DEGREES)
ON LOSS
ON PHASE
OFF ISOLATION
100
0.1
10 1k 10k 30k
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
1
10
MAX4529-11
FREQUENCY (Hz)
THD (%)
100
____________________________Typical Operating Characteristics (continued)
(V+ = +5V, V- = -5V, GND = 0V, TA= +25°C, packages are surface mount, unless otherwise noted.)
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
_______________________________________________________________________________________ 7
Pin Description
6
FUNCTION*
SOT23-6
NAME
Analog Switch Common** Terminal. Analog signal voltages should never exceed
V+ or V-.
—
7
Not Internally Connected
PIN
1
COM
Analog Switch Normally Closed** Terminal
2Positive Supply-Voltage Input (analog and digital). The voltage difference between
V+ and V- should never exceed 12V.
5RF and Logic Ground. Connect to ground plane.
3-5V Supply Input. Connect to GND for single-supply operation.
DIP/SO/µMAX
1, 6
2
8
3
5
N.C.
NC
V+
GND
V-
*All pins except N.C. have ESD diodes to V- and V+.
** NC and COM pins are identical and interchangeable. Either may be considered as an input or output; signals pass equally well in
either direction.
Theory of Operation
Logic-Level Translators
The MAX4529 is constructed as a high-frequency “T”
switch, as shown in Figure 1. The logic-level input, IN,
is translated by amplifier A1 into a V+ to V- logic signal
that drives inverter A2. Amplifier A2 drives the gates of
N-channel MOSFETs N1 and N2 from V+ to V-, turning
them fully on or off. The same signal drives inverter A3
(which drives the P-channel MOSFETs P1 and P2) from
V+ to V-, turning them fully on or off, and drives the N-
channel MOSFET N3 off and on.
The logic-level threshold is determined by V+ and
GND. The voltage on GND is usually at ground poten-
tial, but it may be set to any voltage between
(V+ - 2V) and V-. When the voltage between V+ and
GND is less than 2V, the level translators become very
slow and unreliable. Normally, GND should be connect-
ed to the ground plane.
Switch On Condition
When the switch is on, MOSFETs N1, N2, P1, and P2
are on and MOSFET N3 is off. The signal path is COM to
NC, and because both N-channel and P-channel
MOSFETs act as pure resistances, it is symmetrical (i.e.,
signals may pass in either direction). The off MOSFET,
N3, has no DC conduction, but has a small amount of
capacitance to GND. The four on MOSFETs also have
capacitance to ground that, together with the series
resistance, forms a lowpass filter. All of these capaci-
tances are distributed evenly along the series resis-
tance, so they act as a transmission line rather than a
simple R-C filter. This helps to explain the exceptional
300MHz bandwidth when the switches are on.
Typical attenuation in 50Ωsystems is -2dB and is rea-
sonably flat up to 100MHz. Higher-impedance circuits
show even lower attenuation (and vice versa), but
slightly lower bandwidth due to the increased effect of
the internal and external capacitance and the switch’s
internal resistance.
A1 A2 A3
S
S
P1
N3
D
D
D
N1
V-
GND
IN
V+
V+
V-
COM NC
SD
N2
S
S
P2
D
NORMALLY CLOSED SWITCH CONSTRUCTION
COM - NCIN
0
1
ON
OFF
ESD DIODES
ON GND, IN,
COM, AND NC
Figure 1. T-Switch Construction
4Logic-Level Control Input. Logic-level voltages should never exceed V+ or V-.4IN
The MAX4529 is a optimized for ±5V operation. Using
lower supply voltages or a single supply increases
switching time, on-resistance (and therefore on-state
attenuation), and nonlinearity.
Switch Off Condition
When the switch is off, MOSFETs N1, N2, P1, and P2
are off and MOSFET N3 is on. The signal path is
through the off-capacitances of the series MOSFETs,
but it is shunted to ground by N3. This forms a high-
pass filter whose exact characteristics depend on the
source and load impedances. In 50Ωsystems, and
below 10MHz, the attenuation can exceed 80dB. This
value decreases with increasing frequency and
increasing circuit impedances. External capacitance
and board layout have a major role in determining over-
all performance.
Applications Information
Power-Supply Considerations
Overview
The MAX4529’s construction is typical of most CMOS
analog switches. It has three supply pins: V+, V-, and
GND. V+ and V- are used to drive the internal CMOS
switches and set the limits of the analog voltage on any
switch. Reverse ESD protection diodes are internally
connected between each analog signal pin and both
V+ and V-. If the voltage on any pin exceeds V+ or V-,
one of these diodes will conduct. During normal opera-
tion these reverse-biased ESD diodes leak, forming the
only current drawn from V-.
Virtually all the analog leakage current is through the
ESD diodes. Although the ESD diodes on a given sig-
nal pin are identical, and therefore fairly well balanced,
they are reverse biased differently. Each is biased by
either V+ or V- and the analog signal. This means their
leakages vary as the signal varies. The difference in the
two diode leakages from the signal path to the V+ and
V- pins constitutes the analog signal-path leakage cur-
rent. All analog leakage current flows to the supply ter-
minals, not to the other switch terminal. This explains
how both sides of a given switch can show leakage
currents of either the same or opposite polarity.
When the switch is on, there is no connection between
the analog signal paths and GND. The analog signal
paths consist of an N-channel and P-channel MOSFET
with their sources and drains paralleled and their gates
driven out of phase with V+ and V- by the logic-level
translators.
V+ and GND power the internal logic and logic-level
translators, and set the input logic thresholds. The
logic-level translators convert the logic levels to
switched V+ and V- signals to drive the gates of the
analog switches. This drive signal is the only connec-
tion between the logic supplies and the analog sup-
plies. All pins have ESD protection to V+ and to V-.
Increasing V- has no effect on the logic-level thresh-
olds, but it does increase the drive to the P-channel
switches, reducing their on-resistance. V- also sets the
negative limit of the analog signal voltage.
The logic-level thresholds are CMOS and TTL compati-
ble when V+ is +5V. As V+ is raised, the threshold
increases slightly; when V+ reaches +12V, the level
threshold is about 3.1V, which is above the TTL output
high-level minimum of 2.8V, but still compatible with
CMOS outputs.
Bipolar-Supply Operation
The MAX4529 operates with bipolar supplies between
±2.7V and ±6V. The V+ and V- supplies need not be
symmetrical, but their sum cannot exceed the absolute
maximum rating of 13.0V. Do not connect the
MAX4529 V+ pin to +3V and connect the logic-level
input pins to TTL logic-level signals. TTL logic-level
outputs can exceed the absolute maximum ratings,
causing damage to the part and/or external circuits.
CAUTION:
The absolute maximum V+ to V- differential
voltage is 13.0V. Typical “±6-Volt” or “12-Volt”
supplies with ±10% tolerances can be as high
as 13.2V. This voltage can damage the
MAX4529. Even ±5% tolerance supplies may
have overshoot or noise spikes that exceed
13.0V.
Single-Supply Operation
The MAX4529 operates from a single supply between
+2.7V and +12V when V- is connected to GND. All of
the bipolar precautions must be observed. Note, how-
ever, that these parts are optimized for ±5V operation,
and most AC and DC characteristics are degraded sig-
nificantly when departing from ±5V. As the overall sup-
ply voltage (V+ to V-) is lowered, switching speed,
on-resistance, off isolation, and distortion are degraded
(see Typical Operating Characteristics).
Single-supply operation also limits signal levels and
interferes with grounded signals. When V- = 0V, AC sig-
nals are limited to -0.3V. Voltages below -0.3V can be
clipped by the internal ESD-protection diodes, and the
parts can be damaged if excessive current flows.
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
8 _______________________________________________________________________________________
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
_______________________________________________________________________________________ 9
Single-Supply Operation Above 5V
The MAX4529 is designed for operation from single
+5V or dual ±5V supplies. As V+ is increased above
5V, the logic-level threshold voltage increases and the
supply current increases. In addition, if the logic levels
are not driven rail-to-rail, the analog signal pins, COM
and NC, can conduct a significant DC current (up to
1mA) to the supply pins. This current can add an
unwanted DC bias to the signal. Therefore, when oper-
ating V+ above 5V, always drive the IN pin rail-to-rail.
Power Off
When power to the MAX4529 is off (i.e., V+ = 0V and V-
= 0V), the Absolute Maximum Ratings still apply. This
means that neither logic-level inputs on IN nor signals
on COM or NC can exceed ±0.3V. Voltages beyond
±0.3V cause the internal ESD-protection diodes to con-
duct, and the parts can be damaged if excessive cur-
rent flows.
Grounding
DC Ground Considerations
Satisfactory high-frequency operation requires that
careful consideration be given to grounding. For most
applications, a ground plane is strongly recom-
mended, and GND should be connected to it with
solid copper.
In systems that have separate digital and analog (sig-
nal) grounds, connect these switch GND pins to analog
ground. Preserving a good signal ground is much more
important than preserving a digital ground. Ground cur-
rent is only a few nanoamps.
The logic-level input, IN, has voltage thresholds deter-
mined by V+ and GND. (V- does not influence the
logic-level threshold.) With +5V and 0V applied to V+
and GND, the threshold is about 1.6V, ensuring com-
patibility with TTL- and CMOS-logic drivers.
The GND pin can be connected to separate voltage
potentials if the logic-level input is not a normal logic
signal. (The GND voltage cannot exceed (V+ - 2V) or V-.)
Elevating GND reduces off isolation. Note, however,
that IN can be driven more negative than GND, as far
as V-. GND does not have to be removed from 0V when
IN is driven from bipolar sources, but the voltage on IN
should never exceed V-. GND should be separated
from 0V only if the logic-level threshold has to be
changed.
If the GND pin is not connected to 0V, it should be
bypassed to the ground plane with a surface-mount
10nF capacitor to maintain good RF grounding. DC
current in the IN and GND pins is less than 1nA, but
increases with switching frequency.
AC Ground and Bypassing
A ground plane is mandatory for satisfactory high-
frequency operation. (Prototyping using hand wiring
or wire-wrap boards is strongly discouraged.) Connect
any 0V GND pins to the ground plane with solid cop-
per. (The GND pin extends the high-frequency ground
through the package wire-frame, into the silicon itself,
thus improving isolation.) The ground plane should be
solid metal underneath the device, without interrup-
tions. There should be no traces under the device itself.
For DIP packages, this applies to both sides of a two-
sided board. Failure to observe this will have a minimal
effect on the “on” characteristics of the switch at high
frequencies, but it will degrade the off isolation and
crosstalk.
V+ and V- pins should be bypassed to the ground
plane with surface-mount 10nF capacitors. For DIP
packages, they should be mounted as close as possi-
ble to the pins on the same side of the board as the
device. Do not use feedthroughs or vias for bypass
capacitors. For surface-mount packages, the pins are
so close to each other that the bypass capacitors
should be mounted on the opposite side of the board
from the device. In this case, use short feedthroughs or
vias, directly under the V+ and V- pins. Any GND pin
not connected to 0V should be similarly bypassed. If V-
is 0V, connect it directly to the ground plane with solid
copper. Keep all leads short.
Signal Routing
Keep all signal leads as short as possible. Separate all
signal leads from each other and other traces with the
ground plane on both sides of the board. Where possi-
ble, use coaxial cable instead of printed circuit board
traces.
Board Layout
IC sockets degrade high-frequency performance and
should not be used if signal bandwidth exceeds 5MHz.
Surface-mount parts, having shorter internal lead
frames, provide the best high-frequency performance.
Keep all bypass capacitors close to the device, and
separate all signal leads with ground planes. Such
grounds tend to be wedge-shaped as they get closer to
the device. Use vias to connect the ground planes on
each side of the board, and place the vias in the apex of
the wedge-shaped grounds that separate signal leads.
Logic-level signal lead placement is not critical.
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
10 ______________________________________________________________________________________
50% 50%
tOFF tON
V+
0V
VIN
VOUT
VOUT
V+
IN
NC
COM
3V
50Ω
MAX4529
RL = 50Ω
90%
90%
V- IS CONNECTED TO GND (OV) FOR SINGLE-SUPPLY OPERATION.
0V
VIN
+5V
10nF
GND V-
10nF
-5V
Figure 2. Switching Time
______________________________________________Test Circuits/Timing Diagrams
∆VOUT
V+
0V
VIN
VOUT
∆VOUT IS THE MEASURED VOLTAGE DUE TO CHARGE TRANSFER
ERROR Q WHEN THE CHANNEL TURNS OFF.
Q = ∆VOUT x CL
VOUT
V+
IN
NC
COM
VNC = 0V
V- IS CONNECTED TO GND (0V) FOR SINGLE-SUPPLY OPERATION.
50Ω
MAX4529
CL = 1000pF
VIN
+5V
10nF
GND V-
10nF
-5V
Figure 3. Charge Injection
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
______________________________________________________________________________________ 11
MEASUREMENTS ARE STANDARDIZED AGAINST SHORT AT IC TERMINALS.
OFF ISOLATION IS MEASURED BETWEEN COM_ AND "OFF" NC TERMINAL.
ON LOSS IS MEASURED BETWEEN COM_ AND "ON" NC TERMINAL.
SIGNAL DIRECTION THROUGH SWITCH IS REVERSED; WORST VALUES ARE RECORDED.
V- IS CONNECTED TO GND (0V) FOR SINGLE-SUPPLY OPERATION.
+5V
VOUT
V+
IN NC
COM
VIN
MAX4529
OFF ISOLATION = 20log VOUT
VIN
ON LOSS = 20log VOUT
VIN
NETWORK
ANALYZER
50Ω
50Ω50Ω
50Ω
MEAS REF
10nF
0V OR V+
GND V-
10nF -5V
Figure 4. On Loss and Off Isolation
TRANSISTOR COUNT: 78
SUBSTRATE INTERNALLY CONNECTED TO V+
N.C. = NO CONNECTION
IN
0.054"
(1.372mm)
0.038"
(0.965mm)
COM
N.C.
V-
V+
GND
N.C.
NC
+5V10nF
0V OR V+ V+
IN
NC
COM
MAX4529
1MHz
CAPACITANCE
ANALYZER
GND V-
10nF
-5V
Figure 5. NC and COM Capacitance
_________________________________Test Circuits/Timing Diagrams (continued)
___________________Chip Topography
MAX4529
Low-Voltage, Bidirectional
RF/Video Switch
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
© 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
________________________________________________________Package Information
6LSOT.EPS
