1
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH251
2.5V / 3.3V QUAD 8:1 MUX/DEMUX HIGH BANDWIDTH BUS SWITCH
SEPTEMBER 2008
2008 Integrated Device Technology, Inc. DSC-5944/10c
IDTQS3VH251
INDUSTRIAL TEMPERATURE RANGE
QUICKSWITCH® PRODUCTS 2.5V
/ 3.3V 8:1 MUX/DEMUX HIGH
BANDWIDTH BUS SWITCH
FUNCTIONAL BLOCK DIAGRAM
DESCRIPTION:
The QS3VH251 HotSwitch Quad 2:1 multiplexer/demultiplexer is a high
bandwidth bus switch. The QS3VH251 has very low ON resistance,
resulting in under 250ps propagation delay through the switch. The Select
(Sx) input controls the data flow. The multiplexers/demultiplexers are
enabled when the Enable (E) input is low. In the ON state, the switches can
pass signals up to 5V. In the OFF state, the switches offer very high
impedence at the terminals.
The combination of near-zero propagation delay, high OFF impedance,
and over-voltage tolerance makes the QS3VH251 ideal for high perfor-
mance comminucation applications.
The QS3VH251 is characterized for operation from -40°C to +85°C.
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
APPLICATIONS:
• Hot-swapping
• Multiplexing/demultiplexing
• Low distortion analog switch
• Replaces mechanical relay
• ATM 25/155 switching
FEATURES:
• N channel FET switches with no parasitic diode to VCC
– Isolation under power-off conditions
– No DC path to VCC or GND
– 5V tolerant in OFF and ON state
• 5V tolerant I/Os
• Low RON - 4ΩΩ
ΩΩ
Ω typical
• Flat RON characteristics over operating range
• Rail-to-rail switching 0 - 5V
• Bidirectional dataflow with near-zero delay: no added ground
bounce
• Excellent R ON matching between channels
•VCC operation: 2.3V to 3.6V
• High bandwidth - up to 500MHz
• LVTTL-compatible control Inputs
• Undershoot Clamp Diodes on all switch and control Inputs
• Low Demux capacitance, 4pF typical
• Available in QSOP and TSSOP packages
S0
Y
I0
I1
I2
I3
I4
I5
I6
I7
S1
E
S2
2
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH251
2.5V / 3.3V QUAD 8:1 MUX/DEMUX HIGH BANDWIDTH BUS SWITCH
PIN CONFIGURATION Symbol Description Max Unit
VTERM(2) SupplyVoltage to Ground –0.5 to +4.6 V
VTERM(3) DC Switch Voltage VS–0.5 to +5.5 V
VTERM(3) DC Input Voltage VIN –0.5 to +5.5 V
VAC AC Input Voltage (pulse width ≤20ns) –3 V
IOUT DC Output Current (max. sink current/pin) 120 mA
TSTG Storage Temperature –65 to +150 °C
ABSOLUTE MAXIMUM RATINGS (1)
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation of
the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
2. VCC terminals.
3. All terminals except VCC .
Symbol Parameter(1) Typ. Max. Unit
CIN Control Inputs 3 5 pF
CI/O Quickswitch Channels Demux 4 6 pF
(Switch OFF) Mux 19 25
CI/O Quickswitch Channels Demux 20 28 pF
(Switch ON) Mux 20 28
CAPACITANCE (TA = +25°C, F = 1MHz, VIN = 0V, VOUT =
0V)
NOTE:
1. This parameter is guaranteed but not production tested.
Pin Names I/O Description
I0 - I7I Data Inputs
S0 - S2I Select Input
EI Enable Input
Y O Data Outputs
PIN DESCRIPTION
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
X = Don't Care
Z = High-Impedence
FUNCTION TABLE(1)
QSOP/ TSSOP
TOP VIEW
1
2
3
4
5
6
7
16
15
14
13
12
11
10
I2
I1
Y
NC
GND
VCC
I5
I6
I4
S0
S1
I3
I0
I7
89
E
S2
Select
ES2S1S0Y Function
H X X X Z Disable
LLLLI0S2 - S0 = 0
LLLHI1S2 - S0 = 1
LLHLI2S2 - S0 = 2
LLHHI3S2 - S0 = 3
LHLLI4S2 - S0 = 4
LHLHI5S2 - S0 = 5
LHHLI6S2 - S0 = 6
LHHHI
7S2 - S0 = 7
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INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH251
2.5V / 3.3V QUAD 8:1 MUX/DEMUX HIGH BANDWIDTH BUS SWITCH
TYPICAL ON RESISTANCE vs VIN AT VCC = 3.3V
RON
(ohms)
VIN
(Volts)
16
14
12
10
8
6
4
2
0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 5.04.5
Symbol Parameter Test Conditions Min. Typ.(1) Max. Unit
VIH Input HIGH Voltage Guaranteed Logic HIGH VCC = 2.3V to 2.7V 1.7 — — V
for Control Inputs VCC = 2.7V to 3.6V 2 — —
VIL Input LOW Voltage Guaranteed Logic LOW VCC = 2.3V to 2.7V — — 0.7 V
for Control Inputs VCC = 2.7V to 3.6V — — 0.8
IIN Input Leakage Current (Control Inputs) 0V ≤ VIN ≤ VCC ——±1µA
IOZ Off-State Current (Hi-Z) 0V ≤ VOUT ≤ 5V, Switches OFF — — ±1 µA
IOFF Data Input/Output Power Off Leakage VIN or VOUT 0V to 5V, VCC = 0V — — ±1 µA
VCC = 2.3V VIN = 0V ION = 30mA — 6 8
RON Switch ON Resistance Typical at VCC = 2.5V VIN = 1.7V ION = 15mA — 7 9 Ω
VCC = 3V VIN = 0V ION = 30mA — 4 6
VIN = 2.4V ION = 15mA — 5 8
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: TA = –40°C to +85°C, VCC = 3.3V ±0.3V
NOTE:
1. Typical values are at VCC = 3.3V and TA = 25°C.
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INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH251
2.5V / 3.3V QUAD 8:1 MUX/DEMUX HIGH BANDWIDTH BUS SWITCH
TYPICAL ICCD vs ENABLE FREQUENCY CURVE AT VCC = 3.3V
ICCD (mA)
ENABLE FREQUENCY (MHz)
NOTES:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
2. Per input driven at the specified level. Mux/demux pins do not contribute to ∆Icc.
3. This parameter is guaranteed but not tested.
4. This parameter represents the current required to switch internal capacitance at the specified frequency. The mux/demux inputs do not contribute to the Dynamic Power Supply Current.
This parameter is guaranteed but not production tested.
POWER SUPPLY CHARACTERISTICS
Symbol Parameter Test Conditions(1) Min. Typ. Max. Unit
ICCQ Quiescent Power Supply Current VCC = Max., VIN = GND or VCC, f = 0 — 2 4 mA
∆ICC Power Supply Current (2,3) per Input HIGH VCC = Max., VIN = 3V, f = 0 per Control Input — — 30 µA
ICCD Dynamic Power Supply Current(4) VCC = 3.3V, A and B Pins Open, Control Inputs See Typical ICCD vs Enable Frequency graph below
Toggling @ 50% Duty Cycle
0
2
4
6
0 2 4 6 8 10 12 14 16 18 20
5
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH251
2.5V / 3.3V QUAD 8:1 MUX/DEMUX HIGH BANDWIDTH BUS SWITCH
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
TA = -40°C to +85°C VCC = 2.5 ± 0.2V (1) VCC = 3.3 ± 0.3V (1)
Symbol Parameter Min. (4) Max. Min. (4) Max. Unit
tPLH Data Propagation Delay(2,3) ⎯0.2 ⎯0.2 ns
tPHL Y to Ix or Ix to Y
tSEL Select Time 1.5 9 1.5 8 ns
Sx to Y
tPZH Enable Time 1.5 9 1.5 9 ns
tPZL S to Ix
tPHZ Disable Time 1.5 8 1.5 8 ns
tPLZ S to Ix
tPZH Enable Time 1.5 9 1.5 8 ns
tPZL E to Y or Ix
tPHZ Disable Time 1.5 8 1.5 8 ns
tPLZ E to Y or Ix
fEorSx Operating Frequency - Enable(2,5) ⎯10 ⎯20 MHz
NOTES:
1. See Test Conditions under TEST CIRCUITS AND WAVEFORMS.
2. This parameter is guaranteed but not production tested.
3. The bus switch contributes no propagation delay other than the RC delay of the ON resistance of the switch and the load capacitance. The time constant for the switch alone is of the
order of 0.2ns at CL = 50pF. Since this time constant is much smaller than the rise and fall times of typical driving signals, it adds very little propagation delay to the system. Propagation
delay of the bus switch, when used in a system, is determined by the driving circuit on the driving side of the switch and its interaction with the load on the driven side.
4. Minimums are guaranteed but not production tested.
5. Maximum toggle frequency for Sx or E control input (pass voltage > VCC, VIN = 5V, RLOAD ≥ 1MΩ, no CLOAD).
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INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH251
2.5V / 3.3V QUAD 8:1 MUX/DEMUX HIGH BANDWIDTH BUS SWITCH
MEMORY
MEMORY
CPU
MULTIPLEXING
CONTROL CIRCUITRY
CHARGE PUMP
OE
Vcc = 3.3V
0 to +5V NFET
+6.5V
DRIVER
0 to +5V
SINGLE HOT
SWITCH
CARD I/O ON CARD
LOGIC
CONNECTOR
QS3VHXXX
CPU
RAM
BUS
CARD I/O ON CARD
LOGIC
CONNECTOR
QS3VHXXX
PLUGGABLE CARD/ LIVE SYSTEM ZERO DOWN TIME SYSTEM
1
8
8 BANKS
Rail-to-Rail Switching
SOME APPLICATIONS FOR HOTSWITCH PRODUCTS
Multiplexing/Demultiplexing
Hot-Swapping
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INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH251
2.5V / 3.3V QUAD 8:1 MUX/DEMUX HIGH BANDWIDTH BUS SWITCH
TEST CIRCUITS AND WAVEFORMS
Open
VLOAD
GND
VCC
Pulse
Generator D.U.T.
500Ω
500Ω
CL
RT
VIN VOUT
(1, 2)
SAME PHASE
INPUT TRANSITION
OPPOSITE PHASE
INPUT TRANSITION
0V
0V
VOH
VOL
tPLH tPHL
tPHLtPLH
OUTPUT
VIH
VT
VT
VIH
VT
CONTROL
INPUT
tPLZ 0V
OUTPUT
NORMALLY
LOW tPZH
0V
SWITCH
CLOSED
OUTPUT
NORMALLY
HIGH
ENABLE DISABLE
SWITCH
OPEN
tPHZ
0V
VOL + VLZ
VOH
VT
VT
tPZL
VLOAD/2 VLOAD/2
VIH
VT
VOL
VOH -VHZ
TEST CONDITIONS
Symbol VCC(1)= 3.3V ± 0.3V VCC(2)= 2.5V ± 0.2V Unit
VLOAD 6 2 x Vcc V
VIH 3 Vcc V
VT1.5 VCC/2 V
VLZ 300 150 mV
VHZ 300 150 mV
CL50 30 pF
NOTE:
1. Diagram shown for input Control Enable-LOW and input Control Disable-HIGH.
NOTES:
1. Pulse Generator for All Pulses: Rate ≤ 10MHz; tF ≤ 2.5ns; tR ≤ 2.5ns.
2. Pulse Generator for All Pulses: Rate ≤ 10MHz; tF ≤ 2ns; tR ≤ 2ns.
DEFINITIONS:
CL = Load capacitance: includes jig and probe capacitance.
RT = Termination resistance: should be equal to ZOUT of the Pulse Generator.
SWITCH POSITION
Test Switch
tPLZ/tPZL VLOAD
tPHZ/tPZH GND
tPD Open
Propagation Delay
Test Circuits for All Outputs
Enable and Disable Times
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INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH251
2.5V / 3.3V QUAD 8:1 MUX/DEMUX HIGH BANDWIDTH BUS SWITCH
ORDERING INFORMATION
CORPORATE HEADQUARTERS for SALES: for Tech Support:
6024 Silver Creek Valley Road 800-345-7015 or 408-284-8200 logichelp@idt.com
San Jose, CA 95138 fax: 408-284-2775
www.idt.com
Datasheet Document History
09/01/08 Pg. 4, 8 Revise ICCQ Typ. and Max. Remove non green package version and updated the ordering
information by removing the “IDT” notation.
