SN74CB3Q3245
8-BIT FET BUS SWITCH
2.5-V/3.3-V LOW-VOLTAGE HIGH-BANDWIDTH BUS SWITCH
www.ti.com
SCDS124B – JULY 2003 – REVISED MARCH 2005
•
•
•
(1)
For additional information regarding the performance
characteristics of the CB3Q family, refer to the TI application
report, CBT-C, CB3T, and CB3Q Signal-Switch Families,
literature number SCDA008.
•
•
•
•
DBQ, DGV, OR PW PACKAGE
(TOP VIEW)
NC
A1
A2
A3
A4
A5
A6
A7
A8
GND
1
20
2
19
3
18
4
17
5
16
6
15
7
14
8
13
9
12
10
11
VCC
OE
B1
B2
B3
B4
B5
B6
B7
B8
NC - No internal connection
RGY PACKAGE
(TOP VIEW)
A1
A2
A3
A4
A5
A6
A7
A8
VCC
•
•
1
20
3
4
19 OE
18 B1
17 B2
5
6
16 B3
15 B4
7
8
14 B5
13 B6
2
12 B7
9
10
11
B8
•
•
•
•
Data and Control Inputs Provide Undershoot
Clamp Diodes
Low Power Consumption (ICC = 1 mA Typical)
VCC Operating Range From 2.3 V to 3.6 V
Data I/Os Support 0- to 5-V Signaling Levels
(0.8 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V, 5 V)
Control Inputs Can Be Driven by TTL or
5-V/3.3-V CMOS Outputs
Ioff Supports Partial-Power-Down Mode
Operation
Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
ESD Performance Tested Per JESD 22
– 2000-V Human-Body Model
(A114-B, Class II)
– 1000-V Charged-Device Model (C101)
Supports Both Digital and Analog
Applications: PCI Interface, Differential Signal
Interface, Memory Interleaving, Bus Isolation,
Low-Distortion Signal Gating
NC
•
•
High-Bandwidth Data Path
(up to 500 MHz (1))
Equivalent to IDTQS3VH384 Device
5-V Tolerant I/Os With Device Powered Up or
Powered Down
Low and Flat ON-State Resistance (ron)
Characteristics Over Operating Range
(ron = 4 Ω Typ)
Rail-to-Rail Switching on Data I/O Ports
– 0- to 5-V Switching With 3.3-V VCC
– 0- to 3.3-V Switching With 2.5-V VCC
Bidirectional Data Flow With Near-Zero
Propagation Delay
Low Input/Output Capacitance Minimizes
Loading and Signal Distortion
(Cio(OFF) = 3.5 pF Typ)
Fast Switching Frequency (fOE = 20 MHz Max)
GND
•
FEATURES
•
NC - No internal connection
DESCRIPTION/ORDERING INFORMATION
The SN74CB3Q3245 is a high-bandwidth FET bus switch utilizing a charge pump to elevate the gate voltage of
the pass transistor, providing a low and flat ON-state resistance (ron). The low and flat ON-state resistance allows
for minimal propagation delay and supports rail-to-rail switching on the data input/output (I/O) ports. The device
also features low data I/O capacitance to minimize capacitive loading and signal distortion on the data bus.
Specifically designed to support high-bandwidth applications, the SN74CB3Q3245 provides an optimized
interface solution ideally suited for broadband communications, networking, and data-intensive computing
systems.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2003–2005, Texas Instruments Incorporated
SN74CB3Q3245
8-BIT FET BUS SWITCH
2.5-V/3.3-V LOW-VOLTAGE HIGH-BANDWIDTH BUS SWITCH
www.ti.com
SCDS124B – JULY 2003 – REVISED MARCH 2005
DESCRIPTION/ORDERING INFORMATION (CONTINUED)
The SN74CB3Q3245 is organized as an 8-bit bus switch with a single output-enable (OE) input. When OE is low,
the bus switch is ON and the A port is connected to the B port, allowing bidirectional data flow between ports.
When OE is high, the bus switch is OFF and a high-impedance state exists between the A and B ports.
This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry prevents damaging
current backflow through the device when it is powered down. The device has isolation during power off.
To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
ORDERING INFORMATION
PACKAGE (1)
TA
–40°C to 85°C
(1)
ORDERABLE PART NUMBER
Tape and reel
SN74CB3Q3245RGYR
BU245
SSOP (QSOP) – DBQ
Tape and reel
SN74CB3Q3245DBQR
CB3Q3245
Tube
SN74CB3Q3245PW
Tape and reel
SN74CB3Q3245PWR
TVSOP – DGV
Tape and reel
SN74CB3Q3245DGVR
BU245
VFBGA – GQN
Tape and reel
SN74CB3Q3245GQNR
BU245
TSSOP – PW
BU245
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at
www.ti.com/sc/package.
GQN PACKAGE
(TOP VIEW)
TERMINAL ASSIGNMENTS (1)
1
2
3
4
A
A1
NC
VCC
OE
A
B
A3
B2
A2
B1
B
C
A5
A4
B4
B3
C
D
A7
B6
A6
B5
D
E
GND
A8
B8
B7
1
2
3
4
E
(1)
NC - No internal connection
FUNCTION TABLE
2
TOP-SIDE MARKING
QFN – RGY
INPUT
OE
INPUT/OUTPUT
A
FUNCTION
L
B
A port = B port
H
Z
Disconnect
SN74CB3Q3245
8-BIT FET BUS SWITCH
2.5-V/3.3-V LOW-VOLTAGE HIGH-BANDWIDTH BUS SWITCH
www.ti.com
SCDS124B – JULY 2003 – REVISED MARCH 2005
LOGIC DIAGRAM (POSITIVE LOGIC)
2
18
A1
B1
SW
9
11
A8
SW
B8
19
OE
Pin numbers shown are for the DBQ, DGV, PW, and RGY packages.
SIMPLIFIED SCHEMATIC, EACH FET SWITCH (SW)
A
B
VCC
Charge
Pump
EN(1)
(1) EN is the internal enable signal applied to the switch.
3
SN74CB3Q3245
8-BIT FET BUS SWITCH
2.5-V/3.3-V LOW-VOLTAGE HIGH-BANDWIDTH BUS SWITCH
www.ti.com
SCDS124B – JULY 2003 – REVISED MARCH 2005
Absolute Maximum Ratings (1)
over operating free-air temperature range (unless otherwise noted)
MIN
MAX
VCC
Supply voltage range
–0.5
4.6
V
VIN
Control input voltage range (2) (3)
–0.5
7
V
VI/O
Switch I/O voltage
range (2) (3) (4)
IIK
Control input clamp current
VIN < 0
–50
mA
II/OK
I/O port clamp current
VI/O < 0
–50
mA
±64
mA
±100
mA
IIO
ON-state switch
–0.5
current (5)
Continuous current through VCC or GND
θJA
Tstg
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Package thermal impedance
7
DBQ package (6)
68
DGV package (6)
92
GQN package (6)
78
PW package (6)
83
RGY package (7)
37
Storage temperature range
–65
UNIT
V
°C/W
°C
150
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 under "recommended operating
conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltages are with respect to ground, unless otherwise specified.
The input and output voltage ratings may be exceeded if the input and output clamp-current ratings are observed.
VI and VO are used to denote specific conditions for VI/O.
II and IO are used to denote specific conditions for II/O.
The package thermal impedance is calculated in accordance with JESD 51-7.
The package thermal impedance is calculated in accordance with JESD 51-5.
Recommended Operating Conditions (1)
MIN MAX
VCC
Supply voltage
VIH
High-level control input voltage
VIL
Low-level control input voltage
VI/O
Data input/output voltage
TA
Operating free-air temperature
(1)
4
UNIT
2.3
3.6
VCC = 2.3 V to 2.7 V
1.7
5.5
V
VCC = 2.7 V to 3.6 V
2
5.5
VCC = 2.3 V to 2.7 V
0
0.7
VCC = 2.7 V to 3.6 V
0
0.8
0
5.5
V
–40
85
°C
V
V
All unused control inputs of the device must be held at VCC or GND to ensure proper device operation. Refer to the TI application report,
Implications of Slow or Floating CMOS Inputs, literature number SCBA004.
SN74CB3Q3245
8-BIT FET BUS SWITCH
2.5-V/3.3-V LOW-VOLTAGE HIGH-BANDWIDTH BUS SWITCH
www.ti.com
SCDS124B – JULY 2003 – REVISED MARCH 2005
Electrical Characteristics
(1)
over recommended operating free-air temperature range (unless otherwise noted)
PARAMETER
VIK
MIN TYP (2) MAX
TEST CONDITIONS
VCC = 3.6 V,
II = –18 mA
VCC = 3.6 V,
VIN = 0 to 5.5 V
IOZ (3)
VCC = 3.6 V,
VO = 0 to 5.5 V,
VI = 0,
Switch OFF,
VIN = VCC or GND
Ioff
VCC = 0,
VO = 0 to 5.5 V,
VI = 0
ICC
VCC = 3.6 V,
II/O = 0,
Switch ON or OFF,
VIN = VCC or GND
Control inputs
VCC = 3.6 V,
One input at 3 V,
Other inputs at VCC or GND
ICCD (5)
Per control
input
VCC = 3.6 V,
A and B ports open,
Cin
Control inputs
VCC = 3.3 V,
VIN = 5.5 V, 3.3 V, or 0
Cio(OFF)
VCC = 3.3 V,
Switch OFF,
VIN = VCC or GND,
Cio(ON)
VCC = 3.3 V,
IIN
Control inputs
∆ICC
(4)
ron (6)
VCC = 3 V
(1)
(2)
(3)
(4)
(5)
(6)
V
±1
µA
±1
µA
1
µA
2
mA
30
µA
1
0.30
0.35
mA/
MHz
2.5
3.5
pF
VI/O = 5.5 V, 3.3 V, or 0
3.5
5
pF
Switch ON,
VIN = VCC or GND,
VI/O = 5.5 V, 3.3 V, or 0
9
11
pF
VI = 0,
IO = 30 mA
4
8
VI = 1.7 V,
IO = –15 mA
4.5
9
VI = 0,
IO = 30 mA
4
6
VI = 2.4 V,
IO = –15 mA
4
8
Control input switching at 50% duty cycle
VCC = 2.3 V,
TYP at VCC = 2.5 V
UNIT
–1.8
Ω
VIN and IIN refer to control inputs. VI, VO, II, and IO refer to data pins.
All typical values are at VCC = 3.3 V (unless otherwise noted), TA = 25°C.
For I/O ports, the parameter IOZ includes the input leakage current.
This is the increase in supply current for each input that is at the specified TTL voltage level, rather than VCC or GND.
This parameter specifies the dynamic power-supply current associated with the operating frequency of a single control input (see
Figure 2).
Measured by the voltage drop between the A and B terminals at the indicated current through the switch. ON-state resistance is
determined by the lower of the voltages of the two (A or B) terminals.
Switching Characteristics
over recommended operating free-air temperature range (unless otherwise noted) (see Figure 3)
(1)
(2)
VCC = 2.5 V
± 0.2 V
VCC = 3.3 V
± 0.3 V
FROM
(INPUT)
TO
(OUTPUT)
fOE (1)
OE
A or B
10
20
tpd (2)
A or B
B or A
0.12
0.20
ns
ten
OE
A or B
1.5
7.5
1.5
6.5
ns
tdis
OE
A or B
1
6.5
1
6.5
ns
PARAMETER
MIN
MAX
MIN
UNIT
MAX
MHz
Maximum switching frequency for control input (VO > VCC, VI = 5 V, RL ≥ 1 MΩ, CL = 0)
The propagation delay is the calculated RC time constant of the typical ON-state resistance of the switch and the specified load
capacitance, when driven by an ideal voltage source (zero output impedance).
5
SN74CB3Q3245
8-BIT FET BUS SWITCH
2.5-V/3.3-V LOW-VOLTAGE HIGH-BANDWIDTH BUS SWITCH
www.ti.com
SCDS124B – JULY 2003 – REVISED MARCH 2005
TYPICAL ron
vs
VI
16
Ω
VCC = 3.3 V
TA = 25°C
IO = -15 mA
r on - ON-State Resistance -
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
4.5
5.0
14
16
18
20
VI - V
Figure 1. Typical ron vs VI
TYPICAL ICC
vs
OE SWITCHING FREQUENCY
12
VCC = 3.3 V
TA = 25°C
A and B Ports Open
10
ICC − mA
8
6
4
2
0
0
2
4
6
8
10
12
OE Switching Frequency − MHz
Figure 2. Typical ICC vs OE Switching Frequency
6
SN74CB3Q3245
8-BIT FET BUS SWITCH
2.5-V/3.3-V LOW-VOLTAGE HIGH-BANDWIDTH BUS SWITCH
www.ti.com
SCDS124B – JULY 2003 – REVISED MARCH 2005
PARAMETER MEASUREMENT INFORMATION
VCC
Input Generator
VIN
50 Ω
50 Ω
VG1
TEST CIRCUIT
DUT
2 × VCC
Input Generator
S1
RL
VO
VI
50 Ω
50 Ω
VG2
CL
(see Note A)
RL
TEST
VCC
S1
RL
VI
CL
tpd(s)
2.5 V ± 0.2 V
3.3 V ± 0.3 V
Open
Open
500 Ω
500 Ω
VCC or GND
VCC or GND
30 pF
50 pF
tPLZ/tPZL
2.5 V ± 0.2 V
3.3 V ± 0.3 V
2 × VCC
2 × VCC
500 Ω
500 Ω
GND
GND
30 pF
50 pF
0.15 V
0.3 V
tPHZ/tPZH
2.5 V ± 0.2 V
3.3 V ± 0.3 V
GND
GND
500 Ω
500 Ω
VCC
VCC
30 pF
50 pF
0.15 V
0.3 V
V∆
VCC
Output
Control
(VIN)
VCC/2
VCC
VCC/2
VCC/2
0V
tPLH
VOH
Output
VCC/2
VCC/2
VOL
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES (tpd(s))
Output
Waveform 1
S1 at 2 × VCC
(see Note B)
tPLZ
VCC
VCC/2
VOL + V∆
VOL
tPZH
tPHL
VCC/2
0V
tPZL
Output
Control
(VIN)
Open
GND
Output
Waveform 2
S1 at GND
(see Note B)
tPHZ
VOH
VCC/2
VOH − V∆
0V
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
NOTES: A. CL includes probe and jig capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low, except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high, except when disabled by the output control.
C. All input pulses are supplied by generators having the following characteristics: PRR ≤ 10 MHz, ZO = 50 Ω, tr ≤ 2.5 ns, tf ≤ 2.5 ns.
D. The outputs are measured one at a time, with one transition per measurement.
E. tPLZ and tPHZ are the same as tdis.
F. tPZL and tPZH are the same as ten.
G. tPLH and tPHL are the same as tpd(s). The tpd propagation delay is the calculated RC time constant of the typical ON-state resistance
of the switch and the specified load capacitance, when driven by an ideal voltage source (zero output impedance).
H. All parameters and waveforms are not applicable to all devices.
Figure 3. Test Circuit and Voltage Waveforms
7
PACKAGE OPTION ADDENDUM
www.ti.com
17-Nov-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
74CB3Q3245RGYRG4
ACTIVE
VQFN
RGY
20
3000
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
BU245
Samples
SN74CB3Q3245DBQR
ACTIVE
SSOP
DBQ
20
2500
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
CB3Q3245
Samples
SN74CB3Q3245DGVR
ACTIVE
TVSOP
DGV
20
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
BU245
Samples
SN74CB3Q3245PW
ACTIVE
TSSOP
PW
20
70
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
BU245
Samples
SN74CB3Q3245PWR
ACTIVE
TSSOP
PW
20
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
BU245
Samples
SN74CB3Q3245PWRE4
ACTIVE
TSSOP
PW
20
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
BU245
Samples
SN74CB3Q3245RGYR
ACTIVE
VQFN
RGY
20
3000
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
BU245
Samples
SN74CB3Q3245ZQNR
OBSOLETE
BGA
MICROSTAR
JUNIOR
ZQN
20
TBD
Call TI
Call TI
BU245
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of