Refer to the PDF data sheet for device specific package drawings
The SN74CB3Q3125 device is a high-bandwidth FET bus switch that uses a charge pump to elevate the gate voltage of the pass transistor, thus 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 SN74CB3Q3125 device also features low data I/O capacitance to minimize capacitive loading and signal distortion on the data bus.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
SN74CB3Q3125 | VQFN (14) | 3.50 mm × 3.50 mm |
SSOP (16) | 4.90 mm × 3.90 mm | |
TSSOP (16) | 5.00 mm × 4.40 mm | |
TVSOP (16) | 4.40 mm × 3.60 mm |
Changes from B Revision (March 2005) to C Revision
PIN | I/O | DESCRIPTION | ||
---|---|---|---|---|
NAME | DGV, PW, RGY | DBQ | ||
1OE | 1 | 2 | I | Output Enable (Active Low) |
1A | 2 | 3 | I/O | Channel 1A I/O 1A |
1B | 3 | 4 | I/O | Channel 1B I/O 1B |
2OE | 4 | 5 | I | Output Enable (Active Low) |
2A | 5 | 6 | I/O | Channel 2A I/O 2A |
2B | 6 | 7 | I/O | Channel 2B I/O 2B |
GND | 7 | 8 | — | Ground |
3B | 8 | 10 | I/O | Channel 3B I/O 3B |
3A | 9 | 11 | I/O | Channel 3A I/O 3B |
3OE | 10 | 12 | I | Output Enable (Active Low) |
4B | 11 | 13 | I/O | Channel 4B I/O 4B |
4A | 12 | 14 | I/O | Channel 4A I/O 4B |
4OE | 13 | 15 | I | Output Enable (Active Low) |
NC | — | 1, 9 | — | No Connect |
VCC | 14 | 16 | — | Power |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
VCC | Supply voltage | –0.5 | 4.6 | V | |
VIN | Control input voltage(2)(3) | –0.5 | 7 | V | |
VI/O | Switch I/O voltage(2)(3)(4) | –0.5 | 7 | V | |
II/K | Control input clamp current | VIN < 0 | –50 | mA | |
II/OK | I/O port clamp current | VI/O < 0 | –50 | mA | |
IIO | ON-state switch current(5) | ±64 | mA | ||
Continuous current through VCC or GND | ±100 | mA | |||
TJ | Junction temperature | 150 | °C | ||
Tstg | Storage temperature | –65 | 150 |
VALUE | UNIT | |||
---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) | +2000 | V |
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) | +1000 |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
VCC | Supply voltage | 2.3 | 3.6 | V | |
VIH | High-level control input voltage | VCC = 2.3 V to 2.7 V | 1.7 | 5.5 | V |
VCC = 2.7 V to 3.6 V | 2 | 5.5 | |||
VIL | Low-level control input voltage | VCC = 2.3 V to 2.7 V | 0 | 0.7 | V |
VCC = 2.7 V to 3.6 V | 0 | 0.8 | |||
VI/O | Data input and output voltage | 0 | 5.5 | V | |
TA | Operating free-air temperature | –40 | 85 | °C |
THERMAL METRIC(1) | SN74CB3Q3257 | UNIT | ||||
---|---|---|---|---|---|---|
DBQ (SSOP) | DGV (TVSOP) | PW (TSSOP) | RGY (VQFN) | |||
16 PINS | 14 PINS | 14 PINS | 14 PINS | |||
RθJA | Junction-to-ambient thermal resistance | 90 | 127 | 113 | 47 | °C/W |
PARAMETER | TEST CONDITIONS | MIN | TYP(2) | MAX | UNIT | |||
---|---|---|---|---|---|---|---|---|
VIK | VCC = 3.6 V, | II = –18 mA | –1.8 | V | ||||
IIN | Control inputs | VCC = 3.6 V, | VIN = 0 to 5.5 V | ±1 | µA | |||
IOZ(3) | VCC = 3.6 V, | VO = 0 to 5.5 V, VI = 0, |
Switch OFF, VIN = VCC or GND |
±1 | µA | |||
Ioff | VCC = 0, | VO = 0 to 5.5 V, | VI = 0 | 1 | µA | |||
ICC | VCC = 3.6 V, | II/O = 0, Switch ON or OFF, |
VIN = VCC or GND | 0.3 | 1 | mA | ||
ΔICC(4) | Control inputs | VCC = 3.6 V, | One input at 3 V, | Other inputs at VCC or GND | 30 | µA | ||
ICCD(5) | Per control input |
VCC = 3.6 V, | A and B ports open, | 0.04 | 0.2 | mA/ MHz |
||
Control input switching at 50% duty cycle | ||||||||
Cin | Control inputs | VCC = 3.3 V, | VIN = 5.5 V, 3.3 V, or 0 | 2.5 | 3.5 | pF | ||
Cio(OFF) | VCC = 3.3 V, | Switch OFF, VIN = VCC or GND, |
VI/O = 5.5 V, 3.3 V, or 0 | 4 | 5 | pF | ||
Cio(ON) | VCC = 3.3 V, | Switch ON, VIN = VCC or GND, |
VI/O = 5.5 V, 3.3 V, or 0 | 8 | 10 | pF | ||
ron(6) | VCC = 2.3 V, TYP at VCC = 2.5 V |
VI = 0, | IO = 30 mA | 4 | 8 | Ω | ||
VI = 1.7 V, | IO = –15 mA | 4 | 9 | |||||
VCC = 3 V | VI = 0, | IO = 30 mA | 4 | 6 | ||||
VI = 2.4 V, | IO = –15 mA | 4 | 8 |
PARAMETER | FROM (INPUT) |
TO (OUTPUT) |
VCC = 2.5 V ± 0.2 V | VCC = 3.3 V ± 0.3 V | UNIT | ||
---|---|---|---|---|---|---|---|
MIN | MAX | MIN | MAX | ||||
fOE(1) | OE | A or B | 10 | 20 | MHz | ||
tpd(2) | A or B | B or A | 0.12 | 0.2 | ns | ||
ten | OE | A or B | 1.5 | 6.7 | 1.5 | 6.6 | ns |
tdis | OE | A or B | 1 | 4.6 | 1 | 5.3 | ns |
IO = –15 mA |
A and B Ports Open |
The SN74CB3Q3125 device 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 SN74CB3Q3125 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 SN74CB3Q3125 device provides an optimized interface solution ideally suited for broadband communications, networking, and data-intensive computing systems.
The SN74CB3Q3125 device is organized as four 1-bit bus switches with separate output-enable (1OE, 2OE, 3OE, 4OE) inputs. It can be used as four 1-bit bus switches or as one 4-bit bus switch. When OE is low, the associated 1-bit 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 associated 1-bit 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.
The SN74CB3Q3125 device has a high-bandwidth data path (up to 500 MHz) and has 5-V tolerant I/Os with the device powered up or powered down. It also has low and flat ON-state resistance (ron) characteristics over operating range (ron = 4-Ω Typ).
The SN74CB3Q3125 device has rail-to-rail switching on data I/O ports for 0-V to 5-V switching with
3.3-V VCCand 0-V to 3.3-V switching with 2.5-V VCC as well as bidirectional data flow with near-zero propagation delay and low input/output capacitance that minimizes loading and signal distortion (Cio(OFF) = 3.5-pF Typ).
The SN74CB3Q3125 device also provides a fast switching frequency (fOE = 20-MHz Max) with data and control inputs that provide undershoot clamp diodes as well as low power consumption (ICC = 0.6-mA Typ).
The VCC operating range is from 2.3 V to 3.6 V and the data I/Os support 0-V to 5-V signal levels of
(0.8 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V, 5 V).
The control inputs can be driven by TTL or 5-V or 3.3-V CMOS outputs, and Ioff supports partial-power-down mode operation.
Table 1 lists the functional modes for the SN74CB3Q3125 device.
INPUT OE |
INPUT/OUTPUT A |
FUNCTION |
---|---|---|
L | B | A port = B port |
H | Z | Disconnect |
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The SN74CB3Q3125 device can be used to control up to four channels simultaneously.
The application shown in Figure 5 is a 4-bit bus being controlled. The OE pins are used to control the chip from the bus controller. This is a very generic example and can apply to many situations. If an application requires less than 4 bits, be sure to tie the A side to either high or low on unused channels.
The 0.1-µF capacitor must be placed as close as possible to the SN74CB3Q3257 device.