TI SN74CBTLV3857DW

SN74CBTLV3857
LOW-VOLTAGE 10-BIT FET BUS SWITCH
WITH INTERNAL PULLDOWN RESISTORS
SCDS085B – OCTOBER 1998 – REVISED AUGUST 1999
D
D
D
D
D
D
D
D
DBQ, DGV, DW, OR PW PACKAGE
(TOP VIEW)
Enable Signal Is SSTL_2 Compatible
Flow-Through Architecture Optimizes PCB
Layout
Designed for Use With 200 Mbit/s Double
Data-Rate (DDR) SDRAM Applications
Switch On-State Resistance Is Designed to
Eliminate Series Resistor to DDR SDRAM
Internal 10-kΩ Pulldown Resistors to
Ground on B Port
Internal 50-kΩ Pullup Resistor on
Output-Enable Input
Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
Package Options Include Shrink
Small-Outline (DBQ), Thin Very
Small-Outline (DGV), Small-Outline (DW),
and Thin Shrink Small-Outline (PW)
Packages
VREF
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
GND
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
VCC
OE
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
description
This 10-bit FET bus switch is designed for 3-V to 3.6-V VCC operation and SSTL_2 output-enable (OE) input
levels.
When OE is low, the 10-bit bus switch is on, and port A is connected to port B. When OE is high, the switch is
open, and the high-impedance state exists between the two ports. There are 10-kΩ pulldown resistors to ground
on the B port.
The FET switch on-state resistance is designed to replace the series terminating resistor in the SSTL_2 data
path.
The SN74CBTLV3857 is characterized for operation from –40°C to 85°C.
FUNCTION TABLE
INPUT
OE
FUNCTION
L
A port = B port
H
Disconnect
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.
Copyright  1999, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
SN74CBTLV3857
LOW-VOLTAGE 10-BIT FET BUS SWITCH
WITH INTERNAL PULLDOWN RESISTORS
SCDS085B – OCTOBER 1998 – REVISED AUGUST 1999
logic diagram (positive logic)
22
2
A1
B1
SW
RINT
13
11
A10
B10
SW
RINT
VCC
OE
VREF
23
1
simplified schematic, each FET switch
A
B
(OE)
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 4.6 V
Input voltage range (OE only), VI (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to VCC + 0.5 V
Input voltage range (except OE), VI (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 4.6 V
Continuous channel current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 mA
Input clamp current, IIK (VI/O < 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –50 mA
Package thermal impedance, θJA (see Note 2): DBQ package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103°C/W
DGV package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139°C/W
DW package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81°C/W
PW package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120°C/W
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°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 under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES: 1. The input and output negative-voltage ratings may be exceeded if the input and output current ratings are observed.
2. The package thermal impedance is calculated in accordance with JESD 51.
2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SN74CBTLV3857
LOW-VOLTAGE 10-BIT FET BUS SWITCH
WITH INTERNAL PULLDOWN RESISTORS
SCDS085B – OCTOBER 1998 – REVISED AUGUST 1999
recommended operating conditions (see Note 3)
VCC
VREF
Supply voltage
VIH
VIL
AC high-level control input voltage
VIH
VIL
DC high-level control input voltage
Reference voltage (0.38 × VCC)
MIN
NOM
MAX
3
3.3
3.6
UNIT
V
1.15
1.25
1.35
V
VREF + 350 mV
V
AC low-level control input voltage
VREF – 350 mV
VREF + 180 mV
V
V
DC low-level control input voltage
VREF – 180 mV
85
V
TA
Operating free-air temperature
–40
°C
NOTE 3: 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.
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
TEST CONDITIONS
VCC = 3 V,
MIN
TYP†
II = –18 mA
–1.2
±1
OE
A port
II
B port
VCC = 3
3.6
6V
V,
VI = VCC or GND
VCC = 3.6 V,
VI = 3 V or 0
IO = 0,
VO = 3 V or 0,
OE = VCC
VREF
ICC
Ci
MAX
Control inputs
Cio(OFF)
ron‡
VCC = 3 V
VI = VCC or GND
V
mA
±5
µA
±1
mA
±5
µA
25
mA
3.5
pF
5
pF
VI = 0,
VI = 0.9 V,
II = 24 mA
II = 24 mA
5
8
6
11
VI = 1.25 V,
II = 24 mA
7
13
VI = 1.6 V,
II = 24 mA
9
40
VCC = 0
roff
ff‡
UNIT
Ω
1
MΩ
VCC = 3 V to 3.6 V,
VI = 1.65 V,
OE = VCC
1
† All typical values are at VCC = 3.3 V, TA = 25°C.
‡ Measured by the voltage drop between the A and B terminals at the indicated current through the switch. 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 1)
FROM
(INPUT)
TO
(OUTPUT)
tpd§
A or B
B or A
ten
OE
A or B
tdis
OE
A or B
PARAMETER
VCC = 3.3 V
± 0.3 V
MIN
UNIT
MAX
0.25
ns
1.4
4.2
ns
1.4
4.8
ns
§ 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).
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3
SN74CBTLV3857
LOW-VOLTAGE 10-BIT FET BUS SWITCH
WITH INTERNAL PULLDOWN RESISTORS
SCDS085B – OCTOBER 1998 – REVISED AUGUST 1999
PARAMETER MEASUREMENT INFORMATION
VCC = 3.3 V ± 0.3 V AND VDDQ = 2.5 ± 0.2 V
500 Ω
From Output
Under Test
VDDQ × 2
Open
S1
GND
CL = 50 pF
(see Note A)
500 Ω
Output
Control
LOAD CIRCUIT
TEST
S1
tpd
tPLZ/tPZL
tPHZ/tPZH
Open
VDDQ × 2
GND
VREF†
VREF†
VIH (AC)‡
VIL (AC)§
tPZL
VDDQ
VDDQ/2
Input
VDDQ/2
0V
tPLH
Output
Waveform 1
S1 at 2 × VDDQ
(see Note B)
VDDQ/2
Output
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VDDQ
VDDQ/2
VOL + 0.15 V
VOL
tPZH
tPHL
VOH
VDDQ/2
VOL
tPLZ
Output
Waveform 2
S1 at GND
(see Note B)
tPHZ
VDDQ/2
VOH
VOH – 0.15 V
0V
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
† VREF = 0.38 × VCC
‡ VIH(AC) = VREF + 350 mV
§ VIL(AC) = VREF – 350 mV
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 ns, tf ≤ 2 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.
Figure 1. Load Circuit and Voltage Waveforms
4
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Copyright  1999, Texas Instruments Incorporated