IDT74LVCH646A
3.3V CMOS OCTAL BUS TRANSCEIVER AND REGISTER
EXTENDED COMMERCIAL TEMPERATURE RANGE
3.3V CMOS OCTAL BUS
TRANSCEIVER AND REGISTER
WITH 3-STATE OUTPUTS
AND BUS-HOLD
FEATURES:
–
–
–
0.5 MICRON CMOS Technology
ESD > 2000V per MIL-STD-883, Method 3015;
> 200V using machine model (C = 200pF, R = 0)
1.27mm pitch SOIC, 0.65mm pitch SSOP,
0.635mm pitch QSOP, 0.65mm pitch TSSOP packages
Extended commercial range of – 40°C to +85°C
V
CC
= 3.3V ±0.3V, Normal Range
V
CC
= 2.3V to 3.6V, Extended Range
CMOS power levels (0.4µW typ. static)
Rail-to-Rail output swing for increased noise margin
All inputs, outputs and I/O are 5 Volt tolerant
Supports hot insertion
IDT74LVCH646A
B bus is clocked into the registers on the low-to-high transition of the
appropriate clock (CLKAB or CLKBA) input.
Output-enable (OE) and direction-control (DIR) inputs control the trans-
ceiver functions. In the transceiver mode, data present at the high-imped-
ance port is stored in either register or in both. The select-control (SAB and
SBA) inputs can multiplex stored and real-time (transparent mode) data. DIR
determines which bus receives data when
OE
is low. In the isolation mode
(OE high), A data is stored in one register and B data can be stored in the
other register. When an output function is disabled, the input function is still
enabled and can be used to store and transmit data. Only one of the two
buses, A or B, can be driven at a time.
The LVCH646A has been designed with a ±24mA output driver. This
driver is capable of driving a moderate to heavy load while maintaining speed
performance.
N
O
FO T
R
R E
N CO
EW M
M
D E
ES N
D
IG E
N D
S
–
–
–
–
–
–
–
Drive Features for LVCH646A:
– High Output Drivers:
±24mA
– Reduced system switching noise
APPLICATIONS:
DESCRIPTION:
• 5V and 3.3V mixed voltage systems
• Data communication and telecommunication systems
To ensure the high-impedance state during power up or power down,
OE
should be tied to V
CC
through a pullup resistor; the minimum value of the
resistor is determined by the current-sinking capability of the driver.
Inputs can be driven from either 3.3V or 5V devices. This feature allows
the use of this device as a translator in a mixed 3.3V/5V system environment.
The LVCH646A has “bus-hold” which retains the inputs’ last state
whenever the input goes to a high impedance. This prevents floating inputs
and eliminates the need for pull-up/down resistors.
The LVCH646A device consists of bus-transceiver circuits, D-type flip-
flops, and control circuitry arranged for multiplexed transmission of data
directly from the input bus or from the internal registers. Data on the A or
FUNCTIONAL BLOCK DIAGRAM
OE
21
DIR
3
CLKBA
SBA
23
22
CLKAB
SAB
1
2
One of eight Channels
1
D
C
1
A
1
4
20
B
1
1
D
C
1
TO SEVEN OTHER CHANNELS
EXTENDED COMMERCIAL TEMPERATURE RANGE
1
c
1999 Integrated Device Technology, Inc.
OCTOBER 1999
DSC-4499/-
IDT74LVCH646A
3.3V CMOS OCTAL BUS TRANSCEIVER AND REGISTER
EXTENDED COMMERCIAL TEMPERATURE RANGE
PIN CONFIGURATION
CLKAB
SAB
D IR
A
1
A
2
A
3
A
4
A
5
A
6
A
7
A
8
GND
1
2
3
4
5
6
7
8
9
10
11
12
SO24-2
SO24-7
SO24-8
SO24-9
ABSOLUTE MAXIMUM RATINGS
V
CC
CLKBA
SBA
OE
B
1
B
2
B
3
B
4
B
5
B
6
B
7
B
8
(1)
Unit
V
°C
mA
mA
mA
8LVC
24
23
22
21
20
19
18
17
16
15
14
13
Symbol
V
TERM
T
STG
I
OUT
I
IK
I
OK
I
CC
I
SS
Description
Terminal Voltage with Respect to GND
Storage Temperature
DC Output Current
Continuous Clamp Current,
V
I
< 0 or V
O
< 0
Continuous Current through
each V
CC
or GND
Max.
– 0.5 to +6.5
– 65 to +150
– 50 to +50
– 50
±100
NOTE:
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.
SOIC/ SSOP/ QSOP/ TSSOP
TOP VIEW
CAPACITANCE
(T
A
= +25°C, f = 1.0MH
Z
)
Symbol
C
IN
C
OUT
C
I/O
Parameter
(1)
Input Capacitance
Output
Capacitance
I/O Port
Capacitance
Conditions
V
IN
= 0V
V
OUT
= 0V
V
IN
= 0V
Typ.
4.5
5.5
6.5
Max.
6
8
8
Unit
pF
pF
pF
8LVC Link
PIN DESCRIPTION
Pin Names
Ax
Bx
CLKAB, CLKBA
SAB, SBA
OE
DIR
Description
Data Register A Inputs
(1)
Data Register B Outputs
Data Register B Inputs
(1)
Data Register A Outputs
Clock Pulse Inputs
Output Data Source Select Inputs
Output-enable Input
Direction-control Input
NOTE:
1. As applicable to the device type.
NOTE:
1. These pins have “Bus-hold”. All other pins are standard inputs,
outputs, or I/Os.
FUNCTION TABLE
(1)
Inputs
OE
X
X
H
H
L
L
L
L
DIR
X
X
X
X
L
L
H
H
CLKAB
↑
X
↑
H or L
X
X
X
H or L
CLKBA
X
↑
↑
H or L
X
H or L
X
X
SAB
X
X
X
X
X
X
L
H
SBA
X
X
X
X
L
H
X
X
A1-A8
Input
Unspecified
(2)
Input
Input disabled
Output
Output
Input
Input
Data I/O
B1-B8
Unspecified
(2)
Input
Input
Input disabled
Input
Input
Output
Output
Operation or Function
Store A, B unspecified
(2)
Store B, A unspecified
(2)
Store A and B data
Isolation, hold storage
Real-time B data to A bus
Stored B data to A bus
Real Time A data to B bus
Stored A data to B bus
NOTES:
1. H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
↑
= LOW-to-HIGH Transition
2. The data output functions may be enabled or disabled by various signals at the
OE
or DIR inputs. Data input functions are always enabled; i.e., data
at the bus pins willl be stored on every LOW-to-HIGH transition on the clock inputs.
2
IDT74LVCH646A
3.3V CMOS OCTAL BUS TRANSCEIVER AND REGISTER
EXTENDED COMMERCIAL TEMPERATURE RANGE
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Operating Condition: T
A
= – 40°C To +85°C
Symbol
V
IH
V
IL
I
IH
I
IL
I
OZH
I
OZL
I
OFF
V
IK
V
H
I
CCL
I
CCH
I
CCZ
∆I
CC
Parameter
Input HIGH Voltage Level
Input LOW Voltage Level
Input Leakage Current
High Impedance Output Current
(3-State Output pins)
Input/Output Power Off Leakage
Clamp Diode Voltage
Input Hysteresis
Quiescent Power Supply Current
V
CC
= 0V, V
IN
or V
O
≤
5.5V
V
CC
= 2.3V, I
IN
= – 18mA
V
CC
= 3.3V
V
CC
= 3.6V
V
IN
= GND or V
CC
3.6
≤
V
IN
≤
5.5V
(2)
Quiescent Power Supply
Current Variation
One input at V
CC
- 0.6V,
other inputs at V
CC
or GND
—
—
—
—
—
—
—
– 0.7
100
—
—
—
±50
– 1.2
—
10
10
500
µA
8LVC Link
Test Conditions
V
CC
= 2.3V to 2.7V
V
CC
= 2.7V to 3.6V
V
CC
= 2.3V to 2.7V
V
CC
= 2.7V to 3.6V
V
CC
= 3.6V
V
CC
= 3.6V
V
I
= 0 to 5.5V
V
O
= 0 to 5.5V
Min.
1.7
2
—
—
—
—
Typ.
(1)
—
—
—
—
—
—
Max.
—
—
0.7
0.8
±5
±10
Unit
V
V
µA
µA
µA
V
mV
µA
NOTES:
1. Typical values are at V
CC
= 3.3V, +25°C ambient.
2. This applies in the disabled state only.
BUS-HOLD CHARACTERISTICS
Symbol
I
BHH
I
BHL
I
BHH
I
BHL
I
BHHO
I
BHLO
8LVC Link
Parameter
(1)
Bus-Hold Input Sustain Current
Bus-Hold Input Sustain Current
Bus-Hold Input Overdrive Current
V
CC
= 3.0V
V
CC
= 2.3V
V
CC
= 3.6V
Test Conditions
V
I
= 2.0V
V
I
= 0.8V
V
I
= 1.7V
V
I
= 0.7V
V
I
= 0 to 3.6V
Min.
– 75
75
—
—
—
Typ.
(2)
—
—
—
—
—
Max.
—
—
—
—
± 500
Unit
µA
µA
µA
NOTES:
1. Pins with Bus-hold are identified in the pin description.
2. Typical values are at V
CC
= 3.3V, +25°C ambient.
4
IDT74LVCH646A
3.3V CMOS OCTAL BUS TRANSCEIVER AND REGISTER
EXTENDED COMMERCIAL TEMPERATURE RANGE
OUTPUT DRIVE CHARACTERISTICS
Symbol
V
OH
Parameter
Output HIGH Voltage
V
CC
Test Conditions
(1)
= 2.3V to 3.6V
I
OH
= – 0.1mA
I
OH
= – 6mA
I
OH
= – 12mA
Min.
V
CC
– 0.2
2
1.7
2.2
2.4
I
OH
= – 24mA
I
OL
= 0.1mA
I
OL
= 6mA
I
OL
= 12mA
V
CC
= 2.7V
V
CC
= 3.0V
I
OL
= 12mA
I
OL
= 24mA
2.2
—
—
—
—
—
Max.
—
—
—
—
—
—
0.2
0.4
0.7
0.4
0.55
8LVC Link
Unit
V
V
CC
= 2.3V
V
CC
= 2.3V
V
CC
= 2.7V
V
CC
= 3.0V
V
CC
= 3.0V
V
OL
Output LOW Voltage
V
CC
= 2.3V to 3.6V
V
CC
= 2.3V
V
NOTE:
1. V
IH
and V
IL
must be within the min. or max. range shown in the DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE table for the
appropriate V
CC
range. T
A
= – 40°C to +85°C.
OPERATING CHARACTERISTICS, V
CC
= 3.3V
±
0.3V, TA = 25°C
Symbol
C
PD
C
PD
Parameter
Power dissipation capacitance per transceiver Outputs enabled
Power dissipation capacitance per transceiver Outputs disabled
Test Conditions
C
L
= 0pF, f = 10Mhz
Typical
75
9
Unit
pF
pF
SWITCHING CHARACTERISTICS
Symbol
f
MAX
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
t
PZH
t
PZL
t
PHZ
t
PLZ
t
W
t
SU
t
H
t
SK(o)
Parameter
Propagation Delay
Ax or Bx to Bx or Ax
Propagation Delay
CLK to Ax or Bx
Propagation Delay
SBA or SAB to Ax or Bx
Output Enable Time
OE
to Ax
Output Disable Time
OE
to Ax
Output Enable Time
DIR to Bx
Output Disable Time
DIR to Bx
Pulse Duration
Setup Time, data before CLK↑
Hold Time, data after CLK↑
Output Skew
(2)
Min
.
—
—
—
—
—
—
—
—
—
—
—
—
(1)
V
CC
= 2.7V
Min
.
150
—
—
—
—
—
—
—
3.3
1.6
1.7
—
Max.
—
7.9
8.8
9.9
10.2
8.9
10.4
8.7
—
—
—
—
V
CC
= 3.3V ± 0.3V
Min.
150
1.4
1.3
1.4
1
1
1.2
1.1
3.3
1.5
1.7
—
Max.
—
7.4
8.4
8.6
8.2
7.5
8.3
7.9
—
—
—
500
Unit
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ps
V
CC
= 2.5V ± 0.2V
Max.
—
—
—
—
—
—
—
—
—
—
—
—
NOTES:
1. See test circuits and waveforms. T
A
= – 40°C to + 85°C.
2. Skew between any two outputs of the same package and switching in the same direction.
5
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