IDT74ALVCH16841
3.3V CMOS 20-BIT BUS-INTERACE D-TYPE LATCH WITH 3-STATE OUTPUTS
INDUSTRIAL TEMPERATURE RANGE
3.3V CMOS 20-BIT
BUS-INTERFACE D-TYPE
LATCH WITH 3-STATE OUT-
PUTS AND BUS-HOLD
• 0.5 MICRON CMOS Technology
• Typical t
SK(o)
(Output Skew) < 250ps
• ESD > 2000V per MIL-STD-883, Method 3015; > 200V using
machine model (C = 200pF, R = 0)
• V
CC
= 3.3V ± 0.3V, Normal Range
• V
CC
= 2.7V to 3.6V, Extended Range
• V
CC
= 2.5V ± 0.2V
• CMOS power levels (0.4µ W typ. static)
µ
• Rail-to-Rail output swing for increased noise margin
• Available in SSOP, TSSOP, and TVSOP packages
IDT74ALVCH16841
FEATURES:
DESCRIPTION:
This 20-bit interface D-type latch is built using advanced dual metal CMOS
technology. The ALVCH16841 features 3-state outputs designed specifi-
cally for driving highly capacitive relatively low-impedance loads. This
device is particularly suitable for implementing buffer registers, unidirec-
tional bus drivers, and working registers.
The ALVCH16841 can be used as two 10-bit latches or one 20-bit latch.
The 20 latches are transparent D-type latches. The device has noninverting
data (D) inputs and provides true data at its outputs. While the latch-enable
(1LE or 2LE) input is high, the Q outputs of the corresponding 10-bit latch
follow the D inputs. When LE is taken low, the Q outputs are latched at the
levels set up at the D inputs.
A buffered output-enable (1OE or 2OE) input can be used to place the
outputs of the corresponding 10-bit latch in either a normal logic state (high
or low logic levels) or a high-impedance state. In the high-impedance state,
the outputs neither load nor drive the bus lines significantly.
OE
does not
affect the internal operation of the latches. Old data can be retained or new
data can be entered while the outputs are in the high-impedance state.
The ALVCH16841 has been designed with a ±24mA output driver. This
driver is capable of driving a moderate to heavy load while maintaining
speed performance.
The ALVCH16841 has “bus-hold” which retains the inputs’ last state
whenever the input bus goes to a high impedance. This prevents floating
inputs and eliminates the need for pull-up/down resistors.
DRIVE FEATURES:
• High Output Drivers: ±24mA
• Suitable for heavy loads
APPLICATIONS:
• 3.3V high speed systems
• 3.3V and lower voltage computing systems
FUNCTIONAL BLOCK DIAGRAM
1
OE
1
2
OE
28
1
LE
56
2
LE
29
1
D
1
55
1
D
2
D
1
42
1
D
Q
C
1
2
1
Q
1
Q
C
1
15
2
Q
1
TO NINE OTHER CHANNELS
TO NINE OTHER CHANNELS
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
INDUSTRIAL TEMPERATURE RANGE
1
©1999 Integrated Device Technology, Inc.
MARCH 1999
DSC-4699/2
IDT74ALVCH16841
3.3V CMOS 20-BIT BUS-INTERACE D-TYPE LATCH WITH 3-STATE OUTPUTS
INDUSTRIAL TEMPERATURE RANGE
PIN CONFIGURATION
1
OE
1
Q
1
1
Q
2
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
Description
Max
V
TERM
(2)
Terminal Voltage with Respect to GND
–0.5 to +4.6
–0.5 to V
CC
+0.5
–65 to +150
–50 to +50
±50
–50
±100
Unit
V
V
°C
mA
mA
mA
mA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
1
LE
1
D
1
1
D
2
V
TERM
(3)
Terminal Voltage with Respect to GND
T
STG
I
OUT
I
IK
I
OK
I
CC
I
SS
Storage Temperature
DC Output Current
Continuous Clamp Current,
V
I
< 0 or V
I
> V
CC
Continuous Clamp Current, V
O
< 0
Continuous Current through each
V
CC
or GND
GND
1
Q
3
1
Q
4
GND
1
D
3
1
D
4
V
CC
1
Q
5
1
Q
6
1
Q
7
V
CC
1
D
5
1
D
6
1
D
7
GND
1
Q
8
1
Q
9
1
Q
10
2
Q
1
2
Q
2
2
Q
3
GND
1
D
8
1
D
9
1
D
10
2
D
1
2
D
2
2
D
3
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. V
CC
terminals.
3. All terminals except V
CC
.
CAPACITANCE
(T
A
= +25°C, F = 1.0MHz)
Symbol
C
IN
C
OUT
C
OUT
Parameter
(1)
Input Capacitance
Output Capacitance
I/O Port Capacitance
Conditions
V
IN
= 0V
V
OUT
= 0V
V
IN
= 0V
Typ.
5
7
7
Max.
7
9
9
Unit
pF
pF
pF
GND
2
Q
4
2
Q
5
2
Q
6
GND
2
D
4
2
D
5
2
D
6
NOTE:
1. As applicable to the device type.
PIN DESCRIPTION
Pin Names
xDx
xLE
xOE
xQx
Data Inputs
(1)
Latch Enable Inputs (Active HIGH)
Output Enable Inputs (Active LOW)
3-State Outputs
Description
V
CC
2
Q
7
2
Q
8
V
CC
2
D
7
2
D
8
GND
2
Q
9
2
Q
10
2
OE
GND
2
D
9
2
D
10
2
LE
NOTE:
1. These pins have "Bus-Hold". All other pins are standard inputs, outputs, or I/Os.
FUNCTION TABLE
(EACH 10-BIT LATCH)
(1)
Inputs
xDx
H
L
X
X
xLE
H
H
L
X
xOE
L
L
L
H
Output
xQx
H
L
Q
2
Z
SSOP/ TSSOP/ TVSOP
TOP VIEW
NOTES:
1. H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
Z = High-Impedance
2. Output level before the indicated steady-state input conditions were established.
2
IDT74ALVCH16841
3.3V CMOS 20-BIT BUS-INTERACE D-TYPE LATCH WITH 3-STATE OUTPUTS
INDUSTRIAL 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
V
IK
V
H
I
CCL
I
CCH
I
CCZ
∆I
CC
Parameter
Input HIGH Voltage Level
Input LOW Voltage Level
Input HIGH Current
Input LOW Current
High Impedance Output Current
(3-State Output pins)
Clamp Diode Voltage
Input Hysteresis
Quiescent Power Supply Current
V
CC
= 2.3V, I
IN
= –18mA
V
CC
= 3.3V
V
CC
= 3.6V
V
IN
= GND or V
CC
One input at V
CC
- 0.6V, other inputs at V
CC
or GND
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
CC
= 3.6V
V
I
= V
CC
V
I
= GND
V
O
= V
CC
V
O
= GND
Test Conditions
Min.
1.7
2
—
—
—
—
—
—
—
—
—
Typ.
(1)
—
—
—
—
—
—
—
—
–0.7
100
0.1
Max.
—
—
0.7
0.8
±5
±5
±10
±10
–1.2
—
40
V
mV
µA
µA
µA
µA
V
Unit
V
Quiescent Power Supply Current
Variation
—
—
750
µA
NOTE:
1. Typical values are at V
CC
= 3.3V, +25°C ambient.
BUS-HOLD CHARACTERISTICS
Symbol
I
BHH
I
BHL
I
BHH
I
BHL
I
BHHO
I
BHLO
NOTES:
1. Pins with Bus-Hold are identified in the pin description.
2. Typical values are at V
CC
= 3.3V, +25°C ambient.
Parameter
(1)
Bus-Hold Input Sustain Current
Bus-Hold Input Sustain Current
Bus-Hold Input Overdrive Current
V
CC
= 3V
V
CC
= 2.3V
V
CC
= 3.6V
Test Conditions
V
I
= 2V
V
I
= 0.8V
V
I
= 1.7V
V
I
= 0.7V
V
I
= 0 to 3.6V
Min.
– 75
75
– 45
45
—
Typ.
(2)
—
—
—
—
—
Max.
—
—
—
—
±500
Unit
µA
µA
µA
3
IDT74ALVCH16841
3.3V CMOS 20-BIT BUS-INTERACE D-TYPE LATCH WITH 3-STATE OUTPUTS
INDUSTRIAL TEMPERATURE RANGE
OUTPUT DRIVE CHARACTERISTICS
Symbol
V
OH
Parameter
Output HIGH Voltage
V
CC
= 2.3V
V
CC
= 2.3V
V
CC
= 2.7V
V
CC
= 3V
V
CC
= 3V
V
OL
Output LOW Voltage
V
CC
= 2.3V to 3.6V
V
CC
= 2.3V
V
CC
= 2.7V
V
CC
= 3V
I
OH
= – 24mA
I
OL
= 0.1mA
I
OL
= 6mA
I
OL
= 12mA
I
OL
= 12mA
I
OL
= 24mA
Test Conditions
(1)
V
CC
= 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
2
—
—
—
—
—
Max.
—
—
—
—
—
—
0.2
0.4
0.7
0.4
0.55
V
Unit
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, T
A
= 25°C
V
CC
= 2.5V ± 0.2V
Symbol
C
PD
C
PD
Parameter
Power Dissipation Capacitance Outputs enabled
Power Dissipation Capacitance Outputs disabled
Test Conditions
C
L
= 0pF, f = 10Mhz
Typical
12
1
V
CC
= 3.3V ± 0.3V
Typical
20
3
Unit
pF
SWITCHING CHARACTERISTICS
(1)
V
CC
= 2.5V ± 0.2V
Symbol
t
PLH
t
PHL
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
t
SU
t
H
t
W
t
SK(O)
Parameter
Propagation Delay
xDx to xQx
Propagation Delay
xLE to xQx
Output Enable Time
xOE to xQx
Output Disable Time
xOE to xQx
Set-up Time, data before LE↓
Hold Time, data after LE↓
Pulse Duration, xLE HIGH
Output Skew
(2)
0.9
1.2
3.3
—
—
—
—
—
0.7
1.5
3.3
—
—
—
—
—
1.1
1.1
3.3
—
—
—
—
500
ns
ns
ns
ps
1.1
5.3
—
4.3
1.3
4.1
ns
1
6.2
—
6
1
4.9
ns
1
5.6
—
5.1
1
4.3
ns
Min.
1
Max.
5
V
CC
= 2.7V
Min.
—
Max.
4.7
V
CC
= 3.3V ± 0.3V
Min.
1.2
Max.
3.9
Unit
ns
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.
4
IDT74ALVCH16841
3.3V CMOS 20-BIT BUS-INTERACE D-TYPE LATCH WITH 3-STATE OUTPUTS
INDUSTRIAL TEMPERATURE RANGE
TEST CIRCUITS AND WAVEFORMS
TEST CONDITIONS
Symbol
V
LOAD
V
IH
V
T
V
LZ
V
HZ
C
L
V
CC(1)
= 3.3V±0.3V V
CC(1)
= 2.7V
6
2.7
1.5
300
300
50
6
2.7
1.5
300
300
50
V
CC(2)
= 2.5V±0.2V
2 x Vcc
Vcc
Vcc / 2
150
150
30
Unit
V
V
V
mV
mV
pF
SAME PHASE
INPUT TRANSITION
t
PLH
OUTPUT
t
PLH
OPPOSITE PHASE
INPUT TRANSITION
t
PHL
t
PHL
V
IH
V
T
0V
V
OH
V
T
V
OL
V
IH
V
T
0V
ALVC Link
Propagation Delay
ENABLE
CONTROL
INPUT
t
PZL
OUTPUT
SWITCH
NORMALLY
CLOSED
LOW
t
PZH
OUTPUT
SWITCH
NORMALLY
OPEN
HIGH
V
LOAD/2
V
T
t
PHZ
V
T
0V
t
PLZ
DISABLE
V
CC
500Ω
Pulse
Generator
(1, 2)
V
LOAD
Open
GND
V
IH
V
T
0V
V
LOAD/2
V
LZ
V
OL
V
OH
V
HZ
0V
ALVC Link
V
IN
D.U.T.
R
T
V
OUT
500Ω
C
L
ALVC Link
Test Circuit for All Outputs
DEFINITIONS:
C
L
= Load capacitance: includes jig and probe capacitance.
R
T
= Termination resistance: should be equal to Z
OUT
of the Pulse Generator.
NOTES:
1. Pulse Generator for All Pulses: Rate
≤
1.0MHz; t
F
≤
2.5ns; t
R
≤
2.5ns.
2. Pulse Generator for All Pulses: Rate
≤
1.0MHz; t
F
≤
2ns; t
R
≤
2ns.
NOTE:
1. Diagram shown for input Control Enable-LOW and input Control Disable-HIGH.
Enable and Disable Times
DATA
INPUT
TIMING
INPUT
ASYNCHRONOUS
CONTROL
SYNCHRONOUS
CONTROL
SWITCH POSITION
Test
Open Drain
Disable Low
Enable Low
Disable High
Enable High
All Other Tests
Switch
V
LOAD
GND
Open
t
SU
t
H
t
REM
t
SU
t
H
V
IH
V
T
0V
V
IH
V
T
0V
V
IH
V
T
0V
V
IH
V
T
0V
ALVC Link
INPUT
t
PLH1
t
PHL1
V
IH
V
T
0V
V
OH
V
T
V
OL
V
OH
V
T
V
OL
Set-up, Hold, and Release Times
OUTPUT 1
LOW-HIGH-LOW
PULSE
t
W
HIGH-LOW-HIGH
PULSE
V
T
t
SK
(x)
t
SK
(x)
OUTPUT 2
t
PLH2
t
PHL2
V
T
ALVC Link
Pulse Width
ALVC Link
t
SK
(x)
= t
PLH2
-
t
PLH1
or
t
PHL2
-
t
PHL1
Output Skew - t
SK
(
X
)
NOTES:
1. For t
SK
(o) OUTPUT1 and OUTPUT2 are any two outputs.
2. For t
SK
(b) OUTPUT1 and OUTPUT2 are in the same bank.
5
PCB设计
