Features
Fastest Propagation Speeds in the Industry T
•
Maximum derating for capacitive loads 1.5ns/100 pF (F grade) and 1.1ns/100 pF
•
PD (F grade)
(G grade)
Very low ground bounce < 0.6 V @ VCC=5.00 V, Ta=25°C
•
Typical output skew ≤0.25ns
•
Bus Hold circuitry to retain last active state during Tri-State
•
Available in SSOP and TSSOP packages
•
= 2.5 ns, T
PD (G grade)
AT16646
= 2.0 ns
Description
Atmel’s AT16646 devices are 16-bit high speed, low power Tri-statable D type
registers, ideal for use in systems r equiring both transparent and registered mode
functions. They are organized as two separate 8-bit bus transceivers. Data flow is
bi-directional, and can be controlled for multiplexed transmission between A bus and
B bus either directl y or from the D registers by use of the direction control pin (xDi r),
output enable (xOE), and select lines (xSAB and xSBA). Storage of data on the A bus
and B bus is controlled by the outpu t pins. They have very low ground bounce and
excellent input noise rejection, giving the user stable signals in a high speed
envi ronment . The Bus H old feat ure e liminates the need for p ull-up or p ull-dow n
resistors and retains the last active state during a Tri-State event.
Functional Block Diagra m
AT16646
Fast Logic
16-Bit
Tri-State
Register
AT16646F
AT16646G
Pin Configurations
Pin Names Descriptions
xDir, xO E Output Enable Inpu ts
xCLKAB,xC LKBA Clock Pulse Inputs
xSAB , xSBA Output Data Source Sel ect Inputs
xAχ Data Register A Input s
Data Register B Outp uts
xBχ Data Register B Input s
Data Register A Outp uts
1DIR
1SAB
VCC
GND
GND
2CLKAB
1A1
1A4
1A7
2A1
2A3
2A4
2A6
2A7
SSOP/TSSOP
1CLKAB
GND
1A2
1A3
1A5
11
1A6
13
1A8
15
2A2
17
GND
19
2A5
21
VCC
23
2A8
25
2SAB
27
2DIR
1
2
3
4
5
6
7
8
9
10
12
14
16
18
20
22
24
26
28
Top View
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
1CLKBA
GND
1B2
1B3
1B5
1B6
1B8
2B2
GND
2B5
VCC
2B8
2SBA
2OE
1
OE
1SBA
1B1
VCC
1B4
GND
1B7
2B1
2B3
2B4
2B6
2B7
GND
2CLKBA
0757B
5-21
Function Table
(1)
Inp u ts Dat a I/O
(2)
xOE xDir xCLKAB xC LKB A xSAB xSBA xAχ xBχ
H
H
L
L
L
L
Notes: 1. H = High voltage level, L = Low voltage level, X = Don’t care, ↑ = Low-to-High transition
X
X
L
L
H
H
2. The data output functions may be enabled or disabled by various signals at the x
are always enabled, i.e. data at the bus pins will be stored on every LOW-to-HIGH transition on the clock inputs.
H or L
↑
X
X
X
H or L
H or L
↑
X
H or L
X
X
X
X
X
X
L
H
X
Input Input Isolation
X
L
Output Input Real Ti me B Data t o A Bus
H
X
Input Output Real Time A Data to B Bus
X
OE or xDir inputs. Data input functions
Operation or Funct ion
Store A and B Data
Stored B Data to A Bus
Stored A Data to B Bus
Absolute Maximum Ratings*
Operating Temperature........................0°C to +70°C
Storage Temperature. ........ ..... ........-65°C to +150°C
Voltage on any Pin
with Respect to Ground.................-2.0 V to +7.0 V
Maximum Operating Voltage..............................6.0V
5.0 Volt DC Characteristics
(1)
*NOTICE: Stresses beyond 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 beyond those
indicated in the operational sections of this specification is
not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
Notes: 1. Minimum voltage is -0.6 V dc which may
undershoot to -2.0 V for pulses of less than 20 ns.
Maximum output pin voltage is V
which may overshoot to +7.0 V for pulses of less
than 20 ns.
+0.75 V dc
CC
Applicable over recommended operating range from Ta = 0°C to +70°C, VCC = +5.0V +/- 5% (unless otherwise noted)
Symbol Parameter Test Conditio ns Min Typ Max Units
∆I
CC
Quiescent Power Supply
VCC = Max, VIN = 3.4 V 0.8 1.2 mA
Current
V
IH
V
IL
I
IH
I
IL
I
OZ
VOH(1) Output High Voltage
VOH(2) Output High Voltage
V
OL
V
OL
Note: 1. F grade: At V
2. G grade: At V
Input High Voltage 2.0 V
Input Low Voltage 0.8 V
Input Hi gh C urrent (I/O Pins) VIN = V
CC
±15 µA
Input Low Current (I/O Pins) VIN = GND ±15 µ A
Output Leakage Current ±10 µA
F Grade only
G Grade only
VCC = 4.75 V
IOH = -10 mA
VCC = 4.75 V
IOH = -12 mA
2.7 V
2.7 V
Output Low Volta ge ( F G ra de) IOL = 10 mA 0.55 V
Output Low Volta ge ( G Grade) IOL = 12 mA 0.55 V
CC (max)
CC (max)
, the value of V
, the value of V
OH(max)
= 3.75 V and at V
OH(max)
= 3.75 V and at V
CC(min)
CC(min)
, V
, V
OH(max)
OH(max)
= 3.25 V
= 3.35 V
5-22
AT16646