NSC DS3896 Btl trapezoidalâ ¢ transceiver Datasheet

DS3896/DS3897
BTL Trapezoidal™ Transceivers
General Description
These advanced transceivers are specifically designed to
overcome problems associated with driving a densely populated backplane, and thus provide significant improvement in
both speed and data integrity. Their low output capacitance,
low output signal swing and noise immunity features make
them ideal for driving low impedance buses with minimum
power consumption.
The DS3896 is an octal high speed schottky bus transceiver
with common control signals, whereas the DS3897 is a quad
device with independent driver input and receiver output
pins. The DS3897 has a separate driver disable for each
driver and is, therefore, suitable for arbitration lines. The
separate driver disable pins (En) feature internal pull ups
and may be left open if not required. On the other hand, the
DS3896 provides high package density for data/address
lines.
The open collector drivers generate precise trapezoidal
waveforms, which are relatively independent of capacitive
loading conditions on the outputs. This significantly reduces
noise coupling to adjacent lines. In addition, the receivers
use a low pass filter in conjunction with a high speed comparator, to further enhance the noise immunity and provide
equal rejection to both negative and positive going noise
pulses on the bus.
To minimize bus loading, these devices also feature a schottky diode in series with the open collector output that isolates
the driver output capacitance in the disabled state. The output low voltage is typically “1V” and the output high level is
intended to be 2V. This is achieved by terminating the bus
with a pull up resistor to 2V at both ends. The device can
drive an equivalent DC load of 18.5Ω (or greater) in the
above configuration.
These signalling requirements, including a 1 volt signal
swing, low output capacitance and precise receiver thresholds are referred to as Bus Transceiver Logic (BTL).
Features
n 8 bit DS3896 transceiver provides high package density
n 4 bit DS3897 transceiver provides separate driver input
and receiver output pins
n BTL compatible
n Less than 5 pF output capacitance for minimal bus
loading
n 1 Volt bus signal swing reduces power consumption
n Trapezoidal driver waveforms (tr, tf ≅ 6 ns typical)
reduce noise coupling to adjacent lines
n Temperature insensitive receiver thresholds track the
bus logic high level to maximize noise immunity in both
high and low states
n Guaranteed A.C. specifications on noise immunity and
propagation delay over the specified temperature and
supply voltage range
n Open collector driver output allows wire-or connection
n Advanced low power schottky technology
n Glitch free power up/down protection on driver and
receiver outputs
n TTL compatible driver and control inputs and receiver
outputs
Logic Diagrams
DS3896N, M
DS3897N, M
DS008510-1
DS008510-2
Order Numbers DS3896M, DS3896N, DS3897M or DS3897N
See NS Package Number M20B or N20A
Trapezoidal™ is a trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation
DS008510
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DS3896/DS3897 BTL Trapezoidal Transceivers
January 1996
Absolute Maximum Ratings (Note 1)
Storage Temperature Range
Lead Temperature (Soldering, 4 sec.)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage
Control Input Voltage
Driver Input and Receiver Output
Receiver Input and Driver Output
Power Dissipation at 70˚C N Package
M Package
−65˚C to +150˚C
260˚C
Recommended Operating
Conditions
6V
5.5V
5.5V
2.5V
1480 mW
TBD mW
Supply Voltage, VCC
Bus Termination Voltage
Operating Free Air Temperature
Min
4.75
1.90
0
Max
5.25
2.10
70
Units
V
V
˚C
Electrical Characteristics: (Notes 2, 3)
(0˚C ≤ TA ≤ 70˚C, 4.75V ≤ VCC ≤ 5.25V unless otherwise specified)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Driver and Control Inputs: (An, Dn, En, CD, T/R , RE , TE )
VIH
Logical “1” Input Voltage
VIL
Logical “0” Input Voltage
II
Logical “1” Input Current
IIH
Logical “1” Input Current
IIHC
Logical “1” Input Current
IIL
Logical “0” Input Current
IILC
Logical “0” Input Current
VCL
Input Diode Clamp Voltage
2.0
An = Dn = En = VCC
An = Dn = En = 2.4V
CD = T/R = RE = TE = 2.4V
An = Dn = En = 0.4V
CD = T/R = RE = TE = 0.4V
Iclamp = −12 mA
V
0.8
V
1
mA
40
µA
80
µA
−1
−1.6
mA
−180
−400
µA
−0.9
−1.5
V
1.0
1.2
V
10
100
µA
100
µA
1.62
V
Driver Output/Receiver Input: (Bn)
VOLB
Low Level Bus Voltage
IIHB
Maximum Bus Current (Power On)
IILB
Maximum Bus Current (Power Off)
VTH
Receiver Input Threshold
An = Dn = En = T/R = 2V, VL = 2V
RL = 18.5Ω, CD = TE = 0.8V (Figure 1)
An = Dn = En = 0.8V, VCC = 5.25V
Bn = 2V
An = Dn = En = 0.8V, VCC = 0V
Bn = 2V
VCC = 5V
0.75
1.47
1.55
2.4
3.2
Receiver Output: (An, Rn)
VOH
Logical “1” Output Voltage
VOL
Logical “0” Output Voltage
Bn = 1.2V, IOH = −400 µA
CD = T/R = RE = 0.8V
Bn = 2V, IOL = 16 mA
Output Short Circuit Current
CD = T/R = RE = 0.8V
Bn = 1.2V
ICC
Supply Current (DS3896)
CD = T/R = RE = 0.8V
VCC = 5.25V
ICC
Supply Current (DS3897)
VCC = 5.25V
IOS
−20
V
0.35
0.5
V
−70
−100
mA
90
135
mA
50
80
mA
Note 1: “Absolute maximum ratings” are those beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the device should be
operated at these limits. The table of “Electrical Characteristic” provide conditions for actual device operation.
Note 2: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified.
Note 3: All typicals are given for VCC = 5V and Ta = 25˚C.
DS3896 Switching Characteristics
(0˚C ≤ TA ≤ 70˚C, 4.75V ≤ VCC ≤ 5.25V unless otherwise specified)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
5
9
15
ns
5
9
15
ns
Driver:
tDLH
An to Bn
CD = 0.8V, T/R = 2.0V, VL = 2V
(Figure 2)
tDHL
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2
DS3896 Switching Characteristics
(Continued)
(0˚C ≤ TA ≤ 70˚C, 4.75V ≤ VCC ≤ 5.25V unless otherwise specified)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
5
10
18
ns
5
12
20
ns
5
15
25
ns
5
22
35
ns
3
6
10
ns
3
6
10
ns
5
12
18
ns
5
10
18
ns
5
10
18
ns
5
8
15
ns
2
4
8
ns
3
7
12
ns
5
10
18
ns
14
24
40
ns
Driver:
tDLHC
CD to Bn
An = T/R = 2.0V, VL = 2V
(Figure 2)
tDHLC
tDLHT
T/R to Bn
tDHLT
tR
Driver Output Rise Time
tF
Driver Output Fall Time
VCI = An, VC = 5V, (Figure 5)
CD = 0.8V, RC = 390Ω, CL = 30 pF
RL1 = 18Ω, RL2 = NC, VL = 2V
CD = 0.8V, T/R = 2V, VL = 2V
(Figure 2)
Receiver:
tRLH
Bn to An
CD = 0.8V, T/R = 0.8V
(Figure 3)
tRHL
tRLZC
CD to An
tRZLC
Bn = 2.0V, T/R = 0.8V, CL = 5 pF
RL1 = 390Ω, RL2 = NC, VL = 5V ( Figure 4)
Bn = 2.0V, T/R = 0.8V, CL = 30 pF
tRZHC
RL1 = 390Ω, RL2 = 1.6k, VL = 5V (Figure 4)
Bn = 0.8V, T/R = 0.8V, VL = 0V,
RL1 = 390Ω, RL2 = NC, CL = 5 pF (Figure 4)
Bn = 0.8V, T/R = 0.8V, VL = 0V,
tRLZT
RL1 = NC, RL2 = 1.6k, CL = 30 pF
VCI = Bn, VC = 2V, RC = 18Ω,
tRHZC
T/R to An
(Figure 4)
CD = 0.8V, VL = 5V, RL1 = 390Ω,
RL2 = NC, CL = 5 pF (Figure 5)
VCI = Bn, VC = 2V, RC = 18Ω,
CD = 0.8V, VL = 5V, RL1 = 390Ω,
tRZLT
tRHZT
RL2 = 1.6k, CL = 30 pF (Figure 5)
VCI = Bn, VC = 0V, RC = 18Ω,
CD = 0.8V, VL = 0V, RL1 = 390Ω,
2
4
8
ns
tRZHT
RL2 = NC, CL = 5 pF (Figure 5)
VCI = Bn, VC = 0V, RC = 18Ω,
CD = 0.8V, VL = 0V, RL1 = NC
2
8
15
ns
3
6
RL2 = 1.6k, CL = 30 pF
tNR
(Figure 5)
(Figure 6)
Receiver Noise
ns
Rejection Pulse Width
Note: NC means open
DS3897 Switching Characteristics
(0˚C ≤ TA ≤ 70˚C, 4.75V ≤ VCC ≤ 5.25V unless otherwise specified)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
5
9
15
ns
5
9
15
ns
An = RE = 2.0V, VL = 2V, (Figure 2)
RC = 390Ω, VCI = An, VC = 5V, CL = 30 pF
RL1 = 18Ω, RL2 = NC, VL = 2V (Figure 5)
5
10
18
ns
5
12
20
ns
CD = 0.8V, T/R = 2V, VL = 2V
3
6
10
ns
3
6
10
ns
5
10
18
ns
Driver:
tDLH
Dn, En to Bn
TE = 0.8V, RE = 2.0V, VL = 2V
(Figure 2)
tDHL
tDLHT
TE to Bn
tDHLT
tR
Driver Output Rise Time
tF
Driver Output Fall Time
(Figure 2)
Receiver:
tRLH
Bn to Rn
TE = 2.0V, RE = 0.8V
3
(Figure 3)
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DS3897 Switching Characteristics
(Continued)
(0˚C ≤ TA ≤ 70˚C, 4.75V ≤ VCC ≤ 5.25V unless otherwise specified)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
5
12
18
ns
5
10
18
ns
5
8
15
ns
2
4
8
ns
3
7
12
ns
3
6
10
20
30
ns
10
20
30
ns
Receiver:
tRHL
tRLZR
RE to Rn
tRZLR
Bn = TE = 2V, VL = 5V, CL = 5 pF
RL1 = 390Ω, RL2 = NC (Figure 4)
Bn = TE = 2V, VL = 5V, CL = 30 pF
RL1 = 390Ω, RL2 = 1.6k (Figure 4)
Bn = 0.8V, TE = 2V, VL = 0V,
RL1 = 390Ω, RL2 = NC, CL = 5 pF (Figure 4)
Bn = 0.8V, TE = 2V, VL = 0V,
tRHZR
tRZHR
RL1 = NC, RL2 = 1.6k, CL = 30 pF
tNR
(Figure 4)
(Figure 6)
Receiver Noise
ns
Rejection Pulse Width
Driver plus Receiver:
tDRLH
Dn to Rn
TE = RE = 0.8V
(Figure 7)
tDRHL
Note: NC means open
DS008510-3
FIGURE 1. Driver Output Low Voltage Test
DS008510-4
Note: tr = tf ≤ 5 ns from 10% to 90%
FIGURE 2. Driver Propagation Delays
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4
DS3897 Switching Characteristics
(Continued)
DS008510-5
Note: tR = tF ≤ 10 ns from 10% to 90%
FIGURE 3. Receiver Propagation Delays
DS008510-6
Note: tr = tf ≤ 5 ns from 10% to 90%
FIGURE 4. Propagation Delay from CD pin to An
5
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DS3897 Switching Characteristics
(Continued)
DS008510-7
Note: tr = tf ≤ 5 ns from 10% to 90%
FIGURE 5. Propagation Delay from T/R pin to An or Bn
DS008510-8
Note: tr = tf = 2 ns from 10% to 90%
FIGURE 6. Receiver Noise Immunity: “No Response at Output” Input Waveforms
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6
DS3897 Switching Characteristics
(Continued)
DS008510-9
Note: tr = tf ≤ 5 ns from 10% to 90%
FIGURE 7. Driver Plus Receiver Delays
Typical Application
DS008510-10
7
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Physical Dimensions
inches (millimeters) unless otherwise noted
20-Lead (0.300" Wide) Molded Small Outline Package, JEDEC (M)
Order Number DS3896M or DS2897M
NS Package Number M20B
Molded Dual-In-Line Package (N)
Order Number DS3896N or DS3897N
NS Package Number N20A
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8
DS3896/DS3897 BTL Trapezoidal Transceivers
Notes
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