74ABT657 Datasheet, PDF (7/11 Pages) NXP Semiconductors – Octal transceiver with parity generator/checker 3-State

Philips Semiconductors
Octal transceiver with parity generator/checker
(3-State)
Product specification
74ABT657
AC CHARACTERISTICS
GND = 0V; t_R = t_F = 2.5ns; C_L = 50pF, R_L = 500Ω
SYMBOL
PARAMETER
WAVEFORMS
LIMITS
T_amb = +25^oC
V_CC = +5.0V
T_amb = –40 to +85^oC
V_CC = +5.0V ±10%
UNIT
Min
Typ
Max
Min
Max
t_PLH
Propagation delay
t_PHL
An to Bn or Bn to An
2
1.1
3.3
1.2
3.0
5.0
1.1
4.3
1.2
5.5
4.8
ns
t_PLH
Propagation delay
t_PHL
An to PARITY
1, 2
2.5
6.5
2.8
7.0
8.7
9.1
2.5
2.8
10.1
10.6
ns
t_PLH
Propagation delay
t_PHL
ODD/EVEN to PARITY, ERROR
1, 2
1.7
5.0
1.9
5.0
6.6
1.7
6.6
1.9
7.3
7.3
ns
t_PLH
Propagation delay
t_PHL
Bn to ERROR
1, 2
3.9
4.0
9.2
9.6
11.7
12.1
3.9
4.0
13.8
14.5
ns
t_PLH
Propagation delay
t_PHL
PARITY to ERROR
1, 2
2.7
6.0
3.2
6.4
7.6
2.7
8.0
3.2
9.4
9.4
ns
t_PZH
t_PZL
Output enable time¹
to High or Low level
3, 4
1.3
3.8
1.9
4.4
5.6
1.3
7.0
1.9
6.6
8.2
ns
t_PHZ
Output disable time
t_PLZ
from High or Low level
3, 4
2.4
5.1
2.7
5.4
7.0
2.4
7.6
2.7
7.6
8.1
ns
NOTES:
1. These delay times reflect the 3-State recovery time only and do not include the delay through the buffers and the parity check circuitry which
affect the ERROR output. To assure valid information at the ERROR pin, time must be allowed for the signal to propagate through the
drivers (B to A), through the parity check circuitry (same as A to PARITY), and to the ERROR output. Valid data at the ERROR pin ≥ (B to A)
+ (A to PARITY).
AC WAVEFORMS
NOTE: For all waveforms, V_M = 1.5V.
An, Bn
ODD/EVEN
PARITY
PARITY,
ERROR
V_M
t_PHL
V_M
V_M
t_PLH
V_M
An, Bn
ODD/EVEN
PARITY
An, Bn,
PARITY,
ERROR
V_M
t_PLH
V_M
V_M
t_PHL
V_M
SA00219
Waveform 1. Propagation Delay For Inverting Output
SA00220
Waveform 2. Propagation Delay For Non-Inverting Output
OE
V_M
V_M
t_PZH
t_PHZ
An, Bn
PARITY, ERROR
V_M
V_OH –0.3V
0V
SA00221
Waveform 3. 3-State Output Enable Time to High Level and
Output Disable Time from High Level
OE
V_M
V_M
t_PZL
t_PLZ
An, Bn
PARITY, ERROR
V_M
V_OL +0.3V
0V
SA00222
Waveform 4. 3-State Output Enable Time to Low Level and
Output Disable Time from Low Level
1995 Dec 11
7