Datasheet

SCEA019 - January 2001
Texas Instruments GTLP Frequently Asked Questions 7–103
20 Are the alternate-source devices identical?
While all GTLP devices operate in the same manner and have the same pinout and
functionality, they are not all designed equally. The most important characteristic in GTLP
devices is the B-port OEC circuitry and the corresponding edge rate. Faster edges perform
poorly in backplane. In our demonstration backplane under the same conditions, the
SN74GTLPH16612 had better signal integrity than the FSC GTLP16612, and the
SN74GTLPH1655 had better signal integrity than the FSC GTLP16T1655. We believe that
TI’s GTLP devices exhibit excellent signal integrity due to the improved OEC and TI-OPC
TM
circuitry. If the design is optimized for the worst-case performance of all devices that are used,
FSC or Pericom GTLP can be used as an alternate source.
Additional differences in other manufacturers’ devices are shown in Table 7.
Table 7. Comparison of GTLP Features
Number of Devices
Features
TI Fairchild Pericom
Total number of GTLP devices 13 10 7
3.3-V V
CC
operation
12 5 3
Inputs/outputs 5-V tolerant All 6 5
I
off
– Partial power down (protect device)
All All All
PU3S - Hot insertion (protect equipment) 12 4 1
LFBGA package option 3 None None
Backplane (GTLP/B-Port) Options
BIAS V
CC
- Live insertion (protect data)
10 1 1
Output edge control All All All
TI-OPC circuitry 11 None None
Edge-rate control 7 1 1
Medium drive (34/50 mA) 7 9 6
High drive (100 mA) 6 1 1
Functionality
Transparent mode 12 7 6
Clocked mode 5 6 5
Latched mode 5 6 5
Clock enabled mode 4 5 4
Buffered clock option 2 3 2
1-to-6 TTL/LVTTL fanout driver 1 3 1
TI-OPC is a trademark of Texas Instruments.