Datasheet

SCEA019 - January 2001
Texas Instruments GTLP Frequently Asked Questions 7–99
17 These function numbers are different. How do they compare to normal
logic functions?
When the GTL family was introduced, it was decided to differentiate GTL function numbers
from other similar logic functions because of the V
ref
pin and the reduced B-port GTL signal
levels. The first GTL device (SN74GTL16612) has exactly the same pinout as the 3.3-V V
CC
‘16601 universal bus transceiver, except that the two V
CC
pins on the B-port side serve
different purposes. Pin 34 is used for the GTL differential V
ref
input and pin 50 is used for the
5-V V
CC
that powers the GTL circuitry. The first GTLP device is the SN74GTLPH16612, which
is identical to the SN74GTL16612, except for the improved B-port circuitry that allows better
performance in distributed loads. Based on the SN74GTLPH16612, other existing GTL
devices, and TI's device-naming convention, the names of the additional GTLP devices were
selected as shown in the migration summary below.
GTLPH16945
GTLP817
GTLPH1645GTLPH32945 GTLPH3245
GTLPH306
GTLPH1616
GTLPH1612
GTLPH16916
GTLPH16912
GTLP1394
GTLPH16612
GTLPH1655
High Drive High Drive
High Drive
2 x 8 Bits w/o CE
LFBGA
LFBGA
3.3 & 5V Vcc
8 Bits 2 Bits 3-Wire
Bus Transceiver (‘16245 pinout - 2 x 8 Bits with separate DIR and OE controls)
Buffered Clock
Universal Bus Transceiver (‘16601 pinout - 18 Bits with OE, LE, CLK and CE controls)
1 GTLP to 6 LVTTL
1 LVTTL to 2 GTLP
Fanout Driver
Buffered Clock supports
source-synchronous
applications
GTLP1394 supports
TSB14C01A 1394
Backplane Physical-Layer
Controller Interface and
clock signal applications
Figure 14. GTLP Migration Summary