Datasheet

SN74FB1653
17-BIT LVTTL/BTL UNIVERSAL STORAGE TRANSCEIVER
WITH BUFFERED CLOCK LINE
SCBS702E – AUGUST 1997 – REVISED JUNE 2001
5–22
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
description
The SN74FB1653 contains an 8-bit and a 9-bit transceiver with a buffered clock. The clock and transceivers
are designed to translate signals between LVTTL and BTL environments. The device is designed specifically
to be compatible with IEEE Std 1194.1-1991 (BTL).
The A port operates at LVTTL signal levels. The A outputs reflect the inverse of the data at the B
port when the
A-port output enable (OEA) is high. When OEA is low or when V
CC
(5 V) typically is less than 2.5 V, the A outputs
are in the high-impedance state.
The B
port operates at BTL signal levels. The open-collector B ports are specified to sink 100 mA. Two output
enables (OEB and OEB
) are provided for the B outputs. When OEB is low, OEB is high, or V
CC
(5 V) typically
is less than 2.5 V, the B
port is turned off.
The clock-select (2SEL1 and 2SEL2) inputs are used to configure the TTL-to-BTL clock paths and delays (refer
to the Mux-Mode Delay table).
BIAS V
CC
establishes a voltage between 1.62 V and 2.1 V on the BTL outputs when V
CC
(5 V) is not connected.
BG V
CC
and BG GND are the supply inputs for the bias generator.
V
REF
is used to bypass the internal threshold reference voltage of the device. It is recommended that this
terminal be decoupled with a 0.1-µF capacitor.
Enhanced heat-dissipation techniques should be used when operating this device from AI to A0 at frequencies
greater than 50 MHz, or from AI to B or B to A0 at frequencies greater than 100 MHz.
ORDERING INFORMATION
T
A
PACKAGE
†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
0°C to 70°C TQFP – PCA Tube SN74FB1653PCA FB1653
†
Package drawings, standard packing quantities, thermal data, symbolization, and
PCB design guidelines are available at www.ti.com/sc/package.
Function Tables
TRANSCEIVER
INPUTS
OEA OEA OEB OEB
FUNCTION
X X H L A data to B bus
L HXX B data to A bus
L HHLA data to B bus, B data to A bus
X X L X
X XXH
B-bus isolation
H X X X
X L X X
A-bus isolation
STORAGE MODE
INPUTS
LE CLK
FUNCTION
H X Transparent
L ↑ Store data
L L Storage