Function and Pinout Compatible With FCT
and F Logic
25-Ω Output Series Resistors Reduce
Transmission-Line Reflection Noise
Reduced VOH (Typically = 3.3 V) Versions
of Equivalent FCT Functions
Edge-Rate Control Circuitry for
Significantly Improved Noise
Characteristics
Ioff Supports Partial-Power-Down Mode
Operation
Matched Rise and Fall Times
Fully Compatible With TTL Input and
Output Logic Levels
ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
12-mA Output Sink Current
15-mA Output Source Current
Independent Register for A and B Buses
Multiplexed Real-Time and Stored Data
Transfer
3-State Outputs

description
The CY74FCT2652T consists of bus transceiver circuits, D-type flip-flops, and control circuitry arranged for
multiplexed transmission of data directly from the input bus or from the internal storage registers. Control (GAB
and GBA) inputs control the transceiver functions. Select-control (SAB and SBA) inputs select either real-time
or stored data transfer.
The circuitry used for select control eliminates the typical decoding glitch that occurs in a multiplexer during
transition between stored and real-time data. A low input level selects real-time data, and a high level selects
stored data. Data on the A or B data bus, or both, can be stored in the internal D flip-flops by low-to-high
transitions at the appropriate clock (CPAB or CPBA) inputs, regardless of levels at the select- or enable-control
inputs. When SAB and SBA are in the real-time transfer mode, it also is possible to store data without using
the internal D-type flip-flops by simultaneously enabling GAB and GBA. In this configuration, each output
reinforces its input. Thus, when all other data sources to the two sets of bus lines are at high impedance, each
set of bus lines remains at its last state.
On-chip termination resistors at the outputs reduce system noise caused by reflections. The CY74FCT2652T
can replace the CY74FCT652T to reduce noise in existing designs.
This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs,
preventing damaging current backflow through the device when it is powered down.