Function, Pinout, and Drive Compatible
With FCT and F Logic
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
Dual 1-of-8 Decoder With Enables
ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
CY54FCT138T
– 32-mA Output Sink Current
– 12-mA Output Source Current
CY74FCT138T
– 64-mA Output Sink Current
– 32-mA Output Source Current

description
The ’FCT138T devices are 1-of-8 decoders. These devices accept three binary weighted inputs (A0, A1, A2)
and, when enabled, provide eight mutually exclusive active-low outputs (O0–O7). The ’FCT138T devices
feature three enable inputs: two active low (E1, E2) and one active high (E3).
All outputs are high unless E1 and E2 are low and E3 is high. This multiple-enable function allows easy parallel
expansion of the device to a 1-of-32 (five lines to 32 lines) decoder with just four ’FCT138T devices and one
inverter.
These devices are 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.