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.