SN74AS885 Octal Magnitude Comparators |

SN74AS885 (ACTIVE) Octal Magnitude Comparators

Octal Magnitude Comparators - SN74AS885


These advanced Schottky devices are capable of performing high-speed arithmetic or logic comparisons on two 8-bit binary or two's complement words. Two fully decoded decisions about words P and Q are externally available at two outputs. These devices are fully expandable to any number of bits without external gates. To compare words of longer lengths, the P > QOUT and P < QOUT outputs of a stage handling less significant bits can be connected to the P > QIN and P < QIN inputs of the next stage handling more significant bits. The cascading paths are implemented with only a two-gate-level delay to reduce overall comparison times for long words. Two alternative methods of cascading are shown in application information.

The latch is transparent when P latch-enable (PLE) input is high; the P-input port is latched

when PLE is low. This provides the designer with temporary storage for the P-data word. The enable circuitry is implemented with minimal delay times to enhance performance when cascaded for longer words. The PLE, P, and Q data inputs utilize pnp input transistors to reduce the low-level current input requirement to typically -0.25 mA, which minimizes dc loading effects.

The SN54AS885 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74AS885 is characterized for operation from 0°C to 70°C.



In these cases, P > QOUT follows P > QIN and P < QOUT follows P < QIN.

AG = arithmetically greater than


  • Latchable P-Input Ports With Power-Up Clear
  • Choice of Logical or Arithmetic
    (Two's Complement) Comparison
  • Data and PLE Inputs Utilize pnp Input Transistors to Reduce dc Loading Effects
  • Approximately 35% Improvement in
    ac Performance Over Schottky TTL While Performing More Functions
  • Cascadable to n Bits While Maintaining High Performance
  • 10% Less Power Than STTL for an 8-Bit Comparison
  • Package Options Include Plastic Small-Outline (DW) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (NT) and Ceramic (JT) 300-mil DIPs



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Part number Order Technology Family VCC (Min) (V) VCC (Max) (V) Bits (#) Voltage (Nom) (V) F @ nom voltage (Max) (MHz) ICC @ nom voltage (Max) (mA) tpd @ nom Voltage (Max) (ns) IOL (Max) (mA) IOH (Max) (mA) Operating temperature range (C) Package Group
SN74AS885 Order now AS     4.5     5.5     8     5     35     210     17.5     20     -2     0 to 70     SOIC | 24    
SN54AS885 Samples not available AS     4.5     5.5     8     5     35     210     17.5     20/-2     0     -55 to 125     CDIP | 24
LCCC | 28