74HC85 74HCT85 4-bit magnitude comparator Rev. 4 4 August 2021 Product data sheet 1. General description The 74HC85 74HCT85 is a 4-bit magnitude comparator that can be expanded to almost any length. They perform comparison of two 4-bit binary, BCD or other monotonic codes and present the three possible magnitude results at the outputs (Q , Q and Q ). The 4-bit inputs are A>B A=B A<B weighted (A0 to A3 and B0 to B3), where A3 and B3 are the most significant bits. For proper compare operation the expander inputs (I , I and I ) to the least significant position must A>B A=B A<B be connected as follows: I = I = LOW and I = HIGH. For words greater than 4-bits, units A<B A>B A=B can be cascaded by connecting outputs Q , Q and Q to the corresponding inputs of A>B A=B A<B the significant comparator. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of V . CC 2. Features and benefits Wide supply voltage range from 2.0 to 6.0 V CMOS low power dissipation High noise immunity Latch-up performance exceeds 100 mA per JESD 78 Class II Level B Input levels: For 74HC85: CMOS level For 74HCT85: TTL level Complies with JEDEC standards: JESD8C (2.7 V to 3.6 V) JESD7A (2.0 V to 6.0 V) ESD protection: HBM JESD22-A114-A exceeds 2000 V MM JESD22-A115-A exceeds 200 V Specified from -40 C to +85 C and from -40 C to +125 C 3. Applications Process controllers Servo-motor control 4. Ordering information Table 1. Ordering information Type number Package Temperature range Name Description Version 74HC85D 40 C to +125 C SO16 plastic small outline package 16 leads SOT109-1 body width 3.9 mm 74HCT85D 74HC85PW 40 C to +125 C TSSOP16 plastic thin shrink small outline package 16 leads SOT403-1 body width 4.4 mm 74HCT85PWNexperia 74HC85 74HCT85 4-bit magnitude comparator 5. Functional diagram COMP 10 0 A0 10 10 A0 12 B0 9 P 9 B0 13 A1 12 A1 15 3 B1 12 11 Q 11 B1 A2 A<B 13 7 13 A2 Q 7 9 0 P<Q 7 B2 A<B 14 Q A=B 6 14 B2 11 A3 15 Q Q 6 P=Q 6 A=B Q 15 A3 14 B3 A>B 1 5 1 B3 Q 5 1 3 P>Q 5 A>B I A<B 2 I 2 I 2 P<Q A=B A<B 3 I 3 I 3 P=Q A>B A=B 4 4 I 4 P>Q A>B aaa-028459 aaa-028460 aaa-028461 Fig. 1. Logic symbol Fig. 2. IEC logic symbol Fig. 3. Functional diagram 74HC HCT85 All information provided in this document is subject to legal disclaimers. Nexperia B.V. 2021. All rights reserved Product data sheet Rev. 4 4 August 2021 2 / 17