This part is a kind of semiconductor called 74AC4520.

Function of this product has M74AC4520.

Manufacturers : SGS-THOMSON

Image and pinout :

Some of the text within the PDF file :

www.DataSheet.co.kr M54/M74HC4518 M54/M74HC4520 HC4518 DUAL DECADE COUNTER HC4520 DUAL 4 BIT BINARY COUNTER . . . . . . . . HIGH SPEED fMAX = 55 MHz (TYP.) at VCC = 5 V LOW POWER DISSIPATION ICC = 4 µA (MAX.) AT TA = 25 °C HIGH NOISE IMMUNITY VNIH = VNIL = 28 % VCC (MIN.) OUTPUT DRIVE CAPABILITY 10 LSTTL LOADS SYMMETRICAL OUTPUT IMPEDANCE |IOH| = IOL = 4 mA (MIN.) BALANCED PROPAGATION DELAYS tPLH = tPHL WIDE OPERATING VOLTAGE RANGE VCC (OPR) = 2 V TO 6 V PIN AND FUNCTION COMPATIBLE WITH 4520B/4518B B1R (Plastic Package) F1R (Ceramic Package) M1R (Micro Package) C1R (Chip Carrier) ORDER CODES : M54HCXXXXF1R M74HCXXXXM1R M74HCXXXXB1R M74HCXXXXC1R PIN CONNECTIONS (top view) DESCRIPTION The M54/74HC4518/4520 are high speed CMOS DUAL 4 BIT BINARY COUNTERS fabricated in sili2 con gat [ ... ]

74AC4520 PDF Datasheet Download