TOSHIBA CMOS Digital Integrated Circuit Silicon Monolithic TC74HC148AP,TC74HC148AF 8-to-3 Line Priority Encoder The TC74HC148A is a high speed CMOS 8-to-3 LINE ENCODER fabricated with silicon gate C2MOS technology. It achieves the high speed operation similar to equivalent LSTTL while maintaining the CMOS low power dissipation. All data inputs and outputs of these encoders are active at the low logic level. The encoder detects a low level of the highest order among eight input signals and outputs the corresponding signal position in binaly code. Enable Input EI and Enable Output EO are used to easily cascade without using external circuits. All inputs are equipped with protection circuits agait static discharge or traient excess voltage. TC74HC148AP TC74HC148AF Features High speed: tpd = 15 (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 to 6 V Pin and function compatible with 74LS148 Pin Assignment Weight DIP16-P-300-2.54A SOP16-P-300-1.27A SOP16-P-300-1.27 : 1.00 g (typ.) : 8 g (typ.) : 8 g (typ.) 1
IEC Logic Symbol Truth Table Inputs Outputs E1 0 1 2 3 4 5 6 7 A2 A1 A0 GS EO H X X X X X X X X H H H H H L H H H H H H H H H H H H L L X X X X X X X L L L L L H L X X X X X X L H L L H L H L X X X X X L H H L H L L H L X X X X L H H H L H H L H L X X X L H H H H H L L L H L X X L H H H H H H L H L H L X L H H H H H H H H L L H L L H H H H H H H H H H L H X: Don t care 2
System Diagram Absolute Maximum Ratings (Note 1) Characteristics Symbol Rating Unit Supply voltage range V CC 0.5 to 7 V DC input voltage V IN 0.5 to V CC + 0.5 V DC output voltage V OUT 0.5 to V CC + 0.5 V Input diode current I IK ±20 ma Output diode current I OK ±20 ma DC output current I OUT ±25 ma DC V CC /ground current I CC ±50 ma Power dissipation P D 500 (DIP) (Note 2)/180 (SOP) mw Storage temperature T stg 65 to 150 C Note 1: Exceeding any of the absolute maximum ratings, even briefly, lead to deterioration in IC performance or even destruction. Note 2: 500 mw in the range of Ta = 40 to 65 C. From Ta = 65 to 85 C a derating factor of 10 mw/ C shall be applied until 300 mw. 3
Recommended Operating Conditio (Note) Characteristics Symbol Rating Unit Supply voltage V CC 2 to 6 V Input voltage V IN 0 to V CC V Output voltage V OUT 0 to V CC V Operating temperature T opr 40 to 85 C 0 to 1000 (V CC = V) Input rise and fall time t r, t f 0 to 500 (V CC = V) 0 to 400 (V CC = V) Note: The recommended operating conditio are required to eure the normal operation of the device. Unused inputs must be tied to either VCC or GND. Electrical Characteristics DC Characteristics Characteristics High-level input voltage Low-level input voltage High-level output voltage Low-level output voltage Input leakage current Quiescent supply current Symbol V IH V IL V OH V OL Ta = 40 to Test Condition Ta = 25 C 85 C V CC (V) Min Typ. Max Min Max I OH = 20 µa V IN = V IH or V IL I OH = 4 ma I OH = 5.2 ma I OL = 20 µa V IN = V IH or V IL I OL = 4 ma I OL = 5.2 ma 1.50 3.15 4.20 1.9 4.4 5.9 4.18 5.68 4.31 5.80 0.0 0.0 0.0 7 8 0.50 1.35 1.80 0.26 0.26 1.50 3.15 4.20 1.9 4.4 5.9 4.13 5.63 0.50 1.35 1.80 0.33 0.33 I IN V IN = V CC or GND ± ±1.0 µa I CC V IN = V CC or GND 4.0 40.0 µa Unit V V V V 4
AC Characteristics (C L = 15 pf, V CC = 5 V, Ta = 25 C, input: t r = t f = 6 ) Characteristics Symbol Test Condition Min Typ. Max Unit Output traition time Propagation delay time (IN-A0, A1, A2) Propagation delay time (IN-EO, GS) Propagation delay time (EI-EO) Propagation delay time (EI-GS) Propagation delay time (EI-A0, A1, A2) t TLH t THL 4 8 15 25 15 25 11 19 11 19 11 19 AC Characteristics (C L = 50 pf, input: t r = t f = 6 ) Characteristics Output traition time Propagation delay time (IN-A0, A1, A2) Propagation delay time (IN-EO, GS) Propagation delay time (EI-EO) Propagation delay time (EI-GS) Propagation delay time (EI-A0, A1, A2) Symbol t TLH t THL Test Condition Ta = 25 C V CC (V) Ta = 40 to 85 C Min Typ. Max Min Max Input capacitance C IN 5 10 10 pf 30 8 7 52 19 15 52 19 15 40 14 11 40 14 12 40 14 12 75 15 13 150 30 26 150 30 26 115 23 20 115 23 20 115 23 20 95 19 16 190 38 33 190 38 33 145 29 25 145 29 25 145 29 25 Unit Power dissipation capacitance C PD (Note) 55 pf Note: C PD is defined as the value of the internal equivalent capacitance which is calculated from the operating current coumption without load. Average operating current can be obtained by the equation: I CC (opr) = C PD V CC f IN + I CC 5
Typical Application 6
Package Dimeio Weight: 1.00 g (typ.) 7
Package Dimeio Weight: 8 g (typ.) 8
Package Dimeio Weight: 8 g (typ.) 9
Note: Lead (Pb)-Free Packages DIP16-P-300-2.54A SOP16-P-300-1.27A RESTRICTIONS ON PRODUCT USE 060116EBA The information contained herein is subject to change without notice. 021023_D TOSHIBA is continually working to improve the quality and reliability of its products. Nevertheless, semiconductor devices in general can malfunction or fail due to their inherent electrical seitivity and vulnerability to physical stress. It is the respoibility of the buyer, when utilizing TOSHIBA products, to comply with the standards of safety in making a safe design for the entire system, and to avoid situatio in which a malfunction or failure of such TOSHIBA products could cause loss of human life, bodily injury or damage to property. In developing your desig, please eure that TOSHIBA products are used within specified operating ranges as set forth in the most recent TOSHIBA products specificatio. Also, please keep in mind the precautio and conditio set forth in the Handling Guide for Semiconductor Devices, or TOSHIBA Semiconductor Reliability Handbook etc. 021023_A The TOSHIBA products listed in this document are intended for usage in general electronics applicatio (computer, personal equipment, office equipment, measuring equipment, industrial robotics, domestic appliances, etc.). These TOSHIBA products are neither intended nor warranted for usage in equipment that requires extraordinarily high quality and/or reliability or a malfunction or failure of which may cause loss of human life or bodily injury ( Unintended Usage ). Unintended Usage include atomic energy control itruments, airplane or spaceship itruments, traportation itruments, traffic signal itruments, combustion control itruments, medical itruments, all types of safety devices, etc. Unintended Usage of TOSHIBA products listed in this document shall be made at the customer s own risk. 021023_B The products described in this document shall not be used or embedded to any dowtream products of which manufacture, use and/or sale are prohibited under any applicable laws and regulatio. 060106_Q The information contained herein is presented only as a guide for the applicatio of our products. No respoibility is assumed by TOSHIBA for any infringements of patents or other rights of the third parties which may result from its use. No licee is granted by implication or otherwise under any patent or patent rights of TOSHIBA or others. 021023_C The products described in this document are subject to the foreign exchange and foreign trade laws. 021023_E 10