MM5316

The MM5316 digital alarm clock is a monolithic MOS integrated circuit utilizing Pchannel  law-threshold,enhancement mode and ion-implanted depletion mode devices. MM5316 provides all the logic required to build several types of clocks and timers.Four display modes (time,seconds, alarm and sleep) are provided to optimize circuit utility. The circuit of MM5316 interfaces directly with 7-segment fluorescent tubes, and requires only a single power supply.The timekeeping function operates from either a 50 or 60 Hz input, and the display format may be either 12 hours (with leading-zero blanking and AM/PM indication) or 24 hours.

Features of the MM5316 are:(1)50 or 60 Hz operation; (2)single power supply; (3)low power dissipation (36 mW at 9V); (4)12 or 24-hour display format; (5)24-hour alarm setting; (6)all counters are resettable; (7)fast and slow set controls; (8)power failure indication; (9)blanking/brightness control capability; (10)elimination of illegal time display at turn on; (11)direct interface to fluorescent tubes; (12)9-minute snooze alarm; (13)presettable 59-minute sleep timer.By leaving this pin unconnected, the outputs for the most-significant display digit (10's of hours) are programmed to provide a 12-hour display format. An  internal  depletion pull down device is again provided. Connecting this  pin to  Vss  programs the 24-hour display format.

The absolute maximum ratings of the MM5316 can be summarized as:(1)voltage at any pin:Vss+0.3 to Vss-30 V;(2)storage temperature:-65 to 150;(3)operating temperature:-25 to 70;(4)lead temperature:300.In  the absence of any of these three inputs, the display drivers present  time-of-day  information  to  the  appropriate display digits. Internal pull-down depletion devices allow use of simple SPST switches to select the display mode.If more than one mode is selected, the priorities are as noted in  Table 1. Alternate display  modes of MM5316 are selected by  applying VSS to the appropriate pin. As shown in Figure 1 the code converters receive time, seconds, alarm and  sleep  information from  appropriate points in the clock circuitry. The display  mode of MM5316 select inputs control the gating of  the desired data to the code converter inputs and ultimately (via output drivers) to the display digits.