MM5456, MM5457J Digital Alarm Clocks

MM5456, MM5457J Digital Alarm Clocks
 National
Semiconductor
Digital Clocks |
J J
MM5456, MM5457 Digital Alarm Clocks
General Description
The MM5456, 57 digital alarm clock radio chips
are monolithié MOS integrated circuits utilizing N-chan-
nel, low threshold, enhancement mode and ion-im-
planted depletion mode devices.
Each circuit contains all the logic necessary for a digital
clock with sleep and alarm control and is intended for
clock-radio applications.
Real time and alarm time are displayed in hours-minutes
and sleep time is displayed in minutes when setting
the sleep counter.
An alarm output is provided that ‘beeps’ a 50% duty
cycle, 700 Hz signal gated at 2 Hz rate: when the alarm
set time and the real time matches. A sleep output
that provides a DC level is used to control the radio.
It is activated with the alarm output or programmed
via the sleep counter to turn OFF from 0 to 59 minutes
after the sleep counter is set.
“The MM5456, MM5457 are bonded in a 22-pin package.
The MM5457 has a 24-hour/50 Hz option and the
MM5456 has the 12-hour/50 Hz or 12- hour/60 Hz
options.
Features
Duplex LED display drive
Fast/slow set capability
24-hour alarm
“Snooze’’ function (9 minutes)
On-chip alarm oscillator
Alarm tone output gated at a 2 Hz rate
‘Power fail indication—entire display flashes at a
1 Hz rate
Automatic power-on reset
PM display indicator
2 Presettable 59 minute sleep timer
e ETE
A snooze feature is provided for a 9- minute recurrence Applications
of the alarm after it: has sounded. ® Alarm clocks
o m Desk ciocks
Setting is done via the standard fast and slow set buttons ‚ @® Clock radios
when in the time set, alarm set or sleep set modes. = Aut bile clock
These control inputs are TRI-STATE® inputs to reduce |" Automobile clocks
pin count. Mm Stopwatches
E Industrial clocks
The 50/60 Hz clock selects what segment data is on ® Portable clocks
the outputs, i.e., a duplex LED display interface. m Timers
Block Diagram окон: с
Ÿ Y
+50 OR N REAL TIME ь
+60 ” COUNTER >
| y a SEGMENT OUTPUTS
SLEEP COUNTER AND DÉCIDE MM5456: 12 OUTPUTS
+ COMPARATOR MM5457: 13 OUTPUTS
SNOOZE LOGIC
Î 4
ALARM COUNTER [>
4
TÍME SET/RUN/ У. «O Von
ALARM SET OP
FAST SET/RUN/ Or CONTROL
SLOW SET 1 1 I <«—O ss
RC ALARMOFF/ SLEEP ALARM
ALARMON/ OUT TONE QUT
SLEEP SET
5-70
CR RT
Absolute Maximum Ratings (Exceeding the following ratings may result in permianent damage to the device)
Vss to Vss +12V
—-25°C to +70°C
65°C to +150°C
300°C
Voltage at Any Pin
Operating Temperature
Storage Temperature
Lead Temperature (Soldering, 10 seconds)
Electrical Characteristics Power supply voltage should not exceed a maximum of 12V under any circumstances.
TA within operating range, VDD = 7V to 11V | |
PARAMETER CONDITIONS MIN TYP MAX UNITS
Power Supply Voltage Output Driving Display 9 11 М
Functional — Count Operating 7 - 1 Vv
Power Supply Current No Output Loads ' | |
VDD = 7V 4 mA
VDD = 11V < 5 mA
60/60 Hz Input Frequency DC “50/60 10k Hz
Logical “0”, Low Level Vss Yes Vss+0.5 | Vv
Logica! “17, High Level 0.7 VDD VDD VDD Vv
Input Leakage VIN = VDD or Vss | | 10 pA
All Other Input Voltages
Logica! "0", Low Level Vss Vss Vggt0.5 VW
Logical “1, High Level VpD-1 VDD ~ VDD Vv
Power Failure Detect Voltage (Vpp Voltage) 1 5
Alarm Output, Sleep Output Vpp = 11V
Sourcing, Logical “1” High VoH= VDD —- 1V 1 HA
Sinking, Logical 0” Low VoL =Vss + 6V 5 mA
Alarm Output Frequency В = 68k, C=0.1uF 700 Hz
Segment Outputs (Except Vpp = 10V
HTADEG) |
Output Sink, Logical “0” Low Vou = Vss + 2V 20 «| mA
Leakage, Logical ‘1°’ High VOH = VDD 10 { ЦА
Segment Output (HTADEG) Vpp = 10V
Output Sink, Logical “0” Low | VoL = Vss + 2V 40 | mA
Leakage, Logical “1” High VOH = VDD 10 HA
Functional Description
50 or 60 Hz Input:A shaping circuit is provided inter-
nally to- square the 50 or 60 Hz input. This circuit
allows use of a half sinewave input. A resistor in series
must be used to limit current into the MOS device.
24-Hour/50 Hz, 12-Hour/60 Hz, 12-Hour/50 Hz
(MM5456): When this input is connected to Vpp, the
display will be 12 hours with 50 Hz input. If left floating,
the display will be 12 hours with 60 Hz input. (The
MM5457 is internally bonded to select the 24-hour/50
Hz mode. The MM5456 selects the 12-hour/50 Hz or the
12-hour/60 Hz modes.)
Sleep Set/Alarm Enable/Alarm OFF: Whenever this
input is connected to Vgsg, the sleep counters will
display and be set to 59 minutes, if previously at 00
minutes. Fast set or slow set may be used to preset
time other than 59 minutes. When the alarm sounds,
the snooze can be activated by momentarily con-
necting fast set pin ‚to Vpp. This will turn off the
alarm for 9-10 minutes, after which the alarm will
again be sounded. The snooze alarm feature may be
repeatedly used for up to 59 minutes or until alarm
OFF is activated by momentarily connecting this pin
to Vpp. When alarm OFF is activated, the alarm latch
will reset and silence the alarm. The alarm will auto-
matically sound again in 24 hours (or at a new alarm
setting). If it is desired to silence the alarm for a day
or more, the alarm OFF input should remain at Vpp.
The alarm can be enabled again by allowing the input
to float.
External RC: The resistor and capacitor on this pin
set the frequency of the alarm tone. The frequency is
5-71
4
E E IRA RETA
‚Functional Description (continued
nominally set to 1400 Hz in order to produce a 700 Hz
(50% duty cycle) tone at the alarm output.
Time Set/Run/Alarm Set: This input must be activated
in order to set the time counter and alarm counter. When
connected to Vpp,. the time counter wiil be displayed
and may be set with the fast-slow input. Upon release
of fast and slow set, the time counter will be in a hoid
mode. If time set/alarm set is left floating, the time
counter will be displayed, and the fast-slow input will
be disabled (normal run mode). When this input is con-
nected to Vgg, the alarm counter will be displayed
and may be set with the fast-slow input.
Fast Set/Run/Slow Set: Whenever this input is con-
nected to Vpp and time set or alarm set is activated,
the appropriate counter will advance at a 60 Hz rate.
If connected to Vgg,the minutes counter will advance
at 2 Hz with carry into the hours counter. |f left floating,
the clock will keep normat time. When connected to
VDD and sleep set is activated, the sleep counter will
count downward at a 10 Hz rate. If connected to Vss,
the sleep counter will count downward at the slower
rate; 2 Hz.
Alarm Output: This output remains at Vpp when inac-
tive. When the alarm latch becomes set, the alarm
Typical Application
700 Hz tone will be gated by a 20% duty cycle 2 Hz
signal (i.e., the alarm tone will be ON for 100. ms and
OFF for 400 ms). This output contains an internal
pull-up to Vpp in order to turn OFF the external
PNP transistor driver when the alarm is inactive.
Sleep Output: This output. remains at VDD when
inactive, When the alarm latch becomes set or the sleep
counter is at other than 00 minutes, the sleep output
will be ON. Snooze or alarm OFF function will dis-
able this output simultaneously with alarm output
if activated by alarm latch. Sriooze function will disable
this output at any time if activated by sleep counter
being set. Thistoutpuv contains an internal pull-up
to VDD in order to turn OFF the external PNP trans-
istorswitch when the output is inactive.
Segment Outputs: All segment outputs are open- -drain
devices with all sources common to Vgs.
Power ON and Power Failure: After power ON or
power fail, the display will flash at 1 Hz rate and time,
alarm, and seconds counters will be reset to 0:00:00
(12:00:00). The alarm output will be held OFF also.
The power fail can be reset by enabling time set allow.
DUPLEX DISPLAY
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$ | | Ё Ё |s É | la E F In [22
| | 50/60 Hz . SLEEP
18 | INPUT SLEEP OUT 47k p~ DRIVE
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= EXT AC MMS456 vy
= uF & La. ALARM
[ - 6“ TONE QUT AK MS DRIVE
— ‚ . ; ; . 12 , T Y Y ,
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LS 1 | | AA
У У
—- e] TIMES ALARM — SLEEP |? ALARM FAST|13- _ SLOW AR
SET SET SET OFF SET SET SNOOZE VDD
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12/60 + 1 } + } + +
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5-72
Connection Diagrams (Dual-In-Line Packages, Top Views)
12-Hour/50 or 60 Hz Clock
HUB, HUG — 1 22 [-— HTB, PM
HUC, HUD =i 2 21h HTC, HUE
HUA, HUF === 3 20 |= SLEEP OUT
Ves —. 4 19 b— 12/60, 12/50
MTF, MTA—5 16 {— 50/60 Hz INPUT
MTB, MTG —{6 MM5456 17 fm ALARM OFF/ALARM ON/
MTD, MTC ——f 7 16 p= EXT. RC
MTE, MUE === 8 15— v0 |
MUB, MUG ==. 9 14 }— TIME SET/RUN/ALAR SET
MUC, MUD — 10 13 je FAST.SET (SNOGZE)/RUN /SLOWISET
MUA, MUF — 11 12 fess ALARM TONE OUT —
Order Number MM5456N
See Package 22
24-Hour/50 Hz Clock
HUB, HUG — 1 22 b=" HTB, PM
HUE, HUD — 2 21 == HTADEG
HUA, HUF =i 3 20 p= HTC, HUE
vss —1 4 19 |= SLEEP QUT
MTF, MTA =—1 5 18 -— 50 Hz INPUT
MTB, MTG —{5 MM5457 17 [— ALARM OFF/ALARM ON/
MTD, MTC ===] 7 16 |— EXT. RC
МТЕ, МЧЕ ===} 8 15 Von
MUB, Mus — 9 14 -— TIME SET/RUN/ALARM SET
MUC, MUD ——l 10 13 P FAST SET (SNOOZE)/ RUN/SLOW SET
MUA, MUF —] 11 12 }—— ALARM TONE OUT — и
Order Number MM5457N
See Package 22
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