MM5486N National Semiconductor, MM5486N Datasheet - Page 3

• Manufacturer Part Number: MM5486N
• Description: IC LED DISPLAY DRIVER 40 DIP
• Manufacturer: National Semiconductor

Specifications of MM5486N

• Display Type: LED
• Configuration: 7 Segment
• Interface: Serial
• Digits Or Characters: 4 Digits
• Current - Supply: 7mA
• Voltage - Supply: 4.75 V ~ 11 V
• Operating Temperature: -25°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *MM5486N

Figure 4 shows the input data format Bit ‘‘1’’ is the first bit
Functional Description
The MM5486 is specifically designed to operate four-digit
alphanumeric displays with minimal interface with the dis-
play and the data source Serial data transfer from the data
source to the display driver is accomplished with 3 signals
serial data clock and load The data bits are latched by a
positive-level load signal thus providing non-multiplexed di-
rect drive to the display When load is high the data in the
shift registers is displayed on the output drivers Outputs
change only if the serial data bits differ from the previous
time Display brightness is determined by control of the out-
put current for LED displays A 0 001
be connected to brightness control pin 19 to prevent possi-
ble oscillations The output current is typically 20 times
greater than the current into pin 19 which is set by an exter-
nal variable resistor There is an internal limiting resistor of
400
A block diagram is shown in Figure 1
into the data input pin and it will appear on pin 17 A logical
‘‘1’’ at the input will turn on the appropriate LED The load
signal latches the 33 bits of the shift register into the latch-
es The data out pin allows for cascading the shift registers
for more than 33 output drivers
nominal value
This leading clock is necessary only after power ON
F capacitor should
FIGURE 4 Input Data Format
FIGURE 3
FIGURE 5
3
Figure 3 shows the timing relationship between data clock
Figure 8
When the chip first powers ON an internal power ON reset
signal is generated which resets all registers and latches
The leading clock returns the chip to its normal operation
and data enable A maximum clock frequency of 0 5 MHz is
assumed
For applications where a lesser number of outputs are used
it is possible to either increase the current per output or
operate the part at higher than 1V V
equation can be used for calculations
where
The above equation was used to plot Figure 6 Figure 7 and
T
V
I
T
LED
J
JA
A
JA
JA
OUT
T
e
e
(Socket Mount)
(Board Mount)
J
e
e
e
junction temperature 150 C max
e
ambient temperature
thermal coefficient of the package
the LED current
(V
the voltage at the LED driver outputs
OUT
) (I
LED
e
e
) (No of segments) (
49 C W
54 C W
TL F 6142 – 5
OUT
TL F 6142 – 3
TL F 6142– 4
JA
The following
)
a
T
A