National Semiconductor MM5486 Technical data
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MM5486 LED Display Driver
General Description
The MM5486 is a monolithic MOS integrated circuit utilizing
N-channel metal-gate low-threshold, enhancement mode
and ion-implanted depletion mode devices. It is available in
a 40-pin molded dual-in-line package. The MM5486 is designed to drive common anode-separate cathode LED displays. A single pin controls the LED display brightness by
setting a reference current through a variable resistor connected to V
Features
Y
Continuous brightness control
Y
Serial data input/outut
Block and Connection Diagrams
DD
.
Y
External load input
Y
Cascaded operation capability
Y
Wide power supply operation
Y
TTL compatibility
Y
33 outputs, 15 mA sink capability
Y
Alphanumeric capability
Applications
Y
COPSTMor microprocessor displays
Y
Industrial control indicator
Y
Relay driver
Y
Digital clock, thermometer, counter, voltmeter
Y
Instrumentation readouts
Dual-In-Line Package
MM5486 LED Display Driver
February 1995
FIGURE 1
TL/F/6142– 1
Top View
TL/F/6142– 2
Order Number MM5486N
See NS Package Number N40A
FIGURE 2
Order Number MM5486V
TL/F/6142– 13
See NS Package Number V44A
COPSTMis a trademark of National Semiconductor Corporation.
C
1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.
TL/F/6142
Absolute Maximum Ratings
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Voltage at Any Pin V
Operating Temperature
Storage Temperature
SS
b
b
65§Ctoa150§C
a
to V
12V
SS
25§Ctoa85§C
Power Dissipation at 25
Molded DIP Package, Board Mount 2.5W*
C
§
Molded DIP Package, Socket Mount 2.3W**
Junction Temperature
a
150§C
Lead Temperature (Soldering, 10 seconds) 300§C
*Molded DIP Package, Board Mount, i
C.
above 25
§
**Molded DIP Package, Socket Mount, i
C.
above 25
§
e
49§C/W, Derate 20.4 mW/§C
JA
e
54§C/W, Derate 18.5 mW/§C
JA
Electrical Characteristics
TAwithin operating range, V
e
4.75V to 11.0V, V
DD
Symbol Parameter Conditions Min Typ Max Units
V
DD
I
DD
Power Supply 4.75 11 V
Power Supply Current Excluding Output Loads 7 mA
Input Voltages
V
IL
V
IH
I
BR
Logic ‘‘0’’ Level
Logic ‘‘1’’ Level 4.75sV
Brightness Input (Note 2) 0 0.75 mA
Output Sink Current (Note 3)
I
OH
I
OL
I
O
V
IBR
Segment OFF V
Segment ON V
Maximum Segment Current 40 mA
Brightness Input Voltage (Pin 19) Input Currente750 mA 3.0 4.3 V
OM Output Matching (Note 1)
Data Output
V
OL
V
OH
Logical ‘‘0’’ Level I
Logical ‘‘1’’ Level I
Clock Input (Notes 5 and 6)
f
C
t
h
t
l
Frequency 500 kHz
High Time 950 ns
Low Time 950 ns
Data Input
t
DS
t
DH
Note 1: Output matching is calculated as the percent variation (I
Note 2: With a fixed resistor on the brightness input pin, some variation in brightness will occur from one device to another. Maximum brightness input current can
be 2 mA as long as Note 3 and junction temperature equation are complied with.
Note 3: Absolute maximum for each output should be limited to 40 mA.
Note 4: The V
Note 5: AC input waveform specification for test purpose: t
Note 6: Clock input rise and fall times must not exceed 300 ns.
Set-Up Time 300 ns
Hold Time 300 ns
voltage should be regulated by the user. See
OUT
e
0V, unless otherwise specified
SS
g
10 mA Input Bias
V
DD
OUT
OUT
Brightness Input
s
5.25 2.2 V
DD
l
5.25 V
e
3.0V 10 mA
e
1V (Note 4)
e
0 mA0 10mA
b
0.3 0.8 V
b
2VDDV
DD
Brightness Inpute100 mA 2.0 2.7 4 mA
Brightness Input
OUT
OUT
MAX
Figures 6
s
20 ns, t
r
e
e
a
I
)/2.
MIN
and7for allowable V
s
20 ns, fe500 kHz, 50%g10% duty cycle.
f
e
750 mA15 25mA
0.5 mA V
100 mA 2.4 V
vs I
OUT
OUT
SS
operation.
g
DD
20 %
0.4 V
DD
V
V
2
Functional Description
The MM5486 is specifically designed to operate four-digit
alphanumeric displays with minimal interface with the display 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, direct 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 output current for LED displays. A 0.001 mF capacitor should
be connected to brightness control, pin 19, to prevent possible oscillations. The output current is typically 20 times
greater than the current into pin 19, which is set by an external variable resistor. There is an internal limiting resistor of
400X nominal value.
A block diagram is shown in
Figure 4
shows the input data format. Bit ‘‘1’’ is the first bit
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 latches. The data out pin allows for cascading the shift registers
for more than 33 output drivers.
Figure 1
.
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.
Figure 3
shows the timing relationship between data, clock
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:
e
T
(V
)(I
J
OUT
) (No. of segments) (iJA)aT
LED
. The following
OUT
A
where:
e
T
junction temperature, 150§C max.
J
e
V
the voltage at the LED driver outputs
OUT
e
I
the LED current
LED
e
thermal coefficient of the package
i
JA
e
T
ambient temperature
A
iJA(Socket Mount)e54§C/W
iJA(Board Mount)e49§C/W
The above equation was used to plot
Figure 8
.
Figure 6, Figure 7,
and
*This leading clock is necessary only after power ON.
FIGURE 4. Input Data Format
FIGURE 3
TL/F/6142– 3
TL/F/6142– 4
TL/F/6142– 5
FIGURE 5
3
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