NE587 Philipss, NE587 Datasheet - Page 4

• Manufacturer Part Number: NE587
• Description: LED decoder/driver
• Manufacturer: Philipss

Philips Semiconductors Linear Products
AC ELECTRICAL CHARACTERISTICS
V
NOTES:
t
TRUTH TABLE
NOTES:
H=HIGH voltage level, output is “OFF”
L=LOW voltage level, output is “ON”
X=Don’t care
* The RBI will blank the display only if a binary zero is stored in the latches.
** RBO/BI used as an input overrides all other input conditions.
NE587 PROGRAMMING
587 output current can be programmed by using a programming
resistor, RP, connected between RP (Pin 8) and GND (Pin 9). The
voltage at RP (Pin 8) is constant (
the voltage reference used in the NE587 is shown in Figure 1.
Output current to program current ratio, I
50mA range. Note that I
not from a high-impedance source such as an I
control display brightness.
August 31, 1994
DAV
SYMBOL
SYMBOL
t
t
t
t
t
CC
DAV
DAV
W
S
H
LED decoder/driver
=5V, T
= (t
BINARY
BINARY
INPUT
INPUT
**BI
HL
10
11
12
13
14
15
-
0
0
1
2
3
4
5
6
7
8
9
+t
A
=25 C, R
LH
Propagation delay (Figure 2)
Propagation delay (Figure 3)
Latch enable pulse width (Figure 4)
Latch enable setup time (Figure 4)
Latch enable hold time (Figure 4)
)
LE
L
H
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
X
=130 , C
P
PARAMETER
PARAMETER
must be derived from a resistor (R
RBI
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
L
*
L
=30pF including probe capacity.
K =
D
X
H
H
H
H
H
H
H
H
X
L
L
L
L
L
L
L
L
L
1.3V). A partial schematic of
INPUTS
3
O
/I
P
D
, is 20 in the 15mA to
H
H
H
H
H
H
H
H
X
L
L
L
L
L
L
L
L
L
X
2
OUT
DAC used to
D
H
H
H
H
H
H
H
H
X
X
L
L
L
L
L
L
L
L
L
1
D
X
H
H
H
H
H
H
H
H
X
P
L
L
L
L
L
L
L
L
L
0
), and
H
H
H
H
H
H
H
H
a
L
L
L
L
L
L
L
L
L
L
TEST CONDITIONS
TEST CONDITIONS
From data to output
533
From LE to output
From data to LE
From LE to data
H
H
H
H
H
H
H
H
b
L
L
L
L
L
L
L
L
L
L
POWER DISSIPATION CONSIDERATIONS
LED displays are power-hungry devices, and inevitably, somewhat
inefficient in their use of the power supply necessary to drive them.
Duty cycle control does afford one way of improving display
efficiency, provided that the LEDs are not driven too far into
saturation; but the improvement is marginal. Operation at higher
peak currents has the added advantage of giving much better
matching of light output, both from segment-to-segment and
digit-to-digit.
H
H
H
H
H
H
H
H
c
L
L
L
L
L
L
L
L
L
L
STABLE
OUTPUTS
d
H
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
L
H
H
H
H
H
H
H
H
H
H
e
L
L
L
L
L
L
L
L
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
L
L
f
Min
30
20
0
H
H
H
H
H
H
H
g
L
L
L
L
L
L
L
L
L
L
L
LIMITS
Typ
135
135
RBO
L**
**
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
Product specification
Max
NE587
DISPLAY
DISPLAY
STABLE
BLANK
Blank
Blank
E
H
P
0
1
2
3
4
5
6
7
8
9
L
-
UNIT
UNIT
ns
ns
ns
ns
ns