SP3486 Datasheet, PDF (5/9 Pages) Sipex Corporation – +3.3V Low Power Quad RS-485/RS-422 Line Drivers

FEATURES
The SP3486 and the SP3487 are +3.3V low power
quad line drivers that meet the specifications of
the RS-485 and RS-422 serial protocols. These
devices are pin-to-pin compatible with Sipex's
SP486 and SP487 devices as well as popular
industry standards. The SP3486 and SP3487
devices feature Sipex's BiCMOS process
allowing low power operation without sacrificing
performance.
The RS-485 standard is ideal for multi-drop
applications or for long distance interfaces.
RS-485 allows up to 32 drivers and 32 receivers
to be connected to a data bus, making it an ideal
choice for multi-drop applications. Since the
cabling can be as long as 4,000 feet, RS-485
transceivers are equipped with a wide (-7V to
+12V) common mode range to accomodate
ground potential differences. Data is virtually
immune to noise in the transmission line because
the RS-485 protocol is a differential interface.
Driver
The drivers for both the SP3486 and SP3487
have differential outputs. The typical voltage
output swing with no load will be 0V to +5V.
With worst case loading of 54Ω across the
differential outputs, the driver can maintain
greater than +1.5V voltage levels.
The drivers of the SP3486 feature active HIGH
and active LOW common driver enable
controls. Refer to SP3486 Truth Table in Table
1. The SP3487 provides independent, active
high driver enable controls for each pair of
drivers. Refer to SP3487 Truth Table in Table 2.
The driver outputs are short-circuit limited
to 250mA. The SP3486 and SP3487 drivers
meet the electrical specifications of RS-485
and RS-422 serial protocols up to 10Mbps
under load.
AC PARAMETERS
V_CC = +3.3V±5%; typicals at 25°C; T_AMB = 25°C unless otherwise noted.
PARAMETER
MIN. TYP. MAX.
PROPAGATION DELAY
Driver Input to Output
Low to High (t_PLH)
High to Low (t_PHL)
Differential Driver Skew
20
40
60
20
40
60
5
10
Driver Rise Time (t_R)
SP3486
10
SP3487
10
Driver Fall Time (t_F)
SP3486
10
SP3487
10
DRIVER ENABLE
To Output High
110
To Output Low
110
DRIVER DISABLE
From Output Low
110
From Output High
110
UNIT
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
CONDITIONS
Figure 2 and 5
| t_PHL(Y) - t_PLH(Y) |, | t_PHL(Z) - t_PLH(Z) | ,
Figures 2 and 5
10% to 90% R_DIFF = 60Ω
90% to 10% R_DIFF = 60Ω
Figures 3 and 6
Figures 4 and 6
Figures 4 and 6
Figures 3 and 6
10/15/02
SP3486/3487 Low Power Quad RS485/422 Line Drivers
5
© Copyright 2002 Sipex Corporation