EL7156C
High Performance Pin Driver
Block Diagram
OE
VH
V +
S
IN
Level
Shifter
3-State
Control
OUT
GND
V -
S
VL
Application Information
All input pins are compatible with both 3V and 5V
CMOS signals. With a positive supply (VS+) of 5V, the
EL7156C is also compatible with TTL inputs.
Product Description
The EL7156C is a high performance 40MHz pin driver.
It contains two analog switches connecting VH and VL
to OUT. Depending on the value of the IN pin, one of
the two switches will be closed and the other switch
open. An output enable (OE) is also supplied which
opens both switches simultaneously.
Power Supply Bypassing
When using the EL7156C, it is very important to use
adequate power supply bypassing. The high switching
currents developed by the EL7156C necessitate the use
of a bypass capacitor between the supplies (VS+ & VS-)
and GND pins. It is recommended that a 2.2µF tantalum
capacitor be used in parallel with a 0.1µF low-induc-
tance ceramic MLC capacitor. These should be placed as
close to the supply pins as possible. It is also recom-
mended that the VH and VL pins have some level of
bypassing, especially if the EL7156C is driving highly
capacitive loads.
Due to the topology of the EL7156C, both the VH and
VL pins can be connected to any voltage between the
VS+ and VS- pins.
The EL7156C is available in both the 8-pin SOIC and
the 8-pin PDIP packages. The relevant package should
be chosen depending on the calculated power
dissipation.
Supply Voltage Range and Input Compatibility
Power Dissipation Calculation
The EL7156C is designed for operation on supplies from
5V to 15V (4.5V to 18V maximum). The table on page 6
shows the specifications for the relationship between the
VS+, VS-, VH, VL and GND pins.
When switching at high speeds, or driving heavy loads,
the EL7156C drive capability is limited by the rise in die
temperature brought about by internal power dissipation.
For reliable operation die temperature must be kept
below Tjmax (125°C). It is necessary to calculate the
8
ELANTEC [ ELANTEC SEMICONDUCTOR ]
