LMD18400 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – Quad High Side Driver

June 1996
LMD18400
Quad High Side Driver
General Description
The LMD18400 is a fully protected quad high side driver It
contains four common-drain DMOS N-channel power
switches each capable of switching a continuous 1 Amp
load (^l3 Amps transient) to a common positive power sup-
ply The switches are fully protected from excessive voltage
current and temperature An instantaneous power sensing
circuit calculates the product of the voltage across and the
current through each DMOS switch and limits the power to a
safe level The device can be disabled to produce a ‘‘sleep’’
condition reducing the supply current to less than 10 mA
Separate ON OFF control of each switch is provided
through standard LSTLL CMOS logic compatible inputs
A MICROWIRE^TM compatible serial data interface is built in
to provide extensive diagnostic information This information
includes switch status readback output load fault conditions
and thermal and overvoltage shutdown status There are
also two direct-output error flags to provide an immediate
indication of a general system fault and an indication of ex-
cessive operating temperature
The LMD18400 is packaged in a special power dissipating
leadframe that reduces the junction to case thermal resist-
ance to approximately 20 C W
Features
Y _{Four independent outputs with} l_{3A peak 1A continu-}
ous current capability
Y _{1 3X maximum ON resistance over temperature}
Y _{True instantaneous power limit for each switch}
Y _{High survival voltage (60 VDC 80V transient)}
Y _{Shorted load (to ground and supply) protection}
Y _{Overvoltage shutdown at VCC} l _35V
Y _{LS TTL CMOS compatible logic inputs and outputs}
Y k_{10 mA supply current in ‘‘sleep’’ mode}
Y b_{5V output clamp for discharging inductive loads}
Y _{Serial data interface for 11 diagnostic checks}
Switch ON OFF status
Open or shorted load
Operating temperature
Excessive supply voltage
Y _{Two direct-output error flags}
Applications
Y _{Relay and solenoid drivers}
Y _{High impedance automotive fuel injector drivers}
Y _{Lamp drivers}
Y _{Power supply switching}
Y _{Motor drivers}
Typical Application
Connection Diagram
TRI-STATE is a registered trademark of National Semiconductor Corporation
MICROWIRETM is a trademark of National Semiconductor Corporation
C1996 National Semiconductor Corporation TL H 11026
TL H 11026 – 2
Order Number LMD18400N
See NS Package Number N20A
TL H 11026 – 1
RRD-B30M76 Printed in U S A
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