Datasheets»National Semiconductor (acquired by TI (Texas Instruments))»LMD18400N Datasheet

LMD18400N Datasheet

Download or read online National Semiconductor LMD18400N IC, HIGH SIDE DRIVER, 4CH, 3.75A, DIP-20 pdf datasheet.



Page
1 of 19
next
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 (
3 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 µA.
Separate ON/OFF control of each switch is provided through
standard LSTLL/CMOS logic compatible inputs.
A MICROWIRE
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
excessive operating temperature.
The LMD18400 is packaged in a special power dissipating
leadframe that reduces the junction to case thermal resis-
tance to approximately 20˚C/W.
Typical Application
© 2004 National Semiconductor Corporation
Features
n Four independent outputs with
current capability
n 1.3Ω maximum ON resistance over temperature
n True instantaneous power limit for each switch
n High survival voltage (60 V
n Shorted load (to ground and supply) protection
n Overvoltage shutdown at V
n LS TTL/CMOS compatible logic inputs and outputs
<
10 µA supply current in “sleep” mode
n
n −5V output clamp for discharging inductive loads
n Serial data interface for 11 diagnostic checks:
— Switch ON/OFF status
— Open or shorted load
— Operating temperature
— Excessive supply voltage
n Two direct-output error flags
Applications
n Relay and solenoid drivers
n High impedance automotive fuel injector drivers
n Lamp drivers
n Power supply switching
n Motor drivers
DS011026
June 1996
>
3A peak, 1A continuous
, 80V transient)
DC
>
35V
CC
01102601
www.national.com
Specifications of National Semiconductor LMD18400N
Device Type:
High Side
Driver Case Style:
DIP
Filter Terminals:
Through Hole
No. Of Outputs:
4
Output Current:
3.75A
Output Voltage:
5.5V
Power Driver Type:
High Side
Rohs Compliant:
No
Supply Voltage Max:
60V
Supply Voltage Min:
7V

Summary of Contents

Page 1

... The LMD18400 is packaged in a special power dissipating leadframe that reduces the junction to case thermal resis- tance to approximately 20C/W. Typical Application © 2004 National Semiconductor Corporation Features n Four independent outputs with current capability n 1.3Ω maximum ON resistance over temperature n True instantaneous power limit for each switch ...

Page 2

... Connection Diagram www.national.com 01102602 Order Number LMD18400N See NS Package Number N20A 2 ...

Page 3

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Survival Voltage (Pin 20) Transient ( ms) Continuous Output Transient Current (Each Switch) Output Transient Current (Total, All Switches) Output Steady State Current ...

Page 4

Electrical Characteristics the entire operating temperature range, 25C T Parameter DIGITAL CHARACTERISTICS Logic 1 Input Voltage Logic 0 Input Voltage Logic 1 Input Current Logic 0 Input Current TRI-STATE Output Current Enable Input Current Channel Input Resistance Error Output ...

Page 5

Timing Specification Definitions Error Reporting Delay Typical Performance Characteristics perature unless otherwise noted. Switch ON Resistance vs Temperature Maximum Power Dissipation vs Ambient Temperature (Continued) 01102605 For all curves Sleep Mode Supply Current 01102631 01102633 5 Data Setup ...

Page 6

Typical Performance Characteristics temperature unless otherwise noted. (Continued) Clamp Characteristics vs Temperature Turn ON Rise Time vs Temperature Turn OFF Time vs Temperature www.national.com For all curves 12V, Temperature is the junction CC Error Sense Threshold Voltage vs ...

Page 7

Typical Performance Characteristics temperature unless otherwise noted. (Continued) Enable Threshold Voltage vs Temperature Functional Block Diagram For all curves 12V, Temperature is the junction CC 01102641 7 Error Output Voltage vs Sink Current 01102642 01102608 www.national.com ...

Page 8

Truth Table Enable Chip Select Switch Control Input Input Input (Pin 3) (Pin 4) (Pins 9, 10, 11, 12 Applications Information ...

Page 9

Applications Information 1.3Ω (the ON resistance of the DMOS switch). The voltage applied to the load will depend upon the load current and the designed current capability of the LMD18400. When a switch is commanded OFF, the load will be ...

Page 10

Applications Information FIGURE 4. Turn-OFF Conditions with an Inductive Load When the output inductance produces a negative voltage, the gate of the DMOS transistor is clamped at 0V. At 3.5V, the source of the power device is less than the ...

Page 11

Applications Information Thermal Protection The die temperature of the LMD18400 is continually moni- tored. Should any conditions cause the die temperature to rise to 170C, all of the power switches are turned OFF automatically to reduce the power dissipation. It ...

Page 12

Applications Information The Error Flag output pin is an open drain transistor which requires a pull-up resistor to a positive voltage 16V. Typically this pull- the same 5V supply which is biasing the Enable input ...

Page 13

Applications Information across it. Under this condition, an internal 50 kΩ resistor connected to V will provide a small amount of current to CC the load. If the load resistance is large enough to create a voltage greater than 4.1V ...

Page 14

Applications Information FIGURE 12. Recommended PC Board Layout to Reduce the Thermal Resistance from Junction-to-Ambient FIGURE 13. Switching an Inductive Load When switched ON, the worst case power dissipation is: The steady-state ON current of the inductor should be kept ...

Page 15

Applications Information FIGURE 14. Approximate time required for the die to reach the 170C thermal shutdown point from 25C for different ON/OFF Switching of Multiple Voltage Regulated Circuit Loads (Continued) 01102624 total package power dissipation levels. 15 01102625 www.national.com ...

Page 16

Applications Information Recommended Connection If No Diagnostics are Required www.national.com (Continued) Unipolar Drive for a 4-Phase Stepper Motor 16 01102626 01102627 ...

Page 17

Applications Information Simple protection of the LMD18400 against supply voltage reversal. Loads will be energized through the intrinsic diodes in parallel with the power switches. The Schottky diode will add approximately 0.2V to the logic input switching thresholds and the ...

Page 18

Applications Information Paralleling switches for higher current capability. Positive temperature coefficient of the switch ON resistance provides ballasting to evenly share the load current between the switches. Any combination of switches can be paralleled. Required peak load current will depend ...

Page 19

... National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. inches (millimeters) unless otherwise noted Order Number LMD18400N NS Package Number N20A 2 ...

Comments to this Datasheet