Motor Driver. LMD18245 Datasheet

LMD18245 Driver. Datasheet pdf. Equivalent


National Semiconductor LMD18245
April 1998
LMD18245
3A, 55V DMOS Full-Bridge Motor Driver
General Description
The LMD18245 full-bridge power amplifier incorporates all
the circuit blocks required to drive and control current in a
brushed type DC motor or one phase of a bipolar stepper
motor. The multi-technology process used to build the device
combines bipolar and CMOS control and protection circuitry
with DMOS power switches on the same monolithic struc-
ture. The LMD18245 controls the motor current via a fixed
off-time chopper technique.
An all DMOS H-bridge power stage delivers continuous out-
put currents up to 3A (6A peak) at supply voltages up to 55V.
The DMOS power switches feature low RDS(ON) for high ef-
ficiency, and a diode intrinsic to the DMOS body structure
eliminates the discrete diodes typically required to clamp bi-
polar power stages.
An innovative current sensing method eliminates the power
loss associated with a sense resistor in series with the motor.
A four-bit digital-to-analog converter (DAC) provides a digital
path for controlling the motor current, and, by extension, sim-
plifies implementation of full, half and microstep stepper mo-
tor drives. For higher resolution applications, an external
DAC can be used.
Features
n DMOS power stage rated at 55V and 3A continuous
n Low RDS(ON) of typically 0.3per power switch
n Internal clamp diodes
n Low-loss current sensing method
n Digital or analog control of motor current
n TTL and CMOS compatible inputs
n Thermal shutdown (outputs off) at TJ = 155˚C
n Overcurrent protection
n No shoot-through currents
n 15-lead TO-220 molded power package
Applications
n Full, half and microstep stepper motor drives
n Stepper motor and brushed DC motor servo drives
n Automated factory, medical and office equipment
Functional Block and Connection Diagram (15-Lead TO-220 Molded Power Package (T) )
Order Number LMD18245T
See NS Package Number TA15A
© 1998 National Semiconductor Corporation DS011878
DS011878-1
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LMD18245 Datasheet
Recommendation LMD18245 Datasheet
Part LMD18245
Description 3A / 55V DMOS Full-Bridge Motor Driver
Feature LMD18245; LMD18245 3A, 55V DMOS Full-Bridge Motor Driver April 1998 LMD18245 3A, 55V DMOS Full-Bridge Motor .
Manufacture National Semiconductor
Datasheet
Download LMD18245 Datasheet




National Semiconductor LMD18245
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
DC Voltage at:
OUT 1, VCC, and OUT 2
COMP OUT, RC, M4, M3, M2, M1, BRAKE,
DIRECTION, CS OUT, and DAC REF
DC Voltage PGND to SGND
Continuous Load Current
Peak Load Current (Note 2)
Junction Temperature (TJ(max))
+60V
+12V
±400mV
3A
6A
+150˚C
Power Dissipation (Note 3) :
TO-220 (TA = 25˚C, Infinite Heatsink)
TO-220 (TA = 25˚C, Free Air)
ESD Susceptibility (Note 4)
25W
3.5W
1500V
Storage Temperature Range (TS)
−40˚C to +150˚C
Lead Temperature (Soldering, 10 seconds)
300˚C
Operating Conditions (Note 1)
Temperature Range (TJ) (Note 3)
Supply Voltage Range (VCC)
CS OUT Voltage Range
DAC REF Voltage Range
MONOSTABLE Pulse Range
−40˚C to +125˚C
+12V to +55V
0V to +5V
0V to +5V
10 µs to 100 ms
Electrical Characteristics (Note 2)
The following specifications apply for VCC
perature range, −40˚C TJ +125˚C. All
= +42V, unless otherwise stated. Boldface
other limits apply for TA = TJ = 25˚C.
limits
apply
over
the
operating
tem-
Symbol
Parameter
Conditions
Typical
Limit
Units
(Note 5)
(Note 5)
(Limits)
ICC Quiescent Supply Current
DAC REF = 0V, VCC = +20V
8 mA
15 mA (max)
POWER OUTPUT STAGE
RDS(ON)
Switch ON Resistance
ILOAD = 3A
0.3 0.4 (max)
0.6 (max)
ILOAD = 6A
0.3 0.4 (max)
0.6 (max)
VDIODE
Body Diode Forward Voltage
IDIODE = 3A
1.0 V
1.5 V(max)
Trr
Qrr
tD(ON)
Diode Reverse Recovery Time
Diode Reverse Recovery Charge
Output Turn ON Delay Time
Sourcing Outputs
Sinking Outputs
tD(OFF)
Output Turn OFF Delay Time
Sourcing Outputs
Sinking Outputs
tON Output Turn ON Switching Time
Sourcing Outputs
Sinking Outputs
tOFF Output Turn OFF Switching Time
Sourcing Outputs
Sinking Outputs
tpw Minimum Input Pulse Width
tDB Minimum Dead Band
CURRENT SENSE AMPLIFIER
IDIODE = 1A
IDIODE = 1A
ILOAD = 3A
ILOAD = 3A
ILOAD = 3A
ILOAD = 3A
ILOAD = 3A
ILOAD = 3A
ILOAD = 3A
ILOAD = 3A
Pins 10 and 11
(Note 6)
80 ns
40 nC
5 µs
900 ns
600 ns
400 ns
40 µs
1 µs
200 ns
80 ns
2 µs
40 ns
Current Sense Output
ILOAD = 1A (Note 7)
200 µA (min)
250 175 µA (min)
300 µA (max)
325 µA (max)
Current Sense Linearity Error
0.5A ILOAD 3A (Note 7)
±6 %
±9 %(max)
Current Sense Offset
ILOAD = 0A
5 µA
20 µA (max)
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National Semiconductor LMD18245
Electrical Characteristics (Note 2) (Continued)
The following specifications apply for VCC
perature range, −40˚C TJ +125˚C. All
= +42V, unless otherwise stated. Boldface
other limits apply for TA = TJ = 25˚C.
limits
apply
over
the
operating
tem-
Symbol
Parameter
Conditions
Typical
Limit
Units
(Note 5)
(Note 5)
(Limits)
DIGITAL-TO-ANALOG CONVERTER (DAC)
Resolution
4 Bits (min)
Monotonicity
4 Bits (min)
Total Unadjusted Error
0.125
0.25
LSB (max)
0.5 LSB (max)
Propagation Delay
50 ns
IREF DAC REF Input Current
DAC REF = +5V
−0.5
µA
±10 µA (max)
COMPARATOR AND MONOSTABLE
Comparator High Output Level
6.27 V
Comparator Low Output Level
88 mV
Comparator Output Current
Source
0.2 mA
Sink
3.2 mA
tDELAY
Monostable Turn OFF Delay
(Note 8)
1.2 µs
2.0 µs (max)
PROTECTION AND PACKAGE THERMAL RESISTANCES
Undervoltage Lockout, VCC
5 V (min)
8 V (max)
TJSD
Shutdown Temperature, TJ
Package Thermal Resistances
155 ˚C
θJC Junction-to-Case, TO-220
θJA Junction-to-Ambient, TO-220
LOGIC INPUTS
1.5 ˚C/W
35 ˚C/W
VIL Low Level Input Voltage
−0.1
0.8
V (min)
V (max)
VIH High Level Input Voltage
2 V (min)
12 V (max)
IIN Input Current
VIN = 0V or 12V
±10 µA (max)
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device
outside the rated Operating Conditions.
Note 2: Unless otherwise stated, load currents are pulses with widths less than 2 ms and duty cycles less than 5%.
Note 3: The maximum allowable power dissipation at any ambient temperature is PMax = (125 − TA)/θJA, where 125˚C is the maximum junction temperature for op-
eration, TA is the ambient temperature in ˚C, and θJAis the junction-to-ambient thermal resistance in ˚C/W. Exceeding Pmax voids the Electrical Specifications by forc-
ing TJabove 125˚C. If the junction temperature exceeds 155˚C, internal circuitry disables the power bridge. When a heatsink is used, θJAis the sum of the
junction-to-case thermal resistance of the package, θJC, and the case-to-ambient thermal resistance of the heatsink.
Note 4: ESD rating is based on the human body model of 100 pF discharged through a 1.5 kresistor. M1, M2, M3 and M4, pins 8, 7, 6 and 4 are protected to 800V.
Note 5: All limits are 100% production tested at 25˚C. Temperature extreme limits are guaranteed via correlation using accepted SQC (Statistical Quality Control)
methods. All limits are used to calculate AOQL (Average Outgoing Quality Level). Typicals are at TJ = 25˚C and represent the most likely parametric norm.
Note 6: Asymmetric turn OFF and ON delay times and switching times ensure a switch turns OFF before the other switch in the same half H-bridge begins to turn
ON (preventing momentary short circuits between the power supply and ground). The transitional period during which both switches are OFF is commonly referred
to as the dead band.
Note 7: (ILOAD, ISENSE) data points are taken for load currents of 0.5A, 1A, 2A and 3A. The current sense gain is specified as ISENSE/ILOAD for the 1A data point.
The current sense linearity is specified as the slope of the line between the 0.5A and 1A data points minus the slope of the line between the 2A and 3A data points
all divided by the slope of the line between the 0.5A and 1A data points.
Note 8: Turn OFF delay, tDELAY, is defined as the time from the voltage at the output of the current sense amplifier reaching the DAC output voltage to the lower
DMOS switch beginning to turn OFF. With VCC = 32V, DIRECTION high, and 200connected between OUT1 and VCC, the voltage at RC is increased from 0V to
5V at 1.2V/µs, and tDELAY is measured as the time from the voltage at RC reaching 2V to the time the voltage at OUT 1 reaches 3V.
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