MC34923EG Freescale Semiconductor, MC34923EG Datasheet - Page 13

• Manufacturer Part Number: MC34923EG
• Description: IC PWM MOTOR DRIVER FULL 24-SOIC
• Manufacturer: Freescale Semiconductor
• Type: Full Bridge PWM Motor Driverr

Specifications of MC34923EG

• Applications: PWM Motor Driver
• Number Of Outputs: 1
• Current - Output: 2A
• Voltage - Load: 20 V ~ 45 V
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)
• Operating Supply Voltage: 5 V
• Supply Current: 10 mA
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Current Sensing
which may be caused by ground trace IR drops, the sense
resistor should have an independent ground return to the
ground pin of the device. For low-value sense resistors, the IR
drops in the PCB sense resistor’s traces can be significant and
should be taken into account. The use of sockets should be
avoided because they can introduce variation in R
their contact resistance.
Braking
slow-decay mode via serial port bit D13, enabling synchronous
rectification via bit D12, and chopping with the combination of
D14 and the PWM/ENABLE input pin. Because it is possible to
drive current in either direction through the drivers, this
configuration effectively shorts out the motor-generated back
EMF (BEMF) as long as the PWM/ENABLE chop mode is
asserted. It is important to note that the internal PWM current-
control circuit will not limit the current when braking, because
the current does not flow through the sense resistor. The
maximum brake current can be approximated by V
Care should be taken to ensure that the maximum ratings of the
device are not exceeded in worst-case braking situations of
high-speed and high-inertial loads.
Thermal Protection
reaches 165°C typically. It is intended only to protect the device
from failures owing to excessive junction temperatures and
should not imply that output short circuits are permitted.
Thermal shutdown has a hysteresis of approximately 15°C.
MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
To minimize inaccuracies in sensing the I
The maximum value of R
The braking function is implemented by driving the device in
Circuitry turns off all drivers when the junction temperature
S
is given as R
Freescale Semiconductor, Inc.
For More Information On This Product,
S
TRIP
≤ 0.5/I
Go to: www.freescale.com
current level,
S
BEMF
TRIP
owing to
.
/R
APPLICATIONS
L
.
Layout
For optimum electrical and thermal performance (see following
Note), the driver should be soldered directly onto the board. The
ground side of R
pins of the device. This path should be as short as is possible
physically and should not have any other components
connected to it. It is recommended that a 0.1 µF capacitor be
placed between SENSE and ground as close to the device as
possible; the load supply pin, V
electrolytic capacitor (>47 µF is recommended) placed as close
to the device as is possible.
allowable package power dissipation specified in the
MAXIMUM RATINGS
two-sided PCB with minimal copper ground area. For the
34923, R
ground area, as shown in
The printed wiring board should use a heavy ground plane.
Note The thermal resistance and absolute maximum
Figure 3. Package Dissipation Temperature Derating
5
4
3
2
1
0
25
θJA
can be reduced to 56°C/W with 3.57-in
50
S
should have an individual path to the ground
R
θ JA
table, page 4, is measured on typical
TEMPERATURE (°C)
= 56°C/W
Figure
75
BB
, should be decoupled with an
3.
100
125
2
copper
34923
150
13