MC34923EG Freescale Semiconductor, MC34923EG Datasheet - Page 10

• 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

Serial Interface
serial port. The programmable functions allow maximum
flexibility in configuring the PWM to the motor drive
requirements. The serial data is clocked in starting with bit D19.
D0–D1, Blank Time
driver is switched on in accordance with the table below. f
the oscillator input frequency.
34923
10
The 34923 is controlled via a 3-wire (clock, data, strobe)
The current-sense comparator is blanked when any output
D10
D11
D12
D13
D14
D15
D16
D17
D18
D19
Bit
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D0
0
1
0
1
Synchronous Rectification Enable
Synchronous Rectification Mode
External PWM Decay Mode
D1
0
0
1
1
Fast Decay Time MSB
Fast Decay Time Bit 1
Fast Decay Time Bit 2
Fast Decay Time LSB
Divisor SPAN Select
Fixed Off-Time MSB
Fixed Off-Time Bit 1
Fixed Off-Time Bit 2
Fixed Off-Time Bit 3
Internal PWM Mode
Fixed Off-Time LSB
Blank Time MSB
Blank Time LSB
Direction Logic
Enable Logic
Sleep Mode
Test Mode
Function
Blank Time
12/f
24/f
4/f
6/f
Freescale Semiconductor, Inc.
osc
osc
osc
osc
For More Information On This Product,
FUNCTIONAL DESCRIPTION
Go to: www.freescale.com
osc
is
D2–D6, Fixed Off-Time
current control. The off time is defined as follows:
where N = 0 to 31.
time is adjusted from 1.75 µs to 63.75 µs in increments of
2.0 µs.
D7–D10, Fast Decay Time
for the internal PWM control circuitry. This will only have impact
if the mixed current decay mode is selected (via bit D17 and the
PWMMODE input pin). For t
operate in the fast decay mode. The fast decay portion is
defined as follows:
where N = 0 to 15.
decay time is adjusted from 1.75 µs to 31.75 µs in increments
of 2.0 µs.
D11–D12, Synchronous Rectification Control
off synchronous rectification when a zero current level is
detected. The passive mode will allow reversal of current but
will turn off the synchronous rectifier circuit if the load current
inversion ramps up to the current limit set by V
D13, External PWM Decay Mode
PWM/ENABLE chopping for external PWM current control.
A five-bit word sets the fixed off-time for internal PWM
For example, with an oscillator frequency of 4.0 MHz, the off-
A four-bit word sets the fast decay portion of the fixed off-time
For example, with an oscillator frequency of 4.0 MHz, the fast
The active mode prevents reversal of load current by turning
Bit D13 determines the current decay mode when using
MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
D11
0
0
1
1
t
t
off
fd
= (8[1 + N]/f
= (8[1 + N] /f
D13
0
1
D12
0
1
0
1
fd
Decay Mode
> t
Current
off
osc
osc
Synchronous
Rect. Control
Slow
Fast
, the device will effectively
) - 1/f
) - 1/f
Disabled
Disabled
Passive
Active
osc
osc
REF
/R
S
.