A3948SLB Allegro Microsystems Inc, A3948SLB Datasheet - Page 6

• Manufacturer Part Number: A3948SLB
• Description: IC MOTOR DRIVER PWM FULL 24-SOIC
• Manufacturer: Allegro Microsystems Inc

Specifications of A3948SLB

• Applications: PWM Motor Driver
• Number Of Outputs: 1
• Current - Output: ±1.5A
• Voltage - Load: 20 V ~ 50 V
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)
• Operating Current: 10mA
• Operating Temperature Classification: Commercial
• Package Type: SOIC W
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

(clock, data, strobe) 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 D19.
blanked when any output driver is switched on, according
to the table below. f
fixed-off time for internal PWM current control. The off
time is defined by
where N = 0 … 31
For example, with an oscillator frequency of 4 MHz, the
off time will be adjustable from 1.75 s to 63.75 s in
increments of 2 s.
www.allegromicro.com
t
off
= (8[1 + N]/f
The A3948 is controlled via a 3-wire
osc
is the oscillator input frequency.
The current-sense comparator is
A five-bit word sets the
osc
) - 1/f
osc
fast-decay portion of the fixed-off time for the internal
PWM control circuitry. This will only have impact if the
mixed-decay mode is selected (via bit D17 and the MODE
input terminal). For t
operate in the fast-decay mode. The fast decay portion is
defined by
where N = 0 … 15
For example, with an oscillator frequency of 4 MHz, the
fast decay time will be adjustable from 1.75 s to
31.75 s in increments of 2 s.
mode prevents reversal of load current by turning 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
the current-decay mode when using ENABLE chopping
for external PWM current control.
ENABLE, determines if the output drivers are in the
chopped (OFF)(ENABLE = D14) or ON (ENABLE
D14) state.
REF
/R
S
.
t
fd
= (8[1 + N]/f
PWM MOTOR DRIVER
DMOS FULL-BRIDGE
fd
Bit D14, in conjunction with
> t
off
, the device will effectively
osc
A four-bit word sets the
) - 1/f
Bit D13 determines
osc
The active
3948