L6227Q STMicroelectronics, L6227Q Datasheet - Page 14

• Manufacturer Part Number: L6227Q
• Description: IC DRIVER FULL BRDG PWM 32VFQFPN
• Manufacturer: STMicroelectronics
• Type: H Bridger

Specifications of L6227Q

• Input Type: Non-Inverting
• Number Of Outputs: 4
• On-state Resistance: 730 mOhm
• Current - Output / Channel: 1.4A
• Current - Peak Output: 2.8A
• Voltage - Supply: 8 V ~ 52 V
• Operating Temperature: -25°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN, 32-VFQFPN
• Product: H-Bridge Drivers
• Rise Time: 250 ns
• Fall Time: 250 ns
• Supply Voltage (min): 8 V
• Maximum Operating Temperature: + 150 C
• Mounting Style: SMD/SMT
• Bridge Type: Full Bridge
• Maximum Turn-on Delay Time: 1900 ns
• Minimum Operating Temperature: - 40 C
• Number Of Drivers: 2
• For Use With: 497-6817 - EVAL BOARD FOR L6227Q
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Circuit description
14/27
These values allow a sufficient range of t
The capacitor value chosen for C
pin R
charged before the next time the monostable is triggered. Therefore, the on time t
depends by motors and supply parameters, has to be bigger than t
good current regulation by the PWM stage. Furthermore, the on time t
than the minimum on time t
Figure 12 on page 15
current regulation capacity. It has to be said that t
the device imposes this condition, but it can be smaller than t
the device continues to work but the off time t
So, small C
therefore, higher switching frequency), but, the smaller is the value for C
influential will be the noises on the circuit performance.
Figure 11. t
⎧
⎨
⎩
t
COFF
t
t
RCRISE
ON
ON
>
>
. The rise time t
t
t
ON MIN
TCRISE
OFF
= 600 · C
(
OFF
1 . 10
1 . 10
100
10
value gives more flexibility for the applications (allows smaller on time and,
1
4
3
)
–
versus C
0.1
=
t
DT
2.5µs
OFF
shows the lower limit for the on time t
+
W
RCRISE
ON(MIN)
OFF
and R
R
will only be an issue if the capacitor is not completely
OFF
off
.
also affects the rise time t
= 20kΩ
OFF
1
OFF
R
off
to implement the drive circuit for most motors.
OFF
Coff [nF]
= 47kΩ
ON
is not more constant.
is always bigger than t
R
off
= 100kΩ
10
ON
RCRISE
for having a good PWM
RCRISE
RCRISE
- t
ON
of the voltage at the
DT
OFF
can not be smaller
. In this last case
ON(MIN)
for allowing a
, the more
100
ON
because
L6227Q
, which