L6227Q STMicroelectronics, L6227Q Datasheet - Page 12

• 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
4.3
4.4
12/27
Truth table
Table 7.
1. Valid only in case of load connected between OUT1 and OUT2
2. X = don't care
3. High Z = high impedance output
4. GND (Vs) = GND during Ton, Vs during Toff
PWM current control
The L6227Q includes a constant off time PWM current controller for each of the two bridges.
The current control circuit senses the bridge current by sensing the voltage drop across an
external sense resistor connected between the source of the two lower power MOS
transistors and ground, as shown in
across the sense resistor increases proportionally. When the voltage drop across the sense
resistor becomes greater than the voltage at the reference input (VREF
sense comparator triggers the monostable switching the low-side MOS off. The low-side
MOS remain off for the time set by the monostable and the motor current recirculates in the
upper path. When the monostable times out the bridge will again turn on. Since the internal
dead time, used to prevent cross conduction in the bridge, delays the turn on of the power
MOS, the effective off time is the sum of the monostable time plus the dead time.
Figure 9.
EN
H
H
H
H
L
Inputs
X
Truth table
PWM current controller simplified schematic
IN1
H
H
L
L
(2)
IN2
H
H
X
L
L
GND (Vs)
High Z
OUT1
GND
Vs
Vs
Figure
(3)
(4)
Outputs
9. As the current in the load builds up the voltage
GND (Vs)
High Z
OUT2
GND
Vs
Vs
Disable
Brake mode (lower path)
Forward
Reverse
Brake mode (upper path)
Description
A
or VREF
(1)
B
) the
L6227Q