AN1625 STMicroelectronics, AN1625 Datasheet - Page 20

• Manufacturer Part Number: AN1625
• Description: L6235 THREE PHASE BRUSHLESS DC MOTOR DRIVER
• Manufacturer: STMicroelectronics

AN1625 APPLICATION NOTE
2.13 Power Management
Even when operating at current levels well below the maximum ratings of the device, the operating junction tem-
perature must be kept below 125 °C.
Figure 20 shows the IC dissipated power versus the r.m.s. load current, in 4 different driving sequences, assum-
ing the supply voltage is 24V.
Figure 20. IC Dissipated Power versus Output Current.
2.13.1 Maximum output current vs. selectable devices
Figure 21 reports a performance comparison between L6229 (std. power) and L6235 (high power) for different
packages, with the following assumptions:
- Supply voltage: 24 V; Switching frequency: 30 kHz.
- T
- Maximum R
- Maximum quiescent current I
- PCB is a FR4 with a dissipating copper surface on the top side of 6 cm
SO and PowerDIP packages (D, N suffixes).
- PCB is a FR4 with a dissipating copper surface on the top side of 6 cm
via holes and a ground layer for the PowerSO package (PD suffix).
- For each device (on the x axis) y axis reports the maximum output current.
20/39
amb
= 25 °C, T
P
DS(ON)
D
[W]
J
= 125 °C.
10
(taking into account process spread) has been considered, @ 125 °C.
8
6
4
2
0
0
0.5
Q
(taking into account process spread) has been considered.
1
I
OUT
1.5
[A]
2
2.5
3
Test Condition s:
Supply Voltage = 24 V
I
I
I
1
2
3
No PWM
f
SW
I
= 30 kHz (slow decay)
OUT
2
2
(with a thickness of 35 µm), 16
(with a thickness of 35 µm) for
I
OUT
I
OUT