L6207 datasheet(27/53 Pages) STMICROELECTRONICS

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AN1762 APPLICATION NOTE

3.15 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 28 shows the IC dissipated power versus the r.m.s. load current, in the case of a single IC driving two

loads (for instance 2 DC motors or a two-phase stepper motor) or a single IC, with two full bridges paralleled

(see

Paralleling two Full Bridges section) driving one load (for instance 1 DC motor or one phase of a two-

phase stepper motor) and assuming the supply voltage is 24V.

Figure 28. IC Dissipated Power versus Output Current.

3.15.1 Maximum output current vs. selectable devices

Figure 29 reports a performance comparison between different devices of the PowerSPIN family, for different

packages and in paralleled configuration, with the following assumptions:

- Each equivalent full bridge drives a load.

- Supply voltage: 24 V; Switching frequency: 30 kHz.

- Tamb = 25 °C, TJ = 125 °C.

- Maximum RDS(ON) (taking into account process spread) has been considered, @ 125 °C.

- Maximum quiescent current IQ (taking into account process spread) has been considered.

- PCB is a FR4 with a dissipating copper surface on the top side of 6 cm2 (with a thickness of 35 µm) for

SO and PowerDIP packages (D, N suffixes).

- PCB is a FR4 with a dissipating copper surface on the top side of 6 cm2 (with a thickness of 35 µm), 16

via holes and a ground layer for the PowerSO package (PD suffix).

- For each device configuration (on the x axis) y axis reports the maximum output (load) current.

- 2 x ’device’ means that the two loads are driven by two equivalent full bridges obtained paralleling two full bridg-

es for each of the two IC used. The current reported in Figure 29 is the maximum output current an equivalent

full bridge (a paralleled IC).

0.5

1.5

2.5

IOUT [A]

PD [W]

fSW = 30 kHz (synch. slow decay)

No PWM

2 Full Bridges Paralleled

2 Full Bridges

driving one load

driving two loads

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