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Figure 5. Overcurrent Detection Timing Definition

CIRCUIT DESCRIPTION

POWER STAGES and CHARGE PUMP

Ω (typ-

ical value @ 25°C), with intrinsic fast freewheeling diode. Switching patterns are generated by the PWM Current

Controller and the Phase Sequence Generator (see below). Cross conduction protection is achieved using a

µs typical value) between the switch off and switch on of two Power MOSFETSs in one leg of

a bridge.

supply voltage is in the range from 8V to 12V (see Fig. 34 and 35).

Using N-Channel Power MOS for the upper transistors in the bridge requires a gate drive voltage above the

external components to realize a charge pump circuit as shown in Figure 6. The oscillator output (VCP) is a

square wave at 600KHz (typical) with 10V amplitude. Recommended values/part numbers for the charge pump

circuit are shown in Table 1.

Table 1. Charge Pump External Components Values

220nF

10nF

100

Ω

D1

1N4148

D2

1N4148

90%

10%

D02IN1399

ON

OFF

BRIDGE