L6229 Ver la hoja de datos (PDF) - STMicroelectronics
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L6229 Datasheet PDF : 25 Pages
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L6229
3 CIRCUIT DESCRIPTION
3.1 POWER STAGES and CHARGE PUMP
The L6229 integrates a Three-Phase Bridge, which consists of 6 Power MOSFETs connected as shown on the
Block Diagram. Each Power MOS has an RDS(ON) = 0.73Ω (typical value @25°C) with intrinsic fast freewheeling
diode. Switching patterns are generated by the PWM Current Controller and the Hall Effect Sensor Decoding
Logic (see relative paragraphs). Cross conduction protection is implemented by using a dead time (tDT = 1µs
typical value) set by internal timing circuit between the turn off and turn on of two Power MOSFETs in one leg
of a bridge.
Pins VSA and VSB MUST be connected together to the supply voltage (VS).
Using N-Channel Power MOS for the upper transistors in the bridge requires a gate drive voltage above the
power supply voltage. The Bootstrapped Supply (VBOOT) is obtained through an internal oscillator and few ex-
ternal components to realize a charge pump circuit as shown in Figure 6. The oscillator output (pin VCP) is a
square wave at 600KHz (typically) with 10V amplitude. Recommended values/part numbers for the charge
pump circuit are shown in Table 7.
Table 7. Charge Pump External Component Values.
CBOOT
220nF
CP
10nF
RP
100Ω
D1
1N4148
D2
1N4148
Figure 6. Charge Pump Circuit
D1
D2
CBOOT
RP
CP
VCP
VBOOT
VSA VSB
VS
D01IN1328
3.2 LOGIC INPUTS
Pins FWD/REV, BRAKE, EN, H1, H2 and H3 are TTL/CMOS and µC compatible logic inputs. The internal struc-
ture is shown in Figure 4. Typical value for turn-ON and turn-OFF thresholds are respectively Vth(ON) = 1.8V and
Vth(OFF) = 1.3V.
Pin EN (enable) may be used to implement Overcurrent and Thermal protection by connecting it to the open collector
DIAG output If the protection and an external disable function are both desired, the appropriate connection must be
implemented. When the external signal is from an open collector output, the circuit in Figure 8 can be used . For ex-
ternal circuits that are push pull outputs the circuit in Figure 9 could be used. The resistor REN should be chosen in
the range from 2.2KΩ to 180KΩ. Recommended values for REN and CEN are respectively 100KΩ and 5.6nF. More
information for selecting the values can be found in the Overcurrent Protection section.
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