EVAL6229PD STMicroelectronics, EVAL6229PD Datasheet - Page 7

• Manufacturer Part Number: EVAL6229PD
• Description: EVAL BOARD FOR L6229PD SOIC
• Manufacturer: STMicroelectronics

Specifications of EVAL6229PD

• Mfg Application Notes: L6235, AN1625 App Note
• Main Purpose: Power Management, Motor Control
• Embedded: No
• Utilized Ic / Part: L6229PD SOIC
• Primary Attributes: 3-Ph BLDC, 8 ~ 52V Output, PWM Current Control, Brake Function
• Secondary Attributes: Over Current, Cross Conduction & Temperature Protection
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-5491

High current GND tracks (i.e. the tracks connected to the sensing resistors) must be connected directly to the
negative terminal of the bulk capacitor. A good quality, high-frequency bypass capacitor is also required (typi-
cally a 100nF÷200nF ceramic would suffice), since electrolytic capacitors show a poor high frequency perfor-
mance. Both bulk electrolytic and high frequency bypass capacitors have to be connected with short tracks to
V
them. Logic GND and Power GND should be connected together in a single point , the bulk capacitor, to keep
noise in the Power GND from affecting Logic GND. Specific care should be paid layouting the path from the
SENSE pins through the sensing resistors to the negative terminal of the bulk capacitor (Power Ground). These
tracks must be as short as possible in order to minimize parasitic inductances that can cause dangerous voltage
spikes on SENSE and OUT pins (see the Voltage Ratings and Operating Range section); for the same reason
the capacitors on V
Resistors section for information on selecting the sense resistors. Traces that connect to V
SENSE
these traces, and layer changes should be avoided. Should a layer change prove necessary, multiple and large
via holes have to be used. A wide GND copper area can be used to improve power dissipation for the device.
Figure 6 shows two typical situations that must be avoided. An important consideration about the location of the
bulk capacitors is the ability to absorb the inductive energy from the load, without allowing the supply voltage to
exceed the maximum rating. The diode shown in Figure 6 prevents the recirculation current from reaching the
capacitors and will result in a high voltage on the IC pins that can destroy the device. Having a switch or a power
connection that can disconnect the capacitors from the IC, while there is still current in the motor, will also result
in a high voltage transient since there is no capacitance to absorb the recirculation current.
Figure 6. Two situations that must be avoided.
SA
, V
DON’T connect the Logic GND here
SB
Voltage drop due to current in sense
B
L6208
, and the four OUT pins must be designed with adequate width, since high currents are flowing through
and GND. On the L6208 GND pins are the Logic GND, since only the quiescent current flows through
path can disturb logic GND.
GND
SA
GND
V
, V
SA
GND
SB
V
SENSE
SENSE
SB
GND
and GND should be very close to the GND and supply pins. Refer to the Sensing
A
B
R5
C6
C7
Recirculating current cannot flow into the
bulk capacitor and causes a high voltage
V
+
S
-
= 8 ÷ 52 V
spike that can destroy the IC.
DON’T put a diode here!
AN1451 APPLICATION NOTE
SA
, V
SB
, SENSE
7/43
A
,