STMicroelectronics Stepper motor driver mounting the L6474 in high power PowerSO package EVAL6474PD EVAL6474PD Hoja De Datos
Los códigos de productos
EVAL6474PD
L6474
Functional description
Doc ID 022529 Rev 3
19/52
6 Functional
description
6.1 Device
power-up
At power-up end, the device state is the following:
●
Registers are set to default
●
Internal logic is driven by internal oscillator and a 2 MHz clock is provided by the
OSCOUT pin
OSCOUT pin
●
Bridges are disabled (High Z)
●
UVLO bit in STATUS register is forced low (fail condition)
●
FLAG output is forced low.
During power-up the device is under reset (all logic IO disabled and power bridges in high
impedance state) until the following conditions are satisfied:
●
V
S
is greater than V
SthOn
●
V
REG
is greater than V
REGth
= 2.8 V typical
●
Internal oscillator is operative.
6.2 Logic
I/O
Pins CS, CK, SDI, STCK, DIR and STBY\RST are TTL/CMOS 3.3 V-5 V compatible logic
inputs.
inputs.
Pin SDO is a TTL/CMOS compatible logic output. VDD pin voltage sets the logic output pin
voltage range; when it is connected to VREG or 3.3 V external supply voltage, the output is
3.3 V compatible. When VDD is connected to a 5 V supply voltage, SDO is 5 V compatible.
voltage range; when it is connected to VREG or 3.3 V external supply voltage, the output is
3.3 V compatible. When VDD is connected to a 5 V supply voltage, SDO is 5 V compatible.
VDD is not internally connected to V
REG
, an external connection is always needed.
A 10 µF capacitor should be connected to the VDD pin in order to obtain a proper operation.
Pins FLAG and SYNC are open drain outputs.
6.3 Charge
pump
To ensure the correct driving of the high-side integrated MOSFETs, a voltage higher than
the motor power supply voltage needs to be applied to the VBOOT pin. The high-side gate
driver supply voltage VBOOT is obtained through an oscillator and a few external
components realizing a charge pump (see
the motor power supply voltage needs to be applied to the VBOOT pin. The high-side gate
driver supply voltage VBOOT is obtained through an oscillator and a few external
components realizing a charge pump (see
).