L6470HTR View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'L6470HTR' PDF : 73 Pages View PDF
Functional description
L6470
6.15
Integrated analog-to-digital converter
The L6470 device integrates an NADC bit ramp-compare analog-to-digital converter with
a reference voltage equal to VREG. The analog-to-digital converter input is available
through the ADCIN pin and the conversion result is available in the ADC_OUT register
(see Section 9.1.16 on page 46).
Sampling frequency is equal to the programmed PWM frequency.
The ADC_OUT value can be used for motor supply voltage compensation or can be at the
user’s disposal.
6.16
Internal voltage regulator
The L6470 integrates a voltage regulator which generates a 3 V voltage starting from the
motor power supply (VSA and VSB). In order to make the voltage regulator stable, at least
22 µF should be connected between the VREG pin and ground (suggested value is 47 µF).
The internal voltage regulator can be used to supply the VDD pin in order to make the
device digital output range 3.3 V compatible (Figure 13). A digital output range, 5 V
compatible, may be obtained connecting the VDD pin to an external 5 V voltage source. In
both cases, a 10 µF capacitance should be connected to the VDD pin in order to obtain
a correct operation.
The internal voltage regulator is able to supply a current up to IREG,MAX, internal logic
consumption included (Ilogic). When the device is in Standby mode, the maximum current
that can be supplied is IREG, STBY, internal consumption included (Ilogic, STBY).
If an external 3.3 V regulated voltage is available, it can be applied to the VREG pin in order
to supply all the internal logic and to avoid power dissipation of the internal 3 V voltage
regulator (Figure 13). The external voltage regulator should never sink current from the
VREG pin.
Figure 13. Internal 3 V linear regulator
VBAT
Vs
Vs
3V
3.3V
REG.
VDD
VREG
VDD
VSA
VSB
VREG
VDD
VSA
VSB
μC
IC
IC
DGND
AGND
DGND
AGND
Logig supplied by
INTERNAL voltage regulator
Logig supplied by
EXTERNAL voltage regulator
6.17
BUSY\SYNC pin
This pin is an open drain output which can be used as the busy flag or synchronization
signal according to the SYNC_EN bit value (STEP_MODE register).
32/73
DocID16737 Rev 7
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