ZAMC4100 Datasheet, PDF (73/155 Pages) Integrated Device Technology – Actuator and Motor Controller

ZAMC4100 Datasheet
Figure 3.19 ECM Driver Structure
ECMEN
OVT Reset
OVIF
UVIF
6 _DAC
Error
Amplifier
DSCEN
ECMOCIF
ECMOSF
VDDE
ECM Control
EN
HS
Ctrl
ECMCSHEN
OC
Detect
ECMCSLEN
LS
ctrl
Open/Short
Detect
CSH
EC_RES
EC_M
CSL
RECMs
CECM
RECMp
VSS
VSS
3.11.1. ECM Driver Current/Voltage Limitation and Protection against Short to GND or Vbat
The limitation of the current through the load to safe levels for all conditions is achieved by adding an external
resistor between the EC_RES pin and the mirror terminal. Its value is chosen considering the characteristics of
the EC mirror and the nominal supply voltage of the system (see Table 6.1 for recommended external com-
ponents). In addition, the maximum voltage at the output of the driver is limited to the level specified in Table 1.9.
The limitation of this voltage relies on the feedback connection between the mirror terminal and the EC_M pin. If
this connection is missing, the voltage applied by the driver to its load could rise up to the supply of the system, so
an important step before activating the driver is to perform an open/short diagnostic check (see 3.11.3).
The current through both transistors (high-side and low-side) of the output stage is sensed for protecting the
driver against a short to Vbat or GND of both output pins (EC_RES and EC_M). In the event of such failures, if
the current exceeds a specified threshold level (see Table 1.9), the output stage of the ECM driver is
automatically disabled. This event generates an interrupt to the MCU and the ECMOCIF flag bit in the ECMDIAG
register is set (the ECMOCIF bit in IRQSTAT register is set; see
© 2016 Integrated Device Technology, Inc.
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January 26, 2016