EMC1704 Datasheet, PDF (23/68 Pages) Microchip Technology – High-Side Current-Sense and Multiple 1°C Temperature Monitor

High-Side Current-Sense and Multiple 1°C Temperature Monitor
Datasheet
DC Supply
Sense Resistor
SENSE+ SENSE-
GPIO
2N3904 typ.
Optional
Anti-parallel
Diode
2N3904 typ.
DP1
DN1
DP2 / DN3
DN2 / DP3
THERM
SMCLK
SMDATA
ALERT
3.0V to 5.5V
VDD*
ADDR_SEL
VDD
TH_SEL**
GND
DUR_SEL**
EMC1704
* Can either be DC Supply voltage or a separate supply
** EMC1704-2 only
DC Load
Host
Figure 4.1 EMC1704 System Diagram
4.1 Source Monitoring
The EMC1704 includes circuitry for both source current sensing and source voltage measurement.
From these measurements, a ratiometric value corresponding to the power delivered at the SENSE+
pin is provided.
4.1.1 Current Measurement
The EMC1704 includes a high-side current sensing circuit. This circuit measures the voltage, V_SENSE,
induced across a fixed external current sense resistor, R_SENSE, and stores a representative voltage as
a signed 11-bit number in the Sense Voltage Registers (see Section 5.22).
This circuitry is able to measure the direction of current flow (from SENSE+ to SENSE- or from
SENSE- to SENSE+). Current flowing from SENSE+ to SENSE- is defined as positive current. Current
flowing from SENSE- to SENSE+ is defined as negative.
The EMC1704 contains user programmable bipolar Full Scale Sense Ranges (FSSR) of ±10mV,
±20mV, ±40mV, or ±80mV (see Section 5.20). The default for this setting is ±80mV.
Each V_SENSE measurement is averaged over a user programmable time (see Section 5.20). It is
compared against programmable high and low limits (see Section 5.25). If V_SENSE exceeds (or drops
below) the respective limits, the ALERT pin may be asserted (the default operation is to enable current
sense interrupts on the ALERT pin).
The EMC1704 also contains user programmable current peak detection circuitry (see Section 4.1.4)
that will assert the THERM pin if a current spike is detected larger than the programmed threshold and
of longer duration than the programmed time. This circuitry is independent of V_SENSE.
DS20005239A
23
DATASHEET
EMC1704