Datasheet

90E36A POLY-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC
Function Description 23 April 2, 2013
3.7.3 DETECTION MODE (D MODE)
In Detection mode, the current detector is active. The current detec-
tor compares whether any phase current exceeds the configured thresh-
old using low-power comparators.
When the current of one phase or multiple phases exceeds the con-
figured threshold, the 90E36A asserts the IRQ0 pin to high and hold it
until power mode change. The IRQ0 state is cleared when entering or
exiting Detection mode.
When the current of all three current channels exceed the configured
threshold, the 90E36A asserts the IRQ1 pin to high and hold it until
power mode change. The IRQ1 state is cleared when entering or exiting
Detection mode.
The threshold registers need to be programmed in Normal mode
before entering Detection mode.
The digital I/O state is the same as that in Idle state (except for IRQ0/
IRQ1 and PM1/PM0).
The 90E36A has two comparators for detecting each phase’s posi-
tive and negative current. Each comparator’s threshold can be set indi-
vidually. The two comparators are both active by default, which called
‘double-side detection’. User also can enable one comparator only to
save power consumption, which called ‘single-side detection’.
Double-side detection has faster response and can detect ‘half-wave’
current. But it consumes nearly twice as much power as single-side
detection.
Comparators can be power-down by configuring the DetectCtrl regis-
ter.
Figure-9 Block Diagram in Detection Mode
VDD18 Regulator
Temperature Sensor
Current Detector
ADC-V1
ADC-V2
ADC-V3
ADC-I1
ADC-I2
ADC-I3
ADC-IN
SPI Interface
DSP
Energy Metering
(Forward/Reverse
Active/Reactive/CF generator)
Measure and Monitoring
(V/I/rms, SAG, Phase, Freq)
Signal Analyzer
ADC Sample Capture, THD
Control Logic
Zero
Crossing
CF Out
Power On Reset
Crystal Oscillator
DMA
Reference Voltage
OSCI OSCO
Power Mode
Configuration
Disabled
IRQ
Warn
Out