Datasheet

90E32AS ENHANCED POLY-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC
Function Description 26 April 2, 2013
3.8.3 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 90E32AS 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 90E32AS 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 90E32AS 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. The current detector can be enabled and calibrated in normal mode
using control bits in the DetectCtrl register.
Figure-12 Block Diagram in Detection Mode
VDD18 Regulator
Temperature Sensor
Current Detector
ADC-V1
ADC-V2
ADC-V3
ADC-I1
ADC-I2
ADC-I3
SPI Interface
DSP
Energy Metering
(Forward/Reverse
Active/Reactive/CF Generator)
Measure and Monitoring
(V/I/rms / SAG / Phase /
Frequency)
Control Logic
Zero
Crossing
CF Out
Power On Reset
Crystal Oscillator
On-chip
Reference Voltage
Vref
I1P / I1N
V1P / V1N
CS
SCLK
SDO
SDI
OSCI OSCO
RESET
CF1
ZX0
I2P / I2N
I3P / I3N
V2P / V2N
V3P / V3N
CF2
CF3
CF4
ZX1
ZX2
Power Mode
Configuration
PM1
PM0
IRQ
WarnOut
IRQ0
IRQ1
Warn
Out
Flexible Piece-wise Non-linear
Compensation
Disabled