90E21 Datasheet, PDF (25/57 Pages) Integrated Device Technology – Single-Phase High-Performance Wide-Span Energy Metering IC

90E21/22/23/24
SINGLE-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC
5.3 METERING/ MEASUREMENT CALIBRATION AND CONFIGURATION
5.3.1 METERING CALIBRATION AND CONFIGURATION REGISTER
CalStart
Calibration Start Command
Address: 20H
Type: Read/Write
Default Value: 6886H
15
14
CalStart15
CalStart14
7
6
CalStart7
CalStart6
13
CalStart13
5
CalStart5
12
CalStart12
4
CalStart4
11
CalStart11
3
CalStart3
10
CalStart10
2
CalStart2
9
CalStart9
1
CalStart1
8
CalStart8
0
CalStart0
Bit
15 - 0
Name
CalStart[15:0]
Description
Metering calibration start command:
6886H: Power-on value. Metering function is disabled.
5678H: Metering calibration startup command. After 5678H is written to this register, registers 21H-2BH resume to their power-
on values. The 90E21/22/23/24 starts to meter and output energy pulses regardless of the correctness of diagnosis. The
CalErr[1:0] bits (SysStatus, 01H) are not set and the WarnOut/IRQ pins do not report any warning/interrupt.
8765H: Check the correctness of the 21H-2BH registers. If correct, normal metering. If not correct, metering function is disabled,
the CalErr[1:0] bits (SysStatus, 01H) are set and the WarnOut/IRQ pins report warning/interrupt.
Others: Metering function is disabled. The CalErr[1:0] bits (SysStatus, 01H) are set and the WarnOut/IRQ pins report warning/
interrupt.
PLconstH
High Word of PL_Constant
Address: 21H
Type: Read/Write
Default Value: 0015H
15
14
PLconstH15
PLconstH14
7
6
PLconstH7
PLconstH6
13
PLconstH13
5
PLconstH5
12
PLconstH12
4
PLconstH4
11
PLconstH11
3
PLconstH3
10
PLconstH10
2
PLconstH2
9
PLconstH9
1
PLconstH1
8
PLconstH8
0
PLconstH0
Bit
15 - 0
Name
Description
The PLconstH[15:0] and PLconstL[15:0] bits are high word and low word of PL_Constant respectively.
PL_Constant is a constant which is proportional to the sampling ratios of voltage and current, and inversely proportional to the
Meter Constant. PL_Constant is a threshold for energy calculated inside the chip, i.e., energy larger than PL_Constant will be
PLconstH[15:0]
accumulated in the corresponding energy registers and then output on CFx.
It is suggested to set PL_constant as a multiple of 4 so as to double or redouble Meter Constant in low current state to save ver-
ification time.
Note: PLconstH takes effect after PLconstL are configured.
For details, please refer to IDT application note AN-641.
Register
25
January 10, 2012