71M6515H
Energy Meter IC
DATA SHEET
MARCH 2008
GENERAL DESCRIPTION
FEATURES
The 71M6515H is a high-accuracy analog front end
(AFE) IC that provides measurements for four-
quadrant 3-phase metering. The combination of a
21-bit sigma-delta A/D converter with a six-input
analog front end, a thermally compensated high pre-
cision reference and a compute engine results in
high accuracy and wide dynamic range. Patented
Single-Converter Technology™ reduces cross talk
and cost. This IC also provides RTC and battery
backup for time-of-use (TOU) metering.
Battery
RTC
COMPUTE
ENGINE
VOLTAGE
REFERENCE
RAM
UART, IRQZ
HOST
PRO-
CESSOR
SSI
CONTROL
DIO
High Accuracy
•
< 0.1% Wh accuracy over temperature and
2000:1 range
•
Exceeds IEC62053/ANSIC12.20 specifications.
•
Precision ultra-stable voltage reference
(10PPM/°C)
•
Single Converter Technology
™
reduces cross
talk and power consumption
•
Six sensor inputs—referenced to V3P3
•
Compatible with CTs, resistive shunts and
Rogowski Coil sensors
•
-90dB THD max.
•
Digital temperature compensation
•
Sag detection
•
Measures Wh, VARh, VAh, Vrms, Irms, V-to-V
phase and load angle on each phase
•
Four-quadrant metering.
•
Four low-jitter pulse outputs from selectable
measurements
•
Four pulse count registers
•
Selectable default status for pulse pins
•
Same calibration data for 46Hz to 64Hz line
frequency
•
Broad CT phase compensation (±7deg)
Battery Backup
•
Protects accumulated data and powers real time
clock during power supply outage
•
Compatible with Li-ion, NiCd, or super-capacitor
•
Battery backup current 2µA typical at 25°C
External Data Interface
•
UART Control Interface, two selectable data
rates
•
8 general-purpose I/O pins with alarm capability
•
5 or 10MHz selectable high speed synchronous
serial output for DSP interface
•
IRQ output signal for alarms and end of measure-
ment intervals.
•
Alarms on voltage sag, over-voltage, over-current
Low System Cost
•
Power Consumption 30mW @ 3.3V typical
•
Real-time clock with temperature compensation
•
Built-in power fault detection
•
Single 32kHz crystal time base
•
Single-supply operation (3.3V)
•
64-lead LQFP package
TERIDIAN 71M6515H
Figure 1: Meter block diagram
As shown in the block diagram (Figure 1), the host
processor communicates with the 71M6515H
through a UART interface using the programmable
IRQZ interrupt. The 71M6515H calculates and accu-
mulates meter measurements for each accumulation
interval. A high-speed synchronous serial port (SSI)
is provided to facilitate high-end metering. Integrated
rectifying functions on the battery backup circuit
enable minimal external component usage and
minimum back-up current. Also, eight multi-purpose
pins are provided for control of peripherals.
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VOLTAGE
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