Friday, October 23, 2009

Single-Phase Energy Metering IC


The ADE77631 features proprietary ADCs and fixed function DSP for high accuracy over large variations in environmental conditions and time. The ADE7763 incorporates two second-order, 16-bit Σ-Δ ADCs, a digital integrator (on Ch1), reference circuitry, a temperature sensor, and all the signal processing required to perform active and apparent energy measurements,
line-voltage period measurements, and rms calculation on the voltage and current channels. The selectable on-chip digital integrator provides direct interface to di/dt current sensors such as Rogowski coils, eliminating the need for an external analog integrator and resulting in excellent long-term stability and precise phase matching between the current and the voltage channels.

High accuracy; supports IEC 61036/60687, IEC62053-21, and IEC62053-22
On-chip digital current channel allows direct interface to shunts and current transformers
Active and apparent energy, sampled waveform, and current and voltage rms
Less than 0.1% error in active energy measurement over a dynamic range of 1000 to 1 at 25°C
Positive-only energy accumulation mode available
On-chip user programmable threshold for line voltage surge and SAG and PSU supervisory
Digital calibration for power, phase, and input offset
On-chip temperature sensor (±3°C typical)
SPI®-compatible serial interface
Pulse output with programmable frequency
Interrupt request pin () and status register IRQ
Reference 2.4 V with external overdrive capability
Single 5 V supply, low power (25 mW typical)

ADE5166: Single-Phase Energy Measurement IC with 8052 MCU, RTC, and LCD Driver integrator enables direct interface-to-current sensors with di/dt output

8052-based core
Single-cycle 4 MIPS 8052 core
8052-compatible instruction set
32.768 kHz external crystal with on-chip PLL
2 external interrupt sources
External reset pin
Low power battery mode
Wake-up from I/O, temperature change, alarm, and universal asynchronous receiver/transmitter (UART)
LCD driver operation with automatic scrolling
Temperature measurement
Real-time clock (RTC)
Counter for seconds, minutes, hours, days, months, and years
Date counter, including leap year compensation
Automatic battery switchover for RTC backup
Operation down to 2.4 V
Ultralow battery supply current: 1.7 μA
Selectable output frequency: 1 Hz to 16 kHz
Embedded digital crystal frequency compensation for calibration and temperature variation of 2 ppm resolution
Integrated LCD driver
108-segment driver for the ADE5566 and ADE5569
104-segment driver for the ADE5166 and ADE5169
2×, 3×, or 4× multiplexing
4 LCD memory banks for screen scrolling
LCD voltages generated internally or with external resistors
Internal adjustable drive voltages up to 5 V independent of power supply level
On-chip peripherals
2 independent UART interfaces
SPI or I2C
Watchdog timer
Power supply management with user-selectable levels
Memory: 62 kB flash memory, 2.256 kB RAM
Development tools
Single-pin emulation
IDE-based assembly and C source debugging

Wide supply voltage operation: 2.4 V to 3.7 V
Internal bipolar switch between regulated and battery inputs
Ultralow power operation with power saving modes (PSM)
Full operation: 4.4 mA to 1.6 mA (PLL clock dependent)
Battery mode: 3.3 mA to 400 μA (PLL clock dependent)
Sleep mode
Real-time clock (RTC) mode: 1.7 μA
RTC and LCD mode: 38 μA (LCD charge pump enabled)
Reference: 1.2 V ± 0.1% (10 ppm/°C drift)
64-lead, low profile quad flat, RoHS-compliant package (LQFP)
Operating temperature range: −40°C to +85°C


The only analog circuitry used in the ADE7751 is in the ADCs
and reference circuit. All other signal processing (e.g., multiplication
and filtering) is carried out in the digital domain. This
approach provides superior stability and accuracy over extremes
in environmental conditions and over time.

The ADE7751 incorporates a novel fault detection scheme that
warns of fault conditions and allows the ADE7751 to continue
accurate billing during a fault event. The ADE7751 does this
by continuously monitoring both the phase and neutral (return)
currents. A fault is indicated when these currents differ by more
than 12.5%. Billing is continued using the larger of the two currents.

The ADE7751 supplies average real power information on the
low-frequency outputs F1 and F2. These logic outputs may be
used to directly drive an electromechanical counter or interface
to an MCU. The CF logic output gives instantaneous real power
information. This output is intended to be used for calibration purposes.

The ADE7751 includes a power supply monitoring circuit on the
AVDD supply pin. The ADE7751 will remain in a reset condition
until the supply voltage on AVDD reaches 4 V. If the supply falls
below 4 V, the ADE7751 will also be reset and no pulses will be
issued on F1, F2, and CF.

High Accuracy, Surpasses 50 Hz/60 Hz IEC 687/1036
Less than 0.1% Error over a Dynamic Range of 500 to 1
Supplies Average Real Power on the Frequency
Outputs F1 and F2
High-Frequency Output CF Is Intended for Calibration
and Supplies Instantaneous Real Power
Continuous Monitoring of the Phase and Neutral
Current Allows Fault Detection in 2-Wire
Distribution Systems
ADE7751 Uses the Larger of the Two Currents (Phase
or Neutral) to Bill—Even During a Fault Condition
Two Logic Outputs (FAULT and REVP) Can Be Used to
Indicate a Potential Miswiring or Fault Condition
Direct Drive for Electromechanical Counters and
2-Phase Stepper Motors (F1 and F2)
A PGA in the Current Channel Allows the Use of Small
Values of Shunt and Burden Resistance
Proprietary ADCs and DSP Provide High Accuracy over
Large Variations in Environmental Conditions and Time
On-Chip Power Supply Monitoring
On-Chip Creep Protection (No Load Threshold)
On-Chip Reference 2.5 V _ 8% (30 ppm/_C Typical)
with External Overdrive Capability
Single 5 V Supply, Low Power (15 mW Typical)
Low-Cost CMOS Process

Energy Metering ICs with Active Real Power Pulse Output

The MCP3905A/05L/06A devices are energy-metering
ICs designed to support the IEC 62053 international
metering standard specification. They supply a
frequency output proportional to the average active real
power, as well as a higher-frequency output
proportional to the instantaneous power for meter
calibration. The MCP3905L offers reduced pulse width
of calibration output frequency and mechanical counter
drive for lower power meter designs. They include two
16-bit, Delta-Sigma ADCs for a wide range of IB and
IMAX currents and/or small shunt (<200 µOhms) meter
designs. It includes an ultra-low drift voltage reference
with < 15 ppm/°C through a specially designed band
gap temperature curve for the minimum gradient across
the industrial temperature range. A fixed-function DSP
block is on-chip for active real-power calculation. A noload
threshold block prevents any current creep
measurements. A Power-On Reset (POR) block
restricts meter performance during low-voltage
situations. These accurate energy metering ICs with
high field reliability are available in the industry standard

• Supplies active (real) power measurement for
single-phase, residential energy metering
• Supports IEC 62053 International Energy
Metering Specification and legacy IEC
1036/61036/687 Specifications
• Two multi-bit, DAC, second-order, 16-bit, Delta-
Sigma Analog-to-Digital Converters (ADCs)
• Reduced pulse width of calibration output
frequency and mechanical counter drive for low
power meter designs (MCP3905L)
• Increased output frequency constant options for
meter design (MCP3905L)
• 0.1% typical measurement error over 500:1
dynamic range (MCP3905A / MCP3905L)
• 0.1% typical measurement error over 1000:1
dynamic range (MCP3906A)
• Programmable Gain Amplifier (PGA) for small signal
inputs supports low value shunt current sensor:
- 16:1 PGA - MCP3905A / MCP3905L
- 32:1 PGA - MCP3906A
• Ultra-low drift on-chip reference: 15 ppm/°C (typ.)
• Direct drive for electromagnetic mechanical
counter and two-phase stepper motors
• Low IDD of 4 mA (typ.)
• Tamper output pin for negative power indication
• Industrial Temperature Range: -40°C to +85°C
• Supplies instantaneous real power on HFOUT for
meter calibration