MAX78630+PPM
Energy Measurement Processor
for Polyphase Monitoring Systems
DATA SHEET
GENERAL DESCRIPTION
The MAX78630+PPM is an energy measurement processor
(EMP) for polyphase power monitoring systems. It is
designed for real-time monitoring for a variety of typical
three-phase configurations in industrial applications. It is
available in a 32-pin TQFN package.
The MAX78630+PPM provides up to six analog inputs for
interfacing to voltage and current sensors. Scaled voltages
from the sensors are fed to the single converter front-end
utilizing a high-resolution delta-sigma converter. Supported
current sensors include current transformers (CT),
Rogowski coils, and resistive shunts.
An embedded 24-bit measurement processor and firmware
perform all necessary computations and data formatting for
accurate reporting to the host. With integrated flash
memory for storing nonvolatile calibration coefficients and
device configuration settings, the MAX78630+PPM is
capable of being a completely autonomous solution.
The MAX78630+PPM is designed to interface to the host
2
processor via the UART interface. Alternatively, SPI or I C
may also be used.
BENEFITS AND FEATURES
•
Six Configurable Analog Inputs for Monitoring
a Variety of Delta- and Wye-Connected
Three-phase Topologies
•
Supports Current Transformers (CT),
Resistive Shunts, and Rogowski Coils
•
Delta-Sigma ADC with Precision Voltage
Reference and On-Chip Temperature Sensor
•
Internal or External Oscillator Timing
Reference
2
•
SPI, I C, or UART Interface Options with
Configurable I/O pins for alarm Signaling,
Address Pins, or User Control
•
24-Bit Measurement Processor with
Integrated Firmware and Flash Memory for
Nonvolatile Storage of Calibration and
Configuration Parameters
•
Supports Extraction of Individual Harmonics
•
Small 32-TQFN Package and Reduced Bill of
Materials
Voltage
Sensors
Single Converter
Front End
Measurement
Processor
UART
MUX
Current
Sensors
ADC
RAM
SPI
Digital
I/O
Host
Controller
FLASH
I2C
MAX78630+PPM
For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
19-6679; Rev 3; 8/14
MAX78630+PPM Data Sheet
Table
of Contents
ABSOLUTE MAXIMUM RATINGS ....................................................................................................... 4
Recommended External Components .................................................................................................. 4
Recommended Operating Conditions ................................................................................................... 4
Performance Specifications .................................................................................................................. 5
Input Logic Levels ....................................................................................................................... 5
Output Logic Levels .................................................................................................................... 5
Supply Current ............................................................................................................................ 5
Crystal Oscillator ......................................................................................................................... 5
Internal RC Oscillator .................................................................................................................. 5
ADC Converter, V
3P3
Referenced................................................................................................ 6
Timing Specifications ............................................................................................................................ 7
Reset 7
SPI Slave Port ............................................................................................................................. 7
2
I C Slave Port (Note 1) ................................................................................................................ 8
Pin Configuration ........................................................................................................................................ 9
Package Information ........................................................................................................................... 11
On-Chip Resources Overview ................................................................................................................. 12
IC Block Diagram ................................................................................................................................ 12
Clock Management ............................................................................................................................. 13
Power-On Reset, Watchdog-Timer, and Reset Circuitry .................................................................... 14
Analog Front-End and Conversion ..................................................................................................... 15
24-Bit Measurement Processor .......................................................................................................... 17
Flash and RAM ................................................................................................................................... 17
Digital I/O Pins .................................................................................................................................... 17
Communication Interfaces .................................................................................................................. 17
Functional Description and Operation .................................................................................................... 18
Measurement Interface ....................................................................................................................... 18
AFE Input Multiplexer ................................................................................................................ 18
High Pass Filters and Offset Removal ...................................................................................... 19
Enabling the software integrators for Rogowski Coil current sensors ...................................... 19
Gain Correction ......................................................................................................................... 19
Die Temperature Compensation ............................................................................................... 20
Phase Compensation ................................................................................................................ 20
Voltage Input Configuration....................................................................................................... 21
Current Input Configuration ....................................................................................................... 23
Current Input Flowchart ............................................................................................................. 24
Data Refresh Rates ............................................................................................................................ 25
Scaling Registers and Result Formats ............................................................................................... 25
Calibration ........................................................................................................................................... 26
Voltage and Current Gain Calibration ....................................................................................... 26
Offset Calibration ...................................................................................................................... 26
Die Temperature Calibration ..................................................................................................... 26
Voltage Channel Measurements ........................................................................................................ 27
RMS Voltage ............................................................................................................................. 27
Line Frequency.......................................................................................................................... 27
Current Channel Measurements ......................................................................................................... 28
Peak Current ............................................................................................................................. 28
RMS Current ............................................................................................................................. 28
Current and Voltage Imbalance .......................................................................................................... 29
Power Calculations ............................................................................................................................. 30
Active Power (P) ....................................................................................................................... 30
Reactive Power (Q) ................................................................................................................... 31
Apparent Power (S) ................................................................................................................... 31
Power Factor (PF) ..................................................................................................................... 31
2
Rev 3
MAX78630+PPM Data Sheet
Totals of active power, reactive power, apparent power and power factor .............................. 31
Fundamental and Harmonic Calculations ........................................................................................... 33
Energy Calculations ............................................................................................................................ 34
Bucket Size for Energy Counters .............................................................................................. 35
Min/Max Tracking ................................................................................................................................ 36
Voltage Sag Detection ........................................................................................................................ 37
Voltage Sign Outputs .......................................................................................................................... 38
Alarm Monitoring ................................................................................................................................. 38
Status Registers .................................................................................................................................. 39
Digital IO Functionality ........................................................................................................................ 40
DIO Direction ............................................................................................................................. 41
DIO Polarity ............................................................................................................................... 41
Alarm Pins ................................................................................................................................. 41
Command Register ............................................................................................................................. 42
General Settings ....................................................................................................................... 42
No Action (0x00xxxx) ................................................................................................................ 42
Save to Flash Command (0xACC2xx) ...................................................................................... 43
Clear Flash Storage 0 Command (0xACC0xx) ......................................................................... 43
Clear Flash Storage 1 Command (0xACC1xx) ......................................................................... 43
Calibration Command (0xCAxxxx/0xCBxxxx) ........................................................................... 44
Configuration Register ........................................................................................................................ 45
Application Examples ............................................................................................................................... 46
Wye-connected source, wye-connected load (Y-Y)............................................................................ 47
Isolated configuration, 3 VT, 3 CT ............................................................................................ 47
Non-isolated configuration, 3 voltage-dividers, 3 CTs .............................................................. 48
Non-isolated, 3 voltage-dividers, 2 CTs, 1 Shunt...................................................................... 49
Non-isolated, 3 voltage-dividers, 3 shunts ................................................................................ 50
Delta-connected source, delta-connected load (Δ-Δ) ......................................................................... 51
Isolated configuration, 2 VTs, 2 CT, line current measurement................................................ 52
Non-isolated, 2 voltage-dividers referenced to line, 2 CTs, line current measurements .......... 53
Non-isolated, 1 CT, 2 shunts and 2 voltage-dividers, all referenced to phase ......................... 56
Wye-connected source, delta-connected load (Y-Δ) .......................................................................... 57
Register Access ........................................................................................................................................ 58
Data Types .......................................................................................................................................... 58
Register Locations .............................................................................................................................. 59
Serial Interfaces ........................................................................................................................................ 64
UART Interface ................................................................................................................................... 64
RS-485 Support ........................................................................................................................ 64
Device Address Configuration................................................................................................... 65
SSI Protocol Description ........................................................................................................... 65
SPI Interface ....................................................................................................................................... 69
2
I C Interface ........................................................................................................................................ 72
Device Address Configuration................................................................................................... 72
Bus Characteristics ................................................................................................................... 73
Device Addressing .................................................................................................................... 73
Write Operations ....................................................................................................................... 74
Read Operations ....................................................................................................................... 75
Ordering Information ................................................................................................................................ 76
Contact Information .................................................................................................................................. 76
Revision History ........................................................................................................................................ 77
Rev 3
3
MAX78630+PPM Data Sheet
Electrical Specifications
ABSOLUTE MAXIMUM RATINGS
(All voltages with respect to ground.)
Supplies and Ground Pins:
V
3P3D
, V
3P3A
GNDD, GNDA
Analog Input Pins:
AV1, AV2, AV3, AI1, AI2, AI3
Oscillator Pins:
XIN, XOUT
Digital Pins:
DIO0 through DIO15;
Digital Pins configured as outputs
DIO0 through DIO15,
RESET;
Digital Pins configured as inputs
Temperatures:
Operating Junction Temperature
Peak, 100ms
Continuous
Storage Temperature Range
Lead Temperature (soldering, 10s)
Soldering Temperature (reflow)
ESD Stress on All Pins
+140°C
+125°C
-65°C to +150°C
+260°C
+300°C
±4kV
-30mA to +30mA,
-0.5 to (V
3P3D
+ 0.5V)
-10mA to +10mA,
-0.5V to +6V
-10mA to +10mA
-0.5V to 3.0V
-10mA to +10mA
-0.5V to (V
3P3
+ 0.5V)
-0.5V to 4.6V
-0.5V to +0.5V
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress
ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational
sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Recommended External Components
NAME
XTAL
CXS
CXL
FROM
XIN
XIN
XOUT
TO
XOUT
GNDD
GNDD
20.000MHz
Load capacitor for crystal (exact value
depends on crystal specifications and
parasitic capacitance of board)
FUNCTION
VALUE
20.000
18
±10%
18
±10%
UNITS
MHz
pF
pF
Recommended Operating Conditions
PARAMETER
3.3V Supply Voltage (V
3P3
)
Operating Temperature
CONDITIONS
Normal operation
MIN
3.0
-40
TYP
3.3
MAX
3.6
+85
UNITS
V
°C
4
Rev 3
MAX78630+PPM Data Sheet
Performance Specifications
Note that production tests are performed at room temperature.
Input Logic Levels
PARAMETER
Digital High-Level Input Voltage (V
IH
)
Digital Low-Level Input Voltage (V
IL
)
CONDITIONS
MIN
2
0.8
TYP
MAX
UNITS
V
V
Output Logic Levels
PARAMETER
Digital High-Level Output Voltage
(V
OH
)
Digital Low-Level Output Voltage
(V
OL
)
CONDITIONS
I
LOAD
= 1mA
I
LOAD
= 10mA
I
LOAD
= 1mA
I
LOAD
= 10mA
MIN
V
3P3
-
0.4
V
3P3
-
0.6
0
0.4
0.5
TYP
MAX
UNITS
V
V
V
V
Supply Current
PARAMETER
V
3P3D
and V
3P3A
Current
(Compounded)
CONDITIONS
Normal operation, V
3P3
=
3.3V
MIN
TYP
8.1
MAX
10.3
UNITS
mA
Crystal Oscillator
PARAMETER
XIN to XOUT Capacitance
Capacitance to GNDD (Note 1)
XIN
XOUT
CONDITIONS
(Note 1)
MIN
TYP
3
5
5
MAX
UNITS
pF
pF
Note 1:
Guaranteed by design; not subject to test.
Internal RC Oscillator
PARAMETER
Nominal Frequency
Accuracy
V
3P3
= 3.0V, 3.6V;
temperature = -40°C to
+85°C
CONDITIONS
MIN
TYP
20.000
±1.5
±1.75
MAX
UNITS
MHz
%
Rev 3
5