19-5346; Rev 3/11
A Maxim Integrated Products Brand
78M6618
Octal Power and
Energy Measurement IC
DATA SHEET
DS_6618_005
March 2011
DESCRIPTION
FEATURES
The Teridian 78M6618 is a highly integrated IC for
independent monitoring and measurement of up to eight
single-phase AC outlets. With multiple host interface options,
an integrated LCD driver, and configurable I/Os, the device is
ideal for metered power distribution units (PDUs) and rack
enclosures for the data center, as well as intelligent power
strips and subpanels in the grid-friendly digital home.
< 0.5% Wh Accuracy Over Wide 2000:1
Current Range and Over Temperature
Exceeds IEC 62053/ANSI C12.20 Standards
Voltage Reference < 40ppm/°C
10 Sensor Inputs—V3P3 Referenced
21-Bit Delta-Sigma ADC with Independent
32-Bit Compute Engine (CE)
8-Bit MPU (80515), One Clock Cycle per
Instruction with 4KB MPU XRAM
128KB Flash with Security
Integrated ICE for MPU Debug
32kHz Time Base with Hardware Watchdog
Timer
UART and High-Speed Slave SPI Host Interface
Options
Up to 19 General-Purpose 5V Tolerant I/O Pins
LCD Driver (Up to 70 Pixels)
At the measurement interface, the device provides 10 analog
inputs for interfacing to voltage and current sensors. Scaled
voltages from the sensors are fed to our Single Converter
Technology® that uses a 21-bit delta-sigma ADC, independent
32-bit compute engine (CE), digital temperature compensation,
and precision voltage references to provide better than 0.5%
accuracy over a wide 2000:1 dynamic range.
The integrated MPU core and 128KB of flash memory provides
a flexible means of configuration, postprocessing, data
formatting, interfacing to host processor through a UART or
SPI™ interface, displaying output data to an LCD, or using
DIO pins for intelligent relay control. Complete firmware for
common applications is available from Teridian and can be
loaded into the IC during manufacturing test. Alternatively, a Packaged in a Lead(Pb)-Free/RoHS-Compliant
(6/6) 68-Pin QFN
complete array of ICE, development tools, and programming
libraries are available to allow customization MPU code for Robust Sub-Metering Application Firmware:
each application.
o True RMS Calculations for Current, Voltage,
Line Frequency, Real Power, Reactive
Power, Apparent Power, and Power Factor
o Accumulated Watt-Hours, Kilowatt-Hours,
and Cost
o Intelligent Switch Control at Zero Crossings
o Digital Temperature Compensation
o Phase Compensation (15)
o Quick Calibration Routines
o 46-64Hz Line Frequency Range with Same
Calibration
o Programmable Alarm Thresholds
o High-Level UART Communication Protocols
o High-Level SPI Communication Protocols
Single Converter Technology is a registered trademark of
Maxim Integrated Products, Inc.
SPI is a trademark of Motorola, Inc.
Rev. 1.4
© 2011 Teridian Semiconductor Corporation
1
78M6618 Data Sheet
DS_6618_005
Table of Contents
1
Hardware Functional Description...................................................................................................... 5
1.1 Hardware Overview ..................................................................................................................... 5
1.2 Device Reset ................................................................................................................................ 7
1.3 Power Management ..................................................................................................................... 7
1.3.1 Voltage Regulator ............................................................................................................ 7
1.3.2 Power Fault Management................................................................................................ 7
1.3.3 BROWNOUT.................................................................................................................... 7
1.3.4 SLEEP mode ................................................................................................................... 7
1.4 Analog Front End (AFE)............................................................................................................... 7
1.4.1 Analog Current and Voltage Inputs ................................................................................. 8
1.5 Digital Computation Engine (CE) ................................................................................................. 8
1.6 80515 MPU Core ......................................................................................................................... 8
1.6.1 SFR .................................................................................................................................. 9
1.7 XRAM ........................................................................................................................................... 9
1.8 IORAM ......................................................................................................................................... 9
1.9 FLASH.......................................................................................................................................... 9
1.9.1 Program Security ............................................................................................................. 9
1.10 Oscillator ...................................................................................................................................... 9
1.11 PLL and Internal Clock Generation.............................................................................................. 9
1.12 Real-Time Clock (RTC).............................................................................................................. 10
1.13 Hardware Watchdog Timer ........................................................................................................ 10
1.14 Temperature Sensor .................................................................................................................. 10
1.15 General Purpose Digital I/O ....................................................................................................... 10
1.16 LCD Drivers ............................................................................................................................... 11
1.17 EEPROM Interface .................................................................................................................... 11
1.18 SPI Slave Port ............................................................................................................................ 11
1.19 Test Port..................................................................................................................................... 12
1.20 UARTs........................................................................................................................................ 13
1.20.1 UART1 (OPT_TX/OPT_RX) .......................................................................................... 13
1.21 In Circuit Emulator (ICE) Port .................................................................................................... 13
2
Electrical Specifications................................................................................................................... 14
2.1 Absolute Maximum Ratings ....................................................................................................... 14
2.2 Recommended External Components ....................................................................................... 15
2.3 Recommended Operating Conditions........................................................................................ 15
2.4 Performance Specifications ....................................................................................................... 16
2.4.1 Input Logic Levels .......................................................................................................... 16
2.4.2 Output Logic Levels ....................................................................................................... 16
2.4.3 Power-Fault Comparator ............................................................................................... 16
2.4.4 Battery Monitor............................................................................................................... 17
2.4.5 Supply Current ............................................................................................................... 17
2.4.6 V3P3D Switch ................................................................................................................ 17
2.4.7 2.5 V Voltage Regulator................................................................................................. 18
2.4.8 Low-Power Voltage Regulator ....................................................................................... 18
2.4.9 Crystal Oscillator ............................................................................................................ 18
2.4.10 LCD DAC ....................................................................................................................... 18
2.4.11 LCD Drivers ................................................................................................................... 19
2.4.12 Optical Interface ............................................................................................................. 19
2.4.13 Temperature Sensor ...................................................................................................... 19
2.4.14 VREF ............................................................................................................................. 20
2.4.15 ADC Converter, V3P3A Referenced ............................................................................. 21
2.5 Timing Specifications ................................................................................................................. 22
2.5.1 Flash Memory ................................................................................................................ 22
2.5.2 EEPROM Interface ........................................................................................................ 22
2.5.3 RESET ........................................................................................................................... 22
2.5.4 RTC................................................................................................................................ 22
2.5.5 SPI Slave Port (MISSION Mode) ................................................................................... 23
2
Rev. 1.4
DS_6618_005
78M6618 Data Sheet
3
Packaging .......................................................................................................................................... 24
3.1 68-Pin QFN Package ................................................................................................................. 24
3.1.1 Pinout ............................................................................................................................. 24
3.1.2 68-Pin QFN Package Outline ........................................................................................ 25
3.1.3 Recommended PCB Land Pattern for the QFN-68 Package ........................................ 26
4
Pin Descriptions ................................................................................................................................ 27
4.1 Power and Ground Pins ............................................................................................................. 27
4.2 Analog Pins ................................................................................................................................ 27
4.3 Digital Pins ................................................................................................................................. 28
5
I/O Equivalent Circuits...................................................................................................................... 29
6
Ordering Information ........................................................................................................................ 30
7
Contact Information .......................................................................................................................... 30
8
Appendix A: Acronyms .................................................................................................................... 31
9
Revision History ................................................................................................................................ 32
Rev. 1.4
3
78M6618 Data Sheet
DS_6618_005
Figures
Figure 1: 78M6618 IC Functional Block Diagram ......................................................................................... 6
Figure 2: AFE Block Diagram ....................................................................................................................... 8
Figure 3: SPI Slave Port: Typical Read and Write Operations ................................................................... 12
Figure 4: SPI Slave Port (MISSION Mode) Timing ..................................................................................... 23
Figure 5: Pinout for QFN-68 Package......................................................................................................... 24
Figure 6: QFN-68 Package Outline (Top, Bottom, and Side View) ............................................................ 25
Figure 7: PCB Land Pattern for QFN 68 Package ...................................................................................... 26
Figure 8: I/O Equivalent Circuits ................................................................................................................. 29
Tables
Table 1: SPI Command Description ............................................................................................................ 12
Table 2: Absolute Maximum Ratings .......................................................................................................... 14
Table 3: Recommended External Components .......................................................................................... 15
Table 4: Recommended Operating Conditions ........................................................................................... 15
Table 5: Input Logic Levels ......................................................................................................................... 16
Table 6: Output Logic Levels ...................................................................................................................... 16
Table 7: Power-Fault Comparator Performance Specifications.................................................................. 16
Table 8: Battery Monitor Performance Specifications (BME= 1) ................................................................. 17
Table 9: Supply Current Performance Specifications ................................................................................. 17
Table 10: V3P3D Switch Performance Specifications ................................................................................ 17
Table 11: 2.5 V Voltage Regulator Performance Specifications ................................................................. 18
Table 12: Low-Power Voltage Regulator Performance Specifications ....................................................... 18
Table 13: Crystal Oscillator Performance Specifications ............................................................................ 18
Table 14: LCD DAC Performance Specifications ....................................................................................... 18
Table 15: LCD Driver Performance Specifications ..................................................................................... 19
Table 16: Optical Interface Performance Specifications ............................................................................. 19
Table 17: Temperature Sensor Performance Specifications ...................................................................... 19
Table 18: VREF Performance Specifications.............................................................................................. 20
Table 19: ADC Converter Performance Specifications ............................................................................... 21
Table 20: Flash Memory Timing Specifications .......................................................................................... 22
Table 21: EEPROM Interface Timing.......................................................................................................... 22
Table 22: RESET Timing ............................................................................................................................ 22
Table 23: RTC Range ................................................................................................................................. 22
Table 24: SPI Slave Port (MISSION Mode) Timing .................................................................................... 23
Table 25: Recommended PCB Land Pattern Dimensions.......................................................................... 26
Table 26: Power and Ground Pins .............................................................................................................. 27
Table 27: Analog Pins ................................................................................................................................. 27
Table 28: Digital Pins .................................................................................................................................. 28
Table 29: Ordering Information ................................................................................................................... 30
4
Rev. 1.4
DS_6618_005
78M6618 Data Sheet
1 Hardware Functional Description
1.1
Hardware Overview
The Teridian 78M6618 single-chip measurement and monitoring IC integrates all the primary AC
measurement and control blocks required to implement an 8-outlet single-phase PDU with per outlet
metering and intelligent relay control The 78M6618 includes:
•
A ten-input analog front end (AFE)
•
An independent digital computation engine (CE)
•
An 8051-compatible microprocessor (MPU) which executes one instruction per clock cycle (80515)
•
A precision voltage reference
•
A temperature sensor
•
RAM and Flash memory
•
•
A variety of I/O pins
LCD drivers
Various current sensor technologies are supported including Current Transformers (CT), Resistive Shunts
and Rogowski coils.
In a sub-metering application, the 32-bit compute engine (CE) of the 78M6618 sequentially process the
samples from the analog inputs on pins IA, IB, IC, ID, IE, IF, IG, IH, VA, VB and performs calculations to
measure active energy (Wh) and reactive energy (VARh), as well as A2h and V2h for four-quadrant
measurement. These measurements are then accessed by the MPU, processed further, and output via
the peripheral devices available to the MPU.
In addition to the temperature-trimmed ultra-precision voltage reference, the on-chip digital temperature
compensation mechanism includes a temperature sensor and associated controls for correction of
undesirable temperature effects on measurement accuracy. Temperature-dependent external
components such as a crystal oscillator and current sensors can be characterized and their correction
factors can be programmed to produce measurements with exceptional accuracy over the industrial
temperature range.
A block diagram of the 78M6618 IC is shown in Figure 1. A detailed description of the various functional
blocks follows.
Rev. 1.4
5
78M6618 Data Sheet
DS_6618_005
VREF
V3P3A
GNDA
V3P3SYS
IA
∆Σ ADC
CONVERTER
IB
IC
VBIAS
V3P3D
VBIAS
RTM
FIR
ID
VADC
IE
IF
VREF
VREF
VOLT
REG
RPULSE
CE
MUXP
IG
VBAT
to TMUX
WPULSE
IH
GNDD
XPULSE
VA
16
32
CE_DATA
YPULSE
XPULSE
WPULSE
RPULSE
YPULSE
CE_PROG
VB
V2P5
2.5V to logic
VBAT
TEMP
MCK
PLL
XIN
XOUT
80MHz
CK_CE
FLASH
128KB
MULTIPURPOSE
IO
XRAM
4kB
DIO3
CK_MPU
OSC
(32.768kHz)
DIO43 / SEG63
CKTESTI
DIO19 / SEG39
DIO18 / SEG38
DIO17 / SEG37
DIO16 / SEG36
DIO15 / SEG35
DIO14 / SEG34
DIO13 / SEG33
CKTEST
RTC
LCD DISPLAY
DRIVER
TEST
DIO11 / SEG31
DIO10 / SEG30
TEST
MODE
COM0, COM1
COM1, 0
SEG0...
DIO9 / SEG29
DIO8 / SEG28
DIO7 / SEG27
DIO6 / SEG26
DIO5 / SEG25
DIO4 / SEG24
RX
UART
DIGITAL I/O
TX
DIO_4...
XRAM BUS
8
SPI SLAVE
OPT_RX /
DIO1
80515
MPU
PCSZ
PCLK
PSDI
PSDO
SEG19
SEG18
SEG17
SEG16
SEG15
SEG14
SDATA
EEPROM I/F
SCLK
OPTICAL
OPT_TX /
DIO2
SEG12
SEG11 / E_RST
SEG10 / E_TCLK
SEG9 / E_RXTX
SEG8
SEG7
SEG6 / PSDI
SEG5 / PCSZ
SEG4 / PSDO
SEG3 / PCLK
SEG2
SEG1
SEG0
MOD
SFR
E_RXTX
E_TCLK
EMULATOR
V1
POWER FAULT
E_RSTZ
ICE_E
FAULTZ
TEST
MUX
RESET
TMUXOUT
ICE_E
Figure 1: 78M6618 IC Functional Block Diagram
6
Rev. 1.4
DS_6618_005
1.2
78M6618 Data Sheet
Device Reset
When the RESET pin is pulled high, all digital activity stops. Only the oscillator and RTC module continue
to run. Additionally, all IORAM bits are set to their default states. As long as V1 (the input voltage at the
power fault block) is greater than VBIAS, the internal 2.5 V regulator will continue to provide power to the
digital section.
Once initiated, the reset mode will persist until the reset timer times out. This will occur in 4096 cycles of
the crystal clock after RESET goes low, at which time the MPU will begin executing its preboot and boot
sequences from address 0x0000.
1.3
Power Management
1.3.1 Voltage Regulator
The 78M6618 provides an on chip voltage regulator to create a 2.5V supply for the digital logic. This
regulator can be run off of the V3P3SYS or VBAT inputs depending upon power availability.
1.3.2 Power Fault Management
The 78M6618 includes both hardware and software controlled power fault management. V1 is connected
to a comparator to monitor system power fault conditions. When the output of the comparator falls
(V1