Cirrus Logic CS5466 User Manual
CS5466
IIN+
IIN-
IGAIN0
IGAIN1
VIN+
VIN-
VREFOUT
VA+ RESET VD+
DGNDAGND
FOUT
E1
E2
CPUCLK
XOUT
XIN
FREQ0
FREQ1
FREQ2
PGA
x10
NEG
4th Order
Modulator
2nd Order
Modulator
HPF
Option
Config
Clock
Generator
Digital
Filter
Digital
Filter
2.5V On-Chip
Reference
VREFIN x1
HPF
Option
HPF
Energy-toFrequency
Conversion
Low-cost Power/Energy IC with Pulse Output
Features
Single-chip Power Measurement Solution
Energy Data Linearity:
±0.1% of Reading, over 1000:1 Dynamic Range
On-chip functions: Measures Power and
Performs Energy-to-pulse Conversions
Meets Accuracy Spec for IEC, ANSI, & JIS.
High-pass Filter Option
Four Input Ranges for Current Channel
On-chip, 2.5 V Reference
Pulse Outputs for Stepper Motor or
Mechanical Counter
On-chip Energy Direction Indicator
Ground-referenced Input Signals with Single
Supply
High-frequency Output for Calibration
On-chip, Power-on Reset (POR)
Power Supply Configurations:
VA+ = +5 V; AGND = 0 V; VD+ = +3.3 V to 5 V
I
Description
The CS5466 is a low-cost power meter solution incorporating dual delta-sigma (analog-to-digital converters
ADCs), an energy-to-frequency converter, and energy
pulse outputs on a single chip. The CS5466 is designed
to accurately measure and calculate energy for single
phase, 2- or 3-wire power metering applications with
minimal external components.
The low-frequency pulse outputs, E1
pulses at a frequency which is proprtional to the active
power and can be used to drive a stepper motor or a mechanical counter. Energy direction output, NEG,
indicates when pulse outputs E1
ative active power. The high-frequency pulse output
FOUT is designed to assist in system calibration.
The CS5466 has configuration pins which allow for direct
configuration of pulse output frequency, current channel
input range, and high-pass filter enable option.
The CS5466 also has a power-on reset function which
holds the part in reset until the supply reaches an operable level.
ORDERING INFORMATION
See page 16.
and E2, provide
and E2 represent neg-
http://www.cirrus.com
Copyright Cirrus Logic, Inc. 2011
(All Rights Reserved)
APR ‘11
DS659F2
TABLE OF CONTENTS
1. OVERVIEW ............................................................................................................................... 3
2. PIN DESCRIPTION ...................................................................................................................4
3. CHARACTERISTICS & SPECIFICATIONS ............................................................................. 5
RECOMMENDED OPERATING CONDITIONS ....................................................................... 5
ANALOG CHARACTERISTICS................................................................................................5
VOLTAGE REFERENCE ......................................................................................................... 6
DIGITAL CHARACTERISTICS.................................................................................................7
SWITCHING CHARACTERISTICS ..........................................................................................8
ABSOLUTE MAXIMUM RATINGS ........................................................................................... 9
4. THEORY OF OPERATION ..................................................................................................... 10
4.1 Digital Filters .......................... .......................................... ................................................10
4.2 Active Power Computation ............................... ... .... ... ... ... .... ... ... ... ... .... ... .........................10
5. FUNCTIONAL DESCRIPTION ............................................................................................... 11
5.1 Analog Inputs ................ ... .......................................... ... ... .... ............................................ 11
5.1.1 Voltage Channel ..................... ... .... ... ... .......................................... ... .... ... ... ... ......11
5.1.2 Current Channel ............................... ... ... .... ... ... ... .......................................... ... ... 11
5.2 High-pass Filter ... .............................................................................................................11
5.3 Energy Pulse Outputs ......... .......................................... ... .... ......................................... ... 11
5.3.1 Pulse Output Format. ....................................... ... .... ......................................... ... 11
5.3.2 Selecting Frequency of E1 and E2 ...................... .... ... ... ... ... .... ... ... ... .... ... ............11
5.3.3 Selecting Frequency of FOUT ............................................................................. 12
5.3.4 Absolute Max Frequency on E1 and E2 ..............................................................12
5.3.5 E1 and E2 Frequency Calculation .......................................................................13
5.4 Energy Direction Indicator ............ ... ... ... .... ... ... ... .......................................... ...................13
5.5 Power-on Reset ............................ ... ... .......................................... ... .... ............................13
5.6 Oscillator Characteristics .................... ... .... ... ... ... .... ... ... .......................................... ... ... ...13
5.7 Basic Application Circuit ..................................................................................................14
6. PACKAGE DIMENSIONS ....................................................................................................... 15
7. REVISION HISTORY .............................................................................................................. 16
CS5466
LIST OF FIGURES
Figure 1. Timing Diagram for E1, E2 and FOUT (Not to Scale)...................................................... 8
Figure 2. Data Flow....................................................................................................................... 10
Figure 3. Oscillator Connection.....................................................................................................13
Figure 4. Typical Connection Diagram..........................................................................................14
LIST OF TABLES
Table 1. Current Channel PGA Setting .........................................................................................11
Table 2. Maximum Frequency for E1, E2, and FOUT................................................................... 12
Table 3. Absolute Max Frequency on E1 and E2..........................................................................12
2 DS659F2
CS5466
1. OVERVIEW
The CS5466 is a CMOS monolithic power measurement device with an energy computation engine. The CS5466
combines a programmable gain am plifier, two ADCs, and energy-to-frequency conversion circuitry on a single
chip.
The CS5466 is designed for energy measurement applications and is optimized to interface to a shunt or current
transformer for current measurement, and to a resistive divider or transformer for voltage measurement. The curre nt
channel has a programmable gain amplifier (PGA) which provides four full-scale input options. With a single +5 V
supply on VA+/AGND, both of the CS5466’s input channels accommodate common-mode plus signal levels between (AGND - 0.25 V) and VA+.
The CS5466 has three pulse output pins: E1
counter or stepper motor, or interface to a microcon troller. The FOUT pi n conveys active (real) po wer at a pulse frequency many times higher than that of the E1
, E2, and FOUT. E1 and E2 can be used to directly drive a mechanica l
or E2 pulse frequency, allowing for high-speed calibration.
DS659F2 3
CS5466
VREFIN 12Voltage Reference Input
VREFOUT 11Voltage Reference Out put
VIN- 10Differential Voltage I nput
VIN+ 9Differential Voltage I nput
HPF 8High-pass Filter Ena ble
IGAIN1 7Gain Select 1
NEG 6Negative Energy In di c at or
IGAIN0 5Gain Select 0
DGND 4Digital Ground
VD+ 3Positive Power Supply
CPUCLK 2CPU Clock Out put
XOUT 1Crystal Out
AGND13 Analog G round
VA+14 Positive Anal og S uppl y
IIN-15 Dif ferential Cur r ent I nput
IIN+16 Dif ferential Cur r ent I nput
FREQ217 Frequency Select 2
FOUT18 High-f r equenc y Output
RESET19 Reset
FREQ120 Frequency Select 1
E221 Energy Outpu t 2
E122 Energy Outpu t 1
FREQ023 Frequency Select 0
XIN24 Crystal In
2. PIN DESCRIPTION
Clock Generator
Crystal Out
Crystal In
CPU Clock Output 2
Control Pins
Gain Select 5, 7
Frequency Select 17, 20, 23
High Pass Filter Enable 8
Reset 19
Energy Pulse Outputs
Energy Output 22, 21
High Freq Output 18
Neg Energy Indicator 6
Analog Inputs/Outputs
Differential V ol tage Inputs 9, 10
Voltage Reference
Output
Voltage Reference Input 12
Differential Current Inputs 16, 15
Power Supply Connections
Positive Digital Supply 3
Digital Ground 4
Analog Ground 13
Positive Analog Supply 14
1, 24
11
4 DS659F2
XOUT , X IN - A single stage amplifier inside the chip is connected to these pins and can be used
with a crystal to provide the system clock for the device. Alternatively, an external clock can be
supplied to the XIN pin to provide the system clock for the device.
CPUCLK - Output of on-chip oscillator which can drive one standard CMOS load.
IGAIN1, IGAIN0 - Used to select the current channel input gain range.
FREQ2,FREQ1,FREQ0 - Used to select max pulse output frequency for E1, E2, and FOUT.
HPF - High disables the HPF. Low activates HPF on Voltage channel. Connecting HPF pin to
FOUT pin activates HPF on Current channel.
RESET - Low activates Reset.
E1, E2 - Active low alternating pulses with an output frequency that is proportional to the active
(real) power.
FOUT - Outputs energy pulses at a frequency higher than E1 and E2 outputs. Used for calibra-
tion purposes.
NEG - High indicates negative energy.
VIN+, VIN- - Differential analog input pins for voltage channel.
VREFOUT - The on-chip voltage reference output pin. The voltage reference has a nominal
magnitude of 2.5 V and is referenced to the AGND pin on the converter.
VREFIN - Voltage input to this pin establishes the voltage reference for the on-chip modulators.
IIN+, IIN- - Differential analog input pins for current channel.
VD+ - The positive digital supply.
DGND - Digital Ground.
AGND - Analog Ground.
VA+ - The positive analog supply.
CS5466
3. CHARACTERISTICS & SPECIFICATIONS
RECOMMENDED OPERATING CONDITIONS
Parameter Symbol Min Typ Max Unit
Positive Digital Power Supply VD+ 3.135 5.0 5.25 V
Positive Analog Power Supply VA+ 4.75 5.0 5.25 V
Voltage Reference VREFIN - 2.5 - V
Specified Temperature Range T
A
ANALOG CHARACTERISTICS
• Min / Max characteristics and specifications are guaranteed over all operating ponditions.
• Typical characteristics and specifications are measured at nominal supply voltages and TA = 25 °C.
• VA+ = 5 V ±5% VD+ = 3.3 V ±5% or 5 V ±5%; AGND = DGND = 0 V. All voltages with respect to 0 V.
• MCLK = 4.096 MHz
Parameter Symbol Min Typ Max Unit
Analog Inputs (Current Channel)
Differential Input Range (Gain = 10)
[(I
IN+)-(IIN-)] (Gain = 50)
(Gain = 100)
(Gain = 150)
Input Capacitance (All Gain Ranges) C
Effective Input Impedance (All Gain Ranges) Z
Analog Inputs (Voltage Channel)
Differential Input Range [(V
IN+)-(VIN-)] VIN --±250mV
Input Capacitance C
Effective Input Impedance Z
Accuracy (Energy Outputs)
Active Energy Linearity All Gain ranges
(Note 1) Input Range 0.1% - 100% - - ±0.1 - %
Full-scale Error (Note 2) - - 4.0 - %FS
Offset Error (Note 2) - - 0.06 - %FS
I
IN -
inI -25-pF
inI 30 - - k
inV -0.2-pF
inV 2--M
-40 - +85 °C
±250
-
-
-
±50
±25
±16.7
-
-
-
-
mV
mV
mV
mV
Notes: 1. Applies when the HPF option is enabled
2. Applies before system calibration. Specified as a percentage of full scale (FS).
DS659F2 5
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