The MAX78700 is an isolated analog-to-digital converter
(ADC) for use with a compatible MAX78xxx energy mea-
surement processor. The device provides current and
voltage measurements to the host while the host pro-
vides control, command, and power to the MAX78700. A
pulse transformer provides the isolated data and power
path between the device and host, eliminating the need
for additional isolation components in the measurement
subsystem.
Benefits and Features
● Better Than 0.5% Watt-Hour Accuracy Over Wide
Dynamic Range Using a Single Calibration Point
• High-Resolution Delta-Sigma ADC
• Factory-Trimmed Voltage Reference and Die
Temperature Sensor
● Simplified System Architecture
• No Power Supply Required
• Fully Powered by the Host with the Isolation
Transformer
• Eliminates Data Isolation Components
• Reduced Form Factor and Bill of Materials
● Small 10-Pin μMAX® Package
Ordering Information
appears at end of data sheet.
For related parts and recommended products to use with this part, refer
to
www.maximintegrated.com/MAX78700.related.
Applications
●
●
●
●
●
Smart Grid-Friendly Equipment
Lighting Control Systems
Commercial and Industrial Automation
Renewable Energy Systems
Electric Vehicle Charging Systems
Block Diagram
SYSTEM POWER
ENERGY
MEASUREMENT
PROCESSOR
“HOST”
POWER, TIMING,
CONTROL
ISOP
ADC
ISON
ADC DATA
MUX
INAP
INAN
INBP
INBN
RESISTIVE
SENSORS
HOST INTERFACE
MAX78700
µMAX is a registered trademark of Maxim Integrated Products, Inc.
19-6565; Rev 0; 12/12
MAX78700
Multichannel, Isolated, Precision ADC
Absolute Maximum Ratings
(All voltages with respect to GND.)
Voltage Range INAN, INAP, INBP, INBN
.............-0.5V to +4.6V
Voltage Range ISOP, ISON
..................................-0.5V to +4.6V
Operating Temperature Range
...........................
-40°C to +85°C
Operating Junction Temperature (Peak)
.........................
+140°C
Operating Junction Temperature (Peak, 100ms)
............
+140°C
Operating Junction Temperature (Continuous)
...............
+125°C
Storage Temperature
........................................
-45°C to +165°C
Lead Temperature (soldering, 10s)
.................................
+300°C
Soldering Temperature (reflow)
.......................................+260°C
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
C1
FROM
V
CC
TO
GND
FUNCTION
Bypass capacitor for supply
VALUE
0.5
UNIT
µF
Performance Specifications
(Limits are 100% production tested at T
A
= +22°C. Limits over the operating temperature range and relevant supply voltage range are
guaranteed by design and characterization.)
PARAMETER
Usable Input Range
SYMBOL
V
IN
THD
CONDITIONS
INAP, INAN, INBP, INBN
First 10 harmonics, f
IN
= 65Hz,
V
IN
= 20mV, 64kpts FFT,
Blackman-Harris window
f
IN
= 65Hz
f
IN
= 65Hz (Note 1)
10
6
∆
Nout
PK
357nV / V
IN
100
∆
VCC / 3.3
MIN
V
CC
-
250
TYP
MAX
V
CC
+
250
UNITS
mV
peak
dB
Total Harmonic Distortion
Input Impedance
Temperature Coefficient of Input
Impedance
-85
20
1.7
90
kΩ
Ω/°C
ADC Gain Error vs.
% Power-Supply Variation
50
ppm/%
V
IN
= 200mV
P-P
, 65Hz,
V
CC
= 3.0V, 3.6V
-10
+10
mV
Input Offset
Note 1:
Guaranteed by design, not subject to test.
www.maximintegrated.com
Maxim Integrated │
2
MAX78700
Multichannel, Isolated, Precision ADC
Pin Configuration
TOP VIEW
INBN
INBP
TESTENB
ISON
ISOP
1
2
3
4
5
+
MAX78700
10
9
8
7
6
INAN
INAP
GND
V
CC
TMUX
µMAX
Pin Description
PIN
1
2
3
4
5
6
7
8
9
10
NAME
INBN
INBP
TESTENB
ISON
ISOP
TMUX
V
CC
GND
INAP
INAN
Channel B ADC Negative Input
Channel B ADC Positive Input
Enables the Test Modes. Must be grounded in normal operation.
Transformer Negative
Transformer Positive
Host-Controlled DIO
Output of the Rectifier Block
Ground. The 0.5µF capacitor from V
CC
to GND must be connected to this pin.
Channel A ADC Positive Input
Channel A ADC Negative Input
FUNCTION
www.maximintegrated.com
Maxim Integrated │ 3
MAX78700
Multichannel, Isolated, Precision ADC
Detailed Description
ISO_INT
The MAX78700 is an isolated current and voltage ana-
log-to-digital converter (ADC) that is compatible with
MAX78xxx hosts. The device digitizes low-level signals
from shunt resistor type current sensors and resistive
divider voltage measurements.
The device continuously sends ADC data to the host. The
host can request the device to return certain ancillary data
such as trim information and die temperature data. The
MAX78700 communicates with the host through a pulse
transformer to provide isolation from the high-voltage
power domain.
Figure 1 shows a block diagram of the device with a brief
description of various functional blocks.
The isolated interface block receives the incoming data
from the host and transmits data back to the host through
the isolation transformer.
PLL
The PLL locks to the incoming power pulses to create ref-
erence clocks for the ADC and communications interface
to the host.
ADC
Maxim Integrated’s proven delta-sigma ADC digitizes the
voltage and current-sense voltages.
Bandgap
Rectifier
The active rectifier in the device rectifies the power pulses
received from the host through the isolation transformer to
create the V
CC
voltage. A 2.5V regulator block powers all
the digital blocks of the chip except the PLL and ISO_INT,
which are powered by V
CC
.
INBN
The device includes an on-chip precision bandgap volt-
age reference that incorporates auto-zero techniques as
well as production trims to minimize errors caused by
component mismatch and drift. The result is a voltage
output with a predictable temperature coefficient that is
compensated in firmware by the host.
INAN
INBP
INAP
PLL
TEMP
SENSE
MAX78700
MUX
CLOCK
GEN
IBIAS
GEN
2.5V
REG
V
CC
RECTIFIER
ADC
VREF
VBIAS
GEN
2.5V
FIR
MUX
CONTROL
TMUX
ISO_INT
GND
INTERFACE +
MODE CONTROL
TRIM
OTP
TESTENB
ISOP
Figure 1. Functional Diagram
ISON
www.maximintegrated.com
Maxim Integrated │ 4
MAX78700
Multichannel, Isolated, Precision ADC
Temperature and Power-Supply
Voltage Measurement
Ordering Information
PART
MAX78700+A00
MAX78700+A00T
T = Tape and reel.
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
10 µMAX
10 µMAX
The device includes an on-chip temperature sensor. The
voltage from this sensor is measured by the ADC and
sent to the host. During manufacturing test, the circuit is
calibrated by measuring the voltage at room temperature
and storing the value in the OTP memory.
A resistor-divider scales the rectified power-supply voltage,
V
CC
, to match the input range of the ADC. The ADC mea-
sures the scaled voltage and the value is sent to the host.
+Denotes a lead(Pb)-free/RoHS-compliant package.
Package Information
For the latest package outline information and land patterns
(footprints), go to
www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
Our company makes testing machines, and I am the only one doing RD.
Now we are faced with another problem.
A pressure maintenance problem
The testing machine presses a material through a cylinder
Keep...
Testing a battery-powered product, there is a 26K resistor between the two ends of the battery pad (no battery is soldered at this time!), what is the internal resistance of the board power supply cir...
Dear experts:
When I was debugging the CLA program of 28377D, I encountered a problem that I have not been able to solve. I hope the experts can give me some advice. Thank you very much!
My CLA is tri...
Since the Hall effect was discovered more than 100 years ago, its application has gone through three stages:
The first stage is from the discovery of the Hall effect to the early 1940s. Initially, due...
Abstract: Remember before 2010, there were still big differences in the models of USB data cables of various mobile phone brands, so the data cables of different mobile phone manufacturers were not un...
The Battleship STM32 development board and four multimeters of the Atom on Time This content is originally created by firstain, a netizen of EEWORLD forum . If you need to reprint or use it for commer...
In 2020, my country proposed for the first time: "China will increase its national independent contribution and adopt more powerful policies and measures to strive to peak carbon dioxide emissions be...[Details]
The proportion of renewable energy in Japan's power generation exceeded 20% in 2021. The Japanese government has proposed to increase the proportion of renewable energy power generation to 36-38% b...[Details]
For many people, smartphones have become a part of daily life. As WeChat founder Zhang Xiaolong said: mobile phones have become an extension of human limbs. It is no exaggeration to say that except f...[Details]
Service robots are designed to provide services, so people need a more convenient, natural and humane way to interact with robots, rather than being satisfied with complex keyboard and button opera...[Details]
As we all know, computer monitors and televisions display colors through red, blue and green, which are what we usually call the three primary colors RGB; and data show that red and blue LEDs have ac...[Details]
With the continuous advancement of science and technology,
the medical industry
is also ushering in a revolutionary change. The development of surgical
robotics
technology has broug...[Details]
China Energy Storage Network:
In order to implement the spirit of the Central Economic Work Conference, actively fulfill the political, economic and social responsibilities of central enterpr...[Details]
At present, the design of module power supply is becoming more and more standardized, and the control circuit tends to adopt digital control. The growth rate of non-isolated DC-DC converters (includin...[Details]
120 TOPS AI computing power acceleration! The new generation of AI PC Core Ultra processors is unstoppable
Coherent computing spans Intel data centers, clouds, network edges, and P...[Details]
Jiwei.com reported that "Next year, Visionox's AMOLED production capacity will be further increased, and it will take the lead in domestic LTPO OLED production capacity." On December 23, Visionox hel...[Details]
Introduction to ARM GNU Common Assembly Language
ARM assembly language source program statements are generally composed of instructions, pseudo operations, macro instructions and pseudo instructions...[Details]
Dolby Atmos is a new immersive cinema sound format that transforms sound from flat surround to all-round three-dimensional space, which is equivalent to the advancement of stereo to 5.1 era. The m...[Details]
Foreign media appleinsider today exposed a patent submitted by Apple in 2018 (U.S. Patent No. 10698489), which describes a "compact rotary input device" that will significantly reduce the internal sp...[Details]
Grenoble, France, November 5, 2024 -
Jolt Capital, a European growth-focused deep tech company, announced today that it has acquired the power management and signal processing IP business (the ...[Details]
stm32/stm8
京公网安备 11010802033920号
EEWORLD
