ADM1025ARQ ,Low-Cost PC Hardware Monitor ASICSPECIFICATIONSA MIN MAX CC MIN MAXParameter Min Typ Max Unit Test Conditions/CommentsPOWER SUPPLYSu ..
ADM1025ARQ-REEL ,Remote Multichannel Temperature Sensor, Power Supply Voltage Monitor with Serial Interfaceapplications in personal computers,electronic test equipment, and office electronics.FUNCTIONAL BLOC ..
ADM1025ARQ-REEL ,Remote Multichannel Temperature Sensor, Power Supply Voltage Monitor with Serial InterfaceSPECIFICATIONSA MIN MAX CC MIN MAXParameter Min Typ Max Unit Test Conditions/CommentsPOWER SUPPLYSu ..
ADM1025ARQ-REEL7 ,Remote Multichannel Temperature Sensor, Power Supply Voltage Monitor with Serial InterfaceFEATURES PRODUCT DESCRIPTIONUp to 8 Measurement Channels The ADM1025/ADM1025A is a complete system ..
ADM1025ARQZ ,Remote Multichannel Temperature Sensor, Power Supply Voltage Monitor with Serial InterfaceAPPLICATIONSvoltage, overvoltage, and overtemperature conditions.Network Servers and Personal Compu ..
ADM1026 ,Highly Integrated Thermal and System Monitor for Servers/High Reliability SystemsSPECIFICATIONSA MIN MAX CC MIN MAXParameter Min Typ Max Test Conditions/Comments UnitPOWER SUPPLYSu ..
AH103A-G , High Gain, High Linearity ½-Watt Amplifier
AH103A-G , High Gain, High Linearity ½-Watt Amplifier
AH104F245001-T , CHIP ANTENNA
AH104F245001-T , CHIP ANTENNA
AH104F2450S1-T , CHIP ANTENNA
AH104F2450S1-T , CHIP ANTENNA
ADM1025ARQ
Low-Cost PC Hardware Monitor ASIC
Low-Cost PC
Hardware Monitor ASIC
FUNCTIONAL BLOCK DIAGRAM
VCCPIN
2.5VIN
3.3VIN
5VIN
D–/NTI
VID0
VID1
VID2
VID3
12VIN/VID4
ADD/RST/INT/NTO
SDA
SCL
VCC
GND
FEATURES
Up to Eight Measurement Channels
Five Inputs to Measure Supply Voltages
VCC Monitored Internally
External Temperature Measurement with Remote Diode
On-Chip Temperature Sensor
Five Digital Inputs for VID Bits
Integrated 100 k� Pull-Ups on VID Pins (ADM1025 Only)
LDCM Support2C®-Compatible System Management Bus (SMBus)
Programmable RESET Output Pin
Programmable INT Output Pin
Configurable Offset for Internal/External Channel
Shutdown Mode to Minimize Power Consumption
Limit Comparison of all Monitored Values
APPLICATIONS
Network Servers and Personal Computers
Microprocessor-Based Office Equipment
Test Equipment and Measuring Instruments
*Patent Pending.2C is a registered trademark of Philips Corporation.
PRODUCT DESCRIPTIONThe ADM1025/ADM1025A is a complete system hardware
monitor for microprocessor-based systems, providing measure-
ment and limit comparison of various system parameters. Five
voltage measurement inputs are provided, for monitoring 2.5 V,
3.3 V, 5 V and 12 V power supplies and the processor core
voltage. The ADM1025/ADM1025A can monitor a sixth power
supply voltage by measuring its own VCC. One input (two pins) is
dedicated to a remote temperature-sensing diode, and an on-chip
temperature sensor allows ambient temperature to be moni-
tored. The ADM1025A has open-drain VID inputs while the
ADM1025 has on-chip 100 kΩ pull-ups on the VID inputs.
Measured values and in/out of limit status can be read out via
an I2C-compatible serial System Management Bus. The device
can be controlled and configured over the same serial bus. The
device also has a programmable INT output to indicate under-
voltage, overvoltage and over-temperature conditions.
The ADM1025/ADM1025A’s 3.0 V to 5.5 V supply voltage
range, low supply current, and I2C-compatible interface make
it ideal for a wide range of applications. These include hardware
monitoring and protection applications in personal computers,
electronic test equipment, and office electronics.
ADM1025/ADM1025A–SPECIFICATIONS(TA = TMIN to TMAX, VCC = VMIN to VMAX, unless otherwise noted.)NOTESAll voltages are measured with respect to GND, unless otherwise specified.2Typicals are at TA = 25°C and represent most likely parametric norm. Shutdown current typ is measured with VCC = 3.3 V.
ABSOLUTE MAXIMUM RATINGS*Positive Supply Voltage (VCC) . . . . . . . . . . . . . . . . . . . . .6.5 V
Voltage on 12 V VIN Pin . . . . . . . . . . . . . . . . . . . . . . . . .20 V
Voltage on Any Input or Output Pin . . . . . . . . .–0.3 V to +6.5 V
Input Current at Any Pin . . . . . . . . . . . . . . . . . . . . . . .±5 mA
Package Input Current . . . . . . . . . . . . . . . . . . . . . . .±20 mA
Maximum Junction Temperature (TJ max) . . . . . . . . . .150°C
Storage Temperature Range . . . . . . . . . . . .–65°C to +150°C
Lead Temperature, Soldering
Vapor Phase 60 sec . . . . . . . . . . . . . . . . . . . . . . . . . . .215°C
Infrared 15 sec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200°C
ESD Rating All Pins . . . . . . . . . . . . . . . . . . . . . . . . . .2000 V
Figure 1.Diagram for Serial Bus Timing
*Stresses above those listed under Absolute Maximum Ratings may cause perma-nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
THERMAL CHARACTERISTICS16-Lead QSOP Package:
θJA = 105°C/W
θJC = 39°C/W
ORDERING GUIDE
ADM1025/ADM1025A
PIN FUNCTION DESCRIPTIONS
PIN CONFIGURATION
LEAKAGE RESISTANCE – M�
TEMPERATURE ERROR
�C30
–20Figure 2.Temperature Error vs. PC Board Track Resistance
Figure 3.Temperature Error vs. Power Supply Noise
Frequency
Figure 4.Temperature Error vs. Common-Mode Noise
Frequency
Figure 5.Pentium II® Temperature Measurement vs.
ADM1025/ADM1025A Reading
Figure 6.Temperature Error vs. Capacitance Between D+
and D–
FREQUENCY – Hz5050M500
TEMPERATURE ERROR
�C50k500k5M
100k25MFigure 7.Temperature Error vs. Differential-Mode Noise
Frequency
ADM1025/ADM1025AFigure 8.Standby Current vs. Temperature
GENERAL DESCRIPTIONThe ADM1025/ADM1025A is a complete system hardware
monitor for microprocessor-based systems. The device commu-
nicates with the system via a serial System Management Bus.
The serial bus controller has a hardwired address line for device
selection (Pin 16), a serial data line for reading and writing
addresses and data (Pin 1), and an input line for the serial clock
(Pin 2). All control and programming functions of the ADM1025/
ADM1025A are performed over the serial bus.
MEASUREMENT INPUTSThe device has six measurement inputs, five for voltage and one
for temperature. It can also measure its own supply voltage and
can measure ambient temperature with its on-chip temperature
sensor.
Pins 11 through 15 are analog inputs with on-chip attenuators,
configured to monitor 12 V, 5 V, 3.3 V, 2.5 V and the processor
core voltage, respectively. Pin 11 may alternatively be programmed
as a digital input for Bit 4 of the processor voltage ID code.
Power is supplied to the chip via Pin 4 and the system also
monitors the voltage on this pin.
Remote temperature sensing is provided by the D+ and D–
inputs, to which a diode-connected, external temperature-
sensing transistor may be connected.
An on-chip bandgap temperature sensor monitors system ambi-
ent temperature.
SEQUENTIAL MEASUREMENTWhen the ADM1025/ADM1025A monitoring sequence is started,
it cycles sequentially through the measurement of analog inputs
and the temperature sensors. Measured values from these inputs
are stored in Value Registers. These can be read out over the
serial bus, or can be compared with programmed limits stored
in the Limit Registers. The results of out-of-limit comparisons
are stored in the Status Registers, which can be read over the
serial bus to flag out of limit conditions.
PROCESSOR VOLTAGE IDFive digital inputs (VID4 to VID0—Pins 5 to 8 and 11) read the
processor voltage ID code and store it in the VID registers, from
which it can be read out by the management system over the
serial bus. If Pin 11 is configured as a 12 V analog input (power-
up default), the VID4 bit in the VID4 register will default to 0.
The VID pins have internal 100 kΩ pull-up resistors (ADM1025
only).
ADD/RST/INT/NTOPin 16 is a programmable digital I/O pin. After power-up, at the
first sign of SMBus activity, it is sampled to set the lowest two
bits of the serial bus address. During board-level, NAND tree
connectivity testing, this pin functions as the output of the NAND
tree. During normal operation Pin 16 may be programmed as a
reset output to provide a low going 20 ms reset pulse when
enabled, or it may be programmed as an interrupt output for
out-of-limit temperature and/or voltage events. These functions
are described in more detail later.
INTERNAL REGISTERS OF THE ADM1025/ADM1025AA brief description of the ADM1025/ADM1025A’s principal
internal registers is given below. More detailed information on
the function of each register is given in Tables V to XV.
Configuration Register:Provides control and configuration.
Address Pointer Register:This register contains the address that
selects one of the other internal registers. When writing to the
ADM1025/ADM1025A, the first byte of data is always a register
address, which is written to the Address Pointer Register.
Status Registers:Two registers to provide status of each limit
comparison.
VID Registers:The status of the VID0 to VID4 pins of the
processor can read from these registers.
Value and Limit Registers:The results of analog voltage
inputs and temperature measurements are stored in these regis-
ters, along with their limit values.
Offset Register:Allows either an internal or external tempera-
ture channel reading to be offset by a two’s complement value
written to this register.
SERIAL BUS INTERFACEControl of the ADM1025/ADM1025A is carried out via the
serial bus. The ADM1025/ADM1025A is connected to this
bus as a slave device, under the control of a master device or
master controller.
The ADM1025/ADM1025A has a 7-bit serial bus address. When
the device is powered up, it will do so with a default serial bus
address. The five MSBs of the address are set to 01011, the two
LSBs are determined by the logical states of Pin 16 at power-up.
This is a three-state input that can be grounded, connected to
VCC or left open-circuit to give three different addresses:
Table I.Address Selection
If ADD is left open-circuit the default address will be 0101110.
ADD is sampled only after power-up, so any changes made will
have no effect, unless power is cycled.
The facility to make hardwired changes to A1 and A0 allows the
user to avoid conflicts with other devices sharing the same serial
bus if, for example, more than one ADM1025/ADM1025A is
used in a system. However, as previously mentioned, the ADD
pin may also function as a reset output or interrupt output. Use
of these functions may restrict the addresses that can be set. See
the sections on RST and INT for further information.
The serial bus protocol operates as follows:The master initiates data transfer by establishing a START
condition, defined as a high-to-low transition on the serial
data line SDA while the serial clock line SCL remains high.
This indicates that an address/data stream will follow. All
slave peripherals connected to the serial bus respond to the
START condition, and shift in the next eight bits, consisting
of a 7-bit address (MSB first) plus an R/W bit, which deter-
mines the direction of the data transfer, i.e., whether data
will be written to or read from the slave device.
The peripheral whose address corresponds to the transmitted
address responds by pulling the data line low during the low
period before the ninth clock pulse, known as the Acknowl-
edge Bit. All other devices on the bus now remain idle while
the selected device waits for data to be read from or written
to it. If the R/W bit is a 0, the master will write to the slave
device. If the R/W bit is a 1, the master will read from the
slave device.Data is sent over the serial bus in sequences of nine clock
pulses, eight bits of data followed by an Acknowledge Bit
from the slave device. Transitions on the data line must
occur during the low period of the clock signal and remain
stable during the high period, as a low-to-high transition
when the clock is high may be interpreted as a STOP signal.
The number of data bytes that can be transmitted over the
serial bus in a single READ or WRITE operation is limited
only by what the master and slave devices can handle.When all data bytes have been read or written, stop condi-
tions are established. In WRITE mode, the master will pull
the data line high during the 10th clock pulse to assert a
STOP condition. In READ mode, the master device will
override the acknowledge bit by pulling the data line high
during the low period before the 9th clock pulse. This is
known as No Acknowledge. The master will then take the
data line low during the low period before the 10th clock
pulse, then high during the 10th clock pulse to assert a
STOP condition.
Any number of bytes of data may be transferred over the serial
bus in one operation, but it is not possible to mix read and write
in one operation, because the type of operation is determined at
the beginning and cannot subsequently be changed without
starting a new operation.
In the case of the ADM1025/ADM1025A, write operations
contain either one or two bytes, and read operations contain one
byte, and perform the following functions:
To write data to one of the device data registers or read data
from it, the Address Pointer Register must be set so that the
correct data register is addressed, data can then be written into
that register or read from it. The first byte of a write operation
always contains an address that is stored in the Address Pointer
Register. If data is to be written to the device, the write opera-
tion contains a second data byte that is written to the register
selected by the address pointer register.
This is illustrated in Figure 9a. The device address is sent over
the bus followed by R/W set to 0. This is followed by two data
bytes. The first data byte is the address of the internal data
register to be written to, which is stored in the Address Pointer
Register. The second data byte is the data to be written to the
internal data register.
Figure 9a.Writing a Register Address to the Address Pointer Register, then Writing Data to the Selected Register
ADM1025/ADM1025AWhen reading data from a register there are two possibilities:If the ADM1025/ADM1025A’s Address Pointer Register
value is unknown or not the desired value, it is first necessary
to set it to the correct value before data can be read from the
desired data register. This is done by performing a write to
the ADM1025/ADM1025A as before, but only the data byte
containing the register address is sent, as data is not to be
written to the register. This is shown in Figure 9b.
A read operation is then performed consisting of the serial bus
address, R/W bit set to 1, followed by the data byte read from
the data register. This is shown in Figure 9c.If the Address Pointer Register is known to be already at the
desired address, data can be read from the corresponding
data register without first writing to the Address Pointer
Register, so Figure 9b can be omitted.
NOTESAlthough it is possible to read a data byte from a data register
without first writing to the Address Pointer Register, if the
Address Pointer Register is already at the correct value, it is
not possible to write data to a register without writing to the
Address Pointer Register, because the first data byte of a
write is always written to the Address Pointer Register.In Figures 9a to 9c, the serial bus address is shown as the
default value 01011(A1)(A0), where A1 and A0 are set by
the three-state ADD pin.
3. In addition to supporting the Send Byte and Receive Byte
protocols, the ADM1025/ADM1025A also supports the
Read Byte protocol (see System Management Bus specifica-
tions Rev. 1.1 for more information).
4. If Reset or Interrupt functionality is required, address pin
cannot be strapped to GND, as this would keep the ADD/
RST/INT/NTO pin permanently low.
MEASUREMENT INPUTSThe ADM1025/ADM1025A has six external measurement
A-TO-D CONVERTERThese inputs are multiplexed into the on-chip, successive ap-
proximation, analog-to-digital converter. This has a resolution
of eight bits. The basic input range is zero to 2.5 V, but the
inputs have built-in attenuators to allow measurement of 2.5 V,
3.3 V, 5 V, 12 V and the processor core voltage VCCP, without
any external components. To allow for the tolerance of these
supply voltages, the A-to-D converter produces an output of
3/4 full scale (decimal 192) for the nominal input voltage, and
so has adequate headroom to cope with overvoltages. Table II
shows the input ranges of the analog inputs and output codes of
the A-to-D converter.
When the ADC is running, it samples and converts an input
every 11.6 ms, except for the external temperature (D+ and D–)
input. This has special input signal conditioning and is averaged
over 16 conversions to reduce noise; a measurement on this
input takes nominally 34.8 ms.
INPUT CIRCUITSThe internal structure for the analog inputs are shown in Figure
10. Each input circuit consists of an input protection diode, an
attenuator, plus a capacitor to form a first-order low-pass filter
which gives the input immunity to high frequency noise.
Figure 9b.Writing to the Address Pointer Register Only
Figure 9c.Reading Data from a Previously Selected Register
