ADM1024ARU-REEL View Datasheet(PDF) - Analog Devices
Part Name
Description
View to exact match
ADM1024ARU-REEL Datasheet PDF : 32 Pages
| |||
ADM1024
26.5
26.0
25.5
VDD = 3.3V
25.0
24.5
24.0
23.5
23.0
22.5
–40 –20 0
20 40 60 80 100 120
TEMPERATURE – C
TPC 7. Standby Current vs. Temperature
(continued from page 1)
configured as inputs to monitor a 2.5 V supply and a second
processor core voltage, or as a second temperature-sensing input.
The remaining two inputs can be programmed as general-pur-
pose analog inputs or as digital fan-speed measuring inputs.
Measured values can be read out via an SMBus serial System
Management Bus, and values for limit comparisons can be
programmed in over the same serial bus. The high speed succes-
sive-approximation ADC allows frequent sampling of all analog
channels to ensure a fast interrupt response to any out-of-limit
measurement.
The ADM1024’s 2.8 V to 5.5 V supply voltage range, low sup-
ply current, and SMBus 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.
MEASUREMENT INPUTS
Programmability of the measurement inputs makes the ADM1024
extremely flexible and versatile. The device has a 10-bit ADC
and nine measurement input pins that can be configured in differ-
ent ways.
Pins 5 and 6 can be programmed as general-purpose analog
inputs with a range of 0 V to 2.5 V, or as digital inputs to moni-
tor the speed of fans with digital tachometer outputs. The fan
inputs can be programmed to accommodate fans with different
speeds and different numbers of pulses per revolution from their
tachometer outputs.
Pins 13 and 14 are dedicated temperature inputs and may be
connected to the cathode and anode of an external temperature-
sensing diode.
Pins 15, 16, and 19 are dedicated analog inputs with on-chip
attenuators, configured to monitor 12 V, 5 V, and the processor
core voltage, respectively.
Pins 17 and 18 may be configured as analog inputs with on-chip
attenuators to monitor a second processor core voltage and a
2.5 V supply, or they may be configured as a temperature input
and connected to a second temperature-sensing diode.
The ADC also accepts input from an on-chip band gap tempera-
ture sensor that monitors system-ambient temperature.
Finally, the ADM1024 monitors the supply from which it is
powered, so there is no need for a separate 3.3 V analog input if
the chip VCC is 3.3 V. The range of this VCC measurement
can be configured for either a 3.3 V or 5 V VCC by Bit 3 of the
Channel Mode Register.
SEQUENTIAL MEASUREMENT
When the ADM1024 monitoring sequence is started, it cycles
sequentially through the measurement of analog inputs and the
temperature sensor, while at the same time the fan speed inputs
are independently monitored. 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 Interrupt Status Registers, and will generate an
interrupt on the INT line (Pin 10).
Any or all of the Interrupt Status Bits can be masked by appro-
priate programming of the Interrupt Mask Register.
PROCESSOR VOLTAGE ID
Five digital inputs (VID4 to VID0—Pins 20 to 24) read the
processor voltage ID code. These inputs can also be reconfigured
as interrupt inputs.
The VID pins have internal 100 kΩ pull-up resistors.
CHASSIS INTRUSION
A chassis intrusion input (Pin 7) is provided to detect unautho-
rized tampering with the equipment.
RESET
A RESET input/output (Pin 12) is provided. Pulling this pin low
will reset all ADM1024 internal registers to default values. The
ADM1024 can also be programmed to give a low going 45 ms
reset pulse at this pin.
The RESET pin has an internal, 100 kΩ pull-up resistor.
ANALOG OUTPUT
The ADM1024 contains an on-chip, 8-bit DAC with an out-
put range of 0 V to 2.5 V (Pin 11). This is typically used to
implement a temperature controlled fan by controlling the
speed of a fan dependent upon the temperature measured by the
on-chip temperature sensor.
Testing of board level connectivity is simplified by providing a
NAND tree test function. The AOUT (Pin 11) also doubles as
a NAND test input, while Pin 1 doubles as a NAND tree output.
INTERNAL REGISTERS OF THE ADM1024
A brief description of the ADM1024’s principal internal regis-
ters follows. More detailed information on the function of each
register is given in Tables VI to XIX.
Configuration Registers: Provide control and configuration.
Channel Mode Register: Stores the data for the operating
modes of the input channels.
Address Pointer Register: This register contains the address
that selects one of the other internal registers. When writing to
the ADM1024, the first byte of data is always a register address,
which is written to the Address Pointer Register.
REV. B
–7–
|
|
Share Link: 