Data Sheet

NE1617A
Temperature monitor for microprocessor systems
Rev. 5 — 20 March 2012
Product data sheet
1. General description
The NE1617A is an accurate two-channel temperature monitor. It measures the
temperature of itself and the temperature of a remote sensor. The remote sensor is a
diode connected transistor. This can be in the form of either a discrete NPN/PNP, such as
the 2N3904/2N3906, or a diode connected PNP built into another die, such as is done on
some Intel microprocessors.
The temperature of both the remote and local sensors is stored in a register that can be
read via a 2-wire SMBus. The temperatures are updated at a rate that is programmable
via the SMBus (the average supply current is dependent upon the update rate — the
faster the rate, the higher the current).
In addition to the normal operation, which is to update the temperature at the programmed
rate, there is a one-shot mode that will force a temperature update.
There is also an alarm that senses either an overtemperature or undertemperature
condition. The trip points for this alarm are also programmable.
The device can have one of nine addresses (determined by two address pins), so there
can be up to nine of the NE1617A on the SMBus.
It can also be put in standby mode (in order to save power). This can be done either with
software (over the SMBus) or with hardware (using the STBY pin).
2. Features and benefits
 Replacement for Maxim MAX1617 and Analog Devices ADM1021
 Monitors local and remote temperature
 Local (on-chip) sensor accuracy:
 2 C at 60 C to 100 C
 3 C at 40 C to 125 C
 Remote sensor accuracy:
 3 C at 60 C to 100 C
 5 C at 40 C to 125 C
 No calibration required
 Programmable overtemperature/undertemperature alarm
 SMBus 2-wire serial interface up to 100 kHz
 3 V to 5.5 V supply range; 5.5 V tolerant
 70 A supply current in operating mode
 3 A (typical) supply current in standby mode
NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
 ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM per
JESD22-C101
 Latch-up testing is done to JEDEC standard JESD78, which exceeds 100 mA
 Small 16-lead SSOP (QSOP) package
3. Applications





Desktop computers
Notebook computers
Smart battery packs
Industrial controllers
Telecommunications equipment
4. Ordering information
Table 1.
Ordering information
Tamb = 40 C to +125 C.
Type number
NE1617ADS
[1]
Topside
mark
Package
Name
Description
Version
NE1617A
SSOP16[1]
plastic shrink small outline package; 16 leads; body width 3.9 mm;
lead pitch 0.635 mm
SOT519-1
Also known as QSOP16.
NE1617A
Product data sheet
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NE1617A
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Temperature monitor for microprocessor systems
5. Block diagram
STBY
NE1617A
D+
D−
LOCAL
TEMP
SENSOR
CONTROL
LOGIC
ANALOG
MUX
A-to-D
CONVERTER
ADD1
ADD0
ALERT
ONE-SHOT
REGISTER
CONFIGURATION
REGISTER
COMMAND POINTER
REGISTER
CONVERSION RATE
REGISTER
LOCAL HIGH TEMP
THRESHOLD
LOCAL TEMP HIGH
LIMIT REGISTER
LOCAL TEMP
DATA REGISTER
LOCAL LOW TEMP
THRESHOLD
LOCAL TEMP LOW
LIMIT REGISTER
REMOTE TEMP
DATA REGISTER
REMOTE HIGH TEMP
THRESHOLD
REMOTE TEMP HIGH
LIMIT REGISTER
ADDRESS
DECODER
REMOTE LOW TEMP
THRESHOLD
REMOTE TEMP LOW
LIMIT REGISTER
INTERRUPT
MASKING
STATUS REGISTER
SMBus INTERFACE
VDD
Fig 1.
GND
GND
TEST1
TEST5
TEST9
TEST13 TEST16
SCLK
SDATA
002aad510
Block diagram of NE1617A
NE1617A
Product data sheet
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NE1617A
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Temperature monitor for microprocessor systems
6. Pinning information
6.1 Pinning
TEST1
1
16 TEST16
VDD
2
15 STBY
D+
3
14 SCLK
D−
4
TEST5
5
ADD1
6
11 ALERT
GND
7
10 ADD0
GND
8
NE1617ADS
13 TEST13
12 SDATA
9
TEST9
002aad509
Fig 2.
Pin configuration for SSOP16 (QSOP16)
6.2 Pin description
Table 2.
Pin description
Symbol
Pin
Description
TEST1
1
test pin; factory use only[1]
VDD
2
positive supply[2]
D+
3
positive side of remote sensor
D
4
negative side of remote sensor
TEST5
5
test pin; factory use only[1]
ADD1
6
device address 1 (3-state)
GND
7, 8
ground
TEST9
9
test pin; factory use only[1]
ADD0
10
device address 0 (3-state)
ALERT
11
open-drain output used as interrupt or SMBus alert
SDATA
12
SMBus serial data input/output; open-drain
TEST13
13
test pin; factory use only[1]
SCLK
14
SMBus clock input
STBY
15
hardware standby input
HIGH = normal operating mode
LOW = standby mode
TEST16
NE1617A
Product data sheet
16
test pin; factory use only[1]
[1]
These pins should either float or be tied to ground.
[2]
VDD pin should be decoupled by a 0.1 F capacitor.
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NE1617A
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Temperature monitor for microprocessor systems
7. Functional description
The NE1617A contains an integrating A-to-D converter, an analog multiplexer, a status
register, digital data registers, SMBus interface, associated control logic and a local
temperature sensor or channel (refer to Figure 1 “Block diagram of NE1617A”). The
remote diode-type sensor or channel should be connected to the D+ and D pins properly.
Temperature measurements or conversions are either automatically and periodically
activated when the device is in free-running mode (both STBY pin = HIGH, and the
configuration register bit 6 = LOW) or generated by one-shot command. The free-running
period is selected by changing the programmable data of the conversion rate register, as
described in Section 8.3.4. For each conversion, the multiplexer switches current sources
through the remote and local temperature sensors over a period of time, about 60 ms, and
the voltages across the diode-type sensors are sensed and converted into the
temperature data by the A-to-D converter. The resulting temperature data is then stored in
the temperature registers, in 8-bit two's complement word format and automatically
compared with the limits which have been programmed in the temperature limit registers.
Results of the comparison are reflected accordingly by the flags stored in the status
register, an out-of-limit condition will set the ALERT output pin to its LOW state. Because
both channels are automatically measured for each conversion, the results are updated
for both channels at the end of every successful conversion.
7.1 Temperature measurement
The method of the temperature measurement is based on the change of the diode VBE at
two different operating current levels given by:
KT
V BE =  n  -------  LN  N 

q
(1)
where:
VBE = change in base emitter voltage drop at two current levels
n = non-ideality
K = Boltzman’s constant
T = absolute temperature in  Kelvin
q = charge on the electron
LN = natural logarithm
N = ratio of the two currents
The NE1617A forces two well-controlled current sources of about 10 A and 100 A and
measures the remote diode VBE. The sensed voltage between two pins D+ and D is
limited between 0.25 V and 0.95 V. The external diode must be selected to meet this
voltage range at these two current levels and also the non-ideality factor ‘n’ must be close
to the value of 1.008 to be compatible with the Intel Pentium III internal thermal diode that
the NE1617A was designed to work with. The diode-connected PNP transistor provided
on the microprocessor is typically used, or the discrete diode-connected transistor
2N3904 or 2N3906 is recommended as an alternative.
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
Even though the NE1617A integrating A-to-D converter has a good noise performance,
using the average of 10 measurement cycles, high frequency noise filtering between D+
and D should be considered. An external capacitor of 2200 pF typical (but not higher
than 3300 pF) connected between D+ and D is recommended. Capacitance higher than
3300 pF will introduce measurement error due to the rise time of the switched current
source.
7.2 No calibration is required
As mentioned in Section 7.1, the NE1617A uses two well-controlled current sources of
10 : 1 ratio to measure the forward voltage of the diode (VBE). This technique eliminates
the diode saturation current (a heavily process and temperature dependent variable), and
results in the forward voltage being proportional to absolute temperature.
7.3 Address logic
The address pins of the NE1617A can be forced into one of three levels: LOW (GND),
HIGH (VDD), or ‘not connected’ (n.c.). Because the NE1617A samples and latches the
address pins at the starting of every conversion, it is suggested that those address pins
should be hard-wired to the logic applied, so that the logic is consistently existed at the
address pins. During the address sensing period, the device forces a current at each
address pin and compares the voltage developed across the external connection with the
predefined threshold voltage in order to define the logic level. If an external resistor is
used for the connection of the address, then its value should be less than 2 k to prevent
the error in logic detection from happening. Resistors of 1 k are recommended.
8. Temperature monitor with SMBus serial interface
8.1 Serial bus interface
The device can be connected to a standard 2-wire serial interface System Management
Bus (SMBus) as a slave device under the control of a master device, using two device
terminals SCLK and SDATA. The operation of the device to the bus is described with
details in the following sections.
8.2 Slave address
The device address is defined by the logical connections applied to the device pins ADD0
and ADD1. A list of selectable addresses are shown in Table 3. The device address can
be set to any one of those nine combinations and more than one device can reside on the
same bus without address conflict. Note that the state of the device address pins is
sampled and latched not only at power-up step, but also at starting point of every
conversion.
Table 3.
Device slave address
n.c. = not connected
NE1617A
Product data sheet
ADD0[1]
ADD1[1]
Address byte
GND
GND
0011 000
GND
n.c.
0011 001
GND
VDD
0011 010
n.c.
GND
0101 001
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NE1617A
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Temperature monitor for microprocessor systems
Table 3.
Device slave address …continued
n.c. = not connected
ADD0[1]
ADD1[1]
Address byte
n.c.
n.c.
0101 010
n.c.
VDD
0101 011
VDD
GND
1001 100
VDD
n.c.
1001 101
VDD
VDD
1001 110
[1]
Any pull-up/pull-down resistor used to connect to GND or VDD should be  2 k.
8.3 Registers
The device contains more than 9 registers. They are used to store the data of device
set-up and operation results. Depending on the bus communication (either read or write
operations), each register may be called by different names because each register may
have different sub-addresses or commands for read and write operations. For example,
the configuration register is called as WC for write mode and as RC for read mode.
Table 4 shows the names, commands and functions of all registers as well as the register
POR states.
Remark: Attempting to write to a read-command or read from a write-command will
produce an invalid result. The reserved registers are used for factory test purposes and
should not be written.
Table 4.
NE1617A
Product data sheet
Register assignments
Register name
Command byte
POR state
Function
RIT
00h
0000 0000
read internal or local temp byte
RET
01h
0000 0000
read external or remote temp byte
RS
02h
n/a
read status byte
RC
03h
0000 0000
read configuration byte
RCR
04h
0000 0010
read conversion rate byte
RIHL
05h
0111 1111
read internal temp high limit byte
RILL
06h
1100 1001
read internal temp low limit byte
REHL
07h
0111 1111
read external temp high limit byte
RELL
08h
1100 1001
read external temp low limit byte
WC
09h
n/a
write configuration byte
WCR
0Ah
n/a
write conversion rate byte
WIHL
0Bh
n/a
write internal temp high limit byte
WILL
0Ch
n/a
write internal temp low limit byte
WEHL
0Dh
n/a
write external temp high limit byte
WELL
0Eh
n/a
write external temp low limit byte
OSHT
0Fh
n/a
one-shot command
-
10h
n/a
reserved
-
11h
n/a
reserved
-
12h
n/a
reserved
-
13h
n/a
reserved
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Temperature monitor for microprocessor systems
8.3.1 Low power standby modes
Upon POR, the device is reset to its normal free-running auto-conversion operation mode.
The device can be put into standby mode by either using hardware control (connect the
STBY pin to LOW for hardware standby mode) or using software control (set bit 6 of the
configuration register to HIGH for software standby mode). When the device is put in
either one of the standby modes, the supply current is reduced to less than 10 A if there
is no SMBus activity, all data in the device registers are retained and the SMBus interface
is still alive to bus communication. However, there is a difference in the device ADC
conversion operation between hardware standby and software standby modes. In
hardware standby mode, the device conversion is inhibited and the one-shot command
does not initiate a conversion. In software standby mode, the one-shot command will
initiate a conversion for both internal and external channels.
If a hardware standby command is received when the device is in normal mode and a
conversion is in progress, the conversion cycle will stop and data in reading temperature
registers will not be updated.
8.3.2 Configuration register
The configuration register is used to mask the Alert interrupt and/or to put the device in
software standby mode. Only two bits of this register (bit 6 and bit 7) are used as listed in
Table 5. Bit 7 is used to mask the device ALERT output from Alert interruption when this
bit is set to logic 1, and bit 6 is used to activate the standby software mode when this bit is
set to logic 1.
This register can be written or read using the commands of registers named WC and RC
accordingly. Upon Power-On Reset (POR), both bits are reset to zero.
Table 5.
Configuration register bit assignments
Bit
Symbol
POR state
Function
7 (MSB)
MASK
0
Mask ALERT interrupt. Interrupt is enabled when this bit
is LOW, and disabled when this bit is HIGH.
6
RUN/STOP 0
Standby or run mode control. When LOW, running mode
is enabled; when HIGH, standby mode is initiated.
5 to 0
-
reserved
n/a
8.3.3 External and internal temperature registers
Results of temperature measurements after every ADC conversion are stored in two
registers: Internal Temp register (RIT) for internal or local diode temperature, and External
Temp register (RET) for external or remote diode temperature. These registers can be
only read over the SMBus. The reading temperature data is in 2's complement binary form
consisting of 7-bit data and 1-bit sign (MSB), with each data count represents 1 C, and
the MSB bit is transmitted first over the serial bus. The contents of those two registers are
updated upon completion of each ADC conversion. Table 6 shows some values of the
temperature and data.
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
Table 6.
Temperature data format (2’s complement)
Temperature (C)
Digital output (8 bits)
+127
0111 1111
+126
0111 1110
+100
0110 0100
+50
0011 0010
+25
0001 1001
+1
0000 0001
0
0000 0000
1
1111 1111
25
1110 0111
50
1100 1110
65
1011 1111
8.3.4 Conversion rate register
The conversion rate register is used to store programmable conversion data, which
defines the time interval between conversions in standard free-running auto-convert
mode. Table 7 shows all applicable data and rates for the device. Only three LSB bits of
the register are used and other bits are reserved for future use. This register can be
written to and read back over the SMBus using commands of the registers named WCR
and RCR, respectively. The POR default conversion data is 02h (0.25 Hz).
Notice that the average supply current, as well as the device power consumption, is
increased with the conversion rate.
Table 7.
Conversion rate control byte
Data
Conversion rate (Hz)
Average supply current (A typical at VDD = 3.3 V)
00h
0.0625
67
01h
0.125
68
02h
0.25
70
03h
0.5
75
04h
1
80
05h
2
95
06h
4
125
07h
8
180
08h to FFh
(reserved)
n/a
8.3.5 Temperature limit registers
The device has four registers to be used for storing programmable temperature limits,
including the high limit and the low limit for each channel of the external and internal
diodes. Data of the temperature register (RIT and RET) for each channel are compared
with the contents of the temperature limit registers of the same channel, resulting in alarm
conditions. If measured temperature either equals or exceeds the corresponding
temperature limits, an Alert interrupt is asserted and the corresponding flag bit in the
status register is set. The temperature limit registers can be written to and read back using
NE1617A
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Temperature monitor for microprocessor systems
commands of registers named WIHL, WILL, WEHL, WELL, RIHL, RILL, REHL, RELL,
accordingly. The POR default values are +127 C (0111 1111) for the HIGH limit and
55 C (1100 1001) for the LOW limit.
8.3.6 One-shot command
The one-shot command is not actually a data register as such and a write operation to it
will initiate an ADC conversion. The send byte format of the SMBus, as described later,
with the use of OSHT command (0Fh), is used for this writing operation. In normal
free-running-conversion operation mode of the device, a one-shot command immediately
forces a new conversion cycle to begin. However, if a conversion is in progress when a
one-shot command is received, the command is ignored. In software standby mode the
one-shot command generates a single conversion and comparison cycle and then puts
the device back in its standby mode after the conversion. In hardware standby mode, the
one shot is inhibited.
8.3.7 Status register
The content of the status register reflects condition status resulting from all of these
activities: comparisons between temperature measurements and temperature limits, the
status of ADC conversion, and the hardware condition of the connection of external diode
to the device. Bit assignments and bit functions of this register are listed in Table 8. This
register can only be read using the command of register named RS. Upon POR, the
status of all flag bits are reset to zero. The status byte is cleared by any successful read of
the status register unless the fault condition persists.
Notice that any one of the fault conditions, except the conversion busy, also introduces an
Alert interrupt to the SMBus that will be described in Section 8.3.8. Also, whenever a
one-shot command is executed, the status byte should be read after the conversion is
completed, which is about 170 ms after the one-shot command is sent.
Table 8.
Status register bit assignment
Bit
Symbol
POR state
Function
7 (MSB)
BUSY
n/a
HIGH when the ADC is busy converting
6
IHLF[1]
0
HIGH when the internal temperature high limit has tripped
5
ILLF[1]
0
HIGH when the internal temperature low limit has tripped
4
EHLF[1]
0
HIGH when the external temperature high limit has tripped
3
ELLF[1]
0
HIGH when the external temperature low limit has tripped
2
OPEN[2]
0
HIGH when the external diode is opened
1 to 0
-
0
reserved
[1]
These flags stay HIGH until the status register is read or POR is activated.
[2]
This flag stays HIGH until POR is activated.
8.3.8 Alert interrupt
The ALERT output is used to signal Alert interruption from the device to the SMBus and is
active LOW. Because this output is an open-drain output, a pull-up resistor (10 k typical)
to VDD is required, and slave devices can share a common interrupt line on the same
SMBus. An Alert interrupt is asserted by the device whenever any one of the fault
conditions, as described in Section 8.3.7 “Status register”, occurs: measured temperature
equals or exceeds corresponding temp limits, the remote diode is physically disconnected
from the device pins. Alert interrupt signal is latched and can only be cleared by reading
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
the Alert Response byte from the Alert Response Address, which is a special slave
address to the SMBus. The ALERT output cannot be reset by reading the device status
register.
The device was designed to accommodate the Alert interrupt detection capability of the
SMBus.1 Basically, the SMBus provides Alert response interrupt pointers in order to
identify the slave device which has caused the Alert interrupt. The 7-bit Alert response
slave address is 0001 100 and the Alert response byte reflects the slave address of the
device which has caused Alert interrupt. Bit assignments of the Alert response byte are
listed in Table 9. The ALERT output will be reset to HIGH state upon reading the Alert
response slave address unless the fault condition persists.
Table 9.
Alert response (Alert response address 0001 100) bit description
Bit
Symbol
Description
7 (MSB)
ADD7
indicate address B6 of alerted device
6
ADD6
indicate address B5 of alerted device
5
ADD5
indicate address B4 of alerted device
4
ADD4
indicate address B3 of alerted device
3
ADD3
indicate address B2 of alerted device
2
ADD2
indicate address B1 of alerted device
1
ADD1
indicate address B0 of alerted device
0 (LSB)
1
logic 1
8.4 Power-up default condition
Upon power-up reset (power is switched off-on), the NE1617A goes into this default
condition:
• Interrupt latch is cleared, the ALERT output is pulled HIGH by the external pull-up
resistor.
• The auto-conversion rate is at 0.25 Hz; conversion rate data is 02h.
• Temperature limits for both channels are +127 C for high limit, and 55 C for low
limit.
• Command pointer register is set to ‘00’ for quickly reading the RIT.
8.5 Fault detection
The NE1617A has a fault detector to the diode connection. The connection is checked
when a conversion is initiated and the proper flags are set if the fault condition has
occurred.
Table 10.
1.
Fault detection
D+ and D
ALERT output
RET data storage
Status set flag
opened
LOW
127 C
B2 and B4
shorted
LOW
127 C
B4
The NE1617A implements the collision arbitration function per System Management Bus Specification Revision 1.1, dated
December 11, 1998, which conforms to standard I2C-bus arbitration as described in NXP document UM10204, “I2C-bus
specification and user manual”.
NE1617A
Product data sheet
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NE1617A
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Temperature monitor for microprocessor systems
8.6 SMBus interface
The device can communicate over a standard 2-wire serial interface System Management
Bus (SMBus) using the device pins SCLK and SDATA. The device employs four standard
SMBus protocols: write byte, read byte, send byte and receive byte. Data formats of those
protocols are shown in Figure 3 with following notifications:
• The SMBus master initiates data transfer by establishing a START condition (S) and
terminates data transfer by generating a STOP condition (P).
• Data is sent over the serial bus in sequence of 9 clock pulses according to each 8-bit
data byte followed by 1-bit status of the device acknowledgement.
•
•
•
•
The 7-bit slave address is equivalent to the selected address of the device.
The command byte is equivalent to the selected command of the device register.
The ‘send byte’ format is often used for the one-shot conversion command.
The ‘receive byte’ format is used for quicker transfer data from a device reading
register that was previously selected by a read byte format.
address
S
ACK
7 bits device address
START condition
0
R/W
command
ACK
data
8 bits device register
ACK
8 bits to register
acknowledged
by device
acknowledged
by device
P
acknowledged
by device
STOP
condition
002aad523
a. Write byte format (for writing data byte to the device register)
address
S
7 bits device address
START condition
ACK
0
R/W
command
ACK
8 bits device register
acknowledged
by device
address
S
acknowledged
by device
7 bits device address
(re)START
condition
ACK
NACK
8 bits from register
1
R/W
data
acknowledged
by device
not
acknowledged
by controller
P
STOP
condition
002aad524
b. Read byte format (for reading data byte from the device register)
address
S
ACK
7 bits device address
START condition
0
R/W
command
ACK
8 bits device register
acknowledged
by device
P
STOP
condition
acknowledged
by device
002aad525
c. Send byte format (for sending command without data, such as one-shot command)
address
S
ACK
7 bits device address
START condition
1
R/W
data
NACK
8 bits from register
acknowledged
by device
P
not STOP
acknowledged condition
by controller 002aad526
d. Receive byte format (for continuously reading from device register)
Fig 3.
SMBus programming format
NE1617A
Product data sheet
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NE1617A
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Temperature monitor for microprocessor systems
9. Application design-in information
9.1 Factors affecting accuracy
9.1.1 Remote sensing diode
The NE1617A is designed to work with substrate transistors built into processors’ CPUs
or with discrete transistors. Substrate transistors are generally PNP types with the
collector connected to the substrate. Discrete types can be either a PNP or an NPN
transistor connected as a diode (base shorted to collector). If an NPN transistor is used,
the collector and base are connected to D+ and the emitter to D. If a PNP transistor is
used, the collector and base are connected to D and the emitter to D+. Substrate
transistors are found in a number of CPUs. To reduce the error due to variations in these
substrate and discrete transistors, a number of factors should be taken into consideration:
• The ideality factor, nf, of the transistor. The ideality factor is a measure of the deviation
of the thermal diode from the ideal behavior. The NE1617A is trimmed for an nf value
of 1.008. Equation 2 can be used to calculate the error introduced at a temperature
T C when using a transistor whose nf does not equal 1.008. Consult the processor
data sheet for nf values.
This value can be written to the offset register and is automatically added to or
subtracted from the temperature measurement.
 n natural – 1.008 
T = ------------------------------------------   273.15 Kelvin + T 
1.008
(2)
• Some CPU manufacturers specify the high and low current levels of the substrate
transistors. The Isource high current level of the NE1617A is 100 A and the low level
current is 10 A.
If a discrete transistor is being used with the NE1617A, the best accuracy is obtained by
choosing devices according to the following criteria:
• Base-emitter voltage greater than 0.25 V at 6 mA, at the highest operating
temperature.
• Base-emitter voltage less than 0.95 V at 100 mA, at the lowest operating temperature.
• Base resistance less than 100 .
• Small variation in hFE (say 50 to 150) that indicates tight control of VBE characteristics.
Transistors such as 2N3904, 2N3906, or equivalents in SOT23 packages are suitable
devices to use. See Table 11 for representative devices.
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
Table 11.
Representative diodes for temperature sensing
Manufacturer
Model number
Rohm
UMT3904
Diodes Inc.
MMBT3904-7
Philips
MMBT3904
ST Micro
MMBT3904
ON Semiconductor
MMBT3904LT1
Chenmko
MMBT3904
Infineon Technologies
SMBT3904E6327
Fairchild Semiconductor
MMBT3904FSCT
National Semiconductor
MMBT3904N623
9.1.2 Thermal inertia and self-heating
Accuracy depends on the temperature of the remote-sensing diode and/or the internal
temperature sensor being at the same temperature as that being measured, and a
number of factors can affect this. Ideally, the sensor should be in good thermal contact
with the part of the system being measured, for example, the processor. If it is not, the
thermal inertia caused by the mass of the sensor causes a lag in the response of the
sensor to a temperature change. In the case of the remote sensor, this should not be a
problem, since it is either a substrate transistor in the processor or a small package
device, such as the SOT23, placed in close proximity to it.
The on-chip sensor, however, is often remote from the processor and is only monitoring
the general ambient temperature around the package. The thermal time constant of the
SSOP16 package in still air is about 140 seconds, and if the ambient air temperature
quickly changed by 100 C, it would take about 12 minutes (five time constants) for the
junction temperature of the NE1617A to settle within 1 C of this. In practice, the
NE1617A package is in electrical and therefore thermal contact with a printed-circuit
board and can also be in a forced airflow. How accurately the temperature of the board
and/or the forced airflow reflect the temperature to be measured also affects the accuracy.
Self-heating due to the power dissipated in the NE1617A or the remote sensor causes the
chip temperature of the device or remote sensor to rise above ambient. However, the
current forced through the remote sensor is so small that self-heating is negligible. In the
case of the NE1617A, the worst-case condition occurs when the device is converting at
16 conversions per second while sinking the maximum current of 1 mA at the ALERT
output. In this case, the total power dissipation in the device is about 11 mW. The thermal
resistance, Rth(j-a), of the SSOP16 package is about 121 C/W.
In practice, the package has electrical and therefore thermal connection to the printed
circuit board, so the temperature rise due to self-heating is negligible.
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
9.1.3 Layout considerations
Digital boards can be electrically noisy environments, and the NE1617A is measuring very
small voltages from the remote sensor, so care must be taken to minimize noise induced
at the sensor inputs. The following precautions should be taken.
1. Place the NE1617A as close as possible to the remote sensing diode. Provided that
the worst noise sources, that is, clock generators, data/address buses, and CRTs, are
avoided, this distance can be four to eight inches.
2. Route the D+ and D tracks close together, in parallel, with grounded guard tracks on
each side. Provide a ground plane under the tracks if possible.
3. Use wide tracks to minimize inductance and reduce noise pickup. 10 mil track
minimum width and spacing is recommended (see Figure 4).
4. Try to minimize the number of copper/solder joints, which can cause thermocouple
effects. Where copper/solder joints are used, make sure that they are in both the D+
and D path and at the same temperature.
Thermocouple effects should not be a major problem since 1 C corresponds to about
200 V and thermocouple voltages are about 3 V/C of temperature difference.
Unless there are two thermocouples with a big temperature differential between them,
thermocouple voltages should be much less than 200 V.
5. Place a 0.1 F bypass capacitor close to the VDD pin. In very noisy environments,
place a 1000 pF input filter capacitor across D+ and D close to the NE1617A.
6. If the distance to the remote sensor is more than eight inches, the use of twisted pair
cable is recommended. This works up to about six feet to 12 feet.
7. For really long distances (up to 100 feet), use shielded twisted pair, such as
Belden #8451 microphone cable. Connect the twisted pair to D+ and D and the
shield to GND close to the NE1617A. Leave the remote end of the shield
unconnected to avoid ground loops.
Because the measurement technique uses switched current sources, excessive cable
and/or filter capacitance can affect the measurement. When using long cables, the filter
capacitor can be reduced or removed.
Cable resistance can also introduce errors. 1  resistance introduces about 1 C error.
GND
10 mil
10 mil
10 mil
10 mil
10 mil
10 mil
10 mil
D+
D−
GND
002aag953
Fig 4.
NE1617A
Product data sheet
Typical arrangement of signal tracks
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Temperature monitor for microprocessor systems
9.2 Power sequencing considerations
9.2.1 Power supply slew rate
When powering-up the NE1617A, ensure that the slew rate of VDD is less than 18 mV/s.
A slew rate larger than this may cause power-on reset issues and yield unpredictable
results.
9.2.2 Application circuit
Figure 5 shows a typical application circuit for the NE1617A, using a discrete sensor
transistor connected via a shielded, twisted pair cable. The pull-ups on SCLK, SDATA,
and ALERT are required only if they are not already provided elsewhere in the system.
The SCLK and SDATA pins of the NE1617A can be interfaced directly to the SMBus of an
I/O controller, such as the Intel 820 chip set.
0.1 μF
VDD
2
15
VDD
STBY
R
10 kΩ
R
10 kΩ
R
10 kΩ
NE1617A
3
C1(1)
2200 pF
remote sensor
2N3904 (NPN),
2N3906 (PNP)
or similar stand-alone
ASIC or processor
thermal diode
4
D+
SCLK
SDATA
D−
ADD0 ADD1 GND
10
6
7
ALERT
14
12
11
clock
data
microcontroller
interrupt
GND
8
002aad511
(1) Typical value, placed close to temperature sensor.
Fig 5.
NE1617A
Product data sheet
Typical application circuit
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NXP Semiconductors
Temperature monitor for microprocessor systems
10. Limiting values
Table 12. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter
NE1617A
Product data sheet
Conditions
Min
Max
Unit
0.3
+6
V
VDD
supply voltage
VDD to GND
VI
input voltage
D+, ADD0, ADD1
0.3
VDD + 0.3
V
D to GND
0.3
+0.8
V
SCLK, SDATA, ALERT, STBY
0.3
+6
V
1
+50
mA
II
input current
SDATA
D
-
1
mA
Tamb
ambient temperature
operating
55
+125
C
Tj(max)
maximum junction
temperature
-
+150
C
Tstg
storage temperature
65
+150
C
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
11. Characteristics
Table 13. Characteristics
VDD = 3.0 V to 3.6 V; Tamb = 0 C to +125 C; unless otherwise specified.
Symbol
Parameter
Tres
temperature resolution
Tacc(loc)
local temperature accuracy
Tacc(rem)
remote temperature accuracy
Conditions
Min
Typ
Max
Unit
1
-
-
C
Tamb = +60 C to +100 C
-
< 1
2
C
Tamb = 0 C to +125 C
-
< 2
3
C
Tremote = +60 C to +100 C
-
-
3
C
Tremote = 40 C to +125 C
-
-
5
C
-
2.7
2.95
V
supply[2]
Vth(UVLO)
undervoltage lockout threshold VDD
voltage[1]
Vth(POR)
power-on reset threshold
voltage
VDD supply (falling edge)[3]
1.0
-
2.5
V
IDD(AV)
average supply current
conversion rate = 0.25 per second
-
-
70
A
conversion rate = 2 per second
-
-
180
A
IDD(stb)
standby supply current
SMBus inactive
-
3
10
A
tconv
conversion time
from STOP bit to conversion
complete; both channels
-
-
170
ms
Ef(conv)
conversion rate error
percentage error in programmed
rate
30
-
+30
%
Isource
source current
remote sensor
HIGH level
-
100
-
A
LOW level
-
10
-
A
-
160
-
A
bias current
Ibias
ADD0, ADD1; momentary as the
address is being read
[4][5]
[1]
The value of VDD below which the internal A/D converter is disabled. This is designed to be a minimum of 200 mV above the power-on
reset. During the time that it is disabled, the temperature that is in the ‘read temperature registers’ will remain at the value that it was
before the ADC was disabled. This is done to eliminate the possibility of reading unexpected false temperatures due to the A/D
converter not working correctly due to low voltage. In case of power-up (rising VDD), the reading that is stored in the ‘read temperature
registers’ will be the default value of 0 C. As soon as VDD has risen to the value of UVLO, the ADC will function correctly and normal
temperatures will be read.
[2]
VDD (rising edge) voltage below which the ADC is disabled.
[3]
VDD (falling edge) voltage below which the logic is reset.
[4]
Address is read at power-up and at start of conversion for all conversions except the fastest rate.
[5]
Due to the bias current, any pull-up/pull-down resistors should be  2 k.
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
Table 14. Characteristics
VDD = 3.3 V; Tamb = 40 C to +125 C; unless otherwise specified.[1]
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
8
-
-
bits
-
< 1
2
C
ADC and power supply
temperature resolution
Tres
Tacc(loc)
local temperature
accuracy[3]
monotonicity guaranteed
[2]
Tamb = +60 C to +100 C
Tamb = 40 C to +125 C
Tacc(rem)
remote temperature
accuracy[3]
-
< 2
3
C
Tremote = +60 C to +100 C
[4]
-
-
3
C
Tremote = 40 C to +125 C
[4]
-
-
5
C
3.0
-
5.5
V
VDD
supply voltage
tconv
conversion time
from STOP bit to conversion
complete; both channels
-
125
156
ms
Ef(conv)
conversion rate error
percentage error in programmed
rate
25
-
+25
%
VDD = 3 V
2.2
-
-
V
VDD = 5.5 V
2.4
-
-
V
SMBus interface
VIH
HIGH-level input voltage
STBY, SCLK, SDATA
VIL
LOW-level input voltage
STBY, SCLK, SDATA;
VDD = 3 V to 5.5 V
-
-
0.8
V
Isink
sink current
logic output LOW;
ALERT, SDATA forced to 0.4 V
6
-
-
mA
ILOH
HIGH-level output leakage
current
ALERT; forced to 5.5 V
-
-
1
A
II
input current
logic inputs forced to VDD or GND
2
-
+2
A
[1]
Specifications from 40 C to +125 C are guaranteed by design, not production tested.
[2]
Guaranteed but not 100 % tested.
[3]
Quantization error is not included in specifications for temperature accuracy. For example, if the NE1617A device temperature is exactly
+66.7 C, the ADC may report +66 C, +67 C or +68 C (due to the quantization error plus the 0.5 C offset used for rounding up) and
still be within the guaranteed 1 C error limits for the +60 C to +100 C temperature range.
[4]
Tremote is the junction temperature of the remote diode. See Section 7.1 “Temperature measurement” for remote diode forward voltage
requirements.
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
Table 15. SMBus interface dynamic characteristics[1]
VDD = 3.0 V to 3.6 V; Tamb = 0 C to +125 C; unless otherwise specified.[2]
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
VIH
VIL
HIGH-level input voltage
STBY, SCLK, SDATA
2.2
-
-
V
LOW-level input voltage
STBY, SCLK, SDATA
-
-
0.8
V
IOL
logic output LOW sink current
ALERT; VOL = 0.4 V
1.0
-
-
mA
SDATA; VOL = 0.6 V
6.0
-
-
mA
IIH
HIGH-level input current
VI = VDD
1
-
+1
A
IIL
LOW-level input current
VI = GND
1
-
+1
A
Ci
input capacitance
SCLK, SDATA
-
5
-
pF
fSCLK
SCLK operating frequency
0
-
100
kHz
tLOW
SCLK LOW time
4.7
5.0
-
s
tHIGH
SCLK HIGH time
4.0
5.0
-
s
tBUF
bus free time between a STOP
and START condition
from SDATA STOP
to SDATA START
4.7
-
-
s
tHD;STA
hold time (repeated) START
condition
from SDATA START to first SCLK
HIGH-to-LOW transition
4.0
-
-
s
tHD;DAT
data hold time
from SCLK HIGH-to-LOW transition
to SDATA edges
0
-
-
ns
tSU;DAT
data set-up time
from SDATA edges
to SCLK LOW-to-HIGH transition
250
-
-
ns
tSU;STA
set-up time for a repeated
START condition
from SCLK LOW-to-HIGH transition
to restart SDATA
250
-
-
ns
tSU;STO
set-up time for STOP condition
from SCLK LOW-to-HIGH transition
to SDATA STOP condition
4.0
-
-
s
tf
fall time
SCLK and SDATA signals
-
-
1.0
s
[1]
The NE1617A does not include the SMBus time-out capability (tLOW;SEXT and tLOW;MEXT).
[2]
Device operation between 3.0 V and 5.5 V is allowed, but parameters may be outside the limit shown in this table.
tLOW
tr
tf
tHD;STA
SCLK
tHD;STA
tHD;DAT
tHIGH
tSU;STA
tSU;STO
tSU;DAT
SDATA
tBUF
P
S
S
P
002aae777
Fig 6.
Timing measurements
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
11.1 Typical performance curves
002aab749
20
temp.
error
(°C)
002aab747
6
temp.
error
(°C)
10
2
D+ to GND
0
−2
−10
D+ to VDD
−20
−6
10
102
leakage resistance (MΩ)
1
1
102
10
103
104
f (kHz)
VI = 100 mVpp and AC-coupled to D
Fig 7.
Temperature error versus printed-circuit board
leakage resistance
002aab748
6
temp.
error
(°C)
Fig 8.
Temperature error versus common-mode
noise frequency
002aab750
10
temp.
error
(°C)
2
0
−2
−10
−6
1
10
102
103
104
−20
0
f (kHz)
40
80
120
D+ to D− capacitance (nF)
VI = 100 mVpp and AC-coupled to D and D+
Fig 9.
Temperature error versus differential mode
noise frequency
NE1617A
Product data sheet
Fig 10. Temperature error versus D+ to D
capacitance
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Temperature monitor for microprocessor systems
002aad517
100
002aad518
130
IDD(stb)
(μA)
IDD
(μA)
80
110
60
90
40
70
20
0
1
10
102
50
10−2
103
10−1
fSCLK (kHz)
1
10
conversion rate (kHz)
Fig 12. Operating supply current versus conversion
rate at VDD = 3.3 V
Fig 11. Standby supply current versus clock
frequency at VDD = 3.3 V
002aad519
150
temperature
(°C)
100
50
0
0
2
6
10
time (s)
Fig 13. Response to thermal shock immersed in +115 C fluorinert bath
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
12. Package outline
SSOP16: plastic shrink small outline package; 16 leads; body width 3.9 mm; lead pitch 0.635 mm
D
E
SOT519-1
A
X
c
y
HE
v M A
Z
9
16
A2
A
(A 3)
A1
θ
Lp
L
8
1
e
detail X
w M
bp
0
2.5
5 mm
scale
DIMENSIONS (mm are the original dimensions)
UNIT
A
max.
A1
A2
A3
bp
c
D (1)
E (1)
e
HE
L
Lp
v
w
y
Z (1)
θ
mm
1.73
0.25
0.10
1.55
1.40
0.25
0.31
0.20
0.25
0.18
5.0
4.8
4.0
3.8
0.635
6.2
5.8
1
0.89
0.41
0.2
0.18
0.09
0.18
0.05
8o
o
0
Note
1. Plastic or metal protrusions of 0.2 mm maximum per side are not included.
OUTLINE
VERSION
REFERENCES
IEC
JEDEC
JEITA
EUROPEAN
PROJECTION
ISSUE DATE
99-05-04
03-02-18
SOT519-1
Fig 14. Package outline SOT519-1 (SSOP16)
NE1617A
Product data sheet
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NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
13. Soldering of SMD packages
This text provides a very brief insight into a complex technology. A more in-depth account
of soldering ICs can be found in Application Note AN10365 “Surface mount reflow
soldering description”.
13.1 Introduction to soldering
Soldering is one of the most common methods through which packages are attached to
Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both
the mechanical and the electrical connection. There is no single soldering method that is
ideal for all IC packages. Wave soldering is often preferred when through-hole and
Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not
suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high
densities that come with increased miniaturization.
13.2 Wave and reflow soldering
Wave soldering is a joining technology in which the joints are made by solder coming from
a standing wave of liquid solder. The wave soldering process is suitable for the following:
• Through-hole components
• Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless
packages which have solder lands underneath the body, cannot be wave soldered. Also,
leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered,
due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by
component placement and exposure to a temperature profile. Leaded packages,
packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
•
•
•
•
•
•
Board specifications, including the board finish, solder masks and vias
Package footprints, including solder thieves and orientation
The moisture sensitivity level of the packages
Package placement
Inspection and repair
Lead-free soldering versus SnPb soldering
13.3 Wave soldering
Key characteristics in wave soldering are:
• Process issues, such as application of adhesive and flux, clinching of leads, board
transport, the solder wave parameters, and the time during which components are
exposed to the wave
• Solder bath specifications, including temperature and impurities
NE1617A
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NE1617A
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Temperature monitor for microprocessor systems
13.4 Reflow soldering
Key characteristics in reflow soldering are:
• Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see Figure 15) than a SnPb process, thus
reducing the process window
• Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
• Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the
packages and/or boards are not damaged. The peak temperature of the package
depends on package thickness and volume and is classified in accordance with
Table 16 and 17
Table 16.
SnPb eutectic process (from J-STD-020C)
Package thickness (mm)
Package reflow temperature (C)
Volume (mm3)
< 350
 350
< 2.5
235
220
 2.5
220
220
Table 17.
Lead-free process (from J-STD-020C)
Package thickness (mm)
Package reflow temperature (C)
Volume (mm3)
< 350
350 to 2000
> 2000
< 1.6
260
260
260
1.6 to 2.5
260
250
245
> 2.5
250
245
245
Moisture sensitivity precautions, as indicated on the packing, must be respected at all
times.
Studies have shown that small packages reach higher temperatures during reflow
soldering, see Figure 15.
NE1617A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 5 — 20 March 2012
© NXP B.V. 2012. All rights reserved.
25 of 30
NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
maximum peak temperature
= MSL limit, damage level
temperature
minimum peak temperature
= minimum soldering temperature
peak
temperature
time
001aac844
MSL: Moisture Sensitivity Level
Fig 15. Temperature profiles for large and small components
For further information on temperature profiles, refer to Application Note AN10365
“Surface mount reflow soldering description”.
14. Abbreviations
Table 18.
NE1617A
Product data sheet
Abbreviations
Acronym
Description
A/D
Analog-to-Digital
ADC
Analog-to-Digital Converter
CDM
Charged-Device Model
CPU
Central Processing Unit
CRT
Cathode Ray Tube
ESD
ElectroStatic Discharge
HBM
Human Body Model
LSB
Least Significant Bit
MM
Machine Model
MSB
Most Significant Bit
NPN
bipolar transistor with N-type emitter and collector and a P-type base
PCB
Printed-Circuit Board
PNP
bipolar transistor with P-type emitter and collector and an N-type base
POR
Power-On Reset
SMBus
System Management Bus
UVLO
UnderVoltage LockOut
All information provided in this document is subject to legal disclaimers.
Rev. 5 — 20 March 2012
© NXP B.V. 2012. All rights reserved.
26 of 30
NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
15. Revision history
Table 19.
Revision history
Document ID
Release date
Data sheet status
Change notice
Supersedes
NE1617A v.5
20120320
Product data sheet
-
NE1617A v.4
Modifications:
•
•
Section 2 “Features and benefits”, 11th bullet item: deleted phrase “250 V MM per JESD22-A115”
Section 7.1 “Temperature measurement”:
– section is renamed from “Section 7.1 “Remote diode selection”
– updated Equation 1
– added definition of ‘n’, non-ideality
– third paragraph: appended “and also the non-ideality factor ‘n’ must be close to the value of
1.008 to be compatible with the Intel Pentium III internal thermal diode that the NE1617A was
designed to work with” to end of third sentence.
•
•
•
Section 9.1 “How do D+, D- work?” deleted.
•
•
Section 9 “Application design-in information” is re-written.
Section 9.2 “What is the difference using diode and transistor?” deleted.
Section 9.3 “How is error reduced when necessary to use a wire instead of the PCB trace?”
deleted.
Section 14 “Mounting” deleted.
NE1617A v.4
20090730
Product data sheet
-
NE1617A v.3
NE1617A v.3
(9397 750 14162)
20041005
Product data sheet
-
NE1617A v.2
NE1617A v.2
(9397 750 09273)
20011214
Product specification
ECN 853-2203 27461
of 14 Dec 2001
NE1617A v.1
NE1617A v.1
(9397 750 07322)
20000713
Product specification
ECN 853-2203 24123
of 13 Jul 2000
-
NE1617A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 5 — 20 March 2012
© NXP B.V. 2012. All rights reserved.
27 of 30
NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
16. Legal information
16.1 Data sheet status
Document status[1][2]
Product status[3]
Definition
Objective [short] data sheet
Development
This document contains data from the objective specification for product development.
Preliminary [short] data sheet
Qualification
This document contains data from the preliminary specification.
Product [short] data sheet
Production
This document contains the product specification.
[1]
Please consult the most recently issued document before initiating or completing a design.
[2]
The term ‘short data sheet’ is explained in section “Definitions”.
[3]
The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
16.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
Product specification — The information and data provided in a Product
data sheet shall define the specification of the product as agreed between
NXP Semiconductors and its customer, unless NXP Semiconductors and
customer have explicitly agreed otherwise in writing. In no event however,
shall an agreement be valid in which the NXP Semiconductors product is
deemed to offer functions and qualities beyond those described in the
Product data sheet.
16.3 Disclaimers
Limited warranty and liability — Information in this document is believed to
be accurate and reliable. However, NXP Semiconductors does not give any
representations or warranties, expressed or implied, as to the accuracy or
completeness of such information and shall have no liability for the
consequences of use of such information. NXP Semiconductors takes no
responsibility for the content in this document if provided by an information
source outside of NXP Semiconductors.
In no event shall NXP Semiconductors be liable for any indirect, incidental,
punitive, special or consequential damages (including - without limitation - lost
profits, lost savings, business interruption, costs related to the removal or
replacement of any products or rework charges) whether or not such
damages are based on tort (including negligence), warranty, breach of
contract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason
whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards
customer for the products described herein shall be limited in accordance
with the Terms and conditions of commercial sale of NXP Semiconductors.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
NE1617A
Product data sheet
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in life support, life-critical or
safety-critical systems or equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors and its suppliers accept no liability for
inclusion and/or use of NXP Semiconductors products in such equipment or
applications and therefore such inclusion and/or use is at the customer’s own
risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Customers are responsible for the design and operation of their applications
and products using NXP Semiconductors products, and NXP Semiconductors
accepts no liability for any assistance with applications or customer product
design. It is customer’s sole responsibility to determine whether the NXP
Semiconductors product is suitable and fit for the customer’s applications and
products planned, as well as for the planned application and use of
customer’s third party customer(s). Customers should provide appropriate
design and operating safeguards to minimize the risks associated with their
applications and products.
NXP Semiconductors does not accept any liability related to any default,
damage, costs or problem which is based on any weakness or default in the
customer’s applications or products, or the application or use by customer’s
third party customer(s). Customer is responsible for doing all necessary
testing for the customer’s applications and products using NXP
Semiconductors products in order to avoid a default of the applications and
the products or of the application or use by customer’s third party
customer(s). NXP does not accept any liability in this respect.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) will cause permanent
damage to the device. Limiting values are stress ratings only and (proper)
operation of the device at these or any other conditions above those given in
the Recommended operating conditions section (if present) or the
Characteristics sections of this document is not warranted. Constant or
repeated exposure to limiting values will permanently and irreversibly affect
the quality and reliability of the device.
Terms and conditions of commercial sale — NXP Semiconductors
products are sold subject to the general terms and conditions of commercial
sale, as published at http://www.nxp.com/profile/terms, unless otherwise
agreed in a valid written individual agreement. In case an individual
agreement is concluded only the terms and conditions of the respective
agreement shall apply. NXP Semiconductors hereby expressly objects to
applying the customer’s general terms and conditions with regard to the
purchase of NXP Semiconductors products by customer.
No offer to sell or license — Nothing in this document may be interpreted or
construed as an offer to sell products that is open for acceptance or the grant,
conveyance or implication of any license under any copyrights, patents or
other industrial or intellectual property rights.
All information provided in this document is subject to legal disclaimers.
Rev. 5 — 20 March 2012
© NXP B.V. 2012. All rights reserved.
28 of 30
NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from competent authorities.
Non-automotive qualified products — Unless this data sheet expressly
states that this specific NXP Semiconductors product is automotive qualified,
the product is not suitable for automotive use. It is neither qualified nor tested
in accordance with automotive testing or application requirements. NXP
Semiconductors accepts no liability for inclusion and/or use of
non-automotive qualified products in automotive equipment or applications.
In the event that customer uses the product for design-in and use in
automotive applications to automotive specifications and standards, customer
(a) shall use the product without NXP Semiconductors’ warranty of the
product for such automotive applications, use and specifications, and (b)
whenever customer uses the product for automotive applications beyond
NXP Semiconductors’ specifications such use shall be solely at customer’s
own risk, and (c) customer fully indemnifies NXP Semiconductors for any
liability, damages or failed product claims resulting from customer design and
use of the product for automotive applications beyond NXP Semiconductors’
standard warranty and NXP Semiconductors’ product specifications.
Translations — A non-English (translated) version of a document is for
reference only. The English version shall prevail in case of any discrepancy
between the translated and English versions.
16.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
17. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
NE1617A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 5 — 20 March 2012
© NXP B.V. 2012. All rights reserved.
29 of 30
NE1617A
NXP Semiconductors
Temperature monitor for microprocessor systems
18. Contents
1
2
3
4
5
6
6.1
6.2
7
7.1
7.2
7.3
8
8.1
8.2
8.3
8.3.1
8.3.2
8.3.3
8.3.4
8.3.5
8.3.6
8.3.7
8.3.8
8.4
8.5
8.6
9
9.1
9.1.1
9.1.2
9.1.3
9.2
9.2.1
9.2.2
10
11
11.1
12
13
13.1
13.2
13.3
13.4
General description . . . . . . . . . . . . . . . . . . . . . . 1
Features and benefits . . . . . . . . . . . . . . . . . . . . 1
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Ordering information . . . . . . . . . . . . . . . . . . . . . 2
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pinning information . . . . . . . . . . . . . . . . . . . . . . 4
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 4
Functional description . . . . . . . . . . . . . . . . . . . 5
Temperature measurement . . . . . . . . . . . . . . . 5
No calibration is required . . . . . . . . . . . . . . . . . 6
Address logic . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Temperature monitor with SMBus serial
interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Serial bus interface . . . . . . . . . . . . . . . . . . . . . . 6
Slave address . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Low power standby modes . . . . . . . . . . . . . . . . 8
Configuration register . . . . . . . . . . . . . . . . . . . . 8
External and internal temperature registers . . . 8
Conversion rate register . . . . . . . . . . . . . . . . . . 9
Temperature limit registers . . . . . . . . . . . . . . . . 9
One-shot command . . . . . . . . . . . . . . . . . . . . 10
Status register. . . . . . . . . . . . . . . . . . . . . . . . . 10
Alert interrupt . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power-up default condition . . . . . . . . . . . . . . . 11
Fault detection . . . . . . . . . . . . . . . . . . . . . . . . 11
SMBus interface . . . . . . . . . . . . . . . . . . . . . . . 12
Application design-in information . . . . . . . . . 13
Factors affecting accuracy . . . . . . . . . . . . . . . 13
Remote sensing diode . . . . . . . . . . . . . . . . . . 13
Thermal inertia and self-heating . . . . . . . . . . . 14
Layout considerations. . . . . . . . . . . . . . . . . . . 15
Power sequencing considerations . . . . . . . . . 16
Power supply slew rate. . . . . . . . . . . . . . . . . . 16
Application circuit . . . . . . . . . . . . . . . . . . . . . . 16
Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 17
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 18
Typical performance curves . . . . . . . . . . . . . . 21
Package outline . . . . . . . . . . . . . . . . . . . . . . . . 23
Soldering of SMD packages . . . . . . . . . . . . . . 24
Introduction to soldering . . . . . . . . . . . . . . . . . 24
Wave and reflow soldering . . . . . . . . . . . . . . . 24
Wave soldering . . . . . . . . . . . . . . . . . . . . . . . . 24
Reflow soldering . . . . . . . . . . . . . . . . . . . . . . . 25
14
15
16
16.1
16.2
16.3
16.4
17
18
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . .
Revision history . . . . . . . . . . . . . . . . . . . . . . .
Legal information . . . . . . . . . . . . . . . . . . . . . .
Data sheet status . . . . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . .
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . .
Contact information . . . . . . . . . . . . . . . . . . . .
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26
27
28
28
28
28
29
29
30
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP B.V. 2012.
All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
Date of release: 20 March 2012
Document identifier: NE1617A
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