NE1617ADS,112(2009) View Datasheet(PDF) - NXP Semiconductors.
Part Name
Description
View to exact match
NE1617ADS,112 Datasheet PDF : 27 Pages
| |||
NXP Semiconductors
NE1617A
Temperature monitor for microprocessor systems
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 kΩ to prevent
the error in logic detection from happening. Resistors of 1 kΩ 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
ADD0[1]
ADD1[1]
Address byte
GND
GND
0011 000
GND
n.c.
0011 001
GND
n.c.
VDD
GND
0011 010
0101 001
n.c.
n.c.
0101 010
n.c.
VDD
0101 011
NE1617A_4
Product data sheet
Rev. 04 — 30 July 2009
© NXP B.V. 2009. All rights reserved.
6 of 27
|
|
Share Link: 