Rainbow Electronics MAX1099 - Manual (Page 11)

MAX1098/MAX1099
10-Bit Serial-Output Temperature Sensors
with 5-Channel ADC
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Detailed Description
The MAX1098/MAX1099 are low-power, serial-output,
multichannel ADCs with temperature-sensing capability
for thermostatic, process-control, and monitoring appli-
cations. An algorithmic switched-capacitor converter
with T/H circuitry for both positive and negative inputs
supports fully differential 10-bit conversions from an
internal temperature sensor, two external temperature
sensors, or voltage sources in a variety of channel con-
figurations. Microprocessor (µP) control is made easy
through a flexible 3-wire serial interface.
Figure 1 shows a simplified functional diagram of the
MAX1098/MAX1099 internal architecture. In tempera-
ture-sensing mode, the multiplexer (mux) steers bias
currents through internal or external diodes while the
ADC computes their temperature in relation to changes
in forward voltage. Channels not used for temperature
measurement can be configured to measure other sys-
tem voltages.
INPUT
REGISTER
DIODE
BIAS
CONTROL
CONTROL
LOGIC
INPUT
MUX
OUTPUT
REGISTER
CLOCK
ADC
SHIELD
OUTPUT
T/H
T/H IN+
IN- V DD
GND
DOUT
CS
SCLK
DIN
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
V
DD
/4
SHO REF
REF
Figure 1. MAX1098/MAX1099 Functional Diagram