The MAX6691 four-channel thermistor temperature-to-pulse-width converter measures the temperatures of up
to four thermistors and converts them to a series of output
pulses whose widths are related to the thermistors'
temperatures. Each of the four thermistors and an
external fixed resistor (REXT) form a voltage-divider that
is driven by the MAX6691's internal voltage reference
(VREF). VREF and the voltage across REXT are measured and converted to a pulse.
The MAX6691 has a single open-drain I/O pin that can
be readily connected to a variety of microcontrollers.
The microcontroller initiates a conversion by pulling the
I/O pin low and releasing it. When conversion is done,
the MAX6691 signals the end of conversion by pulling
the I/O pin low once again. The pulse corresponding to
the first thermistor is sent immediately after the release
of the I/O pin.
The on-chip power-management circuitry reduces the
average thermistor current to minimize errors due to
thermistor self-heating. Between conversions, the
MAX6691 falls into a 10µA (max) sleep mode, where
the voltage reference is disabled and the supply current
is at its minimum.
The MAX6691 is available in a 10-pin µMAX package
and is specified from -55°C to +125°C temperature
range.
Key Features
Applications/Uses
Simple Single-Wire Interface
Measures Up to Four Thermistor Temperatures
Low-Average Thermistor Current Minimizes Self-Heating Errors
Internal Voltage Reference Isolates Thermistor from Power-Supply Noise
Notes: **This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
duties, taxes, fees, and exchange rates. For volume-specific prices
and delivery, please see the price and availability page
or contact an authorized distributor.
Download
E-Mail
