PRELIMINARY DATASHEET
MOBILE ACCESS™—CLOCK SYNTHESIZER, TEMPERATURE SENSOR,
& PWM FAN CONTROLLER FOR PORTABLE DEVICES
9TCS1085
IDT®
MOBILE ACCESS™—CLOCK SYNTHESIZER, TEMPERATURE SENSOR, & PWM FAN CONTROLLER FOR PORTABLE DEVICES 1
9TCS1085 REV 0.7 012012
Description
The 9TCS1085 is a highly programmable IC that integrates
clock synthesizers with a PWM Fan controller and
temperature sensor for hardware thermal protection.
The device has an ultra-low-power 32.768 kHz frequency
generator to support Real Time Clocks (RTC). This device
can generate the 32.768 kHz frequency up to four years of
life powered by a CR2032 coin cell battery. The 9TCS1085
can output computer system clock frequencies of 24, 25, 27
and 48 MHz which reduces the component count on the
circuit board.
The fan controller is pulsed width modulated (PWM) used
for the temperature proportional speed control. The device
is highly configurable through I2C for ease and flexibility of
use. The fan controller has three different modes of
operation and will work with multiple pole, brushless DC
fans. An integrated Start-up Timer ensures reliable motor
start-up and turn-on or follows a detected fault condition.
The 9TCS1085 includes temperature monitor function that
measures an external diode. The temperature sensor is
optimized to be accurate within ±1°C between the
temperature range of 60°C to 100°C. This device is highly
programmable through the use of I
2
C to set high and low
limits for the temperature sensor. The hardware limits drive
dedicated ALERT and THERM pins for system shutdown.
The 9TCS1085 is available in a 32-pin QFN package and is
available for commercial temperature range.
Applications
• Notebook Computers
• Netbook Computers
• Smartbook Computers
• Consumer Portable Devices
• Embedded Systems
• Networking Equipment (i.e. Routers, Switches)
• Network Area Storage
Features
Thermal Sensor
• One channel temperature sensor
• Both H/W & S/W programmable over/under temperature
alarms
• No Calibration required in application
• Diode failure detection
• Support SMBUS Alert
• Accuracy: ±1°C (+60°C to +100°C);
±2°C (0°C to + 100°C)
• Offset register for system calibration
• Series resistor cancellation feature
Fan Controller
• High frequency or low frequency PWM outputs for use
with 4-wire fans
• TACH inputs to measure fan speed
• OS independent automatic fan speed control based on
thermal information
• Dynamic TMIN control mode to optimize system
acoustics
• Default startup at 100% PWM for all fans for robust
operation
System Clock PLL Synthesizers
• Scalable low voltage VDD I/O (1.5V to 1.05V) to reduce
power consumption (applies to 25MHz output)
• Integrated series termination resistors
• Selectable – Single-ended 24MHz/27MHz/48MHz clock
output @ VDD3.3V
• 3 – Single ended 25MHz clock outputs (buffer out)
• 32.768 kHz outputs with < 1.8µA power consumption for
system RTC circuit
