f75334 Feature Integration Technology Inc., f75334 Datasheet - Page 17

• Manufacturer Part Number: f75334
• Description: Performance Controller
• Manufacturer: Feature Integration Technology Inc.

Monitor Temperature from “thermistor”
Monitor Temperature from “thermal diode”
ADC Noise Filtering
remote temperature. The specification of thermistor should be considered to (1) β value is
3435K (2) resistor value is 10K ohm at 25°C. In the Figure 7-1, the thermistor is connected by
a serial resistor with 10K ohm, then connected to VREF.
measurement, the F75334DG is capable to these situations. The build-in reference table is for
PNP 2N3906 transistor, and each different kind of thermal diode should be matched with
specific BJT gain. In the Figure 7-1, the transistor is directly connected into temperature pins.
places constraints on high-frequency noise rejection; therefore, careful PCB board layout and
suitable external filtering are required for high-accuracy remote measurement in electronically
noisy environment. High frequency EMI is best filtered at D+ and D- with an external 2200pF
capacitor. Too high capacitance may introduce errors due to the rise time of the switched
current source. Nearly all noise sources tested cause the ADC measurement to be higher
than the actual temperature, depending on the frequency and amplitude.
The F75334DG can connect three thermistor to measure environment temperature or
Also, if the CPU, GPU or external circuits provide thermal diode for temperature
The ADC is integrating type with inherently good noise rejection. Micro-power operation
11011011_111xxxx1
11111111_111xxxx1
11010000_111xxxx1
Manufacturer
Panasonic
Philips
Remote-sensor transistor manufacturers
- 25.125
-48.125 (-25.125 - 23) (offset)
- 0.125
Model Number
2SB0709 2N3906
PMBT3906
10
F75334
July, 2007
V0.25P