© 2002 Microchip Technology Inc.

DS21688B-page 3

TC670

2.0

PIN DESCRIPTIONS

Thedescriptionsof the pins arelistedinTable2-1.

TABLE 2-1:

PIN FUNCTION TABLE

Pin No.

(6-Pin SOT-23)

Symbol

Description

1

THRESHOLD

Analog Input used to set Fan ALERT Threshold Voltage. Input range = 0.0V to

2.4V.

2

GND

Ground Terminal.

3

CLEAR

Digital Input. Active High. The ALERT Output is cleared when a high level signal is

applied to this input.

Power Supply Input, 3.0V to 5.5V.

5ALERT

Digital (Open Drain) Output, active low. This pin goes low to indicate an alert

condition when the fan speed at the SENSE pin reaches the alert threshold

applied on the THRESHOLD pin.

6

SENSE

Analog Input. Current spikes are detected at this pin as the fan excitation signal

transitions from high to low and low to high.