Datasheet

Data Sheet ADT7470
Rev. E | Page 3 of 40
SPECIFICATIONS
T
A
= −40
o
C to +125
o
C, V
CC
= 3.0 V to 5.5 V, unless otherwise noted.
Table 1.
Parameter
1, 2, 3, 4, 5
Min Typ Max Unit Test Conditions/Comments
POWER SUPPLY
1
Supply Voltage 3.0 3.3 5.5 V
Supply Current, I
CC
0.5 0.8 mA
Standby Current, I
CC
4 µA
FAN RPM-TO-DIGITAL CONVERTER
Accuracy ±12 %
Full-Scale Count 65,535
Nominal Input RPM 109 RPM Fan count = 0xBFFF
329 RPM Fan count = 0x3FFF
5,000 RPM Fan count = 0x0438
10,000 RPM Fan count = 0x021C
OPEN-DRAIN DIGITAL OUTPUTS, PWM1 to PWM4,
SMBALERT
Output Low Voltage, V
OL
0.4 V I
OUT
= –8.0 mA, V
CC
= +3.3 V
High Level Output Current, I
OH
0.1 1 µA V
OUT
= V
CC
OPEN-DRAIN SERIAL DATA BUS OUTPUT (SDA)
Output Low Voltage, V
OL
0.4 V I
OUT
= –4.0 mA, V
CC
= +3.3 V
High Level Output Current, I
OH
0.1 1 µA V
OUT
= V
CC
SMBus DIGITAL INPUTS (SCL, SDA)
Input High Voltage, V
IH
2.4 V
Input Low Voltage, V
IL
1.0 V V
CC
= 3.3 V
Hysteresis 500 mV
DIGITAL INPUT LOGIC LEVELS (TACH INPUTS,
FULL_SPEED
, GPIO)
Input High Voltage, V
IH
2.4 V
Input Low Voltage, V
IL
0.8 V
Hysteresis 50 mV p-p
DIGITAL INPUT LOGIC LEVELS (TMP_IN)
Input High Voltage, V
IH
V
DD
– 0.3 V
Input Low Voltage, V
IL
0.4 V
DIGITAL INPUT CURRENT
Input High Current, I
IH
–5 µA V
IN
= V
CC
Input Low Current, I
IL
5 µA V
IN
= 0
Input Capacitance, C
IN
5 pF
1
V
DD
should never be floated in the presence of SCL/SDA activity. Charge injection can be sufficient to induce approximately 0.6 V on V
DD.
2
All voltages are measured with respect to GND, unless otherwise specified.
3
Typical values are at %A = 25°C and represent the most likely parametric norm.
4
Logic inputs accept input high voltages up to 5 V even when the device is operating at supply voltages below 5 V.
5
Timing specifications are tested at logic levels of V
IL
= 0.8 V for a falling edge and V
IH
= 2.0 V for a rising edge.