ADT7421

http://onsemi.com

4

Parameter

Conditions

Min

Typ

Max

Unit

Power Supply

3.0

3.30

3.6

V

0.0625 Conversions/Sec Rate (Note 1)

3.0

4.0

mA

Standby Mode Supply Current

10

20

mA

Power-On-Reset Threshold

1.0

2.8

V

Temperature−To−Digital Converter

Local Sensor Accuracy

±2.75

°C

Resolution

1.0

°C

Remote Transistor Sensor Accuracy

±2.5

±3.25

±1.75

°C

Resolution

0.25

°C

Remote Sensor Source Current

The range of source currents provided to the external

thermal transistor for temperature measurements.

10 to

360

mA

Conversion Time

From stop bit to conversion complete, one-shot mode

with averaging switched on.

One-shot mode with averaging off.

184

20

ms

Maximum Series Resistance Cancelled

Resistance split evenly on both the D+ and D– inputs.

50

W

Open−Drain Digital Outputs (THERM, ALERT/THERM2, SDA)

0.2

V

High Level Output Leakage Current,

0.1

1.0

mA

SMBus Interface (Note 3)

SCL, SDA

2.1

V

SCL, SDA

0.8

V

Hysteresis

500

mV

0.4

V

−1.0

+1.0

mA

SMBus Input Capacitance,

SCLK, SDATA

10

pF

SMBus Clock Frequency

400

kHz

SMBus Timeout (Note 4)

User programmable

25

300

ms

SCLK Falling Edge to SDATA Valid

Time

Master clocking in data

1.0

ms

1. See Table 4 for information on other conversion rates.

2. Guaranteed by characterization, but not production tested.

3. See SMBus Timing Specifications section for more information.

4. Disabled by default. Detailed procedures to enable it are in the Serial Bus Interface section of this datasheet.