LM87 datasheet(5/32 Pages) NSC

5 / 32 page

DC Electrical Characteristics (Continued)

The following specifications apply for +2.8 V

≤ V+ ≤ +3.8 V

DC, Analog voltage inputs RS = 510

Ω, unless otherwise speci-

fied. Boldface limits apply for T

A =T J =TMIN to TMAX; all other limits TA =TJ = 25 ˚C.(Note 8)

Symbol

Parameter

Conditions

Typical

Limits

Units

(Note 9)

(Note 10)

(Limits)

DAC CHARACTERISTICS

DAC Error

0 ˚C

≤ T

≤ +75 ˚C, V+ =

3.3 V, Code = 255

-3.3

% (min)

+ = 3.3 V, 3/4 Scale,

code 192

+3.7

0˚C

≤ T

≤ +75 ˚C, V, V+

= 3.3 V, Code = 8(Note

15)

±3

% (max)

Output Load Resistance

O = 2.5 V

1250

Ω (min)

Output Load Capacitance

pF (max)

FAN RPM-TO-DIGITAL CONVERTER

Fan RPM Error

+25 ˚C

≤ T

≤ +75 ˚C

±10

% (max)

−10 ˚C

≤ T

≤ +100 ˚C

±15

% (max)

−40 ˚C

≤ T

≤ +125 ˚C

±20

% (max)

Full-scale Count

255

(max)

FAN1 and FAN2 Nominal Input

RPM (See Section 6.0)

Divisor = 1, Fan Count =

153 (Note 16)

8800

RPM

Divisor = 2, Fan Count =

153 (Note 16)

4400

RPM

Divisor = 3, Fan Count =

153 (Note 16)

2200

RPM

Divisor = 4, Fan Count =

153 (Note 16)

1100

RPM

DIGITAL OUTPUTS (NTEST_OUT)

OUT(1)

Logical “1” Output Voltage

OUT = ±3.0 mA at

+ = +2.8 V

2.4

V (min)

OUT(0)

Logical “0” Output Voltage

OUT = ±3.0 mA at

+ = +3.8 V

0.4

V (max)

OPEN- DRAIN DIGITAL OUTPUTS (SMBData, RESET#, CI, INT#, THERM#)

OUT(0)

Logical “0” Output Voltage (SMBData)

OUT = −755 µA

0.4

V (min)

OUT(0)

Logical “0” Output Voltage (Others)

OUT =−3 mA

0.4

V (min)

High Level Output Current

OUT =V

µA (max)

RESET# and Chassis Intrusion

ms (min)

Pulse Width

DIGITAL INPUTS: VID0–VID4, NTEST_IN, ADD/NTEST_OUT, Chassis Intrusion (CI)

IN(1)

Logical “1” Input Voltage

2.0

V (min)

IN(0)

Logical “0” Input Voltage

0.8

V (max)

SMBus DIGITAL INPUTS (SMBCLK, SMBData)

IN(1)

Logical “1” Input Voltage

2.1

V (min)

IN(0)

Logical “0” Input Voltage

0.8

V (max)

HYST

Input Hysteresis Voltage

243

Tach Pulse Logic Inputs (FAN1, FAN2)

IN(1)

Logical “1” Input Voltage

0.7xV

V (min)

IN(0)

Logical “0” Input Voltage

0.3xV

V (max)

ALL DIGITAL INPUTS

IN(1)

Logical “1” Input Current

IN =V

−12

µA (min)

IN(0)

Logical “0” Input Current

IN =0 VDC

µA (max)

Digital Input Capacitance

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