LTM2987 datasheet(12/114 Pages) AD

12 / 114 page

LTC2971

Rev. 0

For more information www.analog.com

ELECTRICAL CHARACTERISTICS

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating for extended periods may affect device reliability and

lifetime.

Note 2: All currents into device pins are positive. All currents out of device

pins are negative. All voltages are referenced to GND unless otherwise

specified. If power is supplied to the chip via the VDD33 pin only, connect

VPWR and VDD33 pins together.

Note 3: The ADC total unadjusted error includes all error sources. First,

a two-point analog trim is performed to achieve a flat reference voltage

(VREF) over temperature. This results in minimal temperature coefficient,

but the absolute voltage can still vary. To compensate for this, a high

resolution, drift-free, and noiseless digital trim is applied at the output of

the ADC, resulting in a very high accuracy measurement.

Note 4: Hysteresis in the output voltage is created by package stress

that differs depending on whether IC was previously at a higher or lower

temperature. Output voltage is always measured at 25°C, but the IC is

cycled to 125°C or –40°C before successive measurements. Hysteresis is

roughly proportional to the square of the temperature change.

Note 5: Internal circuitry processes the absolute value of VOUT_SNS –

GNDSNS. Thus, all digital voltages read and programmed are positive.

Note 6: Channels with negative range lack IMON capability. On these

channels, setting Mfr_config_imon_sel to 1 does not harm the part but

returns incorrect results.

Note 7: The current sense resolution is determined by the L11 format,

the values of IOUT_CAL_GAIN, and the magnitude of the current being

measured. See Table 3 for details.

Note 8: The nominal time between successive ADC conversions (latency of

the ADC) for any given channel is tUPDATE_ADC.

Note 9: VOUT_SNS, GNDSNS, and IOUT_SNS input currents are characterized

by input current and input differential current. Input current is defined as

current into a single device pin (see Note 2). Input differential current is

defined as (I+ – I–) where I+ is the current into the positive device pin and

I– is the current into the negative device pin.

Note 10: Nonlinearity is defined from the first code that is greater than or

equal to the maximum offset specification to full-scale code, 1023.

Note 11: While READ_VIN operates with 0V ≤ VVIN_SNS ≤ 60V, the valid

READ_IIN, READ_PIN, and MFR_EIN operating range is 3V ≤ VIIN_SNSP/M

≤ 60V.

Note 12: EEPROM endurance and retention will be degraded when TJ >

125°C.

Note 13: EEPROM endurance and retention are guaranteed by design,

characterization and correlation with statistical process controls. The

minimum retention specification applies for devices whose EEPROM has

been cycled less than the minimum endurance specification.

Note 14: The LTC2971 will not acknowledge any PMBus commands,

except for MFR_COMMON, when a STORE_USER_ALL command is being

executed. See also OPERATION section.

Note 15: Maximum capacitive load, CB, for SCL and SDA is 400pF. Data

and clock rise time (tr) and fall time (tf) are: (20 + 0.1• CB) (ns) < tr <

300ns and (20 + 0.1 • CB) (ns) < tf < 300ns. CB = capacitance of one bus

line in pF. SCL and SDA external pullup voltage, VIO, is 3.13V < VIO < 3.6V.

The l denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TJ = 25°C. VVPWR = 12V, VVDDIO = VVDD33,VDD33, VDD25, REFP, and REFM pins

floating, unless otherwise indicated. CVDD33 = 100nF, CVDD25 = 100nF, and CREF = 100nF. (Note 2)

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

tHD,DAT

Data Hold Time (LTC2971 Receiving

Data) (Note 15)

Data Hold Time (LTC2971

Transmitting

Data) (Note 15)

300

900

tSU,DA

Data Setup Time (Note 15)

100

tSP

Pulse Width of Spike Suppressed

(Note 15)

tTIMEOUT_BUS Time Allowed to Complete any

PMBus Command After Which Time

SDA Will Be Released and Command

Terminated

Mfr_config_all_longer_pmbus_timeout = 0

Mfr_config_all_longer_pmbus_timeout = 1

200

280

Additional Digital Timing Characteristics

tOFF_MIN

Minimum Off-Time for Any Channel

100

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