Analog Devices Linear ADI Power LTM4681 Manual page 98

LTM4681
PMBus COMMAND DETAILS
IOUT_OC_FAULT_LIMIT
The IOUT_OC_FAULT_LIMIT command sets the value of the peak output current limit, in Amperes. When the control-
ler is in current limit, the overcurrent detector will indicate an overcurrent fault condition. The following table lists the
progammable peak output current limit value in mV between I
+ –
(I – I )/IOUT_CAL_GAIN in Amperes.
SENSE SENSE
BASED ON PEAK-TO-PEAK INDUCTOR CURRENT = 50% OF 30A FOR WORSE CASE, THESE ARE APPROXIMATES, SO USE GUARDBAND AND CHECK
MFR_PWM_MODE[7] = 1
High Current Range (mV)
17.73
18.86
20.42
21.14
22.27
23.41
24.55
Note: This is the peak of the current waveform. The READ_IOUT command returns the average current. The peak output
current limits are adjusted with temperature based on the MFR_IOUT_CAL_GAIN_TC using the equation:
Peak Current Limit = IOUT_CAL_GAIN • (1 + MFR_IOUT_CAL_GAIN_TC • (READ_TEMPERTURE_1-27.0)).
The LTM4681 automatically convert currents to the appropriate internal bit value.
The I range is set with bit 7 of the MFR_PWM_MODE command.
OUT
The IOUT_OC_FAULT_LIMIT is ignored during TON_RISE and TOFF_FALL.
If the IOUT_OC_FAULT_LIMIT is exceeded, the device:
• Sets the IOUT bit in the STATUS word
• Sets the IOUT Overcurrent fault bit in the STATUS_IOUT
• Notifies the host by asserting ALERT, unless masked
This command has two data bytes and is formatted in Linear_5s_11s format.
98
~ILPeak (A) ~IOUT (A)
44.33 36.83
47.15 39.65
51.05 43.55
52.85 45.35
55.68 48.18
58.53 51.03
61.38 53.88
For more information
+ –
and I . The actual value of current limit is
SENSE SENSE
MFR_PWM_MODE[7] = 0
Low Current Range (mV)
9.85
10.48
11.34
11.74
12.37
13.01
13.64
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~ ILPeak (A) ~ IOUT (A)
24.63 17.13
26.20 18.70
28.35 20.85
29.35 21.85
30.93 23.43
32.53 25.03
34.10 26.60
Rev. A