Linear ANALOG DEVICES LTM4680, Руководство по эксплуатации, Страница: 31 / 126

LTM4680
31
Rev. B
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OPERATION
NOTE:
Per the PMBus specification, pin programmed
parameters can be overridden by commands from the
digital interface with the exception of ASEL which is
always honored. Do not set any part address to 0x5A or
0x5B because these are global addresses and all parts will
respond to them.
Table 1. VOUT n _CFG Pin Strapping Look-Up Table for the
LTM4680’s Output Voltage, Coarse Setting (Not Applicable if
MFR_CONFIG_ALL[6] = 1b)
R
VOUT n _CFG
*
(kΩ)
V
OUT n
(V)
SETTING COARSE
MFR_PWM_
MODE n [1] BIT
Open NVM NVM
32.4 NVM NVM
22.6 3.3 0
18.0 3.1 0
15.4 2.9 0
12.7 2.7 0
10.7 2.5 0, if V
TRIMn
> 0mV
1, if V
TRIMn
≤ 0mV
9.09 2.3 1
7.68 2.1 1
6.34 1.9 1
5.23 1.7 1
4.22 1.5 1
3.24 1.3 1
2.43 1.1 1
1.65 0.9 1
0.787 0.7 1
0 0.5 1
*R
VOUT n _CFG
value indicated is nominal. Select R
VOUT n _CFG
from a
resistor vendor such that its value is always within 3% of the value
indicated in the table. Take into account resistor initial tolerance, T.C.R.
and resistor operating temperatures, soldering heat/IR reflow, and
endurance of the resistor over its lifetime. Thermal shock/cycling,
moisture (humidity) and other effects (depending on one’s specific
application) could also affect R
VOUT n _CFG
’s value over time. All such
effects must be taken into account in order for resistor pin strapping to
yield the expected result at every SV
IN
power-up and/or every execution
of MFR_RESET or RESTORE_ USER_ALL, over the lifetime of one’s
product.
Table 2. VTRIM n _CFG Pin Strapping Look-Up Table for the
LTM4680’s Output Voltage, Fine Adjustment Setting (Not
Applicable if MFR_CONFIG_ALL[6] = 1b)
R
VTRIMn_CFG
*
(kΩ)
V
TRIM
(mV) FINE ADJUSTMENT TO V
OUT n
SETTING WHEN RESPECTIVE
Open 0
32.4 99
22.6 86.625
18.0 74.25
15.4 61.875
12.7 49.5
10.7 37.125
9.09 24.75
7.68 12.375
6.34 –12.375
5.23 –24.75
4.22 –37.125
3.24 –49.5
2.43 –61.875
1.65 –74.25
0.787 –86.625
0 –99
*R
VTRIMn_CFG
value indicated is nominal. Select R
VTRIMn_CFG
from a
resistor vendor such that its value is always within 3% of the value
indicated in the table. Take into account resistor initial tolerance, T.C.R.
and resistor operating temperatures, soldering heat/IR reflow, and
endurance of the resistor over its lifetime. Thermal shock/cycling,
moisture (humidity) and other effects (depending on one’s specific
application) could also affect R
VTRIMn_CFG
’s value over time. All such
effects must be taken into account in order for resistor pin strapping to
yield the expected result at every SV
IN
power-up and/or every execution
of MFR_RESET, or RESTORE_USER_ALL over the lifetime of one’s
product.