Or 2,3 Channels, Set Top Resistor To 14.3K - Analog Devices Linear ADI Power LTM4681 Manual

OPERATION
Table 3. FSWPH_nn_CFG Pin Strapping Look-Up Table to Set the LTM4681's Switching Frequency and Channel Phase-Interleaving
Angle (Not Applicable if MFR_CONFIG_ALL[6] = 1b), nn = 0,1 or 2,3 Channels, set top resistor to 14.3k.
R * SWITCHING
FSWPH_CFG
(kΩ) FREQUENCY (kHz)
NVM; LTM4681
Open Default = 500
32.4
22.6
18.0
15.4
12.7
10.7
7.68
6.34
5.23
4.22
3.24
2.43
1.65
0.787
0
*R value indicated is nominal. Select R
FSWPH_nn_CFG
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
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
every execution of MFR_RESET or RESTORE_USER_ALL, over the lifetime of one's product.
**External setting corresponds to FREQUENCY_SWITCH (Register 0x33) value set to 0x0000; the device synchronizes its switching frequency to that of
the clock provided on the SYNC_nn pin, provided MFR_CONFIG_ALL[4] = 1b. R
Example:
V
θSYNC TO θ0
NVM; LTM4681
Default = 0°
250 0°
350 0°
425 0°
575 0°
650 0°
750 0°
500 120°
500 90°
External** 0°
External** 0°
External** 60°
External** 120°
External** 90°
External** 0°
External** 120°
FSWPH_nn_CFG
DD25
14.3k
FSWPH_ _CFG PIN
nn
R CFG BOT
FSWPH_
For more information
θSYNC TO θ1
NVM; LTM4681
Default = 180°
180°
180°
180°
180°
180°
180°
240°
270°
240°
120°
240°
300°
270°
180°
240°
from a resistor vendor such that its value is always within 3% of the value indicated in
= 14.3k is external to the part.
TOP
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LTM4681
bits [2:0] of bit [4] of
MFR_PWM_CONFIG MFR_CONFIG_ALL
NVM; LTM4681 NVM; LTM4681
Default = 000b Default = 0b
000b
000b
000b
000b
000b
000b
100b
001b
010b
011b
101b
110b
001b
000b
100b
FSWPH_nn_CFG
power-up and/or
IN
0b
0b
0b
0b
0b
0b
0b
0b
1b
1b
1b
1b
1b
1b
1b
's
Rev. A
37