ltc2978 Linear Technology Corporation, ltc2978 Datasheet - Page 35

• Manufacturer Part Number: ltc2978
• Description: Octal Pmbus Power Supply Monitor And Controller With Eeprom
• Manufacturer: Linear Technology Corporation

MANUFACTURER SPECIFIC COMMANDS
MFR_CONFIG:
This command is used to configure various manufacturer
specific operating parameters for each channel.
MFR_CONFIG Data Contents
operaTion
b[15:12] Reserved
BIT(S)
b[5:4] Mfr_config_dac_mode
b[11]
b[10]
b[9]
b[8]
b[7]
b[6]
b[3]
b[2]
b[1]
b[0]
SYMBOL
Mfr_config_fast_servo_off
Mfr_config_supervisor_resolution Selects supervisor resolution:
Mfr_config_adc_hires
Mfr_config_controln_sel
Mfr_config_servo_continuous
Mfr_config_servo_on_warn
Mfr_config_vo_en_wpu_en
Mfr_config_vo_en_wpd_en
Mfr_config_dac_gain
Mfr_config_dac_pol
OPERATION
Don’t care. Always returns 0.
Disables fast servo when margining or trimming output voltages:
0: fast-servo enabled.
1: fast-servo disabled.
0: high resolution – 4mV/LSB, range for V
1: low resolution – 8mV/LSB, range for V
Selects ADC resolution for odd channels. Ignored for even channels (they always use low res).
0: low resolution – 122µV/LSB.
1: high resolution – 15.6µV/LSB.
Selects the active control pin input (CONTROL0 or CONTROL1) for this channel.
0: Select CONTROL0 pin.
1: Select CONTROL1 pin.
Select whether the UNIT should continuously servo V
target. Only applies when Mfr_dac_mode = 2’b00.
0: Do not continuously servo V
1: Continuously servo V
Control re-servo on warning feature. Only applies when Mfr_config_dac_mode = 2’b00 and
Mfr_config_servo_continuous = 0.
0: Do not allow the unit to re-servo when a V
1: Allow the unit to re-servo V
V
V
Determines how DAC is used when channel enters ON state or is already in ON state.
00: Soft connect (if needed) and servo to target. Wait for TON_RISE if just entering ON state.
01: DAC not connected.
10: DAC connected using value from MFR_DAC command. Does not wait for TON_RISE if just entering ON state.
11: DAC is soft connected. After soft connect is complete MFR_DAC may be written.
V
0: Disable weak pull-up. V
1: Use weak current-limited pull-up on V
For channels 4-7 this bit is treated as a 0 regardless of its value.
V
0: Use a fast N-channel device to pull down V
1: Use weak current-limited pull-down to discharge V
pin and/or OPERATION command. If the channel is off due to a fault, use the fast pull-down on V
For channels 4-7 this bit is treated as a 0 regardless of its value.
DAC buffer gain.
0: Select DAC buffer gain dac_gain_0 (1.38V full-scale)
1: Select DAC buffer gain dac_gain_1 (2.65V full-scale)
DAC output polarity.
0: Encodes negative (inverting) DC/DC converter trim input.
1: Encodes positive (noninverting) DC/DC converter trim input.
OUT
OUT
O_EN
O_EN
≥ V(Vout_ov_warn_limit) or
≤ V(Vout_uv_warn_limit).
charge pumped, current-limited pull-up enable.
current-limited pull-down enable.
OUT
O_EN
to target.
OUT
OUT
driver is three-stated when channel is on.
to nominal target if
after reaching initial target.
O_EN
SENSEP
SENSEP
OUT
O_EN
when the channel is on.
is 0V to 6.0V.
warning threshold is met or exceeded.
is 0V to 3.8V.
when the channel is off for any reason.
O_EN
OUT
when channel is off due to soft stop by the CONTROLn
after it has reached a new margin or nominal
LTC2978
O_EN
.

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