LTC2978C View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC2978C' PDF : 64 Pages View PDF
LTC2978
PMBus Command Description
Manufacturer Specific Commands
MFR_CONFIG_LTC2978
This command is used to configure various manufacturer specific operating parameters for each channel.
MFR_CONFIG_LTC2978 Data Contents
BIT(S) SYMBOL
OPERATION
b[15:12] Reserved
Don’t care. Always returns 0.
b[11] Mfr_config_fast_servo_off
Disables fast servo when margining or trimming output voltages:
0: fast-servo enabled.
1: fast-servo disabled.
b[10] Mfr_config_supervisor_resolution Selects supervisor resolution:
b[9] Mfr_config_adc_hires
0: high resolution – 4mV/LSB, range for VVSENSEPn – VVSENSEMn is 0V to 3.8V.
1: low resolution – 8mV/LSB, range for VVSENSEPn – VVSENSEMn is 0V to 6.0V.
Selects ADC resolution for odd channels. This is typically used to measure current. Ignored for even
channels (they always use low resolution).
0: low resolution – 122µV/LSB.
1: high resolution – 15.6µV/LSB.
b[8] Mfr_config_controln_sel
Selects the active control pin input (CONTROL0 or CONTROL1) for this channel.
0: Select CONTROL0 pin.
1: Select CONTROL1 pin.
b[7] Mfr_config_servo_continuous Select whether the UNIT should continuously servo VOUT after it has reached a new margin or nominal
target. Only applies when Mfr_config_dac_mode = 00b.
b[6] Mfr_config_servo_on_warn
0: Do not continuously servo VOUT after reaching initial target.
1: Continuously servo VOUT to target.
Control re-servo on warning feature. Only applies when Mfr_config_dac_mode = 00b and
Mfr_config_servo_continuous = 0.
0: Do not allow the unit to re-servo when a VOUT warning threshold is met or exceeded.
b[5:4] Mfr_config_dac_mode
1: Allow the unit to re-servo VOUT to nominal target if
VOUT ≥ V(Vout_ov_warn_limit) or
VOUT ≤ V(Vout_uv_warn_limit).
Determines how DAC is used when channel is in the ON state and TON_RISE has elapsed.
00: Soft-Connect (if needed) and servo to target.
01: DAC not connected.
10: DAC connected immediately using value from MFR_DAC command. If this is the configuration after a
reset or Restore_user_all, Mfr_dac will be undefined and must be written to desired value.
11: DAC is soft connected. After soft-connect is complete MFR_DAC may be written.
b[3] Mfr_config_vo_en_wpu_en
VOUT_EN pin charge pumped, current-limited pull-up enable.
0: Disable weak pull-up. VOUT_EN pin driver is three-stated when channel is on.
1: Use weak current-limited pull-up on VOUT_EN pin when the channel is on.
For channels 4-7 this bit is treated as a 0 regardless of its value.
b[2] Mfr_config_vo_en_wpd_en
VOUT_EN pin current-limited pull-down enable.
0: Use a fast N-channel device to pull down VOUT_EN pin when the channel is off for any reason.
1: Use weak current-limited pull-down to discharge VOUT_EN pin when channel is off due to soft stop by the
CONTROLn pin and/or OPERATION command. If the channel is off due to a fault, use the fast pull-down on
VOUT_EN pin.
For channels 4-7 this bit is treated as a 0 regardless of its value.
b[1] Mfr_config_dac_gain
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)
42
For more information www.linear.com/LTC2978
2978fd
Share Link: 
