ADP1048DC1-EVALZ Analog Devices, ADP1048DC1-EVALZ Datasheet - Page 33

• Manufacturer Part Number: ADP1048DC1-EVALZ
• Description: Daughter Cards & OEM Boards ADP1048 DAUGHTERCARD
• Manufacturer: Analog Devices
• Series: ADP1048r

Specifications of ADP1048DC1-EVALZ

• Rohs: yes
• Product: Daughter Cards
• Description/function: 100 kHz daughter board
• Dimensions: 40 mm x 25 mm
• Interface Type: I2C
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 3.3 V
• Factory Pack Quantity: 1
• For Use With: ADP1048

Data Sheet
POWER SUPPLY SYSTEM CALIBRATION AND TRIM
The
calibrated and trimmed digitally in the production environ-
ment. The device can calibrate items including the output
voltage, input voltage, input current, and input power, and it
can trim for tolerance errors introduced by sense resistors,
current transformers, and resistor dividers, as well as for its
own internal circuitry.
The part comes factory trimmed at 90% of the input range at a
3.3 V supply, but it can be re-trimmed by the user to compen-
sate for the errors introduced by external components. With the
exception of the gain and offset trim registers for input power,
the trim registers must be unlocked for write access. To unlock
the trim registers, write to the TRIM_PASSWORD register
(Register 0xD6).
OUTPUT VOLTAGE (VFB) CALIBRATION AND TRIM
The voltage sense inputs are optimized for sensing signals at
90% of the input range and cannot sense signals greater than
1.6 V. In a high voltage system, a resistor divider is required to
reduce the high voltage signal to below 1.6 V. It is recommended
that the high voltage signal be reduced to 1 V for best perfor-
mance. The resistor divider can introduce errors, which must be
trimmed out as follows:
1.
2.
3.
INPUT VOLTAGE (VAC) GAIN AND OFFSET TRIM
The input voltage sense point on the power rail requires an
external resistor divider to bring the signal within the operating
input range of the VAC ADC (0 V to 1.6 V). The resistor divider
can introduce errors, which must be trimmed out as follows:
1.
ADP1047/ADP1048
Turn on the power supply with no load attached.
The output voltage is divided down by the feedback resistor
divider to supply 1 V across the VFB and AGND pins.
Use a calibrated multimeter to perform the output voltage
reading.
Adjust the VFB ADC gain trim register (Register 0xFE41)
until the power supply outputs the exact value in the
READ_VOUT register (Register 0x8B).
Apply the maximum line voltage value to the input of the
power supply.
The VAC resistor divider divides this voltage down at the VAC
pin. The VAC resistor divider is programmed in linear format
using the VIN scale monitor register (Register 0xFE3B).
allow the entire power supply to be
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2.
For VAC offset trim, adjust the value in Register 0xFE53.
CURRENT SENSE GAIN AND OFFSET TRIM
The current sense can be calibrated digitally to remove any
errors due to external components.
1.
2.
For CS offset trim, adjust the values in Register 0xFE54 (500 mV
input range) or Register 0xFE7F (750 mV input range).
INPUT POWER GAIN AND OFFSET TRIM
The input power trim has separate trim registers for high line
and low line input.
1.
2.
3.
4.
For input power offset trim, adjust the values in Register 0xFE33
(for low line input) and Register 0xFE8E (for high line input).
Adjust the VAC ADC gain trim register (Register 0xFE40)
until the VAC value (Register 0x88, READ_VIN) equals
the input voltage reading from a calibrated multimeter.
This step trims for errors in the resistor divider network.
Apply the maximum load to the output with the low line
input voltage.
To match the input current reading at the maximum
nominal input current, adjust the CS ADC gain trim
register until the CS value (Register 0x89, READ_IIN)
equals the measured result of the input current from
calibrated equipment.
If the 500 mV input range is used, adjust Register 0xFE42.
If the 750 mV range is used, adjust Register 0xFE7E.
Apply the maximum load to the output with the low line
input voltage.
Adjust the power metering gain trim for low line input
register (Register 0xFE34) until the input power value in
the READ_PIN register (Register 0x97) equals the
measured result of the input power from calibrated
equipment.
Apply the maximum load to the output with the high line
input voltage.
Adjust the power metering gain trim for high line input
register (Register 0xFE8F) until the input power value in
the READ_PIN register (Register 0x97) equals the
measured result of the input power from the calibrated
equipment.
ADP1047/ADP1048