ADP1050ACPZ-R7 datasheet(36/93 Pages) AD

36 / 93 page

Data Sheet

ADP1050

POWER SUPPLY CALIBRATION AND TRIM

All the ADP1050 devices are factory trimmed. If the ADP1050

is not trimmed in the power supply production environment, it

is recommended that components with a 0.1% tolerance be

used for the inputs to the CS1, VS±, VF, and OVP pins to meet

data sheet specifications (see the Specifications section).

In the power supply production environment, the ADP1050 can

calibrate items, such as output voltage and trim, for tolerance

errors that are introduced by sense resistors and resistor dividers,

as well as its own internal circuitry. The ADP1050 allows the

user enough trim capability to trim for external components

with a tolerance of ≤0.5%.

To unlock the trim registers for write access, the user must

perform two consecutive write actions with the correct password

(factory default value = 0xFF), using the TRIM_PASSWORD

command (Register 0xD6). Any read or write action to another

interrupts the unlocking of the chip password.

The trim registers are Register 0xFE14, Register 0xFE20,

For complete information about these registers, see the

Manufacturer Specific Extended Commands Descriptions section.

IIN TRIM (CS1 TRIM)

Using a DC Signal

A known dc voltage (Vx) is applied at the CS1 pin. The IIN_

SCALE_MONITOR command (Register 0xD9) is set to 0x0001.

The READ_IIN input current reading command (Register 0x89)

generates a digital code (representing the input current in amperes)

that is equal to the Vx voltage value. The CS1 gain trim register

(Register 0xFE14) is adjusted until the input current reading in

Using an AC Signal

A known ac current (Ix) is applied to the PSU input. This current

passes through a current transformer, a diode rectifier, and an

external resistor (RCS1) to convert the current information to a

voltage (Vx). This voltage is fed into the CS1 pin. The IIN_SCALE_

MONITOR is calculated as follows:

IIN_SCALE_MONITOR = (NPRI/NSEC) × RCS1

where NPRI and NSEC are the turns of the primary side and secondary

side windings, respectively, of the current transformer.

The READ_IIN input current reading command generates a digital

code, representing the input current, Ix. The CS1 gain trim register

(Register 0xFE14) is adjusted until the input current reading in

VOUT TRIM (VS TRIM)

The voltage sense input at the VS± pins is optimized for sensing

signals at 1 V and cannot sense a signal greater than 1.6 V. It is

recommended that the nominal output voltage be reduced to 1 V

for best performance. The resistor divider introduces errors that

must be trimmed. The ADP1050 has enough trim range to trim

errors that are introduced by resistors with a tolerance of ≤0.5%.

To trim the errors introduced by the resistor divider, use the

following procedure:

1. Set the VOUT_COMMAND (Register 0x21) with the

nominal output voltage value. Set the VOUT_SCALE_

LOOP command (Register 0x29) and the VOUT_SCALE_

MONITOR command (Register 0x2A) based on the resistor

divider information.

2. Enable the power supply with the no-load current. The voltage

of the VS± pins is divided down by the VS± resistor dividers

to give a target of 1 V at the VS± pins.

3. Adjust the VOUT_CAL_OFFSET trim (Register 0x23) to

ensure that the output voltage is exactly the target output

voltage.

4. Adjust the VS gain trim register (Register 0xFE20) when

the READ_VOUT reading in Register 0x8B is the exact

output voltage reading.

VIN TRIM (VF GAIN TRIM)

The voltage sense inputs are optimized for the VF pin signals at

1 V and cannot sense a signal greater than 1.6 V. A resistor divider

is required to divide the sensed voltage signal into a voltage of

less than 1.6 V. It is recommended that the VF voltage signal be

reduced to 1 V for best performance. The resistor divider

introduces errors, which must be trimmed.

Use the following procedure:

1. Set the VIN_SCALE_MONITOR command in Register 0xD8

based on the resistor divider information (see Figure 20)

and the turns ratio information of the transformer.

IN_SCALE_MONITOR =

PRI

SEC

where NPRI and NSEC are the turns of the primary side

and secondary side windings, respectively, of the

transformer.

2. Apply the nominal input voltage at the no load condition

to achieve a targeted voltage of approximately 1 V at the

VF pin.

3. Adjust the VF gain trim register (Register 0xFE28) when

the READ_VIN reading in Register 0x88 is the exact

nominal voltage reading.

4. Adjust the input voltage compensation multiplier

(Register 0xFE59) to make the READ_VIN reading

match the exact input voltage at the full load condition.

Rev. A | Page 35 of 92

ADP1050ACPZ-R7 数据表(PDF) 36 Page - Analog Devices

ADP1050ACPZ-R7 数据表(HTML) 36 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93

数据表下载