DS_DNK12SIP_09062016

11

FEATURES DESCRIPTIONS (CON.)

Table 1 provides Rtrim values required for some common

output voltages. By using a 0.5% tolerance trim resistor,

set point tolerance of ±1.5% can be achieved as specified

in the electrical specification.

Table 1

VO (V)

Rtrim (Ω)

0.8

Open

1.2

2900

1.5

1614

1.8

1100

2.5

606

3.3

380

5.0

185.7

Voltage Margining

Output voltage margining can be implemented in the

Trim pin to the ground pin for margining-up the output

Trim pin to the output pin for margining-down. Figure 39

shows the

circuit configuration for

output voltage

margining. If unused, leave the trim pin unconnected. A

calculation tool is available from the evaluation procedure

a specific output voltage and margin percentage.

Vo

On/Off

Vin

GND

Trim

Q2

Q1

Rmargin-up

Rmargin-down

Rtrim

Figure 39: Circuit configuration for output voltage margining

FEATURES DESCRIPTIONS (CON.)

Voltage Tracking

The DNK family was designed for applications that have

output voltage tracking requirements during power-up

and power-down. The devices have a TRACK pin to

implement three types of tracking method: sequential,

simultaneous and ratio-metric. TRACK simplifies the task

of supply voltage tracking in a power system by enabling

modules to track each other, or any external voltage,

during power-up and power-down.

By connecting multiple modules together, customers can

get multiple modules to track their output voltages to the

voltage applied on the TRACK pin.

The DNK family has option code A for TRACK function.

The output voltage Track characteristic can be achieved

when the output voltage of PS2 follows the output

voltage of PS1 on a volt-to-volt basis.

Figure 40: Simultaneous tracking

Simultaneous tracking (Figure 40) is implemented by

using a voltage divider around the TRACK pin. The

objective is to minimize the voltage difference between

the power supply outputs during power up and down.

For type A (DNX0A0XXXX A), the simultaneous tracking

pin of PS2 where the voltage divider is inside the PS2.