12a digital picodlynx, Non-isolated dc-dc power modules, Data sheet – GE Industrial Solutions 12A Digital PicoDLynx User Manual

Page 14: Analog feature descriptions

Data Sheet

12A Digital PicoDLynx

: Non-Isolated DC-DC Power Modules

3Vdc –14.4Vdc input; 0.45Vdc to 5.5Vdc output; 12A Output Current

November 19, 2013

Page 14

Analog Feature Descriptions

Remote On/Off

The module can be turned ON and OFF either by using the

ON/OFF pin (Analog interface) or through the PMBus interface
(Digital). The module can be configured in a number of ways
through the PMBus interface to react to the two ON/OFF

inputs:

• Module ON/OFF can be controlled only through

the analog interface (digital interface ON/OFF
commands are ignored)

• Module ON/OFF can be controlled only through

the PMBus interface (analog interface is ignored)

• Module ON/OFF can be controlled by either the

analog or digital interface

The default state of the module (as shipped from the factory)
is to be controlled by the analog interface only. If the digital
interface is to be enabled, or the module is to be controlled

only through the digital interface, this change must be made
through the PMBus. These changes can be made and written
to non-volatile memory on the module so that it is

remembered for subsequent use.

Analog On/Off

The 12A Digital PicoDLynx

power modules feature an

On/Off pin for remote On/Off operation. Two On/Off logic
options are available. In the Positive Logic On/Off option,

(device code suffix “4” – see Ordering Information), the
module turns ON during a logic High on the On/Off pin and
turns OFF during a logic Low. With the Negative Logic On/Off

option, (no device code suffix, see Ordering Information), the
module turns OFF during logic High and ON during logic Low.

The On/Off signal should be always referenced to ground. For
either On/Off logic option, leaving the On/Off pin
disconnected will turn the module ON when input voltage is

present.

For positive logic modules, the circuit configuration for using
the On/Off pin is shown in Figure 39. When the external

transistor Q2 is in the OFF state, the internal transistor Q1 is
turned ON, and the internal PWM #Enable signal is pulled low
causing the module to be ON. When transistor Q2 is turned

ON, the On/Off pin is pulled low and the module is OFF. A
suggested value for R

pullup

is 20k

Ω.

For negative logic On/Off modules, the circuit configuration is
shown in Fig. 40. The On/Off pin should be pulled high with
an external pull-up resistor (suggested value for the 3V to
14V input range is 20Kohms). When transistor Q2 is in the
OFF state, the On/Off pin is pulled high, transistor Q1 is
turned ON and the module is OFF. To turn the module ON, Q2
is turned ON pulling the On/Off pin low, turning transistor Q1
OFF resulting in the PWM Enable pin going high.

Digital On/Off

Please see the Digital Feature Descriptions section.

Figure 39. Circuit configuration for using positive On/Off
logic.

Figure 40. Circuit configuration for using negative On/Off
logic.

Monotonic Start-up and Shutdown

The module has monotonic start-up and shutdown behavior

for any combination of rated input voltage, output current
and operating temperature range.

Startup into Pre-biased Output

The module can start into a prebiased output as long as the
prebias voltage is 0.5V less than the set output voltage.

Analog Output Voltage Programming

The output voltage of the module is programmable to any
voltage from 0.6dc to 5.5Vdc by connecting a resistor
between the Trim and SIG_GND pins of the module. Certain
restrictions apply on the output voltage set point depending
on the input voltage. These are shown in the Output Voltage
vs. Input Voltage Set Point Area plot in Fig. 41. The Upper
Limit curve shows that for output voltages lower than 1V, the
input voltage must be lower than the maximum of 14.4V. The
Lower Limit curve shows that for output voltages higher than
0.6V, the input voltage needs to be larger than the minimum

10K

22K

Rpullup

+3.3V

+VIN

GND

ON/OFF

ENABLE

DLYNX MODULE

10K

22K