Output Voltage Programming; Over-Current And Short-Circuit Protection - Delta Electronics 0.59V~5.1Vout Specification Sheet

Delphi ne series non-isolated point of load dc/dc modules: 4.5v~13.8vin, 0.59v~5.1vout, 20a

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Table Of Contents

Table of Contents

FEATURES DESCRIPTIONS (CON.)

The ENABLE input can be driven in a variety of ways as

shown in Figures 19 and 20. If the ENABLE signal comes

from the primary side of the circuit, the ENABLE can be

driven through either a bipolar signal transistor (Figure

18).If the enable signal comes from the secondary side,

then an opto-coupler or other isolation devices must be

used to bring the signal across the voltage isolation

(please see Figure 19).

ND6A/10A

Vin

Enable

Ground

Figure 19: Enable Input drive circuit for NE series

Figure 20: Enable input drive circuit example with isolation.

Input Under-Voltage Lockout

The input under-voltage lockout prevents the converter

from being damaged while operating when the input

voltage is too low. The lockout occurs between 3.3V to

4.3V.

Over-Current and Short-Circuit Protection

The NE series modules have non-latching over-current

and short-circuit protection circuitry. When over current

condition occurs, the module goes into the non-latching

hiccup mode. When the over-current condition is

removed, the module will resume normal operation.

An over current condition is detected by measuring the

voltage drop across the MOSFETs. The voltage drop

across the MOSFET is also a function of the MOSFET's

Rds(on). Rds(on) is affected by temperature, therefore

ambient temperature will affect the current limit inception

point.

The detection of the Rds(on) of MOSFETs also acts as

an over temperature protection since high temperature

will cause the Rds(on) of the MOSFETs to increase,

eventually triggering over-current protection.

Preliminary DS_NE12S20A_07272007

NE20A

Vout

Trim

Ground

ND 6A/10A

NE20A

Vout

Vin

Enable

Trim

Ground