Application Notes

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PT6510 Series

Using the PT6510 Series as a Replacement for the

PT6500 Series in Existing Designs

Scope

The PT6510 series of power modules is the recommended

plug-in replacement for PT6500 series parts. The PT6510

series uses the same single-in-line package (SIP) outlines

and footprint as the PT6500 series, and was designed to be

functionally identical to the PT6500. This application

note highlights the differences in electrical performance

between a PT6510 series replacement compared to an

original PT6500 series part.

Overview

The features that the PT6510 series share with the

PT6500 series includes the output current rating, thermal

shutdown, and on/off standby. The input voltage range,

output voltage adjustment, and output voltage options

are also the same. In addition, applications that use the

PT6510 series as a replacement will experience a number

of performance enhancements. These include improved

efficiency and power dissipation, lower in-rush current

and output ripple voltage. The ‘off’ standby current is

also significantly reduced. Table 1-1 provides a cross

reference between the current PT6500 series part num-

bers and their equivalent PT6510 series part.

Table 1-1; PT6500 / PT6510 Series Equivalent Parts

PT6500 Series

PT6510 Series

PT6501

3.3 V

PT6511

PT6502

1.5 V

PT6512

PT6503

2.5 V

PT6513

PT6504

3.6 V

PT6514

PT6505

1.2 V

PT6515

PT6506

1.8 V

PT6516

Electrical and Functional Differences

Although the PT6510 series was designed as a drop-in

replacement for PT6500 series, there are minor differences

in the electrical characteristics. These are described in the

following text and should be used to assess the replace-

ment part’s compatibility with the system or end product.

A replacement part’s compatibility with the system can

be further verified with appropriate board-level tests.

On/Off Standby: The Standby input of the PT6510 series

is compatible with both the logic polarity and thresholds

of PT6500 series. One exception is the internal pull-up

voltage, which is slightly higher on the PT6510 parts.

The open-circuit voltage for the PT6510 series is the

This should not be a problem if the standby input is

controlled with an open-drain transistor with a sufficient

max-Vds rating.

Over-Current & Over-Temperature Protection:

To protect against short circuits and load impedance

faults, the PT6500 employs a constant output current

limit combined with over-temperature shutdown. The

PT6500 will feed a limited steady-state current into a

load fault. When limiting output current, the PT6500

exhibits higher power dissipation, which increases the

module's operating temperature. When its internal tem-

perature rises above the over-temperature threshold, the

module will shut itself down for a few seconds. The

module will then continue to periodically shut down until

the load fault is removed.

The over-current protection mechanism of the PT6510

series is different. If the output current increases above

the modules over-current threshold, its output voltage

is momentarily turned off. It then attempts to recover

by executing a soft-start power up. The module will

continue in a rapid succession of shutdowns and restarts

until the load fault is removed. During this period the

output current is not steady state, but a series of short

high-amplitude pulses (frequency <100 Hz). However,

when operating into a short-circuit load fault, the average

output current and power dissipation are significantly

lower than under normal operation.

Power-Up Characteristic: Following the application of a

valid input source, the PT6510 series modules exhibit a

slightly longer time delay than the equivalent PT6500

series part. The PT6510 series has a soft-start power-up

feature, which lowers the in-rush current at its input.

Figure 1-1 and Figure 1-2 show the power-up charac-

teristics of the PT6501 and PT6511 respectively. Both

modules have a 3.3-V regulated output, and rise to their

regulated output voltage in a similar period. Note that

the output voltage of the PT6501 begins to rise when

the input voltage reaches 2.2 V, whereas the output voltage

of the PT6511 doesn’t begin to rise until the input voltage

has reached 3.5 V.